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2005-9116 G ENGINEERING SERVICES DEPARTMENT Capital Improvement Projects District Support Services Field Operations Sand Rep lenishment/Stormwater Compliance Subdivision Engineering July 6, 2005 Traffic Engineering Attn: Wells Fargo Bank, N.A. 245 Santa Helena Solana Beach, Ca 92075 RE: Kerry Rutherford 2600 Montgomery Avenue APN 261-191-16 Grading Permit 9116-GI Partial release of security Permit 9116-GI authorized earthwork, private drainage improvements, and erosion control, all as necessary to build described project. The Field Inspector has approved rough grade. Therefore, release of the remainder of the security deposit is merited. The following Certificate of Deposit Account has been cancelled by the Financial Services Manager and is hereby released for payment to the depositor. Account# 5153397350 in the amount of$ 42,779.25. The document originals are enclosed. Should you have any questions or concerns, please contact Debra Geishart at (760) 633- 2779 or in writing, attention the Engineering Department. Sinc ely, #ac Debra Geishart r� er y Engineering Technician Finance Manager Subdivision Engineering g Financial Services CC: Jay Lembach, Finance Manager Kerry and Lynn Rutherford Debra Geishart File Enc. I F1 -(r1 333- ('0') 1 AX Ili lllllan. t .i��� n�ni i _'ti_'a- i;;; �� recvcieGpaper City N�INEERING SER VICES DEPARTMENT Encinitas Capital Improvement Projects District Support Services Field Operations Sand Replenishment/Stormwater Compliance Subdivision Engineering April 28, 2006 Traffic Engineering Attn: Wells Fargo Bank, N.A. 245 Santa Helena Solana Beach, Ca 92075 RE: Kerry Rutherford 2600 Montgomery Avenue APN 261-191-16 Grading Permit 9116-GI Final release of security Permit 9116-GI authorized earthwork, private drainage improvements, and erosion control, all as necessary to build described project. The Field Inspector has approved rough grade. Therefore, release of the remainder of the security deposit is merited. The following Certificate of Deposit Account has been cancelled by the Financial Services Manager and is hereby released for payment to the depositor. Account#5153397368 in the amount of$14,259.75. The document originals are enclosed. Should you have any questions or concerns,please contact Debra Geishart at (760) 633- 2779 or in writing, attention the Engineering Department. Sinqv0y, Debra Geishart Engineering Technician ay in Subdivision Engineering Finance Manager Financial Services CC: Jay Lembach, Finance Manager Kerry and Lynn Rutherford Debra Geishart File Enc. TEL 760-633-2600/FAX 760-633-2627 505 S.Vulcan Avenue, Encinitas, California 92024-3633 TDD 760-633-2700 �� recycled paper Recording Requested By: ) TINE ORIGINAL OF THIS DOCUMENT City of Encinitas ) WAS RECORDED ON MAY 19,2005 DOCUMENT NUMBER 2005-0425555 When Recorded Mail To: 1 r,�EGORYi SMITH COUNTY RECORDER City Clerk ) `-AN DIEGO COUNTY RECORDER'S OFFICE City of Encinitas TIME 3 54 PM) 505 South Vulcan Avenue ) Encinitas, CA 92024 ) SPAi COVENANT REGARDING REAL PROPERTY: HOLD CITY HARMLESS FOR GRADING/DRAINAGE/SLOPE INSTABILITY Assessor's Parcel No. 261-191-16 Project .:04-142 CDP A. Kerry P. Rutherford and Lynn M. Rutherford, husband and wife as joint tenants ("OWNER" hereinafter) is the owner of real property which is commonly known as 04-142 CDP ("PROPERTY" hereinafter) and which is described as follows: See Attachment A which is attached hereto and made a part hereof. B. In consideration of 04-142 CDP by the City of Encinitas ("CITY" hereinafter), OWNER hereby covenants and agrees for the benefit of CITY, to do the following: See Attachment B which is attached hereto and made a part hereof. C. This Covenant shall be binding upon and inure to the benefit of the future owners, encumbrancers, successors, heirs, personal representatives, transferees and assigns of the respective parties. D. OWNER agrees that OWNER's duties and obligations under this Covenant are a lien upon the PROPERTY. Upon notice and opportunity to respond, CITY may add to the property tax bill of the PROPERTY any past due financial obligation owing to CITY by way of this Covenant. E. If either party is required to incur costs to enforce the provisions of this Covenant, the prevailing party shall be entitled to full reimbursement of all costs, including reasonable attorneys' fees, from the other party. F. Failure of OWNER to comply with the terms of this Covenant shall constitute consent to the filing by CITY of a Notice of Violation of Covenant. ACCEPTED AND AGREED: OWNER /i Kerry Rutherford Dated Lynn Rutherford Dated (Notarization of OWNER signature is attached.) C Y OF ENCINITAS Dated .: /(� CJ��J By (Notarization not required) Peter Cota-Robles Director of Engineering Services ATTACHMENT A TO COVENANT REGARDING REAL PROPERTY: HOLD CITY HARMLESS FOR GRADING/DRAINAGE/SLOPE INSTABILITY PROJECT NO. 04-142 CDP PROPERTY DESCRIPTION Parcel 2 of Map No. 17367 in the City of Encinitas, County of San Diego, State of California, filed in the Office of the County Recorder of San Diego County May 27, 1994 as Instrument No. 94-349102 of Official Records. ATTACHMENT B TO COVENANT REGARDING REAL PROPERTY: HOLD CITY HARMLESS FOR GRADING/DRAINAGE/SLOPE INSTABILITY PROJECT NO. 04-142 CDP OWNER'S DUTIES AND OBLIGATIONS 1. For claims that are alleged to have arisen, directly or indirectly, from any grading or drainage runoff, or slope instability on the land as described in Exhibit A or damage on adjacent land either private or public roadway right-of-way associated with the PROPERTY or the plans, design, construction or maintenance of OWNER' s improvements, OWNER unconditionally waives all present and future claims against CITY and CITY's officers, officials, employees, and agents. This waiver does not apply to claims that are alleged to have arisen out of the sole, active negligence or deliberate, wrongful act of CITY. 2. It is further understood and agreed that all of OWNER'S rights under §1542 of the C ivil C ode o f, t he S tate o f C alifornia a nd a ny s imilar I aw o f a ny state or territory of the United States are hereby expressly waived. 9 1542 reads as follows: 1542. Certain claims not affected by general release. A general release does not extend to claims which the creditor does not know or suspect to exist in his favor at the time of executing the release, which if known by him must have materially affected his settlement with the debtor. 3. OWNER agrees to indemnify and hold CITY and CITY's officers, officials, employees and agents harmless from, and against any and all liabilities, claims, demands, causes of action, losses, damages and costs, including all costs of defense thereof, arising out of, or in any manner connected directly or indirectly with, any negligent acts or omissions of OWNER or OWNER's agents, employees, subcontractors, officials, officers or representatives that arise from or in connection with Project No. 04-142 CDP improvements constructed on or about slopes that prove to be instable; provided, however, notwithstanding anything contained herein to the contrary such indemnity shall be limited to the amount of the builders risk liability insurance policy currently held by the original Owner for such project. Upon demand, OWNER shall, at its own expense, defend CITY and CITY's officers, officials, employees and agents, from and against any and all such liabilities, claims, demands, causes of action, losses, damages and costs. Notwistanding anything contained herein to the contrary, this indemnity obligation shall terminate ten (10) years after the date of this Covenant Agreement. OWNER' s obligation herein includes, but is not limited to, alleged defects in the plans, specifications and design of the improvements; but does not extend to liabilities, claims, demands, causes of action, losses, damages or costs that arise out of a defect in the plans, specifications or design that is a result of a change required by CITY to the OWNER's proposed plans, specifications or design so long as such change is objected to, in writing, by OWNER, and the writing is filed with the City Engineer more than ten days prior to the commencement of work. OWNER's obligation herein includes, but is not limited to, alleged defects in the construction of the improvements; alleged defects in the materials furnished in the construction of the improvements; alleged injury to persons or property; and any alleged inverse condemnation of property as a consequence of the design, construction, or maintenance of the improvements. By approving the improvement plans, specifications and design or by inspecting or approving the improvements, CITY shall not have waived the protections afforded herein to CITY and CITY's officers, officials, employees and agents or diminished the obligation of OWNER who shall remain obligated in the same degree to indemnify and hold CITY and CITY's officers, officials, employees and agents, harmless as provided above. OWNER's obligation herein does not extend to liabilities, claims, demands causes of action, losses, damages or costs that arise out of the CITY's intentional wrongful acts, CITY's violations of law, or CITY's sole active negligence. 4. OWNER hereby agrees not to develop in any manner the PROPERTY except as authorized by CITY's ordinances and then only in accordance with issued permits. Among other things, but without limitation, this shall prohibit the alteration of land forms, removal of vegetation and the erection of structures of any type, except as permitted or authorization by CITY. 5. This Covenant does not Preclude OWNER taking emergency, protective measures as approved by CITY. CALIFORNIA ALL-PURPOSE ACKNOWLEDGMENT State of California ss. County of :2,//7? " On Pll� CC before Dare Name J Tile or C]FCer,2.g personally appeared " y tit yO J Namels)of Signed s) '>; personally known to me X roved to me on the basis of satisfactory r evidence h' to be the person(s) whose name(s) is/5e—'- ICANDA G.MU subscribed to the within inst nt an ti 4ondon#1389203 acknowledged to me that he/ xecuted r. vy PiibUc• � ' the same in his/he thei tuho�ri ' > son Oia9O county (!� nwNlabn Exp.Jan.6,2007 capacity(ies), and that by his/her signature(s) on the instrument the person(s), or the entity upon behalf of which the person(s) acted, executed the instrument. ' c ALINESS my hand and official seal. r l Place Notary Seal Above Sigr9ture of Notary Public Though OPTIONAL ' . ( g the information below is not required by law, it may prove valuable to persons relying on the document T� T and could prevent fraudulent removal and reattachment of this form to another document. f i Description of Attached Document Title or Type of Document: Document Date: Number of Pages: Signer(s) Other Than Named Above: Capacity(ies) Claimed by Signer Signer's Name: Individual rTopofb here X, J Corporate Officer—Title(s): ❑ Partner—❑ Limited 1:1 General ❑ Attorney in Fact ❑ Trustee ❑ Guardian or Conservator t � ❑ Other: I Signer Is Representing: = --_ _�t;'C"C=<�'CC-^�t.`�,'�'�C�'�.'ZSC.•C`.-4��Cv^�C%�(:'t_`�C-�'�c.'S4�4�,�G�'�4'�C-?-C.`CC,�C.'tC-�C-�`-C:'�.C.'Z%C,'C:(.'�G'CG'C4�.T� 1997 National Notary Association•9350 De Soto Ave.PO.Box 2402•Chatsworth.CA 91313-2402 Prcd.No.5907 Reorder Call Toll-Free 1-800-876-6827 HYDROLOGY CALCULATIONS For RUTHERFORD RESIDENCE APN: 261-191-16 ENCINITAS, CALIFORNIA r Prepared For , ,S Mr. Kelly Rutherford `ti`t �01� 2600 Montgomery Avenue �1�v Cardiff, CA 92007 " PE 966 • y PREPARED BY: PASCO ENGINEERING, INC. 535 N. HIGHWAY 101, SUITE A SOLANA BEACH, CA 92075FES�7� (858)259-8212 %e A. DATE: 7/5/04 ILU No. 29577 m °C EV.3/31/07 N� �@ OF WAYNE A. ASCO, RCE 29577 DATE �Y \\ServeNob files\Hydrology& Hydraulics\966 HYDRO REPORT.doc PE#966 10:29 AM 7/1/2004 HYDROLOGY STUDY for RUTHERFORD RESIDENCES PE 966 TABLE OF CONTENTS SECTION DISCUSSION..............................................................................A CONCLUSION.............................................................................B PRE AND POST DEVELOPMENT HYDROLOGY CALCULATIONS.......C POST DEVELOPMENT TREATMENT RUNOFF CALCULATIONS.........D APPENDIX...................................................... E Isopluvials Intensity Duration Curve Runoff Coefficients Hydrology Map \\ServeNob files\Hydrology& Hydraulics\966 HYDRO REPORT.doc PE#966 10:29 AM 7/1/2004 HYDROLOGY STUDY for RUTHERFORD RESIDENCES PE 966 A. INTRODUCTION The purpose of this report is to analyze the storm water runoff produced from the 100 year storm event of the existing and post-developed condition of the Crest Drive development site. The subject property is physically located at 2600 Crest Drive, Cardiff California. The property is geographically located at N 33°00'50" W 117°16'25". Pre-Developed Conditions The existing condition of the project site consists of a vacant lot with an existing asphalt paved driveway and retaining wall. The vacant lot slopes dramatically downhill from the existing asphalt paved driveway and retaining wall westerly to the backyard boundary. Existing slopes of 2:1 and greater exist downhill near the westerly boundary. Some drainage from Montgomery Street, the asphalt driveway and up hill neighbor all drain onto the site. There is an existing ac apron that directs this drainage along the southerly boundary. All drainage runs over the natural steep slope that continues over an on-site open space easement. Eventually the drainage sheet flows over the open space and then reaches Manchester Drive. Post- Development Conditions The proposed development consists of the construction of a single family residence. Part of the existing asphalt paved driveway will be removed and reconstructed to accommodate a garage. The existing retaining wall will be removed in order to accommodate the residence. Existing drainage from the driveway and uphill neighbor will continue pre development runoff conditions. The existing ac apron will be removed and replaced with a channel grate type inlet. The inlet will divert drainage to a rip-rap energy dissipater before it is released onto the open space as sheet flow. The diversion of this drainage will decrease existing runoff that makes its way to the existing cut slope in the backyard. The cut slope is very steep (over 1:1 slope) and is eroding. The proposed drainage system will decrease the amount of runoff going over the cut slope and reduce erosion on it. Drainage from the proposed roof will be collected in downspouts and routed to the northerly boundary where it will be, treated in a grass lined ditch, released onto rip-rap and then return to sheet flow conditions before entering the on-site open space easement. The area at the side and front of the residence near the northerly boundary will be used to treat runoff from the proposed development. A grass lined swale will be used as a treatment facility and then sheet flow across existing natural slope to Manchester Drive. The pre-development and post-development runoff coefficient and area basin remain the same; therefore, there is no increase in runoff from the site. The pre and post runoff is 0.86 cfs. All post-developed drainage, using the 85h percentile storm calculation, will be \\Server\job files\Hydrology& Hydraulics\966 HYDRO REPORT.doc PE#966 3:16 PM 7/28/2004 HYDROLOGY STUDY for RUTHERFORD RESIDENCES PE 966 treated before released off-site. The treatment runoff is 0.008 cfs and is treated in a grass lined channel near the front of the proposed residence. (See plan) Methodology and Results The hydrologic soil group classification for the site is "D". The methodology used herein to determine Qroo is the rational method. The pre and post-development runoff coefficients, used to analyze the both conditions, were obtained from Table 3-1 of the June 2003 revision of the San Diego County Hydrology Manual. B. CONCLUSION Based on the information and calculations contained in this report it is the professional opinion of Pasco Engineering, Inc. that the storm drain system as proposed on the corresponding Grading Plan will function to adequately intercept, contain and convey Qroo to the appropriate points of discharge. \\ServeNob files\Hydrology& Hydraulics\966 HYDRO REPORT.doc PE#966 3:16 PM 7/28/2004 HYDROLOGY STUDY for RUTHERFORD RESIDENCES PE 966 C. PRE AND POST DEVELOPMENT HYDROLOGY CALCULATIONS \1ServeNob files\Hydrology& Hydraulics\966 HYDRO REPORT.doc PE#966 10:29 AM 7/1/2004 HYDROLOGY STUDY for RUTHERFORD RESIDENCES PE 966 PRE-DEVELOPMENT AND POST-DEVELOPMENT RUNOFF: Q= CIA Where, C = 0.60(Per Table 3-1 Runoff Coefficients for Urban Areas) Iioo= 5.11 in/hr A= 0.28ac (Existing area where improvements are proposed) Qloo= (0.60)(5.11)(0.28) Qtoo= 0.86 cfs \\ServeNob files\Hydrology&Hydraulics\966 HYDRO REPORT.doc PE#966 10:29 AM 7/1/2004 HYDROLOGY STUDY for RUTHERFORD RESIDENCES PE 966 D. POST DEVELOPMENT TREATMENT RUNOFF CALCULATIONS 11ServeNob files\Hydrology& Hydraulics\966 HYDRO REPORT.doc PE#966 10:29 AM 7/1/2004 HYDROLOGY STUDY for RUTHERFORD RESIDENCES PE 966 TREATMENT RUNOFF CALCULATION FOR 801h PERCENTILE STORM Q= CIA Where, C = 0.95 (impervious surfaces) I8m=0.16 in/hr A= 0.05 ac (Directly connected impervious surface) Q8m_ (0.95)(0.16)(0.05) QWth=0.008 cfs GRASS TREATMENT CHANNEL SCOUR CALCULATION v=0.04 ft/s(See worksheet next page) <1.0ft/s checks okay for scour GRASS TREATMENT CHANNEL MAXIMUM FLOW CALCULATION Qmax= 0.021 cfs (See worksheet on following pages)>0.008cfs checks okay for capacity \\ServerNob files\Hydrology& Hydraulics\966 HYDRO REPORT.doc PE#966 8:45 AM 7/27/2004 GRASS TREATMENT CHANNEL Worksheet for Rectangular Channel Project Description Project File c:lhaestadlacademiclfmw1966.fm2 Worksheet GRASS MOW STRIP BMP AT CARPORT Flow Element Rectangular Channel Method Manning's Formula Solve For Channel Depth Input Data Mannings Coefficient 0.200 Channel Slope 0.1000% Bottom Width 2.00 ft Discharge 0.008 cfs Results Depth 1.1 in Flow Area 0.18 ft2 Wetted Perimeter 2.18 ft Top Width 2.00 ft Critical Depth 0.01 ft Critical Slope 2.954748 ft/ft Velocity 0.04 ftis Velocity Head 0.31 e-4 ft Specific Energy 0.09 ft Froude Number 0.03 Flow is subcritical. 07/27/04 Academic Edition FlowMaster v5.17 08:41:25 AM Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 (203)755-1666 Page 1 of 1 GRASS TREATMENT CHANNEL Cross Section for Rectangular Channel Project Description Project File c:\haestad\academic\fmw\966.fm2 Worksheet GRASS MOW STRIP BMP AT CARPORT Flow Element Rectangular Channel Method Manning's Formula Solve For Channel Depth Section Data Mannings Coefficient 0.200 Channel Slope 0.1000% Depth 1.1 in Bottom Width 2.00 ft Discharge 0.008 cfs 1.1 in 1 2.00 ft v H 1 NTS 0727/04 Academic Edition 08:41:39 AM FbwMaster v5.17 Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 (203)755-1666 Page 1 of 1 GRASS TREATMENT CHANNEL MAX FLOW Worksheet for Rectangular Channel Project Description Project File c:lhaestadlacademiclfmw1966.fm2 Worksheet GRASS MOW STRIP BMP AT CARPORT Flow Element Rectangular Channel Method Manning's Formula Solve For Discharge Input Data Mannings Coefficient 0.200 Channel Slope 0.1000% Depth 2.0 in Bottom Width 2.00 ft Results Discharge 0.021 cfs Flow Area 0.33 ftz Wetted Perimeter 2.33 ft Top Width 2.00 ft Critical Depth 0.02 ft Critical Slope 2.397492 ft/ft Velocity 0.06 ft/s Velocity Head 0.64e-4 ft Specific Energy 0.17 ft Froude Number 0.03 Flow is subcritical. 07/27/04 Academic Edition 08:40:41 AM FlowMaster v5.17 Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 (203)755-1666 Page 1 of 1 GRASS TREATMENT CHANNEL MAX FLOW Cross Section for Rectangular Channel Project Description Project File c:lhaestadlacademiclfmw1966.fm2 Worksheet GRASS MOW STRIP BMP AT CARPORT Flow Element Rectangular Channel Method Manning's Formula Solve For Discharge Section Data Mannings Coefficient 0.200 Channel Slope 0.1000% Depth 2.0 in Bottom Width 2.00 ft Discharge 0.021 cfs 2.0 in 1 2.00 ft v H 1 NTS 07127/04 Academic Edition 08:40:56 AM FbwMaster v5.17 Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 (203)755-1666 Page 1 of 1 HYDROLOGY STUDY for RUTHERFORD RESIDENCES PE 966 E. APPENDIX \\Server\job files\Hydrology& Hydraulics\966 HYDRO REPORT.doc PE#966 10:29 AM 7/1/2004 b 0 2.33-4 00001E M U. LD v \ 1 \ / m Lo } V { ...� n p U t C c C u o LU La Cl) a v r I D � i A w w ON N n. O M N A M v v v, v1 ONO w tn V) a •4) C e... O O O O O O O O O O O O C O O ,u 4 r ^� O �p c� U M M V et o f vi o�0 - R O O C O O O O O C O O �• � O C O C O yca v o0o U u C u cc � c N t'U _• Do LTa N M t+1 '7 'tt trf 4�7 ^ �•.O �' t!' n M U C C C C C C C v' n o 0 0O' = 3 0 o c o C . o .R u o C v] u •- v� o cc o -D c 00 00 N v1 �O �O �O '�• O°O W OMO OHO ai ,� O G O O O O C C C O C O C C C OQ 'fl � G °. N N rai'.v° v �°n b o°o o°o o`�o o°� CD %n w eZ z N U c c r.r = C h h in H N N fyn % q O O O O O U aaaaaAAAA z c = A A A A A ,n o o U u 0 U C) C4 e y ca R w E 0 '.y ' •� L c a c C c c c c o U •� .5 D O 'Cpp N U H cu cu a u a"'i ai u 'u aCi e�"_ E a[i E cl o b ie > as a _ W ca �. 0. a. � :E R A A A A :E o 0 od r o u" C o C A A A ` A A o o U o C U ca cn "a E vW� .. v n v. to 'in .O .0 of m ce U _ b O a� ca°v ° v b E in H H h h v �• C C� o c ca a'di S S S S CLO CR al co Ca u u u E A E E a Q A °' °~ a~i cc A A a UUU � .� Az San Diego County Hydrology Manual Date: June 2003 Section: 3 Page: 12 of 26 Note that the Initial Time of Concentration should be reflective of the general land-use at the Upstream end of a drainage basin. A single lot with an area of two or less acres does not have a significant effect where the drainage basin area is 20 to 600 acres. Table 3-2 provides limits of the length (Maximum Length (LM)) of sheet flow to be used in hydrology studies. Initial Ti values based on average C values for the Land Use Element are also included. These values can be used in planning and design applications as described below. Exceptions may be approved by the "Regulating Agency" when submitted with a . . detailed study. Table 3-2 MAXIMUM OVERLAND FLOW LENGTH (LM) & INITIAL TIME OF CONCENTRATION T, Element* DU/ .5% 1% o ° 2/0 3% 5% 10% Acre LM T; LM T; LM T; LM T. LM T. LM Ti Natural 50 13.2 70 12.5 85 10.9 100 10.3 100 8.7 100 6.9 LDR 1 50 12.2 70 11.5 85 10.0 100 9.5 100 8.0 100 6.4 LDR 2 50 11.3 70 10.5 85 9.2 100 8.8 100 7.4 100 5.8 LDR 2.9 50 10.7 70 10.0 85 8.8 95 8.1 100 7.0 100 5.6 MDR 4.3 50 10.2 70 9.6 80 8:1 95 7.8 100 6.7 100 5.3 MDR 7.3 50 9.2 65 8.4 80 7.4 95 7.0 100 6.0 100 4.8 MDR 10.9 50 8.7 65 7.9 80 6.9 90 6.4 100 5:7 100 4.5 MDR 14.5 50 8.2 65 7.4 80 6.5 90 6.0 100 5.4 100 4.3 HDR 24 50 6.7 65 6.1 75 5.1 90 4.9 95 4.3 100 3.5 HDR 43 50 5.3 65 4.7 75 4.0 85 3.8 95 3.4 100 2.7 N. Corn 50 5.3 60 4.5 75 4.0 85 3.8 95 3.4 100 2.7 G. Com 50 4.7 60 4.1 75 3.6 85 3.4 90 2.9 100 2.4 O.P./Com 50 4.2 60 3.7 70 3.1 80 2.9 90 2.6 100 2.2 Limited I. 50 4.2 60 3.7 70 3.1 80 2.9 90 2.6 100 2.2 General I. 50 3.7 60 3.2 70 2.7 80 2.6 90 2.3 100 1.9 *See Table 3-1 for more detailed description 3-12 G:r W y nl -0 r C• N 0 Q► IC >,S_ Y —*a rO- Q1 b O > 1. X tn 4j N O •r {� V C S_ C C U iii L n C G-4 ID 4- 0.,r C!LO S_ Il C Z I +-1 W R �- p S 0 I CL. Q O C .� S- N CJ r 10 C C: 1 -0 Q) 17 O C f- O O C O Q. +�I N Ci N N Y R +� L C C O C C].C!'p O i O O C7 a 4-) •'-' +3 4.1 r d •r-.0 Cu /6 4J N C CJ It A S. S..•� 't77 Y '�• .^ 'Cf C .0 .D V O O S.- C U = fJ. G :3 .r. V ON •E C V •� .r.4-.C. _ CJ Cl.•-..r „r C 4-3 V L L U V S_ ..0.O Q rJ N C) C O C+-1 C) V 4J r- L CZ +1 +3 S- L7 L O CL CL 4.j Cu N O S_ L Cu •rC- 11 C1 C Y O N O .0 N ,a a.- .-• O Ci a V E a.— C L i-1 i L •.•-.-- aI +� - +3 C) R /6�.• to O C a L QI•--- C -r- W r vl t0 W tO CJ r O O J..1 4J �1 O E.0 N A (m CA N C) t 41 r -� '0 O C) 1 C •N -.-•1 C) 0 4J i-1 3 +1 N 4J (U 11 O 11 +3 S. ..0 b QJ Z7_G.0 O r-4- L .0 C C 1 11 U !t N F--�`- D C+•+ -w 41 0- O O C_ }—+1 eU O 1 1p to J CL. Q 4J r-r N M -0' o r•. N c+� 6-Hour Precipitation (inches)CD O in jEr LO Cu Fi let • f. r N v. 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N' � �� �•�/ `nom <�^w•L� ,o �: � M W n ,✓� � wl' C= ALM CD kr JA LU mat \i VN Ln CN LLJ CM s � j o � Q• / oC M v co c z < r z W <3 a .3 f4 H <. _ b H W o< , O pu } �-e �o v o e LCJ : - - F- C � q tr1 - 1 Ott¢ M Ln - V < y 0. G o O d00 LLzr M W z � O LLJ p w C O aC o CD O La o a V 0 L0. F W < z a l � F a u CO 06 I C _. � v ' v � i I i \.. - Ii •f= I f I ;Q-•-ter"' �� ca r•. Q � I ..r / -J!.! /�,'�I - .�� •rat` ' ,O � , ' _ o � o o I % .� CD co LIJ em 0 C4 CA ci ��! �" �- r •< ° -� - " ` / \cam. o p... .� o u • O u • 2 M ed • < V < 1 - 0 I I I I � z co Z CL —1 O O u tL z z M Ln O w O u >- jam_ C 7 vi O j ZCOO in = < < CL O W .J n c.loti r � < o z N V L _..._ _.__...._ . .__ II_IN-13 A w CHRISTIAN WHEELER ENGINEERING ADDENDUM GEOTECHNICAL REPORT °- PROPOSED SINGLE-FAMILY RESIDENCE 2600 MONTGOMERY AVENUE ENCINITAS, CALIFORNIA PREPARED FOR: K R BUILDING COMPANY 1242 CAMBIRA WAY ENCINITAS, CALIFORNIA 92024 PREPARED BY: CHRISTIAN WHEELER ENGINEERING 4925 MERCURY STREET SAN DIEGO, CALIFORNIA 92111 L JA N 1 3 2005 -, 4925 Mercury Street ♦ San Diego, CA 9211 1 i 858-496.9760 ♦ FAX 858-496-9758 W CHRISTIAN WHEELER January 6, 2005 EN (� INEERINC; K R Building Company 1242 Cambria Way CWE 2040232.3 Encinitas, California 92024 City of Encinitas Case No. 04-142 CDP SUBJECT: ADDENDUM GEOTECHNICAL, PROPOSED SINGLE-FAMILY RESIDENCE, 2600 MONTGOMERY AVENUE, ENCINITAS, CALIFORNIA. REFERENCES: 1) Update Report of Preliminary Geotechnical Investigation, Proposed Single-Family Residence, 2600 Montgomery Avenue,Encinitas, California, G Engineering, Report No. 2040232.1,dated March 11, 2004. y Christian Wheeler 2) Report of Preliminary Geotechnical Investigation, Proposed Nommesen Residence, 2600 I\fontgomery Avenue, Encinitas, California, by Christian Wheeler Engineering,Report No. 199.099.2, dated December 28, 1999,revised March 7,2000. 3) Site Plan/Grading Plan, Rutherford Residence,2600 Montgomery Avenue,Cardiff, California, 92007, by Caitlin Kelley,AIA,print date June 22, 2004. 4) Review of Geotechnical Report and Grading Plan,Rutherford Residence, 2600 I\fontgomery, Encinitas, California, 9116GR, 04-142 CDP, by Geopacifica, Inc., dated August 30,2004. Attention: I\Ir. Kerry Rutherford In accordance with your request, this addendum report has been prepared to address the geotechnical considerations of the referenced third party review of our Update Report of Preliminary Geotechnical Investigation for the subject project. The following presents each of the geotechnical"items"presented on the referenced third party review of our updated geotechnical report, followed by our response. Review Comment 1: Based on stability analyses of the subject site the lot and adjacent slope to the south are not stable based upon the City of Encinitas minimum requirement of 1.5 safety factor for static and 1.1 safety factor for seismic. Also no surficial stability analysis was performed. What does the consultant propose to bring the lot and slope into conformance with the City of Encinitas requirements? CWE Res onse• In consideration of the fact that the current site development plan includes the construction of a partially subterranean basement for the proposed residence (reducing the driving forces 4925 Mercury Street ♦ San Diego, CA 92111 ♦ 858-496-9760 ♦ FAX 858-496-9758 CWE 2040232.3 January 6,2005 Page 2 contributing to slope instability), whereas our original analyses were conducted assuming that no grading was to be performed as part of the site development,we have prepared an updated geologic cross section A-A'to represent the proposed site conditions and the steepest topographies on and to the west (downhill) of the subject site. This updated cross section,included herein as Plate No. 2,was created utilizing the topographies presented on the above referenced site/grading plans and the County of San Diego 200-scale ortho-topographic map of the area (sheet 203-1683). The location of the updated geologic cross section A-A' is presented on the Site Plan and Geotechnical Map that is included herein as Plate No. 1. Utilizing the geologic conditions and proposed site topographies presented on the above-described eolo "c cross section,we have conducted supplemental,gross stability analyses of the subject site and adjacent hillside. Our supplemental analyses included both static and pseudo-static (utilizing kh values of 0.15 , circular-type failure mechanisms. Based on the neutral to favorable bedding orientation within the materials of the Delmar Formation that underlie the site and crop out along the existing hillside downslope of the site (see below), die use of anisotropic soil strength parameters or the modeling of block-type failure mech were not included in our supplemental,gross stability analyses. amsms Furthermore, as also considered prudent and appropriately conservative, the strength parameters of the lowest claystone unit within the Delmar Formation,which were modeled in our original analyses to represent the material's residual shear strength values,were modeled in the supplemental analyses contained herein to represent values between the residual and peak shear strength values. Specifically, the strength parameters modeled within our original stability analyses to represent the lowest claystone unit were a cohesion (c of 425 psf and an angle of internal friction (4)) of 29° CWE 2000). ) lowest claystone unit within the supplemental analyses cotinedr comparison, the values used to model the 30.5° for the angle of internal friction. It should be recognized that the utilization of for the cohesion and model the lower claystone unit that are between the residual and peak values is a procedure that gunderlbo to vaues static and seismic loading conditions, conservatively follows the recommendations presented in the workshop pertaining to the"Recommended Procedures for Implementation of Dl\1G Special Publication 117: P Guidelines for Analyzing and Mitigating Landslide Hazards in California (held in June 2002 at the Southern California Earthquake Center). As such,it is our professional opinion and judgment that the revised strength parameters utilized to model the lowest claystone unit along with the residual shear strength values utilized to represent the other units within the Delmar Formation,provide a conservative level of slope stability analyses. The results of our supplemental,gross stability analyses (performed with the use of the GSTABL 7®softwar e package) are presented on Plate Nos. 3 through 8 of this report. As is demonstrated on Plates Nos. 3 and 4 our supplemental,gross stability analyses indicate that the subject slope demonstrates minimum static and C\VE 2040232.3 January 6, 2005 Page 3 pseudo-static factors-of-safety of 1.47 and 1.17,respectively, for circular failures that terminate on the subject site. It should however be recognized that although the 1.47 factor-of-safety demonstrated on Plate No. 3 for static failures is slightly less than the generally accepted minimum that is considered to be stable of 1.5,all failure mechanisms demonstrated on Plate No. 3 that terminate within the area of or uphill of the proposed residence demonstrate factors-of-safety in excess of 1.5. _ Plate Nos. 5 and 6 present the results of the static and pseudo-static analyses in which all of the failure mechanisms terminate within or uphill of the area of the proposed residence. As demonstrated on these plates, the subject slope demonstrates minimum factors-of-safety against static and pseudo-static slope failures of 1.5 and 1.1 or greater,respectively, for all failures that terminate within the area of or uphill of the proposed residence. Plate Nos. 7 and 8 present the results of the static and pseudo-static analyses in which all of the failure mechanisms terminate downhill of the subject site. As demonstrated on these plates, the subject slope demonstrates minimum factors-of-safety against static and pseudo-static slope failures of 1.43 and 1.09, respectively, for all gross, circular failures that terminate within the offsite area downhill of the subject site. Three key points are demonstrated by the above described supplemental gross stability analyses. The first of these points is that the subject hillside demonstrates minimum static and pseudo-static factors-of-safety in excess of 1.5 and 1.1, respectively for gross failures terminating within or uphill of the residence. The second Point is that downhill of the proposed residence the site demonstrates a minimum factor-of-safety against gross, static failures slightly less than 1.5 and a minimum factor-of-safety against gross,pseudo-static failures in excess of 1.1. Lastly, the off-site portions of the hillside,assumed to be City property, demonstrate both minimum factors-of-safety against gross, static and pseudo-static failures slightly less than 1.5 and 1.1, respectively. In consideration of the fact that the subject slope demonstrates minimum Factors-of-safety that are generally considered to be stable against static and pseudo-static slope failures that terminate within or uphill of the proposed residence, no mitigative measures are considered necessary to further increase the factor-of-safety of tine site beneath or uphill of the proposed residence. Although the subject slope does demonstrate a minimum factor-of-safety of 1.47 for static,gross failures that terminate on the subject site, only within the open space easement along the site's western perimeter,which was granted to the County of San Diego per document# 81-180997 recorded on June 10, 1981, do failure surfaces terminate that have factors-of-safe below 1.5. We understand that per the requirements of the California Coastal Commission, no grading, ty improvements,or slope mitigation procedures are allowed within this open space area or the adjacent off-site portions of the subject hillside. As such,it is not considered feasible to perform mitigative measures to raise C\VE 2040232.3 January 6, 2005 Page 4 the minimum factors-of-safety of the subject hillside, for failures terminating both on and off of the subject site, from the existing minimums of 1.43 against static failures and 1.09 against pseudo-static failures to 1.5 and 1.1, respectively. However,it is our professional opinion and judgment that both our original and supplemental stability analyses included herein have been performed to conservatively analyze the stability of the subject hillside. In consideration of this conservative level of analysis and the fact that the proposed residence, although it is to be situated in an area that demonstrates adequate factors-of-safety against slope failure,will be founded on a deep foundation system consisting of drilled, cast-in-place concrete piers that are tied together at the top with grade beams,it is our opinion that the portions of the subject hillside that demonstrate factors-of-safety that are slightly less than those that are generally considered to be stable will not adversely affect the integrity of the proposed residence. Surficial slope stability analyses have been performed during the preparation of this addendum report. Plate No. 9 presents the results of our surficial stability analysis for the steepest portion of the subject property. This analysis incorporated the steepest on-site gradient,where materials of the Delmar Formation will be exposed, of 2:1 (H:V) and a depth of saturation of 3 feet. The results of this analysis indicate that the subject site demonstrates a minimum factor-of-safety in excess of the minimum that is generally considered to be stable of 1.5. For comparison,Plate No. 10 presents the results of our surficial stability analysis for the steepest portion of the subject slope, located off-site and downhill of the subject site. This analysis incorporated the steepest, average gradient of the subject slope adjacent to Manchester Avenue of approximately 0.6:1 (H:V) and a depth of saturation of 3 feet. The results of this analysis indicate that portions of the subject slope that are downhill of the subject site possess a factor-of-safety against surficial slope failures of 1.1,which is less than the minimum that is generally considered to be stable of 1.5. However, as described above in reference to those portions of the subject slope that are downhill of the subject site and which demonstrate minimum factors-of-safety against gross slope failures that are slightly below those which are generally considered to be stable,in consideration of the fact that the residence will be founded on a deep foundation system condititin of drilled, cast-in-place concrete piers that are tied together at the top with grade beams,it is our opinion th a the portions of the subject hillside that demonstrate factors-of-safety against surficial failures that are less than 1.5 will not adversely affect the integrity of the proposed residence. Review Comment 2:The proposed foundation design for the house is not acceptable. Although the consultant proposes a caisson design drilled through the deepest failure surface. If the slope or lot were to fail the caissons would be sheared and the house would be damaged. This is not an acceptable mitigation for the existing condition. Please address Item #1. CNVE 2040232.3 January 6, 2005 CWE Response. refer to our response to Review Comment#1. Additionally in con Page 5 fact that our supplemental analyses described above indicate that the site will possess minimum fac oors-of-the safety against gross, static and pseudo-static slope failures of 1.5 and 1.1 or greater,respectively,for terminating within or uphill of the proposed residence, the required depths of embedment of he cast-in-place concrete piers to support the proposed residence no longer need to be determined by the depth equal to five feet below the slope failure surface that exhibits a minimum factor-of-safety of 1.5"(CWE, 2000 . Rather, the foundation system of the residence needs to be constructed such that it does not impose an surcharge' loads into the zones of the critical, circular failure paths and will not do so over the anticipated lifetime of the residence. As such,we recommend that all piers have a minimum embedment depth of at least 25 feet below the proposed site grades. All other foundation recommendations contained in our referenced eotechnical report that are not specifically amended herein remain applicable. g Review Comment 3: The slope stability analyses indicate a slightly dipping surface into the slope area. No evidence, through geologic mapping or from downhole logging would indicate that this i P condition. In fact, based upon existing information the dip of the geologic units are horizontal o dipping in out of slope. ��/hy was no geologic mapping performed or a large diameter boring drilled to provide the information? geologic CWE Response- Our authorized scope of services for our original geotechnical investigation and for preparation of our updated geotechnical report did not include the drilling of a large-diameter boring on-site. However, our previous and recent surface reconnaissance of the subject site and adjacent hillside indicates that the bedding of the materials of the Delmar Formation that underlie the subject site and comprise th subject hillside dips up to 4 degrees to the north 87 E 4 N). P e � ° Such field measurements correlate with the bedding attitude of the Delmar Formation measured to the southwest of the subject site along Manchester Avenue,which is presented in DMG Open-File Report 96-02 g ter P as dipping 5 degrees to the north. The original slope stability analyses included within our referenced geotechnical report as well as e supplemental analyses included herein have all been prepared by modeling he stratigraphy of thetvarious units of the Dehnar Formation as having an apparent dip of 0°along the cross section A-A'. Such an apparent dip presents a neutral bedding orientation of the Delmar Formation along the west-southwest facin hillside, where the bedding was measured to demonstrate neutral to favorable (into slope) orientations g regards to the stability of the subject hillside. with Review Comment 4: No geologic map or cross-sections were included in the referenced re ort. Please Provide this information. P CkVE 2040232.3 January 6, 2005 CWE Res onset As presented above, a site plan and geotechnical m Page 6 site/grading plan as a base,is included as Plate No. 1 of this report. This that was created utilizin g the presents the observed bedding orientation of the materials of the Delmar site plan and geotechnical map lower portion of the existing slope to the southwest of the subject site, Formation as observed along the A-A', the location of our exploratory boring, l , the trace of our geologic cross section rY g, and the geologic unit underlying the site and adjacent hillside (Td). Additionally, Plate No. 2 of this report presents our geologic cross Proposed site topography, the location of the proposed residence, the location A-A'which depicts die the bedding of the Delmar Formation on-site (as described above). As n of our exploratory boring, reco ) g, and gnized that the trace of our previously mentioned,it should be geologic cross section was chosen to represent the steepest gradient along subject site and adjacent hillside areas. g the If you have questions after reviewing this report,please do not hesitat be of professional sen ice is sincere] appreciated. to contact our office. This opportunity to y ppreciated. Respectfully submitted, CHRISTIAN WHEELER ENGINEERING C Charles H. Christian,GE 215 --�� (A[C:I)ItR David R. Russell, CEG 2215 cc: (4) Subnittcd (2) Jim Knowlton,Geopacl6ea,Inc.,3060 Industry Street#105,Oceanside,CA 92054 - = RED G �� FG! c4l `�5 `0 R. R VS O ,t,st`�' ��,� h,9�s E•2 Q•<, �J S'� �iN No.2215 <� J U No.GE215 z rn o CERTIFIED ExP 9-30-05 ENGINEERING ° 7� GEOLOGIST CPA CF01-ECHN1GP * �� Exp.09-0r�, `P qj�OF GALIFOP�\P ��GF CALVFox� H CA Lp 0 O N O LO° n V1 N W LO 0 w o v U N Z O O w O 0 Z I 'C w o cr z Wu r � W F co a 3 o a w LU¢z a w �v o J C3' cG Z ifi Z U W CO N N O w Cc 0 I 0 O CV a I ~ N Cn 0 0 cc a z a J N m Q O m N I 0 I O I 0 I N z � N Ir r I 0 LL O Q N Z Cc LL \ I Z 0 O Z a W LL Z w ° C7 a Q Co W 2 o a 0 J CL w m Q Z o I w \ w z w 0 O c cn 0 0 0 N N I- I I n. T LEI J Q U � o i O co 3 ° ° Q 'C N V! TW N , N O O ` O /O V/ M M M � O M A O � M � 7 N u O LO a� O N cu O u Q CM- of N 0 a N N m M ::3 N � r, � O N c n 0 -a _ N cv c E Li O N 0000000 d J _ m E cn r1 Q N E ho :5 � 'Z°Mmmmm o cm = i m O c Q o 3: ° C,�000000 u M � U� O N O N 0 0 0 0 0 0 � r I� � d Qto to O to to Ln c0 00 °�v���Nln In m O N U— 2��000000 t6 F aN m C""m m N 0 co � `-����tititi L -�,-�5 0 0 0 0 0 0 N i O v OOOOU'>OLn � r... cc U- 0 0 r-+NCn�lnl0 rte+ cn Z lD w M n '� uVi �JUUJJ (n U)dacncn U�U�� L z 4t (U-0 U-0 m-- oo.c - — —- M 5= O O O O O O O ko Z' 00 Ln N a) W M ri ri ri �J PLATE No. 3 M M M M p O M A O a- 00 06 LO N v 0 LO 0 � c�v � v Q d' o N L � O w m N c v n s0 Z3(D ri d O N >U - LO Q N o � o ccoo U LNa. —1 CD y J L co d Y N O 9 . a io °'�°zO00000 m E s E U) N E 72 y d O ° � L U ��(mMMM N° M W 0 0 0 0 0 0 M Vl N U N t �a0000000 lLn m U 75 V) _0 U c,�5 w00000 c0 oC0 V O to O LO 0 LO LO O o N cl M Q ���000000 N i UOOOLO OLO r'1 0 n-N N N N(h ti U R — U L.� CO~z�--cNfh�Lo IO 10 r- f9 cp-0 U'O a) w J-z L=- M 5N O O O O O O O Z' �J PLATE No_ 4 M M M M 0 O M n O m M Q n LO N u LO O � � O u M y cl� _ Of a r N L Q m N a (V O M � Lit N N M ri ° H O c N c N E N N LL. � (D v N o) iz000000 �t m E 0 co Ln Q N F- E ° m 0 0 �ooLnoLn n of �ammr.4imcNO u ~ = L LLQ` 0 i m C M 'p N ' U X000000 N L N 5 m Ln O In Ln Ln LC1 fC n O `��--� t—N Ln Ln 3 to v v N 000000 1"1 f0 E :3 O-NmNmmN G1 cn:D M Q O i a ���000000 N 0 a000N�oLo � R o ao �Nmd Ln� M cu o vO J U U-i J N ow cn U cn(n U U coo �tMLo�or,0000� Ln Ln Ln Ln Ln Ln Ln Lo Ln Ln k Lug C)'D O w tz -•— (D �=J M 5Y O O O O O O O Z� co to N C) (O PLATE No. 5 M M M M O O M A O M p, 0 (V v 0 0 47 � M y T N w Q m N 04 O M n t N moo rl ca O a N m s O N fN m p � > Y N •� Q N U �Z000000 m O 2 �U) ~ N 2 °'mggLqq nLq w N s p r p i c a M.� 4] 0 0 0 0 0 0 0 M N t a� 0-LO LO O in to LO Ln co N O �'' d�•-+N to to rl M U C V a) O 0 0 0 0 0 0 w f°' Z.)uioui0LO ri V QNMNMMN y 0 _ O 0 0 0 0 0 0 N i o-i o- ,N,c. u O QNNNii R U. 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N - 0 0 0 0 0 0 0 M N N U✓t000000 Cr .� a`� o-to to O to LO to N N m 0 C `-'�--�d ti N LO In u r� 3 -0 _ V 0 0 0 0 0 0 V 2 U to O Lo O to to C'J C-NM—c\jmmN a r,000000 N i U UOOOtn66 � O F- `-' .-i U) 6�-+N(h d'tnO L(D m �Q cnUc/�cnUU� O O O O O O O O 00 to N O tD M �J PLATE No. 7 M M M M d' O M � M CI- 0 O d o N v O Ln s o Q Of .1 d tea o N -� Q (Ni N m v N Of moo o O N >` - Ln d a 06 ,i c_ N N � s o �1 0 1 t o m � = N Q = 3 U � °a z000000 J '° 00 3 co Q v E ~ O ° a a o O Ln o Ln Ln N U Q) U �MN�OoN0 L Q-O M M M M M M i = i LL Q O C: - 3 O a') ,-,000000 M i `) v L N000000 ^� O N a) d to Ln O 0 Ln M Ln V m U C`-'ti NLnLn r"1 La 000 ri E UMOLnOMU-) :3'E E-N M N M M N o 14 M Cn Lr u U 0 O Ln O Ln p..� �- aN N N N M ti az NMtLntD H WT lD NQ 0U(ncoUU dal al 01(3)al 0)C)00 0 0 0 0 0 0 0 M 5= O O O O O to <' PLATE No_ 8 ON-SITE SURFICIAL SLOPE STABILITY z A a SEEPAGE PARALLEL TO SLOPE ASSUMED PARAMETERS z Depth of Saturation ft 3 a Slope Angle H:1 2 yAl Unit Weight of Water(pc� 62.4 YT Saturated Unit Weight of Soil(pco 135 An le of Internal Friction Along Plane of Failure (degrees) 33 c Cohesion Along Plane of Failure(pso 150 FACTOR OF SAFETY FS = c +T(tan�) _. FS _ c + (YT-Y\X)(z)(cos2 a)(tan�) T (yr)(z)(sin a)(cos a) FS = 1.6 or PROPOSED SINGLE-FAMILY RESIDENCE �0- A' 2600 1\,fontgomery Ave.,Encinitas,California CHRISTIAN WHEELER. BY: DRR-CHC DATE: an-05 N G I N l: II R I N G JOB NO.: 203.497.3 Plate No. 9 OFF-SITE SURFICIAL SLOPE STABILITY z _.. a SEEPAGE PARALLEL TO SLOPE ASSUMED PARAMETERS z Depth of Saturation ft 3 a Slope Angle H:1 0.6 yw Unit Weight of Water(pco 62.4 yl- Saturated Unit Weight of Soil(pcf) 130 An le of Internal Friction Along Plane of Failure(degrees) 33 c Cohesion Along Plane of Failure(pso 150 FACTOR OF SAFETY FS _ c +T(tan�) FS _ c + (yr-Yw)(z)(Cos 2 a)(tan�) T (yl)(z)(sin a)(cos a) FS= 1.1 PROPOSED SINGLE-FAMILY RESIDENCE 2600 Montgomery Ave.,Encinitas,California CHRISTIAN WHEELER BY: DRR-CHC DATE: Jan-05 I: N G I N EE PL I N G JOB NO.: 203.497.3 Plate No. 10 w CHRISTIAN WHEELER CNCINEI= RING SECOND ADDENDUM GEOTECHNICAL REPORT PROPOSED SINGLE-FAMILY RESIDENCE 2600 MONTGOMERY AVENUE ENCINITAS, CALIFORNIA PREPARED FOR: K R BUILDING COMPANY 1242 CAMBIRA WAY ENCINITAS, CALIFORNIA 92024 PREPARED BY: CHRISTIAN WHEELER ENGINEERING 4925 MERCURY STREET SAN DIEGO, CALIFORNIA 92111 _J 4925 Mercury Street ♦ San Diego, CA 92111 ♦ 858-496-9760 ♦ FAX 858-496-9758 W CHRISTIAN WHEELER CNGINI-"" I- RING March 21, 2005 K R Building Company CNVE 2040232.4 1242 Cambria Way City of Encinitas Case No. 04-142 CDP Encinitas, California 92024 SUBJECT: SECOND ADDENDUM GEOTECHNICAL REPORT, PROPOSED SINGLE-FAMILY RESIDENCE, 2600 MONTGOMERY AVENUE, ENCINITAS, CALIFORNIA. REFERENCES: 1) Update Report of Preliminary Geotechnical Investigation,Proposed Single-Family Residence,2600 Montgomery Avenue,Encinitas, California, by Christian\Wheeler Engineering, - Report No. 2040232.1,dated March 11,2004. 2) Report of Preliminary Geotechnical Investigation, Proposed Nommesen Residence,2600 Montgomery Avenue, Encinitas, California, by Christian Wheeler Engineering,Report No. 199.099.2,dated December 28, 1999,revised March 7, 2000. __. 3) Site Plan/Grading Plan, Rutherford Residence,2600 Montgomery avenue,Cardiff, California, 92007, by Caitlin Kelley,AIA,print date June 22,2004. 4) Review of Geotechnical Report and Grading Plan,Rutherford Residence,2600 Montgomery,Encinitas, California, 9116GR,04-142 CDP, ly Geopacifica,Inc., dated August 30,2004. 5)Addendum Geotechnical Report,Proposed Single-Family Residence, 2600 Montgomery Avenue, Encinitas, California, by Christian NX/heeler Engineering,Report No. 2040232.3,dated January 6,2005. Attention: Mr. Kerry Rutherford In accordance with your request, this addendum report has been prepared to address the geotechnical considerations discussed during our February 8, 2005 meeting with yourself,representatives of the City of Encinitas'engineering department, and Mr.James Knowlton of Geopacifica, Inc., the City's geotechnical consultant. Specifically discussed during said meeting was the need to perform additional geologic mapping of the expressed geologic conditions presented along the face of the existing cut slope that extends from the western portion of the subject site down to Manchester Avenue and the need to perform additional gross stability analyses - to determine if the site will possess minimum static and pseudo-static factors-of-safety of 1.5 and 1.1 or greater, respectively, should a slope failure occur along the portion this slope that does not currently demonstrate minitnum 4925 Mercury Street ♦ San Diego, CA 92111 ♦ 858-496-976o i FAX 858-496-9758 C\X/T 2040232.4 March 21,2005 Page 2 static and pseudo-static factors-of-safety of 1.5 and 1.1,respectively. The following presents discussions of both our supplemental geologic mapping and supplemental stability analyses. SUPPLEMENTAL GEOLOGIC MAPPING: In consideration of the fact that the geologic structure of the materials of the Delmar Formation that underlie the subject site plays a significant role in the stability of the site and adjacent cut slope and is integral in the manner in which such stability is analyzed,per the request of Mr. Knowlton we have conducted supplemental field mapping of the geologic structure exposed along the face of the cut slope below the site and to the east of Manchester Avenue. As noted during our supplemental mapping, the distinct claystone unit that crops out along the face of the existing hillside to the west of the site at elevations ranging from approximately 74 feet to 77 feet(MSL)was measured to dip to the north 4 degrees and strike nearly east to west (N81°E,4°N). Similarly, although less pronounced due to surficial weathering of the outermost slope face,an attitude of N76°E, 5°N was measured within the lowest claystone unit,approximately five feet above the break in the relatively steep slope face adjacent to Manchester Avenue. Such measured attitudes have been plotted on our revised Site Plan and Geotechnical Map included herein as Plate No. 1r. It should be recognized that such measured bedding orientations correlate with the previously provided bedding measurement,which was measured along a distinct exposure within the lower portions of the subject slope face approximately 60 feet south of the downhill projection of the subject site. Specifically, our previous addendum report stated that"our previous and recent surface reconnaissance of the subject site and adjacent hillside indicates that the bedding of the materials of the Delmar Formation that underlie the subject site and comprise the subject hillside dips up to 4 degrees to the north (N87°E,4°N). Such field measurements correlate with the bedding attitude of the Delmar Formation measured to the southwest of the subject site along Manchester Avenue,which is presented in DIVIG Open-File Report 96-02 as dipping 5 degrees to the north" (C\TE,2005). Based on our original and supplemental geologic mapping of the cut slope within the western portion of the subject site and to the west of the site,which demonstrate slightly favorable bedding characteristics within the Delmar Formation with regards to slope stability on-site,it is our professional opinion and judgment that the methodologies employed in our previous and supplemental stability analyses are valid and proper to assess the gross stability of the site. It should be recognized that during our supplemental geologic mapping, several zones of generally northwest to southeast dipping cross bedding were noted along the cut slope to the south of the westward projection of the subject site. These cross beds were observed in the distinct clayey sand unit that crops out approximately two- thirds up the slope face. Based on their localized nature and existence within the dense to very dense, clayey sand CWE 2040232.4 March 21,2005 Page 3 portions of the Delmar Formation that underlie the site and subject slope,such cross bedding is not anticipated to affect the gross stability of the subject site. SUPPLEMENTAL GROSS STABILITY ANALYSES: In order to determine if the site will possess miniunum static and pseudo-static factors-of-safety of 1.5 and 1.1 or greater,respectively, should a deep-seated slope failure occur along the portion this slope that does not currently demonstrate minimum static and pseudo-static factors- of-safety of 1.5 and 1.1,we have performed four additional analyses modeling a theoretical future slope configuration. The modeled slope configuration represents our interpretation of the most probable geometry of the subject slope along our previously presented and analyzed geologic cross section A-A', should a future gross failure terminate within the uppermost (most easterly) portion of the subject slope that does not,it it's current condition, demonstrate minimum factors-of-safety of 1.5 against static failures and 1.1 against pseudo-static failures. The results of these supplemental analyses are included within Appendix A of this report. The first two analyses demonstrate the results of our static,gross stability analyses while the third and fourth analyses present the results of our pseudo-static analyses. These supplemental analyses incorporated all of the same soil characteristics,kh values, and failure mechanisms presented and discussed in our previous addendum report. As presented on the computer printouts of these supplemental analyses,should the over-steepened, outermost portions of the existing cut slope,which currently demonstrate factors-of-safety of less than 1.5 (static) and 1.1 (pseudo-static), fail, the resultant hillside would demonstrate minimum static and pseudo-static factors-of-safety in excess of 1.5 and 1.1, respectively. As such, although the subject hillside demonstrates a minimum factor-of-safety of 1.47 for static,gross failures that terminate within the westernmost portion of the subject site,downhill of the proposed residence (as presented in our previous addendum report), should gross failure occur along the subject hillside the existing cut slope would recede to a more natural and gentle inclination resulting in minimum factors-of-safety against both static and pseudo-static slope failures that are considered to be stable. Therefore it is our professional opinion and judgment that the slope along the west side of the proposed residence, both in its current and possible future configurations, will not adversely affect the integrity of the proposed residence,which is to be founded on a deep foundation system consisting of drilled, cast-in-place concrete piers that are tied together at the top with grade beams. CWE 2040232.4 March 21,2005 Page 4 If you have questions after reviewing this report,please do not hesitate to contact our office. This opportunity to be of professional service is sincerely appreciated. Respectfully subinitted, CHRISTIAN WHEELER ENGINEERING Charles H. Christian,GE 215 David R. Russell, CEG 2215 (:I ICaKFt cc: (4) Submitted (2) dim Knowlton,GcoPacifica,Inc.,3060 Industry Strcct#105,Oceanside,CA 92054 NCO H. Cy9� ley : ��a (3 W U No.GE215 z m�`. @ a, o ac Exp.9-30-05 a t ,+:.::.,ir-'-T Fxp .�r°? 3"?' OF CALIF��� OF`CA4 fl Appendix A Supplemental Stability Analyses M M M M p O M A ri s O � d M Q Lq ca Li o v ^ u N _ w Ln O = N Lp 3 ` M M 41 O N O .O m N "C ++ C O r Ln Ln LL O L. N M a _ :3 N C Q � LL. "7 Q N Q cp Lei H M N CL (V �_1°Z000OOO m E M c'n Q N N OQ ° °'mooLn0LOLO s o t C11:0�rMicmmmmoM ~ L-Q La >. N -� _ m c a U i 0 0 0 0 0 0 M 3: CDU �000000 QN O -,t N Ln Ln i a� �3:c00 00 0 0 U O L— OLOOMOInitd 7 - 5NMNMMN O �� m Ln O L�00CDLnOLO ri �- Q-N NNNM• -+ V U. Cn a 0.-+N M"t Lo LO ~ (D vim. _ M � 'p cUn --�UUJJ N C/)Q 000000 (D 07 HMmmt olOLOn CO nn In Ln n Ln L-)Ln Ln Ln Uf tL... 9 u'O 0 v- DD-r- —-_ M 5- O O O O O O O O Z 0000 Ln cli O t0 M (! 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G 00 00 00 O)6)(3)(3)m Ol(7) •• �N N N N N N N N N N CIO t.- M i O O O O O O O O - 00 to N O t0 M H H r-1 w CHRISTIAN WHEELER ENCINCI- R I N G, SUPPLEMENTAL DESCRIPTION OF ADDITIONAL DIRECT SHEAR TESTING AND SLOPE STABILITY ANALYSES PROPOSED SINGLE-FAMILY RESIDENCE 2600 MONTGOMERY AVENUE ENCINITAS, CALIFORNIA PREPARED FOR: K R BUILDING COMPANY 1242 CAMBIRA WAY ENCINITAS, CALIFORNIA 92024 PREPARED BY: CHRISTIAN WHEELER ENGINEERING 4925 MERCURY STREET SAN DIEGO, CALIFORNIA 92111 4925 Mercury Street ♦ San Diego, CA 92111 ♦ 858-496-9760 ♦ FAX 858-496-9758 CHRISTIAN WHEELER I- NCINl FRING May 13,2005 K R Building Company CAVE 2040232.7 1242 Cambria Way City of Encinitas Case No. 04-142 CDP Encinitas, California 92024 SUBJECT: SUPPLEMENTAL DESCRIPTION OF ADDITIONAL DIRECT SHEAR TESTING AND SLOPE STABILITY ANALYSES, PROPOSED SINGLE- FAMILY RESIDENCE, 2600 MONTGOMERY AVENUE, ENCINITAS, CALIFORNIA. REFERENCES: 1) Update Report of Preliminary Geotechnical Investigation,Proposed Single-Family Residence, 2600 Montgomery Avenue,Encinitas,California, by Christian W%eeler Engineering, Report No. 2040232.1, dated March 11,2004. 2)Report of Preliminary Geotechnical Investigation,Proposed Nommesen Residence,2600 Montgomery Avenue, Encinitas, California, by Christian Wheeler Engineering,Report No. 199.099.2, dated December 28, 1999,revised March 7,2000. 3)addendum Geotechnical Report,Proposed Single-Family Residence, 2600 Montgomery Avenue, Encinitas, California, by Christian\YVheeler Engineering, Report No. 2040232.3,dated January 6, 2005. °- 4)Second Addendum Geotechnical Report,Proposed Single-Family Residence,2600 Montgomery Avenue,Encinitas, California, by Christian Wheeler Engineering, Report No. 2040232.4, dated March 21,2005. Attention: Mr. Kerry Rutherford In accordance with your request, this addendum report has been prepared to address the geotechnical considerations discussed between our staff and representatives of Geopacifica, Inc., the City of Encinitas' geotechnical consultant pertaining to the gross stability analyses presented in the above referenced geotechnical reports for the project site. Specifically discussed between our staff and representatives from Geopacifica was the need to substantiate the strength parameters utilized to model the lower claystone unit within our analyses,which is exposed along the face of the existing cut slope to the south of the subject site. In order to justify the modeling of the lower claystone unit exposed along the face of the existing cut slope located downhill of(to the south) of the subject site, per our conversations with representatives of Geopacifica and in 4925 Mercury Street ♦ San Diego, CA 921 11 ♦ 858-496-9760 ♦ FAX 858-496-9758 C\VE 2040232.7 May 13, 2005 Page 2 accordance with the recommendations presented in the referenced Recommended Procedures for the Implementation of SP 117,we first collected a relatively undisturbed,"chunk" sample of the claystone in question from the face of the outcrop along Manchester Avenue. The sample vas sealed in a plastic bag and carefully transported to our laboratory for supplemental direct shear testing. It should be recognized that since the area from which the sample was collected is not on the subject site,we were limited to collecting the sample from a somewhat fractured portion of the slope face. Specifically, the collected sample was taken from a jointed area of the slope face where it appeared that the sample was about to fall away from the slope face. Other than the scraping off of loose surficial soils from the face of the cut slope, no appreciable destruction of the outcrop was performed in the collection of the tested sample. Upon arrival in our laboratory, three specimens from the sample were hand carved to dimensions such that they could fit into our testing apparatus. Although the hand carving was performed very slowly and carefully,a rather small yet appreciable amount of sample disturbance was observable around the periphery of each carved specimen. Nonetheless, the resultant specimens,obtained from the outermost and most potentially weathered portions of the slope face,were significantly less disturbed than those samples collected from our original subsurface explorations. The results of this additional direct shear test are presented on the stress deformation curves and plot of the failure envelope presented on Plate Nos. 1 and 2 of this report,respectively. As presented on the plot of the failure envelope (Plate No. 2), the additional direct shear test of the recently collected"chunk" sample of the lower claystone unit along the subject slope demonstrates a cohesion value of 925 psf and an angle of internal friction of 26°. For comparison,our previous stability analyses included within our first and second addendum reports referenced above (references #s 3 and 4) modeled the lower claystone unit along the subject slope face as having a cohesion value of 550 psf and an angle of internal friction of 30'/2°. Based on the fact that the results of our supplemental direct shear testing indicated a higher cohesion value and lower angle of internal friction of the subject claystone unit than which were modeled in our previous analyses described above, each of the gross stability analyses presented in our addenda reports C\UE 2040232.3 (1/6/05) and 2040232.4 (3/21/05) has been re-run incorporating the results of supplemental direct shear testing. Appendix A of this report presents the plots of revised analyses of each of the gross stability analyses that were originally presented in our first addendum report dated January 6,2005 (C\X/T 20=10232.3). Appendix B of this report presents the plots of revised analyses of each of the gross stability analyses that were originally presented in our second addendum report dated March 21,2005 (C\\/T- 2040232.4). As demonstrated on the plots of every one of the revised gross stability analyses (including both static and pseudo-static analyses), the utilization of the supplemental direct shear test results in our stability analyses demonstrates minimum factors-of-safety in excess of those previously presented in our referenced addenda reports. CWE 2040232.7 May 13,2005 page 3 Based on the results of our supplemental direct shear testing and revised stability analyses described above and included in Appendices A and B herewith,it is our professional opinion and judgment that.the strength parameters modeled to represent the claystone unit in question along the base of the slope as well as the other sediunentary units that comprise the subject hillside,provide a conservative level of analyses for the subject hillside and proposed construction. The discussions presented herein are solely intended to provide additional clarification of the strength parameters used to model the lower claystone unit within our previous stability analyses prepared for the proposed project. This report presents no conclusions or recommendations that amend the findings, conclusions, or recommendations presented in our referenced reports for the subject site or our additional addenda. As such,all observations,recommendations, and conclusions presented within our referenced Update Report of Preliminary Geotechnical Investigation and addenda remain valid and applicable to the subject project. If you have questions after revie«ing this report,please do not hesitate to contact our office. This opportunity to be of professional service is sincerely appreciated. - Respectfully submitted, CHRISTIAN WHEELER ENGINEERING Charles H. Christian,GE 215 David R. Russell,CEG 2215 CI]CAM, cc: (4) Submitted Jim Knrnclton,GcoPacifiea,Inc.,3660 Indu.,m St7cct#105,Occanside,CA 92054 rF0 I;U ES S� C� P0.2215 << , � Ef•1t,fUEEP.fP13 ° C3 �0 No.GE215 Z rt' GEJLC�tST M CC Exp.9-M-05 ��� Eat• Ob Q CAvW STRESS-DEFORMATION PLOT(new machine) 20 kg-1440 psf , 40 kg-2880 psf 10 kg-720 psf Deflection Shear Stress Dial Reading Deflection . Shear Stress Dial Reading Deflection Shear Stress Dial Reading 0.000 0 0 0.000 0 0 0.000 0 80 0.010 85.8 12 0.010 114.4 16 0.010 572 140 122 0.020 486.2 68 0.020 579.15 2 0.030 1222.65 171 81 0.020 1001 0.030 536.25 75 0.030 872.3 0.040 643.5 90 0.040 1001 140 0.040 1272.7 178 0.050 793.65 111 0.050 1129.7 158 0.050 1430 200 0.060 1029.6 144 0.060 1322.75 185 0.060 1623.05 227 0.070 1158.3 162 0.070 1480.05 207 0.070 109.5 250 0.080 1194.05 167 0.080 1601.6 224 0.080 1909.05 267 0.090 1244.1 174 0.090 1651.65 231 0.090 284 2030.6 0.100 1222.65 171 0.100 1630.2 228 0.100 2109.25 295 0.110 1251.25 175 0.110 1580.15 221 0.110 2180.75 305 0.120 1229.8 172 0.120 1508.65 211 0.120 2195.05 307 _ 00.170 130 1179.75 165 0.130 1451.45 203 0.130 2180.75 305 1144 160 0.140 1422.85 199 0.140 2159.3 302 150 1108.25 155 0.150 1401.4 196 0.150 2130.7 298 160 1093.95 153 0.160 1387.1 194 0.160 2087.8 292 1079.65 151 0.170 1387.1 194 0.170 2044.9 286 0.180 1072.5 150 0.180 1394.25 195 0.180 2023.45 283 0.190 1065.35 149 0.190 1394.25 195 0.190 1994.85 279 - 0.200 1973.4 276 0.200 1051.05 147 0.200 1401.4 196 105.6 cf a 19.0°.o M.C. 103.2 pcf 0 20.9°,%'M.C. 100.9 pcf a)21.7 7o M.C. P C Proposed Rutherford Residence Claystone Chunk from Base of Adjacent Outcrop _. 2500 -- - I - - - 7 - - !- -!--- --- ------- - I ---i-�L� 2000 -- -0 720 psf ---- - -- - _-- �- -- -X 1440 psf - -- - -;-._2880 psf _ a ,sou -�- - / -- �- ,-- --1---, L 11110 -------- /--_-�-- --I-- -- -�- - - - ---_-- ---- -_-!------- (ij)Oo 0.010 0.020 0.030 ().040 0.050 0.060 0.070 0.090 0.090 0.100 0.110 0.120 0.130 0.140 0.150 0.160 0.170 0.160 0.190 0.200 Shear Displacement(in.) I C\FL 2040232.7 May 2005 Plate No. 1 Direct Shear Summary 5000 - 4500 4000 3500 C., 3000 LO 2500 vi i lr u 2000 1500 1000 500 0 . 0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 Normal Stress (psf): 2.375-inch Sample .Angle of Internal Cohesion Sample No Sample Type Friction Intercept Cla�-stone Collected Caned from 260 925 psf from Bottom of Outcrop Chunk Sample PROPOSED HENDRICK RESIDENCE .r Pi�L' 2600 T\fontLomcry Ave.,Encinitas,California CI-IRI�FIAN WHEELER B1 DRR DATE: May-05 I NGINCP. RIVG JOB NO.: 2040232.7 PLATE, NO.: 2 Appendix Revisions of Gross Stability Analyses Presented in CWE Report 2040232.3 titled "Addendum Geotechnical Report, Proposed Single-Family Residence, 2600 Montgomely Avenue, Encinitas, California", dated January 6, 2005. C\\rL 2010232.7 Proposed Single-Family Residence 2600 montgomery Avenue,Encinitas, CA M d' M I M M O O M A t O � .fl M � r. M ❑. LO N U O �- O rn .1 two U M y T 1-4 Q m N 0 O 0 -p Q N r N t M a d M N in I E N 'i C N N co N u N d > 0 M d Q °' m E U y U a, t: 0000000 .4. N ri '> OLqO(n0 �-I f- O d IID t Co Cq 0 DAiQ�MMMn7 _ -2 M D O o t j C a 00000 o ,0 a° u n00000- s ' QLn�OLD toN 7 O C r.d N(n 0) U U U— _0 U "° N �'J�000000 R n 41 U L.()O In O In N i- 7'- aNMN(h(Y) M Q a) (N � N w N 0 ... E m3r.000000 � � UOOOU1o(n OD NNm� p IT M to J J J (p Q7 (° CO Uco U UU Nmdd(n(nOOr-r- - -> Ct i z Cfl O O O 0 M O i O 00 Ln N cn .: � M M I M M O O M A t 2 Q n in N u 0 n o a� a LO ,1 R u � M � L.. 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O O C d O G L i in OOOo O N r•{ �p i U N ���000000 jp 00 O Lo O Ln o Ln Ln fn - - aN(oN(h(nN \ M — � N .-000000 O._ dNNNNm�"� l0� d — O i O OTzr Nc�dLn� cO Cf)F- M U) ai cnUco V)UU �NNNNNNN CO cq NNNNNN LL p O p 00 LLn N CO M _- Appendi* x Revisions of Gross Stability Analyses Presented in CWE Report 2040232.4 titled "Second Addendum Geotechnical Report,Proposed Single-Family Residence, 2600 Montgomery Avenue, Encinitas, California", dated March 21, 2005. CWE 2040232.7 Proposed Single-Fain ly Residence 2600 montgomery Avenue,Encinitas, CIS M M M M 0 O O M A o rn O '5: t �ca o N u a) Lr) N 0 o a �' Co r+ (11 0 0 :3 N r � +-a+ a ur LL �' kD M i '1 N C Va 3 -a � N Gl CIO, Q v m E U U N 0000000 � N e-i M �� N N 70 a °_ � 0 N 2 m0 o 0rnino ^ � �OMNcf�NIJ A O ` N C 1 o o 000000 Ln •' cv L Qoo0OOON > O �r-+d�NLo(3) v ( 0 0 0 0 0 V U0 Li0mouiui \ a) L. i bA 000000 � +� mar- � C E U000 rio�n <v c� O" aNNNNM LL- O - N d O r+NMd Lol0 Cf) Z M J J J LD D L N-,D00(3)(3)NL0L()Lnr- �O_0 U-0 O H � O O O (� O N O i r-I —- M M M M i O M A .cc a V .1 0 - .0 O co Q O r U N N O in O O � � U � M O :3 LL. 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U ` U O -o �y S 0OO000 N @�L)Lf)O�OLo U i- C�- fl-N MNm(hN M Q > Q 000000 m O d (n aZ_N M tIno co C) ~ M V) U O N � C.) � CO �Ucn�UU O G p rl'tt1)lot,Q)OO�N �NNNNNNMChchM 7 co_0 70 a)-- O - O O O O O CO M f c O Ln N O .i rl _- M M M i O O li 'i O _ a � 0 L M O. C O 3 v O N 0 m o O o u C L rL N o ti d 0 Q ai V o bo LO M O 3 300 O M Q >Ln —b0 4 C 7 � U N cv V o Q a> 4, —1 o _ co aoi t L N (n O U N ru m �_ % � Z000000 Q N > CO \. N lv N V o a�pp0 O Ln o Ln O F a ` �a) ,t 00N Io T L Q-0 m m m M m N m > LL N o 20-0000n O r a Ln Lo O to In N ri O p v.--�d�NLn 61 [t U` v O 3 -S ,� U fa °:�„00000 0 = aNmNmmN '- ' hD V) Ln Qi N a a 000000 ,-i o �°�u000LnoLn u y_ o dNNNNm� c9 Q) co :D E tb — a) ip Z•--�N m Ln--0 CO M fC d U _ N O � �JUU iJ L° a� �UmmUU C° - V)Mm(�mmmr�mcl�m m= � i r O O O O O cy') r� co 04 m W CHRISTIAN WHEELER E N G I N E E R I N G March 11,200.1 C��/E 2040232.01 K.R. Building Company �1` `� 1242 Cambria Way 2 } Encinitas,California 92024 Attention: Kerry Rutherford SUBJECT: UPDATE OF REPORT OF PRELIMINARY GEOTECHNICAL INVESTIGATION,PROPOSED SINGLE-FAMILY RESIDENCE,2600 MONTGOMERY AVENUE,ENCINITAS,CALIFORNIA Reference: Report of Preliminary Geotechnical Investigation,Proposed Nomtnesen Residence,2600 Montgomery Avenue,Encinitas,California,by Christian Wheeler Engineering,dated December 28,1999,reiised March 7,2000. Dear Mr. Rutherford: In accordance with your request we have prepared this letter to update the referenced geotechnical investigation. Based on our review,it is our opinion that the geologic/geotechnical findings and recommendations given in the investigation report remain applicable to the proposed project. If you have any questions after reviewing this report,please do not hesitate to contact our office. This opportunity to be of professional service is sincerely appreciated. Respectfully submtted ;E3 (3Fp15 z, rt, CHRISTIAN WHEELER ENGINEERING or Cr:t1F � LSD GF Charles H. Christian,R.G.E. #00215 Curtis R. Burdett C.E.G. #1090 ? �`o.1a GECtPR- CHC:CRB:scc ENG NIEMING ., cc: (4) Submitted E 0-041T �OF Ci�L1� 4925 Mercury Street + San Diego, CA 92111 + 858-496-9760 + FAX 858-496-9758 W CHRISTIAN WHEELER F N C, I N V L R I N C, October 19,2004 K R Building Company CWE 2040232.2 1242 Cambria Way Coastal Commission Appeal No.:A 6-ENG04-125 Encinitas,California 92024 City of Encinitas Case No. 04-142 CDP SUBJECT: DISCUSSION OF GEOLOGIC AND GEOTECHNICAL FACTORS AFFECTING SITE STABILITY, PROPOSED SINGLE-FAMILY RESIDENCE,2600 MONTGOMERY AVENUE, ENCINITAS, CALIFORNIA. REFERENCES: 1) Update Report of Preliminary Geotechnical Investigation,Proposed Single-Farnily Residence,2600 Montgomery Avenue,Encinitas,Califomia,by Christian Wheeler Engineering,Report No. 2040232.1,dated March 11,2003. 2) Site Plan/Grading Plan,Rutherford Residence,2600 Montgomery Avenue,Cardiff, California,92007,by Caitlin Kelley,AIA,print date June 22,2004. 3) Deed Restriction,2600 Montgomery Avenue,Encinitas,California,by The California Coastal Commission,Document No. 1994-01-50173,recording date March 7, 1994. 4) Review of Geotechnical Report and Grading Plan,Rutherford Residence,2600 Montgomery,Encinitas,California,9116GR,04-142 CDP,by Geopacifica,Inc.,dated August 30,2004. Attention: Mr.Kerry Rutherford In accordance with your request,this report has been prepared to discuss the effects of the proposed site grading and construction of the proposed basement on the stability(both long and short term) of the subject site and adjacent sloping areas. It is our understanding that pursuant to the above-referenced California Coastal Commission's 1994 deed restriction on the property,no additional grading is to be permitted on the subject site and that any proposed structures on-site are to be founded on"pole or pier" foundation systems (page 1872 item F). We also understand that the referenced deed restriction stipulates that no new improvements be constructed closer to the existing open space easement along the southwest portion of toe lot,than the-s—& hest edge of the car deck that previously existed within the southwest portion of the property(page 1-873 item F). 4925 Mercury Street + San Diego, CA 92111 ♦ 858-496-9760 ♦ FAX 858-496-9758 OWE 204.232.2 October 19,2004 Page 2 As presented is our referenced update report of geotechnical investigation for the subject project,in order to ensure that the proposed structure will not adversely effect the stability of the adjacent sloping hillside by adding a surcharge load to the slope and also to ensure that improvements be founded upon competent materials of the Delmar Formation that posses a minimum factor-of-safety against slope failures in excess of 1.5,the proposed residence and garage are to be supported by a deep foundation system consisting of drilled,cast-in-place concrete piers tied together with grade beams. Furthermore,as part of our response to the referenced third party review of our update report,we are currently preparing design recommendations for the proposed foundation system that will raise the minimum factors-of-safety across all portions of the site to be developed to 1.5 and 1.1 against static and pseudo-static slope failures,respectively. The above-described increases in the minimum factors-of-safety(both static and pseudo-static) across those portions of the site to be developed,which,as presented in our update report,in their current configuration possess a minimum factor-of-safety against static slope failures of approximately 1.34,will be achieved by designing the proposed deep foundation system to not only provide bearing support for the proposed residence but to also act as shear pins,and to reduce the driving forces which adversely affect the stability of the subject site and adjacent hillside. The designing of the proposed foundation piers to act as shear pins will serve to provide lateral resistance along the face of the subject slope and therefore increase the forces resisting slope failure (resisting forces). Such an increase in the resisting forces will also increase the ratio of forces resisting slope failure to the forces contributing to slope failure (driving forces). This ratio of forces resisting slope failure to forces contributing to slope failure defines what is commonly referred to as the factor-of-safety. As such,by reducing the driving forces that contribute to slope failure by reducing the weight of the soil mass along the upper portions of the subject slope as the result of the proposed site grading and construction of the propose basement,the factors-of-safety against static and pseudo-static,deep-seated slope failures along the subject hillside will be further increased. Conversely,should the proposed site grading and basement construction not be permitted as part of the proposed site development,no reduction in the driving forces affecting slope stability(those forces that adversely affect the stability of the slope) will be achieved. Therefore,from a geologic and geotechnical perspective,the proposed site grading and construction of the proposed basement will serve to increase the factors-of-safety of the subject hillside. In consideration of this,we recommend that the Coastal Commission consider amending the referenced deed restriction to allow the proposed site grading and construction of the basement as part of the proposed site development. CWE 204.232.2 October 19,2004 Page 3 If you have questions after reviewing this report,please do not hesitate to contact our office. This opportunity to be of professional service is sincerely appreciated. Respectfully submitted, CHRISTIAN WHEELER ENGINEERING r Charles H.Christian,GE 215 David R-Russell,CMG 2215 CHC:DRR CC: (5) Submitted VOFESS Quo �S H. C CID W U No.GE215 Z m ° CC Exp.9-30-05 GF��fCHN��P� ��q�OF CALIFO��`P W CHRISTIAN WHEELER L N C I N I I R I N G March 21, 2005 h R Building Company CWE 2040232.5 1242 Cambria Way Encinitas, California 92024 Attention: Mr. Kerry Rutherford SUBJECT: FOUNDATION PLAN REVIEW, PROPOSED SINGLE-FAMILY RESIDENCE, 2600 MONTOGOMERY AVENUE,ENCINITAS, CALIFORNIA. REFERENCES: 1) Update Report of Preliminary Geotechnical Investigation,Proposed Single-Family Residence,2600 Montgomery Avenue, Encinitas,California, by Christian Wheeler Engineering, Report No. 2040232.1, dated March 11, 2004. 2) Report of Preliminary Geotechnical Investigation,Proposed Nommesen Residence,2600 Montgomery Avenue, Encinitas, California, by Christian Wheeler Engineering,Report No. 199.099.2, dated December 28, 1999,revised March 7,2000. 3)Addendum Geotechnical Report, Proposed Single-Family Residence,2600 Montgomery Avenue, Encinitas California by Christian Wheeler Engineering,Report No. 2040232.3, dated January 6,2005. 4)Structural Plans for: Rutherford Residence,2600 Montgomery Avenue, ri rt California, by Jacobs Consulting,Inc., dated December 10,2004. V, Dear Ladies and Gentlemen: { 5 In accordance with your request,we have reviewed the referenced structural plans. In general,rl efeotechnical recommendations presented in the referenced reports have been properly incorporated into the structural plan; however, our recommendations presented in the referenced addendum geotechnical report called for all piers to have a minimum embedment depth of at least 25 feet below the proposed site grades.The recomunencied depth for the piers is not shown on the structural plans. Provided this discrepancy is revised on the structural plan,it is our opinion that our recommendations have been properly incorporated into the structural plan. 4925 Mercury Street i San Diego, CA 92 11 1 ♦ 858-496-9760 ♦ FAX 858-496-9758 W CHRISTIAN WHEELER ENGINEERING March 11,2004 1, t K R. Building Company �1 i - / C\X'E 3040233.01 1242 Cambria Way Encinitas,California 92024 Attention: Kerry Rutherford SUBJECT: UPDATE OF REPORT OF PRELIMINARY GEOTECHNICAL INVESTIGATION,PROPOSED SINGLE-FAMILY RESIDENCE,2600 MONTGOMERY AVENUE,ENCINITAS,CALIFORNIA Reference: Report of Preliminary Geotechnical Investigation,Proposed Nommesen Residence,2600 Montgomery Avenue,Encinitas,California,by Christian Wheeler Engineering,dated December 28,1999,reazsed March 7,2000. Dear Mr. Rutherford: In accordance with your request we have prepared this letter to update the referenced geotechnical investigation. Based on our review,it is our opinion that the geologic/geotechnical findings and recommendations given in the investigation report remain applicable to the proposed project. If you have any questions after reviewing this report,please do not hesitate to contact our office. This opportunity to be of professional service is sincerely appreciated. <C S � y H.C, Respectfully submitted, W U No GE215 z m CHRISTIAN WHEELER ENGINEERING Exp.9 30 05 rM cP. C 1�+, Charles H. Christian,R.G.E. #00215 Curtis R. Burdett,C.E.G. #1090 CHC:CRB:scc Gtr T'-iE1) ENC,:tir--:1!NG cc: (4) Submitted CEOLt::�=.i T r r� Ehp. 'i o-04^ .4`925 Mercury Street San Diego, CA 92111 v 858-496-9760 FAX 858-496-9 FC�1`rC. Geopacifica, Inc. Me -1-111-10 To: Duane Thompson, Engineering Plan Check, Encinitas From: James Knowlton, Geotechnical Consultant Date: August 30, 2004 Re: Review of Geotechnical Report and Grading Plan, Rutherford Residence, 2600 Montgomery, Encinitas, California, 9116GR, 04-142 CDP In response to your request I have reviewed the following items: "Update of Report of Preliminary Geotechnical Investigation, Proposed Single-Family Residence, 2600 Montgomery Avenue, Encinitas, California.", by Christian Wheeler Engineering, dated March 11, 2004 "Grading Plans for 2600 Montgomery Avenue", by Pasco Engineering, Undated The purpose of my review was to determine if the subject geotechnical meets the requirements of the City of Encinitas. Based upon my review the report does not meet all applicable requirements and is not approved. The following items need to be addresse prior to review: 1. Based upon stability analyses of the subject site the lot and the adjacent slope to the south are not stable based upon the City of Encinitas minimum requirement of 1.5 safety factor for static and 1.1 safety factor for seismic. Also, no surficial stability analysis was performed. What does the consultant propose to bring the lot and slope into conformance with the City of Encinitas requirements? 2. The proposed foundation design for the house is not acceptable. Although the consultant proposes a caisson design drilled through the deepest failure plane, this does not mitigate the potential failure surface. If the slope or lot were to fail the caissons would be sheared and the house would be damaged. This is not an acceptable mitigation for the existing condition. Please address Item#1. 3. The slope stability analyses indicate a slightly dipping surface into the slope area. No evidence, through geologic mapping or from downhole logging would indicate that this is the correct condition. In fact, based upon existing information the dip of the geologic units are horizontal to dipping out of slope. Why was no geologic mapping performed or a large diameter boring drilled to provide the geologic information? 4. No geologic map or cross-sections were included in the referenced report. Please provide this information. 1 W CHRISTIAN WHEELER I N G I N I. 1: R I N G March 11,2004 K R Building Company CWE 2040232.01 1242 Cambria Way Encinitas,California 92024 Attention: Kerry Rutherford SUBJECT: UPDATE OF REPORT OF PRELIMINARY GEOTECHNICAL INVESTIGATION, PROPOSED SINGLE-FAMILY RESIDENCE,2600 MONTGOMERY AVENUE,ENCINITAS,CALIFORNIA Reference: Report of Preliminary Geotechnical Investigation,Proposed Nommesen Residence,2600 Montgomery Avenue,Encinitas,California,by Christian Wheeler Engineering,dated December 28,1999,mimed March 7,2000. Dear Mr. Rutherford: In accordance with your request we have prepared this letter to update the referenced geotechnical investigation. Based on our review,it is our opinion that the geologic/geotechnical findings and recommendations given in the investigation report remain applicable to the proposed project. If you have any questions after reviewing this report,please do not hesitate to contact our office. This opportunity to be of professional service is sincerely appreciated. ^ C\ Respectfully submitted, ' CHRISTIAN WHEELER ENGINEERING d i Charles H. Christian,R.G.E. #00215 Curtis R. jt1�ett,C.E.G. #1090 t!o 1 m� `� ! i 1 GERT!FIED CHC:CRBacc 7- cc: (4) Submitted - - _-- -- EY4 0. T 4925 Mercury Street + San Diego, CA 92111 + 858-496-9760 + FAX 858-496-97 Geopacifica, Inc. Me-1-1-10 To: Duane Thompson, Engineering Plan Check, Encinitas From: James Knowlton, Geotechnical Consultant Date: August 30,2004 Re: Review of Geotechnical Report and Grading Plan, Rutherford Residence, 2600 Montgomery, Encinitas, California, 9116GR, 04-142 CDP In response to your request I have reviewed the following items: "Update of Report of Preliminary Geotechnical Investigation, Proposed Single-Family Residence, 2600 Montgomery Avenue, Encinitas, California.", by Christian Wheeler Engineering, dated March 11, 2004 "Grading Plans for 2600 Montgomery Avenue", by Pasco Engineering, Undated The purpose of my review was to determine if the subject geotechnical meets the requirements of the City of Encinitas. Based upon my review the report does not meet all applicable requirements and is not approved. The following items need to be addresse prior to review: 1. Based upon stability analyses of the subject site the lot and the adjacent slope to the south are not stable based upon the City of Encinitas minimum requirement of 1.5 safety factor for static and 1.1 safety factor for seismic. Also, no surficial stability analysis was performed. What does the consultant propose to bring the lot and slope into conformance with the City of Encinitas requirements? 2. The proposed foundation design for the house is not acceptable. Although the consultant proposes a caisson design drilled through the deepest failure plane, this does not mitigate the potential failure surface. If the slope or lot were to fail the caissons would be sheared and the house would be damaged. This is not an acceptable mitigation for the existing condition. Please address Item#1. 3. The slope stability analyses indicate a slightly dipping surface into the slope area. No evidence, through geologic mapping or from downhole logging would indicate that this is the correct condition. In fact, based upon existing information the dip of - the geologic units are horizontal to dipping out of slope. Why was no geologic mapping performed or a large diameter boring drilled to provide the geologic information? 4. No geologic map or cross-sections were included in the referenced report. Please provide this information. 1 Apr 24 05 11 : 13a Kerry 1 -760-487-1873 p. 2 Fipr -22 2005 8: 22RM Flores Lund Consultants 858 566 0627 P- 1 RPM 22 2005 9: 15RM CHRISTIHN WHEELER ENGINEE 0584969758 P. 1 W CHPLISTJA, C11. 1 W WGER April 21,200 CWB 2040232.6 K R Building Company 1242 CAntbrk W-AV Encinitas,Califoniis 92021 Attention: bit.Kerry Rutherford SUBJECT: REVIEW,2600 MONTOGOMERY VNUE AVENUE, CALIFORNIp�IDENCE, REFEREWCILS: 1)Update Report ofprelirninary Gcowchnical Investiigation.Proposed Single-Furwy Rpidence,2600 Montgomery Avenue,Encinitas,Californiia,!y Cluia6ae Whedes Engineering; Report No.20402321,dated March 11,2004. 2)Report oEPrditninncy GeotecbnicR)Investigation,Proposed N0nunere0 Residence,2600 Adontgornery•Avenue,1rnr-inizR$,CaliforrliR, 0 Christian Wheeler Sngineetisig,Report No. 199,099.2, dated Doccmbcr 2%9999,revised Nfarch 7,,2000. Dear Ladies and Gentlemen: in accordance vAth die requrst of Flores Lund Conaulanta,we have reviewed the"KEY"diagram depicting the loading conditions%wed for dte design of temporary sh*Ang. In our opirtior,the loading conditions used in the design,including the Values for Acive and passive pressures,are saitable for the subject project. If you have questions after reviewing this repots,please do not hesitate to contact Out oMc- 'Din opporrunity to be of professiouat service is aineeaely appreciated. 4gQFESd/pj;_ Respeccfu]ly eubiivtted, C*MMT AN WHEELER ENGINEERING '` _� N4'`r�•��r rrt.CE215 Era.a.34os � Charles H.Christian,R.G.E. #00215 AeL`JIL CHC.scc cc: (2) Submitted (1) Via Fax:Att:Krrry Rutherford,Fax No.760-487-1873 (1) ViA Fax:Att:lArsy Pitkiti,Fax No.858-566-0627 4925 Mcccury Street ♦ San Diego, CA 92111 ♦ 858-496-9760 t FAX 858.496-9738 i w CHRISTIAN WHEELER ENGINEERING I f REPORT OF PRELIMINARY GEOTECHNICAL INVESTIGATION t PROPOSED NOMMESEN RESIDENCE 2600 MONTGOMERY AVENUE ENCINITAS, CALIFORNIA t PREPARED FOR: MR.JOHN NOMMESEN 2540 MONTGOMERY AVENUE 4 ENCINITAS, CALIFORNIA 92007 nircEIVEI) CITY OF ENCINITAS BUILDING INSPECTION DIVISION a PREPARED BY: STIAN WHEELER ENGINEERING 4925 MERCURY STREET DIEGO, CALIFORNIA 92111 � 03 4925 Mercury Street ♦ San Diego, CA 92111 ♦ 858-496-9760 ♦ FAX 858-496-9758 W CHRISTIAN WHEELER ENGINEERING December 28, 1999 (revised 3-7-00) Mr.John Nommesen CWE 199.099.2 2540 Montgomery Avenue Encinitas, California 92007 SUBJECT: REPORT OF PRELIMINARY GEOTECHNICAL INVESTIGATION, PROPOSED NOMMESEN RESIDENCE,2600 MONTGOMERY AVENUE, ENCINITAS, CALIFORNIA Dear Mr. Nommesen: In accordance with your request-a.ad our Proposal dated October 27, 1999,we have completed a geotechnical investigation for the subject property. We are presenting herewith our findings and recommendations. In general,we found that the site is suitable for support of the proposed single-family residence,provided the recommendations provided in our report are followed. The most significant geotechnical condition that will affect the construction of the proposed home is the existing moderately to steeply sloping hillside upon which the proposed residence is to be constructed. Our quantitative analyses indicate that the stability of this slope will require that a deep foundation system which will not adversely affect the stability of the slope be used for structural support of the proposed structure. If you have any questions after reviewing this report,please do not hesitate to contact our office. This opportunity to be of professional service is sincerely appreciated. Respectfully submitted, (j�G' R. 80 �<3 QQpFESS10Nq1� No 1090 CHRISTIAN WHEELER ENGINEERING Quo �$ �h9,F,t�A ° OERTIFEED t ENCG11NEERING ° No.GEOW215 GEOLOGIST Exp.9-3M1 r� Nj Exp. 10-00 I chtk CAL David R. Russell, Staff Geologist gjEOF CAI.\' Charles H. Christian, R.G.E. #00215 Curtis R. Burdett, C.E.G. #1090 CHC:CRB:drr cc: (4) Submitted AQ7S Merrnry I,t rep t ♦ Can Tliron CA 0 71 1 1 ♦ A1;R-4n(,_n7((1 ♦ FAX 958.49(-9759 TABLE OF CONTENTS PAGE Introduction and Project Description..............................................................................................................1 ProjectScope........................................................................................................................................................2 Findings.................................................................................................................................................................3 SiteDescription.............................................................................................................................................3 General Geology and Subsurface Conditions..........................................................................................4 Geologic Setting and Soil Description..................................................................................................4 Fill.............................................................................................................................................................4 DelmarFormation.................................................................................................................................4 Groundwater.............................................................................................................................................5 TectonicSetting........................................................................................................................................5 GeologicHazards.........................................................................................................................................5 General.......................................................................................................................................................5 GroundShaking.........................................................................................................:.................:..........5 Seismic Design Parameters.......:..::::::::................................................. .. .................... ...........................6 Landslide Potential and Slope Stability.................................................................................................7 Liquefaction......................................................................:.......................................................................7 Flooding.....................................................................................................................................................7 Tsunamis...................................................................................................................................................7 Seiches........................................................................................................................................................7 Groundwater.............................................................................................................................................7 SlopeStability Analysis .....................:.........................................................................:................................8 General.......................................................................................................................................................8 Methodof Analysis..................................................................................................................................8 Resultsof Stability Analysis....................................................................................................................8 Conclusions...........................................................................................................................................................9 Recommendations.............................................................................................................................................10 Gradingand Earthwork.............................................................................................................................10 General.....................................................................................................................................................10 Observationof Grading........................................................................................................................10 SitePreparation......................:...............................................................................................................10 1:xcavarlo.i Characteristics....................................................................................................................10 Compaction and Method of Filling.....................................................................................................10 SurfaceDrainage....................................................................................................................................11 GradingPlan Review.............................................................................................................................11 TemporaryCut Slopes...........................................................................................................................12 FoundationSystems...................................................................................................................................12 General.....................................................................................................................................................12 FoundationDesign.....................................................................................................................................12 General.......................................................:........................................................................................12 MinimumPier Dimensions.............................................................................................................12 PierReinforcing.................................................................................................................................13 BeatingCapacity ........................................................................................13 LateralPier Capacity.........................................................................................................................13 LateralCreep......................................................................................................................................13 Cleaning of Pier Excavations..........................................................................................................13 Foundation Excavation Observation..................................................................................................13 On-Grade Slabs..........................................................................................................................................14 InteriorFloor Slabs................................................................................................................................14 Moisture Protection for Interior Slabs...............................................................................................14 ExteriorConcrete Flatwork.................................................................................................................14 EarthRetaining Walls ................................................................................................................................14 PassivePressure......................................................................................................................................14 Active Pressure for Unrestrained Retaining Walls............................................................................14 At-Rest Pressure for Restrained(Basement)Retaining Walls........................................................15 Ba ckfill.....................................................................................................................................................15 Factorof Safety......................................................................................................................................15 Limitations..........................................................................................................................................................15 Review, Observation and Testing............................................................................................................15 Uniformityof Conditions........................................................................:.................................................16 Changein Scope.........................................................................................................................................16 TimeLimitations.................:.......................................................................................................................16 ProfessionalStandard.......................................:.........................................................................................16 Client's Responsibility FieldExplorations.......... ....................:...........................................................................................................17 LaboratoryTesting.............................................................................................................................................18 ATTACHMENTS TABLES Table I Maximum Bedrock Accelerations,Page 6 Table II Seismic Design Parameters,Page 6 FIGURES Figure 1 Site Vicinity Map,Follows Page 1 PLATES Plate 1 Site Plan Plates 2-6 Boring Logs Plate r Cross Section A A " Plates 8-13 Slope Stability Analysis Plate 14 Subdrain Detail APPENDICES Appendix A References,Topographic Maps,Photographs Appendix B Recommended Grading Specifications—General Provisions PRELIMINARY GEOTECHNICAL INVESTIGATION PROPOSED NOMMESEN RESIDENCE 2600 MONTGOMERY AVENUE ENCINITAS, CALIFORNIA INTRODUCTION AND PROJECT DESCRIPTION ? This report presents the results of a preliminary geotechnical investigation performed for the proposed single family residence to be constructed at 2600 Montgomery Avenue in the City of Encinitas, California. The following Figure Number 1 presents a vicinity map showing the location of the property. i The subject lot is located south of the terminus of Montgomery Avenue and is accessed by a 20-foot- wide driveway easement extending south from the Montgomery Avenue cul-de-sac. We understand that a three-story single-family residence is proposed for the site. The first floor level will be about ten feet below the driveway grade and will consist of a workroom,bathroom,and sauna. The middle level is to be dose to the driveway grade and will consist of a garage,an office, and a bedroom. The ? upper level will have a living room,kitchen,dining room, and a bedroom. A large outside deck is € also proposed on the upper level. Retaining walls up to about ten feet high will be required for the project. Based on the stability characteristics of the moderately to steeply sloping hillside on-site,the proposed residence will need to be supported by a cast-in-place concrete pier and grade beam F;°!r+l rjn system. Grading will basically be limited to cutting into a portion of the hillside for the µ lower level. To aid in the preparation of this report we were provided with a limited preliminary geotechnical report for the site prepared by Barry and Associates, and an untitled site plan for the project. A copy of this site plan was used as the base for our Site Plan and is included herewith as Plate Number 1. This report has been prepared for the exclusive use of Mr.John Nommesen and his design consultants for specific application to the project described herein. Should the project be modified, the conclusions and recommendations presented in this report should be reviewed by Christian Wheeler Engineering for conformance with our recommendations and to determine if any additional 1k i 1� kr Mal .�y �1 a,, rF �j • A > ` , + �.:: - � s I✓' f.. ..i�7'" ® ;l 'f,f 7{�-afii`ts., �; ''tx' G ,r �y ® i :.0 g'S.r,� '� h �Xy`H`p tiyl� 1< . p nJ.J��HHa46i&AG �}^K'[1£.;`( ^ AE i .s S rb ¢'.�i"�4' f tF �iL° ii �'i'`� '0�9 '� ``��, C 4'E" F „+ •� f ,� k h f e e:.,�"�� ��� � �� F..� � b+�� 3 k � �yF m ,.. �� i r. i. annl z. t `t'qn; � :.r?. � d r f[r ♦- [ 3 r �r y i`r � ��i'F,�a :4.�• µ,,^' � ��"i� ,. �� �d,�r�.[a t �� L,�t Q`�`f� i` �—d` �� '� � > � � L� a[ � r �� `[ J,� aFg r }'� a e ti t ✓ 1 z 3°a 1 >v I 2s� s Fr ��� h � F - r. ��n��, '� 4os iK Yr a s at i °' efi sztg % 4 x y r Y i tip w Y � ]� b.t.p a .•� _.� .�� t [ ��'%d " is i J Ll ,is �.�y 44 [ ' sr `a, 5��. '!1r' r ��°" � +be+5? r L 's` `� r .;^1`sfi� �. ,f >! .r. �v Y..•,« �}j �fit,� '�' 'A 2 t,.tY �C Y [ Ai ..f � - 1 .L'E�' * • ���s `� � .f}- �' I'V,a S 1 " i ixi=.:,�£ti:t�.`.�.�,.":�e�nz"`,:,iiLn�siz:s.��s�ibif'u'.et._�A.ems&��.Y�..La�*s.;.U•��,.£:�.}a.�i,:oti,.£1st..LLfn9 .__ t`.. s• l�g .P • t ��� �� _:.:F_, CWE 199.099.2 December 28, 1999 Page No. 2 (revised 3-7-00) subsurface investigation,laboratory testing and/or recommendations are necessary. Our professional services have been performed, our findings obtained,and our recommendations prepared in accordance with generally accepted engineering principles and practices. This warranty is in lieu of all other warranties, expressed or implied. PROJECT SCOPE The scope of our preliminary investigation included: surface reconnaissance, subsurface exploration, obtaining representative soil samples,laboratory testing, analysis of the field and laboratory data and review of readily available,pertinent geologic and geotechnical literature. In consideration of our 1. Est experience in the vicinity of the subject site alone with agcess considerations,an 8-inch boring was advanced within the eastern portion of the proposed building footprint in order to explore the subsurface soil conditions,and to obtain representative soil samples for laboratory testing. More specifically, the intent of this investigation was to: a) Explore the subsurface conditions of the site to the depths influenced by the proposed construction. b) Evaluate,by laboratory tests, the engineering properties of the various strata that may influence the proposed construction,including bearing capacities,expansive characteristics and settlement potential. c) Describe the general geology at the site +ncluding possible geologic factors could have an effect on the site development d) Address potential construction difficulties that may be encountered due to soil conditions,groundwater,or geologic hazards,and provide recommendations concerning these problems. e) Develop soil engineering criteria for site preparation and grading. f) Address the stability of the existing cut slope for Manchester Avenue and determine the foundation setback from this slope. g) Provide design parameters for unrestrained and restrained retaining walls. C`VE 199.099.2 December 28, 1999 Page No. 3 (revised 3-7-00) h) Recommend an appropriate foundation system for the type of structure anticipated and develop soil engineering criteria for the recommended foundation design. i) Present our professional opinions in a report,which will include in addition to our conclusions and recommendations,a plot plan,exploration logs and a summary of the laboratory test results. It was not within the scope of our services to perform laboratory tests to evaluate the chemical characteristics of the on-site soils in regard to their potentially corrosive impact to on-grade concrete and below grade improvements. If desired,we can obtain samples of representative soils and submit them to a chemical laboratory for analysis. Further,it sh^,Utld be iinderstood that Christian v 1= Engineering does not practice corrosion engineering. If such an analysis is necessary,we recommend that the client retain an engineering firm that specializes in this field to consult with them on this matter. FINDINGS SITE DESCRIPTION The subject site consists of an irregular-shaped parcel of land of less than one-quarter acre in size,which is located south of the terminus of Montgomery Avenue,in Encinitas,California,and is accessed by a 20-foot-wide driveway easement extending south from the Montgomery Avenue cul-de-sac. The site is bounded to north and southeast by existing single-family="iL :_ s,to the east by the existing access driveway, and the west by Manchester Avenue. The lot was once part of the adjacent lot to the north, and,as such,supports an observation and parking deck that extends out over the hillside. The deck is supported by continuous footings on the east and by two columns with pier footings on the west. Except for a relatively level area south and east of the deck,the property slopes moderately to steeply to the southwest. Below the deck,the ground slopes at a ratio of between about 4:1 and 2:1,horizontal to vertical. An existing cut slope along Manchester Avenue ranges in height form approximately 20 to 35 feet,increasing in height from west to east,along the southwest portion of the site. The lower approximately ten feet has a slope ratio of about 0.75:1 to 1:1 (H:V). Above this the slope is steeper, varying from about 0.5:1 (H:V) to near-vertical in localized areas. On-site elevations range from approximately 95 feet above sea level within the southeast portion of the site,to approximately 35 feet C`VE 199.099.2 December 28, 1999 Page No. 4 (revised 3-7-00) above sea level along the base of the cut slope along Manchester Avenue. Please refer to the Site Vicinity Map included herewith as Figure No. 1 and the site plan included herewith as Plate No. 1. GENERAL GEOLOGY AND SUBSURFACE CONDITIONS GEOLOGIC SETTING AND SOIL DESCRIPTION:The subject site is located in the Coastal Plains Physiographic Province of San Diego County. Based upon the results of our limited exploration and analysis of readily available,pertinent geologic and geotechnical literature,the site appears to be underlain by a minor amount`of man-made fill materials which overlie formational materials of the Tertiary-age Delmar Formation (Tan&Kennedy, 1996).These materials are described below. FILL: Approximately eighteen inches of fill material was encountered within our Exploratory Boring B-1. Based on our site reconnaissance,similar or shallower depths of man-placed fill soils can be expected across those portions of the site to receive the proposed single-family residence. The fill was noted to consist of light olive brown,silty sand(SNP which was generally damp and loose in consistency. No documentation as to the placement and compaction of these fill soils has been provided to us at this time. As such,the fill soils are not considered suitable to support settlement-sensitive structures. Based upon visual observation of the encountered soils,laboratory testing,and experience with . similar soils in the vicinity of the project site,the fill soils are anticipated to possess a"low" expansion potential (based upon UBC Test Method 27-2). DELMAR FORMATION:As noted within our exploratory boring,the site was observed to be underlain at a depth of 1'A feet by Tertiary-age sedimentary deposits of the Delmar Formation. These formational materials were observed to consist of interbedded white,olive, yellowish-brown, and pinkish silty sand and sandstone(SNi,clayey sand and sandstone(SC), and sandy clay and claystone(CL). The silty sands (SM) of the Delmar Formation encountered within approximately five feet of the existing ground surface,within the vicinity of our boring location,were noted to be generally moist and medium dense. Below this depth,the sandy portions of the formational materials were noted to be generally moist and very dense,while the clayey portions were noted to be generally moist and hard. Analysis of readily available, pertinent geologic literature indicates that bedding within the Delmar Formation is nearly horizontal within the vicinity of the subject site(Tan&Kennedy,1996). CWE 199.099.2 December 28, 1999 Page No. 5 (revised 3-7-00) GROUNDWATER No groundwater was encountered in our boring and we do not anticipate any significant groundwater related problems,either during or after construction. However,it should be recognized that minor groundwater seepage problems might occur after development of a site even where none were present before development These are usually minor phenomena and are often the result of an alteration in drainage patterns and/or an increase in irrigation water. Based on the permeability characteristics of the soil and the anticipated usage and development,it is our opinion that any seepage problems which will be minor in extent. These potential"nuisance"problems can be mitigated by the use of proper landscaping techniques. TECTONIC SETTING:No major faults are known to traverse the subject site but it should be noted that much of Southern California,including the San Diego County area,is character;,-,i b-'T q�:.ries of Quaternary-age fault zones which typically consist of several individual,en echelon faults that generally strike in a northerly to north-westerly direction. Some of these fault zones (and the individual faults within the zones)are classified as active while others are classified as only potentially active,according to the criteria of the California Division of Mines and Geology. Active fault zones are those which have shown conclusive evidence of faulting during the Holocene Epoch(the most recent 11,000 years)while potentially active fault zones have demonstrated movement during the Pleistocene Epoch (11,000 to 1.6 million years before the present) but no movement during Holocene time. A review of available geologic maps indicates that a portion of the Rose Canyon Fault Zone is located approximately two and one-half mile west of the site. Other active fault zones in the region that could possibly affect the site include the Coronado Bank and San Clemente Fault Zones to the southwest and the Elsinore,San Jacinto,and San Andreas Fault Zones to the no*t11-st.__.. GEOLOGIC HAZARDS GENERAL: No geologic hazards of sufficient magnitude to preclude development of the site as we presently contemplate it are known to exist. In our professional opinion and to the best of our knowledge,the site is suitable for the proposed development. GROUND SHAKING:-A likely geologic hazard to affect the site is ground shaking as result of movement along one of the major active fault zones mentioned above. The maximum bedrock accelerations that would be attributed to a maximum magnitude earthquake occurring along the nearest fault segments of selected fault zones that could affect the site are summarized in the following Table I. CWE 199.099.2 December 28, 1999 Page No. 6 (revised 3-7-00) TABLE I Fault Zone Distance Maximum Magnitude Maximum Bedrock Earth uake Acceleration Rose Canyon 2'/z miles 6.9 magnitude 0.52 g Coronado Bank 18 miles 7.4 magnitude 0.21 g Elsinore 29 miles 7.1 magnitude 0.12 g San Jacinto 52 miles 7.2 magnitude 0.06 g San Clemente 56 miles 7.3 magnitude 0.06 g Probable ground shaking levels at the site could range from slight to moderate,depending on such factors as the magnitude of the seismic event and the distance to the epicenter. it is likely that the site will experience the effects of at least one moderate to large earthquake during the life of the proposed improvements. SEISMIC DESIGN PARAMETERS:Based on a maximum magnitude(Mmax) earthquake of 6.9 along the nearest portion of the Rose Canyon Fault Zone, the Maximum Bedrock Acceleration at the site would be approximately 0.52 g. For structural design purposes,a damping ratio not greater than 5 percent of critical dampening,and Soil Profile Type Sc are recommended(UBC Table 16-J). Based upon the location of approximately 4 kilometers from the Rose Canyon Fault(Type B Fault),Near Source Factors Na equal to 1.1 and N„equal to 1.33 are also applicable.These values,along with other seismically related design parameters from the Uniform Building Code(UBC) 1997 edition,Volume H, Chapter 16,utilizing a Seismic Zone 4 are presented in tabular form below. TABLE II UBC—CHAPTER 16 SEISMIC RECOMMENDED TABLE No. PARAMETER VALUE 16-I Seismic Zone Factor Z 0.40 16-j Soil Profile Type Sc 16 Seismic Coefficient Ca .40 Na 16-R Seismic Coefficient C, 0.56 NQ 16-S Near Source Factor N, 1.1 16-T Near Source Factor N, 1.33 16-U Seismic Source T e B C`}VE 199.099.2 December 28, 1999 Page No. 7 (revised 3-7-00) LANDSLIDE POTENTIAL AND SLOPE STABILITY:The site is identified as being in an area which is considered most susceptible to slope stability hazards due to such factors as the character of the geologic units;the presence of fractures or other planes of weakness;and the presence of steep slopes. The Relative Landslide Susceptibility and Landslide Distribution Map of the Encinitas Quadrangle prepared by the California Division of Mines and Geology indicates that the site is situated within Relative Landslide Susceptibility Area 4-1. Area 4 is considered to be a"most susceptible"to slope failures;Subarea 4-1 includes slopes considered to be outside the limits of known landslides but contains observably unstable materials such as the Delmar Formation. Although most slopes within Subarea 4-1 do not currently contain landslide deposits, they can be expected to fail even in the absence of activities of man. A specific slope stability analysis was performed for the sloping site and that analysis is presented in the"Slope Stability Analysis"section of this report - LIQUEFACTION: The soils encountered at the site are not considered susceptible to liquefaction due to such factors as soil density,grain-size distribution and the absence of shallow groundwater conditions. FLOODING: The site is located outside the boundaries of both the 100-pear and the 500-year floodplains according to the maps prepared by the Federal Emergency Management Agency. TSUNAMIS: Tsunamis are great sea waves produced by submarine earthquakes or volcanic eruptions. Due to the site's setback from the ocean and elevation,the site will not be affected by a tsunami. SEICHES: Seiches are periodic oscillations in large bodies of water suet. :: >.es,Larbors,bays or reservoirs. Due to the site's location and elevation,it will not be affected by seiches. GROUNDWATER: No groundwater was encountered in our test trenches and we do not anticipate any significant groundwater related problems,either during or after construction. However,it should be recognized that minor groundwater seepage problems might occur after development of a site even where none were present before development. These are usually minor phenomena and are often the result of an alteration in drainage patterns and/or an increase in irrigation water. Based on the permeability characteristics of the soil and the anticipated usage and development,it is our opinion that any seepage problems which will be minor in extent. These potential"nuisance"problems can be mitigated by the use of proper landscaping techniques. CWE 199.099.2 December 28, 1999 Page No. 8 (revised 3-7-00) SLOPE STABILITY ANALYSIS GENERAL:To analyze the stability of the steepest portion of the existing slope along the western portion of the site,a cross-section of the slope was drawn perpendicular to the face of the slope at the point where the slope is steepest. This cross-section,which shows the site topography and approximate location of the proposed residence,is presented on the attached Plate No. 7. METHOD OF ANALYSIS:The analysis of the stability of the natural hillside slope was performed using the PCSTABL6 computer program developed at Purdue University. The program analyzes circular,block and randomly shaped failure surfaces using the Simplified Bishop,Jambu,and Spencer's Methods. Sted 6.5 PCSTABL6 Editor,developed by Harold W.Var_n" r,n F.,was used in conjunction with this program for data entry and graphics display.The selected cross-sections were analyzed for both circular and bock-type failures and each failure analysis was programmed to run 100 random failure surfaces. The most critical failure surfaces are accumulated and sorted by value of the factor-of-safety. After the specified number of failure surfaces are successfully generated and analyzed, the ten most critical surfaces are plotted so that the pattern may be studied. These plots with the computer printout of each run are presented as Plate Nos. 8 through 13. RESULTS OF STABILITY ANALYSIS:Our quantitative analyses of the slope stability of the existing slope along the western side of the site,have demonstrated a minimum factors-of-safety of 1.31 and 1.32 for block type and rotational slip failures,respectively(see Plate Nos. 8&9). Additionally,the minimum factors-of-safety increase only to 1.35 and 1.34 for block type and rotational slip failures, respectively,when the location of the slope failure initiation point is extcnaed from the western edge of the proposed residence towards the east(see Plate Nos. 10&11). Scenarios in which rotational and block type slope failures yield the minimum factor-of-safety considered safe of 1.5 or greater,indicate that the point of slope failure initiation be located at least approximately 46 feet or 40 feet east of the western perimeter of the proposed residence,for block type and rotational slip failures,respectively(see Plate Nos. 12& 13). As such, the proposed residence will need to be supported on a deep foundation system consisting of cast-in-place concrete piers tied together with concrete reinforced grade beams. Such a deep foundation system will need to transmit the loads of the proposed residence to competent formational materials at depths of at least five feet below the slope failure surface that exhibits a minimum factor-of-safety of 1.5. Our analyses indicate that such depths range from 28 feet below existing site grades along the western C%VE 199.099.2 December 28, 1999 Page No. 9 (revised 3-7-00) perimeter of the proposed residence to 19 feet below existing site grades along the eastern perimeter of the proposed structure. These depths have been calculated using Plate No. 7,which plots the surfaces of the rotational slip and block type failures,which exhibit minimum factors-of-safety of 1.5. Please refer to the Foundation Design section of this report for further information regarding the design and depths of such a foundation system. The potential for slope instability should not be increased by the construction of the proposed residence, provided the recommendations provided in this report as well as additional sound geotechnical, construction,and maintenance standards are followed. It can also be noted that the proposed grading, which involves creating cuts and retaining walls within the slope,will somewhat increase the stability of the slope from the ungraded condition by removing part of the d ,.ing wcisht,provided sound engineering and construction practices are followed Furthermore, the construction of the deep foundation system will help stabilize the hillside by providing additional resistance to lateral movement. Care should be taken to ensure the proper drainage of all surface runoff away from the entire slope face. Saturation of the slope caused by excessive or improperly channeled runoff could detrimentally affect the surficial stability of the slope. Irrigation on and adjacent to the slope should be carefully monitored to insure that only the minimum amount necessary to sustain plant life is used. Over- irrigating could not only be erosive but may significantly increase the chance for slope stability problems and should be avoided. CONCLUSIONS In general,we found the subject property suitable for the proposed construction,provided the recommendations provided herein are followed. The most significant geotechnical condition that will affect the construction of the proposed residence as proposed,is the stability of the existing moderately to steeply sloping hillside,which extends from the footprint of the proposed residence westward down to Manchester Avenue. As such,the proposed residence will need to be supported on a deep foundation system consisting of cast-in-place concrete piers tied together with concrete reinforced grade beams. CWE 199.099.2 December 28, 1999 Page No. 10 (revised 3-7-00) RECOMMENDATIONS GRADING AND EARTHWORK GENERAL: No project grading plans have been provided to us at this time.However,it is our understanding that site grading is to be limited to cuts of about ten feet or less into the hillside,to create the building pad for the lower level of the proposed residence. OBSERVATION OF GRADING:Observation by the Geotechnical Consultant is essential during the grading operation to confirm conditions anticipated by our investigation,to allow adjustments in design criteria to reflect actual field conditions exposed,and to determine that the grading proceeds in general accordance with the recommendations contained here'-,< SITE PREPARATION: Site grading should begin with the removal of all existing improvements and vegetation and other deleterious materials from the portions of site that will be graded and/or will receive new improvements. This should include all grasses,iceplant,and significant root material. The resulting materials should be disposed of off-site. Any resulting depressions should be cleaned out of loose or disturbed soils and be backfilled with properly compacted soil EXCAVATION CHARACTERISTICS:Based upon the manner of auger penetration,our experience with similar materials in the vicinity of the site,and review of the referenced geotechnical reports,.the subsurface materials at the site appear generally rippable with conventional earthmoving equipment to a depths of at least ten feet below existing site grades. Furthermore,no distinct �_- concretions were observed within the formational materials during uut subsurface exploration. However,it should be noted that very dense concretions are sometimes encountered within the Delmar Formation. The contractor is solely responsible for designing and constructing stable,temporary excavations and may need to shore,slope,or bench the sides of trench excavations as required to maintain the stability of the excavation sides where friable sands or loose soils are exposed. The contractor's"responsible person",as defined in the OSHA Construction Standards for Excavations,29 CFR,Part 1926, should evaluate the soil exposed in the excavations as part of the contractor's safety process. In no case should slope height,slope inclination, or excavation depth,including utility trench excavation depth,exceed those specified in local,state,and federal safety regulations. COMPACTION AND METHOD OF FILLING:Any structural fill placed at the site should be compacted to a relative compaction of at least 90 percent of maximum dry density as determined by CWE 199.099.2 December 28, 1999 Page No. 11 (revised 3-7-00) ASTM Laboratory Test D1557-91. Fills should be placed at or slightly above optimum moisture content,in lifts six to eight inches thick,with each lift compacted by mechanical means. Fills should consist of approved earth material,free of trash or debris,roots,vegetation,or other materials determined to be unsuitable by our soil technicians or project geologist. Fill material should be free of rocks or lumps of soil in excess of twelve inches in maximum dimension.However,in the upper two feet of pad grade,no rocks or lumps of soil in excess of six inches should be allowed Based upon the results.of our sub-surface exploration and laboratory testing,all of the on-site soils appear suitable for use as structural fill material. Fills should be benched into all temporary slopes and into competent formational materials when the natural slope is steeper than an inclination of 5:1 (horizon'�' ��, rt',-al). Keys should be constructed at the toe of all fill slopes. The keys should extend at least 12 inches into competent formational material and should be sloped back at least two percent into the slope area. Slope keys should have a minimum width of 10 feet. Utility trench backfill within five feet of the proposed structures and beneath driveways,concrete flatwork,and pavements should be compacted to a minimum of 90 percent of its maximum dry density. All grading and fill placement should be performed in accordance with the City of Encinitas Grading Ordinance,the Uniform Building Code,and the attached Recommended Grading Specifications and Special Provisions attached hereto as Appendix B. SURFACE DRAINAGE:Surface runoff into downslopc:",i,lr'ai areas and graded areas sl,otild hP minimized. Where possible, drainage should be directed to suitable disposal areas via non-erodible devices such as paved swales,gunited brow ditches,and storm drains. Drainage around the proposed residence should be designed to collect and direct surface water away from proposed structures and the top of slopes and toward approved drainage areas. GRADING PLAN REVIEW: Once available,the project grading plans should be submitted to this office for review in order to analyze all proposed slopes,cuts,and fills. The final grading plans should be submitted to this office for review in order to ascertain that the recommendations of this report have been implemented,and that no additional recommendations are needed due to changes in the anticipated development plans. C%VE 199.099.2 December 28, 1999 (revised 3-7-00) Page No. 12 TEMPORARY CUT SLOPES:Unshored temporary cut slopes of up to eight feet in height can be excavated at inclinations of 0.5 to 1.0 (horizontal to vertical)or flatter,within competent formational materials. Temporary excavations of between eight and fifteen feet in height can be constructed at inclinations of 0.75 to 1.0 (horizontal to vertical) or flatter,within competent formational material$. i All temporary cut slopes should be observed by the engineering geologist during grading to ascertain that no unforeseen adverse conditions exist No surcharge loads such as stockpiles,vehicles,etc.should be allowed within a distance from the top of temporary slopes equal to half the slope height FOUNDATION SYSTEMS f GENERAL: Based on the calculated factors-of-safety for the existing slope, the proposed residence will need to be supported on a deep foundation system consisting of cast-in-place concrete piers tied together with concrete reinforced grade beams. Such a deep foundation system will need to transmit the loads of the proposed residence to competent formational materials at depths of at least five feet below the slope failure surface that exhibits a minimum factor-of-safety of 1.5. FOUNDATION DESIGN GENERAL: Augered, cast-in-place concrete piers which are tied together with concrete reinforced grade beams,are considered suitable for support of the structure loads of the proposed residence. Pier support will be afforded by end bearing within the hard/very dense formational materials. MINIMUM PIER DIMENSIONS:All drilled,cast-in-place concrete piers should extend at least five feet below the slope failure surface that exhibits a minimum factor-of-safety of 1.5. Our analyses indicate that such depths range from 2.8 feet below existing site grades along the western perimeter of the proposed residence to 19 feet below existing site grades along the eastern perimeter of the proposed structure. These depths have been calculated using Plate No. 7,which plots the surfaces of the block type failures which exhibit minimum factors-of-safety of 1.5. Once the exact location of the piers has been determined by the project structural engineer, we should be contacted to determine the minimum depth requirements for each individual pier. Ii;however,we are not contacted to determine the depth of each individual pier,the minimum depth shall.be 28 feet below the existing ground surface for all of the proposed piers. Piers CWE 199.099.2 December 28, 1999 (revised 3-7-00) Page No. 13 should have a minimum diameter of 24 inches. All pier dimensions should be determuned by the project structural engineer. PIER REINFORCING:Piers should also be reinforced in accordance with the recommendations of the project structural engineer. The reinforcing cage should extend the full height of the pier. BEARING CAPACITY: Incorporating the minimum dimensions presented above and depths of at least five feet below the slope failure surface that exhibits a minimum factor-of- safety of 1.5,the cast-in-place concrete piers may be designed for an allowable downward axial bearing capacity of 15 kips per square fr,,,. '" ,,clue maybe increased by 500 psf for each additional foot of pier embedment below the slope failure surface that exhibits a minimum factor-of-safety of 1.5,up to a maximum allowable bearing capacity of 25 kips per square foot LATERAL PIER CAPACITY:The passive pressure for the formational materials may be considered to be 450 pounds per square foot per foot of depth,up to a maximum value of 2,500 psf. These values may be assumed to act on an area equal to twice the pier diameter. LATERAL CREEP:Drilled piers should be designed fora lateral dowmlope load of 50 pounds per square foot per foot of depth,for a depth of 23 feet This lateral load application is recommended to increase the factor-of-safety of the existing hillside under the house to a minimum of 1.5 against slope failure. CLEANING OF PIER EXCAVATIONS: If 24-inch diameter piers are used,the cleaning of the bottom of the pier excavation may be performed by careful operations of the driller and back-spinning the drill auger under pressure or utilizing a clean-out plate. For larger diameter piers,hand cleaning may be required. This will be determined by the observation of a geologist or engineer from our staff during the excavation of the piers. FOUNDATION EXCAVATION OBSERVATION:All pier foundation excavations should be observed by the Geotechnical Consultant prior to placing concrete to determine if the foundation recommendations presented herein are complied with. All loose or unsuitable material should be removed from the foundation excavations prior to the placement of concrete. CWE 199.099.2 December 28, 1999 (revised 3-7-00) Page No. 14 ON-GRADE SLABS INTERIOR FLOOR SLABS: For conventional floor slabs,the minimum slab thickness should be five inches. Interior floor slabs should be reinforced with at least No. 3 bars placed at 12 inches on center each way. The slab reinforcing bars should be turned down to extend at least six inches into the perimeter footings. Slab reinforcing should be positioned on chairs at mid-height in the floor slab. MOISTURE PROTECTION FOR INTERIOR SLABS: Interior concrete on-grade floor slabs that will support moisture-sensitive floor covering should be underlain by a moisture barrier. We recommend that the minimum configuration of the subslab moisture barrier consist of a four-inch-thick t:�f coarse clean sand. The moisturr-oaric..material should have less than ten percent and five percent passing the No. 100 and No.200 sieves,respectively. A visqueen vapor barrier should be placed in the center of the sand blanket. i EXTERIOR CONCRETE FLATWORM Exterior slabs should have a minimum thickness of four inches. Reinforcement and control joints should be constructed in exterior concrete flatwork to reduce the potential for cracking and movement joints should be placed in exterior concrete flatwork to help control the location of shrinkage cracks. Spacing of control joints should be in accordance with the American Concrete Institute specifications. When patio,walks and porch slabs abut perimeter foundations they should be doweled into the footings. EARTH RETAINING WALLS PASSIVE PRESSURE:The passive pressure for the prevailing soil conditions may be considered to be 400 pounds per square foot per foot of depth. These pressures maybe increased one-third for seismic loading. The lateral pier capacity provided in the Foundation Design section of this report may be utilized for the resistance to lateral movement. ACTIVE PRESSURE FOR UNRESTRAINED RETAINING WALLS: The active soil pressure for the design of unrestrained earth retaining structures with level backfill may be assumed to be equivalent to the pressure of a fluid weighing 35 pounds per cubic foot An additional 13 pounds per cubic foot should be added to said value for 2:1 (horizontal to vertical) sloping backfill. These pressures do not consider any other surcharge. If any are anticipated, this office should be contacted for the necessary increase in soil pressure. These values assume a drained backfill condition. Waterproofing CWE 199.099.2 December 28, 1999 Page No. 15 (revised 3-7-00) details should be provided by the project architect. A suggested wall subdrain detail is provided on the attached Plate Number 14. We recommend that the Geotechnical Consultant observe all retaining wall subdrains to verify proper construction. AT-REST PRESSURE FOR RESTRAINED (BASEMENT) RETAINING WALLS: In the design of wall restrained from movement at the top(non-yielding)such as basement walls,the at-rest soil pressure may be assumed to be equivalent to the pressure of a fluid weighing 50 pounds per cubic foot, provided a level backfill surface. An additional 15 pounds per cubic foot should be added to said value for 2:1 (horizontal to vertical)sloping backfill. These values assume a drained backfill condition. Waterproofing details should be provided by the project architect A suggested wall subdrain detail is pr ,<;?-d-,z7 the attached Plate Numbci .,. ' ; recommend that the Geotechnical Consultant observe all retaining wall subdrains to verify proper construction. BACKFILL: All backfill soils should be compacted to at least 90 percent relative compaction. Expansive or clayey soils should not be used.for backfill material. The wall should not be backfilled until the masonry has reached an adequate strength. FACTOR OF SAFETY:The above values,with the exception of the allowable soil friction coefficient, do not include a Factor-of-safety. Appropriate factors-of-safety should be incorporated into the design to prevent the walls from overturning and sliding. LIMITATIONS REVIEW, OBSERVATION AND TESTING The recommendations presented in this report are contingent upon our review of final plans and specifications. Such plans and specifications should be made available to the geotechnical engineer and engineering geologist so that they may review and verify their compliance with this report and with the Uniform Building Code. It is recommended that Christian Wheeler Engineering be retained to provide continuous soil engineering services during the earthwork and foundation construction operations. This is to verify compliance with the design concepts,specifications or recommendations and to allow design changes in the event that subsurface conditions differ from those anticipated prior to start of construction. C``UE 199.099.2 December 28, 1999 Page No. 16 (revised 3-7-00) UNIFORMITY OF CONDITIONS The recommendations and opinions expressed in this report reflect our best estimate of the project requirements based on an evaluation of the subsurface soil conditions encountered at the subsurface exploration locations and on the assumption that the soil conditions do not deviate appreciably from those encountered. It should be recognized that the performance of the foundations and/or cut and fill slopes may be influenced by undisclosed or unforeseen variations in the soil conditions that may occur in the intermediate and unexplored areas. Any unusual conditions not covered in this report that may be encountered during site development should be brought to the attention of the geotechnical engineer so that he may make modifications if necessary. CHANGE IN SCOPE This office should be advised of any changes in the project scope or proposed site grading so that we may determine if the recommendations contained herein are appropriate. This should be verified in writing or modified by a written addendum. TIME LIMITATIONS The findings of this report are valid as of this date. Changes in the condition of a property can,however, occur with the passage of time,whether they be due to natural processes or the work of man on this or adjacent properties. In addition,changes in the Standards-of-Practice and/or Government Codes may occur. Due c.,such changes,the findings of this report may be invalidated wholly or in part by changes beyond our control. Therefore,this report should not be relied upon after a period of,two years without a review by us verifying the suitability of the conclusions and recommendations. PROFESSIONAL STANDARD In the performance of our professional services,we comply with that level of care and skill ordinarily exercised by members of our profession currently practicing under similar conditions and in the same locality. The client recognizes that subsurface conditions may vary from those encountered at the locations where our borings,surveys,and explorations are made,and that our data,interpretations,and recommendations be based solely on the information obtained by us. We will be responsible for those data,interpretations,and recommendations,but shall not be responsible for the interpretations by others r ' CWE 199.099.2 December 28, 1999 (revised 3-7-00) Page No. 17 of the information developed. Our services consist of professional consultation and observation only, and no warranty of any kind whatsoever,express or implied,is made or intended in connection with the work performed or to be performed by us,or by our proposal for consulting or other services,or by our furnishing of oral or written reports or findings. CLIENT'S RESPONSIBILITY It is the responsibility of Mr.John Nommesen,or,his representatives to ensure that the information and recommendations contained herein are brought to the attention of the structural engineer and architect for the project and incorporated into the project's plans and specifications. It is further their responsibility to take the nec2s�_ r1f,a Tres to insure that the contractor and his subcontractors carry out such recommendations during construction. FIELD EXPLORATIONS A subsurface exploration was performed at the location indicated on the site plan included herewith as Plate Number 1 on November 16, 1999. This exploration consisted of a small diameter,hollow stem auger advanced with a truck-mounted drill rig. Additionally,the lower portions of the existing moderate to steep slope were examined and logged to determine the stratigraphy within the Delmar Formation. The fieldwork was conducted by or under the observation of our engineering geology personnel. The boring lcgs ar,presented on tilt io:lowing Plate Numbers 2 through 6.The soils are described in accordance with the Unified Soils Classification. In addition,a verbal textural description,the wet color, the apparent moisture and the density or consistency are provided.The density of granular soils is given as either very loose,loose,medium dense, dense or very dense. The density of cohesive soils is given as either very soft,soft,medium stiff,stiff,very stiff,or hard. Relatively undisturbed,"ring" samples of typical and representative soils were obtained and returned to the laboratory for testing. The undisturbed samples were obtained by driving a split-tube sampler ahead of the auger,using a 140-pound hammer free falling a distance of 30 inches. The number of blows to drive the sampler twelve inches is presented on the boring logs as "Penetration Resistance." Bulk samples of disturbed soil from the auger spoil were also collected in bags from the boring location. CWE 199.099.2 December 28, 1999 (revised 3-7-00) Page No. 18 LABORATORY TESTING Laboratory tests were performed in accordance with the generally accepted American Society for Testing and Materials (ASTlvi) test methods or suggested procedures. A brief description of the tests performed are presented below: a) CLASSIFICATION: Field classifications were verified in the laboratory by visual examination. The final soil classifications are in accordance with the Unified Soil Classification System. b) MOIS"TRF:-$—iSNSI1`Y: In-place moisture contents and dry densities were determined for representative soil samples. This information was an aid to classification and permitted recognition of variations in material consistency with depth. The dry unit weight is determined in pounds per cubic foot,and the in-place moisture content is determined as a percentage of the soil's dry weight. The results of these tests are summarized on the boring logs. c) GRAIN SIZE DISTRIBUTION:The grain size distribution was determined from a representative sample of the fill in accordance with ASTM D422. The results of this test are presented below. Sample Number Boring B-1 @ 15' Siev-Size Percent Passing #4 100 #8 100 #16 99 #30 84 #50 71 #100 65 #200 65 0.05 mm 56 0.005 mm 31 0.001 mm 4 CWE 199.099.2 December 28, 1999 (revised 3-7-00) Page No. 19 Sample Number Boring B-1 @ 29'/2' Sieve Size Percent Passing #4 100 #8 100 #16 99 #30 92 #50 74 #100 56 #20 39 Sample Number Boling B-1 @ 44'/2' Sieve Size Percent Passing . #4 100 #8 100 #16 98 #30 94 #50 85 #100 71 #200 54 0.05 im-n 46 0.005 mm 20 0.001 mm 4 CWE 199.099.2 December 28, 1999 Page No. 20 (revised 3-7-00) d) DIRECT SHEAR TEST:Direct shear tests were performed to determine the failure envelope of representative materials based on yield shear strength. The shear bog was designed to accommodate a sample having a diameter of 2.375 inches or 2.50 inches and a height of 1.0 inch. Samples were tested at different vertical loads and a saturated moisture content. The shear stress was applied at a constant rate of strain of approximately 0.05 inch per minute. The results of this test are presented below: Sample Number Boring B-1 @ 8' ivescnpt;On .... . In-place Angle of Friction 341/2 Degrees Apparent Cohesion 100 psf Sample Number Boring B-1 @ 15' Description In-place Angle of Friction 32 Degrees Apparent Cohesion 450 psf Sample Number Boring B-1 @ 25' Description In-place Angle of Friction 38 Degrees Apparent Ccllizt�ion 250 psf Sample Number Boring B-1 @ 391/2' Description In-place Angle of Friction 321/2 Degrees Apparent Cohesion 550 psf Sample Number Boring B-1 @ 50' Description In-place Angle of Friction 29 Degrees Apparent Cohesion 425 psf --------------- PROP UE f N57'23'25"E 51.02' 0 5TW LAY=f&E f n _ I B#2 r:,asr. BR#2 I I i ; ' I I . l I i l � - 6AW E { E* r l I ' FAST. i O r 11 1 y 11 l 1 1 l I , l Dw 1 , ENTRY B1 + PORCH ry FIDE u. -- X49'24'27 E 76 4' - --.^------- — My 5'7 d7 viol MIDDLE LEVEL IIIII,, ,�IIIII va'+rte NORTH I�II1IfIlI�l' LEGEND CHRISTIAN WHEELER 0 APPROXIMATE BORING LOCATION ENGINEERING NOMMESEN RESIDENCE FY nL r, I MATD 44 47_4 LOG OF TEST BORING NUMBER B-1 Date Excavated: 11/16/99 Equipment. Logged by: DRR CIA 55 Project Manager. CHC Surface Elevation: N/A Depth to Water. N/A Hammer Weight: 140 pounds Drop of Hammer. 30 inches SAMPLES 0 Q SUMMARY OF SUBSURFACE CONDITIONS a a w O IvL C7 w H z O x #. �< FILL fOa_f1,,�Light olive brown,damp,loose,fine to medium z grained SILTY SANL (S�) 't ELAI"FORMATION 2 D :�•j '. (T'LD:Light olive brown,moist, medium dense, fine to medium grained SILTY SAND(Slut). 3 �{ us 21 5.0 93.8 4 _ 5 ........................................... ................................................... .... ... ........... ........... ............. ......... Olive,moist,hard,SANDY CLAY and claystone (CL),abundant us 36 13.8 100.4 iron stains. ................. Olive to white,moist; r: ? :e,fine to medium grained ....... ......... ..... �f � # CLAYEY SAND ( � g 7 and sandstone S ,slight iron stains. ::fit•:�j2;. $ <£ us 50/6" 7.3 101.0 DS 1:41(1}•i. ' g ; ...................................................................... .. .. .... ......... Light olive to white,moist,very dense,fine to medium grained SILTY SAND and sandstone S Q (SNi ,occasional iron stains. 30Eijg continues on Plate Number 3. P� NOMMESEN RESIDENCE `Air 2600 Montgomery Avenue,Encinitas CHRISTIAN WHEELER BY: SD DATE: ENGINEERING Dec-99 JOB NO. : 199.099 PLATE NO.: 2 LOG OF TEST BORING NUMBER B-I(Continued) Date Excavated: 11/16/99 Equipment. Logged by- DRR CNIE 55 Project Manager: CHC Surface Elevation: N/A E Hammer Weight. .140 pounds Depth to Water.. N/A Drop of Hammer. 30 inches SAMPLES 0 p o z v O W SUIvI1biARY OF SUBSURFACE CONDITIONS C7 ua W y Z'- O x Light olive to white,moist,very dense,fine to medium grained SILTY SAND and sandstone(SS'vij uccasional iron staining. 17 Us 50/4" 11.8 103.7 12i t 13 ?> : ...................................................................................................................... .... Light olive,moist,hard,SANDY CLAY and claystone (CL), 14 slight iron stains. 15 US 76 18.1 1124 DS Grades to pinkish-brown. 9 HA 16 17 p 18 '• ..................................................................................................................................................... Yellowish-brown,moist,very dense,fine to medium grained 19 >< { SILTY SAND(Slv),slight iron stains. ' 20 ``� US 501,V'/ 123 104.1 Boring continues on Plate Number 4. NOMMESEN RESIDENCE 2600 Montgomery Avenue,Encinitas CHRISTIAN WHEELER- BY: SF DATE: ENGINEERING Dec-99 JOB NO. : 199.099 PLATE NO.: g LOG OF TEST BORING NUMBER B-I(Continued) Date Excavated. 11/16/99 Equipment•. CME 55 Logged by: DRR Project Manager. CHC Surface Elevation: NSA Depth to Water. N/A Hammer Weight. 110 pounds Drop of Hammer: 30 inches SAMPLES +^. Q P4 V Q SUMMARY OF SUBSURFACE CONDITIONS a ° :D 2 C Z O W o O 2, '>' 3 Q v '#' Yellowish-brown,moist,very dense,fine to medium grained 21 y SILTY SAND(SN) slight iron _ 22 ;fit is 23 ?�. > .................................................... ............................ : ................ ............... _ "+�'• -;= Li g ht yellowish-brown to olive brown,moist,very dense,fine 24 �- ${ to medium grained CLAYEY SAND(SC). 25 :¢. #: US 50/4" 126 111.6 DS 26 ,•:c;,v` . 27 28 29 US 50/6" 124 1120 SA 30 Borine continues on Plate Number 5. NOMMESEN RESIDENCE 2600 Montgomery Avenue,Encinitas CHRISTIAN WHEELER BY: SD DATE: ENCI NEEfLINC Dec-99 OB NO. : 199.099 PLATE NO.: 4 LOG OF TEST BORING NUMBER B-I(Continued) Date Excavated: 11/16/99 Equipment: CME 55 Logged by: DRR Surface Elevation: NSA Project Manager. CHC Hammer Weight. 1=40 pounds Depth to Water. N/A Drop of Hammer. 30 inches SAMPLES .� O v �, a4 SUMMARY OF SUBSURFACE CONDITIONS _ o �O 04 z 0 Light yellowish-brown to olive brown,moist,very dense,fine 31 "- to medium grained CLAYEY SAID kSQj.' 32 < .......................... ......... ....................................................... ` White,moist,very dense fine to medium grained SILTY SAND 4�M1. 33 _ <<:{ (SM),abundant iron stains. 34 nti Us 50/4" 11.6 104.6 35 ? 36 ' 37 38 k, ..................................................................................................................................................... Olive,moist,hard, SANDY CLAY and claystone (CL). 39 US 50/3" 14.6 116.6 DS 40 Boring continues on Plate Number 6. o. NOMMESEN RESIDENCE 2600 Montgomery Avenue,Encinitas CHRISTIAN WHEELER TB : SD DATE:ENGINEERING Dec-99 B NO. : 199.099 PLATE NO.: 5 LOG OF TEST BORING NUMBER B-I(Continued) Date Excavated: 11/16/99 Equipment Logged by: DRR Surface Elevation: NS/A A C 55 Project Manager. CHC Hammer Weight 140 pounds Depth to Water. N/A Drop of Hammer: 30 inches SAMPLES v 0 z ^ 4� t-� o d x 04 Ww SUMMARY OF SUBSURFACE CONDITIONS a o �O :D W y ~ z O x Q Olive,moist,hard,SANDY CLAY and clays tone(CL). 41 42 43 44 US 50/5" 139 111.8 HA 45 4A 47 Grades to olive to pinkish in color. 48 49 50 US 50/5" 19.5 97.8 DS Bottom of boar at 50 feet. NOMMESEN RESIDENCE `�� 2600 Montgomery Avenue, Encinitas CHRISTIAN WHEELER, BY: SD DATE: ENGINEERING Dec-99 OB NO. : 199.099 PLATE NO.: 6 L 0 (0 1 1 t 0 Ln 1 CL .- N cu M � O O T' 1 Q1 w w RI 6 C) d t7f w fj n N 4- p CYN W 0 `"a000000 1 to •-� II 3 av x o U A e Q x � N W c m C, w o o �- (n N 0 C y CC.)C.) C4 V I I i7 Lo o `<.. M E cts 2 0 o IN W M i V C) �"t l4�3iU�3l�3l0 ♦ ♦ m -N Z ,. �L Q cD L 5 `� %0 N L' ♦ �n +J _— n p v-- ♦ O - L O O N o 0 <O w JJ UU JJ �O M Co 0 r N N U�U��D�O�D �O �D Im t .. •.•. e O C r U CD G p N ri X ^ Q a-.+ 4- O OD r•- O E Ul) R1 `- U '0 tf) '- a O O� 4.4 , w T !!W 0 i 0 O N O _ - CYA 0 N A w V C) aN N --j m O% ° �" 0 4- b + - ltl a000000 w N +. .1 3 -• a" X o b 7 t? x U °p g L O O O O O O N N M- • -.�i O n O r m ,.Vi C� N� C/) LLI (D O •+••) O.' Z c v cE LL_ LLI w U +'39, m O N �,ni4f31U534t310 U N in N 4-j .,�RRRi4-3^ o o ..y Ln C L O ~ `p N M v Ln%0 U Ll._ b 0 .G A gJUUJJ J N U N N U U P,00 NNN O C C\j N X ^ 4-J 4- O 00 r- T Q _ i 1 i 1 1 ) 1 1 1 1 1 0 CL 1 l N ) O O 1 E O 1 1 a O O O to 4-J '0� „ N m 0' b 4- (1) ct -F-4^ N•- LAJ w. 3 a000000 X O V v V m LL w O 7 E U X c �a000000 CL N w d as M A O 0 C> • m Cy - � . ��� w M: '� c a� CIC O E coo Z °a LL-.. o^ U w U) w O +� tea,����� � ♦CL.-.- ♦ Q O v) �f?iR�F?i10.63� .o♦ ♦ O w�.-.-. O Q, o ~ �� r- C%JMt Lno V LL o O A JUUJ J �UNNUU LO MMInCPNIA0% 0,0h a M e}-sr er eh In In!n to In c v v o a c .. ., �o O O O V) .ti X ^ 4.4 v- O F 00 E 1L? [L f� .., Z7 0 M 4-1 N O O o 1> 0 o in O m OM a z .,roe N ^ CN " n o r- +' '0 Qall o►+ 4' N IL ��•M w— a ® d Cv000000 •� ••y 3 _• a c� x o U � X n � o X p V oh�000000 L F- W a M >+ OM m in ul (n cq a-ORR R � C � W --C , O 4.) c (n LL LLJ y U r-i W c.) g v M 4-J----- '< Q) U n En p F.zy-- -- -- cn C L N do O cu m fh .G a JUUJJ J �UNNUU �O ettnCAOCVP,fl_0000 LNLMMMdofd �Ln a O .N- C O O T O M N r-I X ^ 4-J 4-- 0 00 a v - - T ' V L 1 w r r � O E Ln _a - N „ O t -N O O O 1 O� C) �°, C CN w w tC O 0 aNZ° v, N 7 o 4- O� 4- (D •� a-- w o^ 4.. a) n `a a0000a to r+ 3 LLJ a c� x o C.) ` d 0 7 E x N Lil O»LO00000 -O C-) aid N O LlJ CL m Os.. •E C13 Z 0 n LL: b� LLJ 8. Cl) r- W O U) N O F- +' fa U- � M cu J UJJ J �v�NUU � OnLnL n% % %D%0 l .t!1 11 f In In�D�D�O 1 . CM � N .' X ^ .� 4-) 4- C) 00 I i I EE o c L O �_ T V O cV O r' t � N j p Z O Q Q� CV ^ o O I -°• z° to (T n N -F+ 10 � N ia"a000000 LLJ c. o •� C.� � n�000000 x J O ~ CL c m W Liv M& of O m Z o 06 M W i Cn W d Z •,-i �?.. ..0 4- cn 1 O (1)L 4 U m LL. � Ma A J �z�bZb3z�zi I %0\0 u�Un Un Un in Lo En LN I n a � ., .� b oN— O� O V) .P4 X ^ 4j 4- } I I I I I I � I � --+--�% SLOPE MINIMUM __ 6" MIN 6" MAX WATERPROOF BACK OF WALL e ° PER ARCHITECT'S SPECIFICATIONS o • 3/4 INCH CRUSHED ROCK or ° MIRADRAIN 60000 or EQUIVALENT O o GEOFABRIC BETWEEN ROCK AND SOIL o. . -12" 0 . o TOP OF GROUND . a . or CONCRETE SLAB s' o 6" MIN MINIMUM 4 INGH DIAMETER PERFORATED PIPE RETAINING WALL SUBDRAIN DETAIL No Scale F hristian Wheeler Engineering b Number: 199. 099 . 2 ate: MARCH 7 2000 Plate Number: 14 CWT- 199.099 December 28, 1999 Appendix A, Page Al REFERENCES Anderson,J.G,;Rockwell,R.K. and Agnew,D.C., 1989,Past and Possible Future Earthquakes of Significance to the San Diego Region,Earthouake Sbec�tra -- ,Volume 5,No.2, 1989. Barry And Associates Geotechnical Engineering, 1998, Preliminary Family Residence,2600 Mon tgomeryAvenue, Cardiff, Californiaarc�2,of Investigation,Proposed Single dated November 16, 1998. Parcel Map 17367,W.O. P-1639, Jennings, C.W., 1975,Fault Map of California, California Division of Mines and Geology,lap No. 1,Scale 1:750,000. Marls of Known Active Fault Near Source-Zones in Calif, and Ad'acent Por California Division of Mines and Geology, tins of Nevada, 1998, Mualchin,L. and Jones,A.L., 1992,Peak Acceleration from M aximum Credible Earthquakes in Mines California(Rock and Stiff-Soil Sites) California Division of and Geology Open-File Report 92-1. Owen Geotechnical Consultants, 1981,Nommesen Condominium project,Project N 1 o. 124.1.1. Tan,Siang S. and Giffen,Desmond G., 1995,Landslide Hazards In The Northern P Metropolitan Area, San Diego Coun art Of The San Diego Geology Open-File Report ty,California,Encinitas 7.5'Quadrangle,California Division of Mules and 95-04, scale 1:24,000. Tan,Siang S. and Kennedy,Michael P., 1996, Geologic Map Of The Encinitas and Rancho Santa Fe 7.5' Quadrangles,San Diego County, California, California Division of Mines and Geology scale 1:24,000. gy Open-File Report 96-02, Wesnousky, S.G., 1986, "Earthquakes, Quaternary Faults, and Seismic H Journal of Geophysical Research,Volume 91,No. B12 azards in California,,,in pp 12,587 to 12,631,November 1986. CWE 199.099 December 28, 1999 Appendix A,Page A2 TOPOGRAPHIC MAPS County of San Diego,1985,Orthographic Map Sheet 306-1683,Scale: 1 inch=200 feet. U.S. Geological Survey, 1968 (Photo-revised 1975),T/i Minute Topographic Map,Encinitas Quadrangle,scale 1:24,000. AERIAL PHOTOGRAPHS Aerial FotoBank/Thomas Bros.,Inc,Aerial Foto-Map Book,.San Diego County,1995-96,Sheet 1147,Scale: 1 inch=2000 feet(approximate). Aerial Graphics,Aerial Foto-Map Book,San Diego County, 1982,Sheet E-10,Scale: 1 inch =2000 feet (approximate). Aerial Graphics,Aerial Foto-Map Book,San Diego County,1984-85,Sheet 10-E,Scale: 1 inch =2000 feet (approximate). Lenska Aerial Images, 1994,The Thomas Guide,Commercial Edition,Page 1147,Scale: 1 inch =2000 feet (approximate). San Diego County, 1928,Flight 37B,Photographs 1 and 2;Scale: 1 inch = 1000 feet(approximate). San Diego County, 1953,Flight 8M,Photograph 78,Scale: linch = i700 feet(approximately). San Diego County, 1960,Flight 3,Photographs 73 and 74;Scale: 1 inch = 1000 feet(approximate). San Diego County, 1970,Flight 4,Photograph 12;Scale: 1 inch = 1000 feet(approximate). San Diego County, 1974,Flight 33,Photographs 4,5,and 6;Scale: 1 inch = 1000 feet(approximate). San Diego County, 1978,Flight 16B,Photographs 43 and 44;Scale: 1 inch= 1000 feet(approximate). San Diego County, 1983,Photographs 545 and 546;Scale: 1 inch = 1000 feet(approximate). San Diego County, 1989,Photograph 1-209;Scale:1 inch= 2000 feet(approximate). CWE 199.099.1 December 28, 1999 Appendix B,Page B1 PROPOSED NOMMESEN RESIDENCE 2600 MONTGOMERY AVENUE ENCINITAS, CALIFORNIA RECOMMENDED GRADING SPECIFICATIONS- GENERAL PROVISIONS GENERAL INTENT The intent of these specifications is to establish procedures for clearing,compacting natural ground, preparing areas to be filled,and placing and compactiw,fill soils to the lines and grades shown on the accepted plans. The recommendations contained in the preliminary geotechnical investigation report arid/or the attached Special Provisions are a part of the Recommended Grading Specifications and shall supersede the provisions contained hereinafter in the case of conflict These specifications shall only be used in conjunction with the geotechnical report for which they are a part. No deviation from these specifications will be allowed, except where specified in the geotechnical report or in other written communication signed by the Geotechnical Engineer. OBSERVATION AND TESTING Christian Wheeler Engineering shall be retained as the Geotechnical Engineer to observe and test the earthwork in accordance with these specifications. It will be necessary that the Geotechnical Engineer or his representative provide adequate observation so that' ;ride his opinion as to whether or not the work was accomplished as specified. It shall be the responsibility of the contractor to assist the Geotechnical Engineer and to keep him appraised of work schedules, changes and new information and data so that he may provide these opinions. In the event that any unusual conditions not covered by the special provisions or preliminary geotechnical report are encountered during the grading operations,the Geotechnical Engineer shall be contacted for further recommendations. If,in the opinion of the Geotechnical Engineer,substandard conditions are encountered, such as questionable or unsuitable soil,unacceptable moisture content,inadequate compaction, adverse weather, etc., construction should be stopped until the conditions are remedied or corrected or he shall recommend rejection of this work. r C%VE 199.099.1 December 28, 1999 Appendix B,Page 32 Tests used to determine the degree of compaction should be performed in accordance with the following American Society for Testing and Materials test methods: Maximum Density& Optimum Moisture Content-ASTM D-1557-91 I Density of Soil In-Place-ASTM D-1556-90 or ASTM D-2922 All densities shall be expressed in terms of Relative Compaction as determined by the foregoing ASTM testing procedures. PREPARATION OF AREAS TO RECEIVE FILL i t1ll vegetation,brush and debris derived from clearing operations shall be removed,and legally disposed of. All areas disturbed by site grading should be left in a neat and finished appearance, free from unsightly debris. After clearing or benching the natural ground,the areas to be filled shall be scarified to a depth of 12 inches, brought to the proper moisture content,compacted and tested for the specified minimum degree of compaction. All loose soils in excess of 6 inches thick should be removed to firm natural ground which is defined as natural soil which possesses an in-situ density of at least 90 percent of its maximum dry density. When the slope of the natural ground receiving fill exceeds 20 percent(5 horizontal units to 1 vertical unit), the original ground shall be stepped or benched. Benches shall be cut to a firm competent formational soil. The lower bench shall be at least 10 feet wide or 1-1/2 times the equipment width,whichever is greater,and shall be sloped back into the hillside at a gradiw-^F n-*1—s than two (2)percent. All other benches should be at least 6 feet wide. The horizontal portion of each bench shall be compacted prior to receiving fill as specified herein for compacted natural ground. Ground slopes flatter than 20 percent shall be benched when considered necessary by the Geotechnical Engineer. Any abandoned buried structures encountered during grading operations must be totally removed. All underground utilities to be abandoned beneath any proposed structure should be removed from within 10 feet of the structure and properly capped off. The resulting depressions from the above described procedure should be backfilled with acceptable soil that is compacted to the requirements of the Geotechnical Engineer. This includes,but is not limited to, septic tanks,fuel tanks, sewer lines or leach lines, storm drains and water lines. Any buried structures or utilities not to be abandoned should be brought to the attention of the Geotechnical Engineer so that he may determine if any special recommendation will be necessary. CWE 199.099.1 December 28, 1999 Appendix B,Page B3 FILL MATERIAL Materials to be placed in the fill shall be approved by the Geotechnical Engineer and shall be free of organic matter and other deleterious substances. Granular soil shall contain sufficient fine material to fill the voids. The definition and disposition of oversized rocks and expansive or detrimental soils are covered in the geotechnical report or Special Provisions. Expansive soils,soils of poor gradation,or soils with low strength characteristics may be thoroughly mixed with other soils to provide satisfactory fill material, but only with the explicit consent of the Geotechnical Engineer. Any import material shall be approved by the Geotechnical Engineer before being brought to the site. J PLACING AND COMPACTION OF FILL Approved fill material shall be placed in areas prepared to receive fill in layers not to exceed 6 inches in compacted thickness. Each layer shall have a uniform moisture content in the range that will allow the compaction effort to be efficiently applied to achieve.the specified degree of compaction. Each layer shall be uniformly compacted to the specified minimum degree of compaction with equipment of adequate size to economically compact the layer. Compaction equipment should either be specifically designed for soil compaction or of proven reliability. The minimum degree of compaction to be achieved is specified in either the Special Provisions or the recommendations contained in the preliminary geotechnical investigation report. When the structural fill material includes rocks,no rocks will be allowed to nest and all voids must be carefully filled with soil such that the minim,1m 4----of compaction recommended in the Special Provisions is achieved. The maximum size and spacing of rock permitted in structural fills and in non- structural fills is discussed in the geotechnical report,when applicable. Field observation and compaction tests to estimate the degree of compaction of the fill will be taken by the Geotechnical Engineer or his representative. The location and frequency of the tests shall be at the Geotechnical Engineer's discretion. When the compaction test indicates that a particular layer is at less than the required degree of compaction, the layer shall be reworked to the satisfaction of the Geotechnical Engineer and until the desired relative compaction has been obtained. Fill slopes shall be compacted by means of sheepsfoot rollers or other suitable equipment. Compaction by sheepsfoot roller shall be at vertical intervals of not greater than four feet. In addition, fill slopes at a ratio of two horizontal to one vertical or flatter, should be trackrolled. Steeper fill slopes shall be over-built and cut- CkVVE 199.099.1 December 28, 1999 Appendix B,Page B4 back to finish contours after the slope has been constructed. Slope compaction operations shall result in all fill material six or more inches inward from the finished face of the slope having a relative compaction of at least 90 percent of maximum dry density or the degree of compaction specified in the Special Provisions section of this specification. The compaction operation on the slopes shall be continued until the Geotechnical Engineer is of the opinion that the slopes will be surficially stable. Density tests in the slopes will be made by the Geotechnical Engineer during construction of the slopes to determine if the required compaction is being achieved. Where failing tests occur or other field problems arise, the Contractor will be notified that day of such conditions by written communication from the Geotechnical Engineer or his representative in the form of a daily field report. If the method of achieving the required slope compaction selected by the Contractor fails to produce the necessary results, the Contractor shall rework or rebuild such slopes until the required degree of compaction is obtained, at no cost to the Owner or Geotechnical Engineer. CUT SLOPES The Engineering Geologist shall inspect cut slopes excavated in rock or lithified formational material during the grading operations at intervals determined at his discretion. If any conditions not anticipated in the Preliminary report such as perched water, seepage,lenticular or confined strata of a potentially adverse nature,unfavorably inclined bedding,joints or fault planes are encountered during grading, these conditions shall be analyzed by the Engineering Geologist and Geotechnical Engineer to determine if mitigating measures are necessary. Unless otherwise specified in the geotechnical report,no cut slopes shall be excavated higher or steeper than that allowed by the ordinances of the controlling governmental agency. ENGINEERING OBSERVATION Field observation by the Geotechnical Engineer or his representative shall be made during the filling and compaction operations so that he can express his opinion regarding the conformance of the grading with acceptable standards of practice. Neither the presence of the Geotechnical Engineer or his representative or the observation and testing shall release the Grading Contractor from his duty to compact all fill material to the specified degree of compaction. CWE 199.099.1 December 28, 1999 Appendix B,Page B5 SEASON LIMITS Fill shall not be placed during unfavorable weather conditions. When work is interrupted by heavy rain, filling operations shall not be resumed until the proper moisture content and density of the fill materials can be achieved. Damaged site conditions resulting from weather or acts of God shall be repaired before acceptance of work RECOMMENDED GRADING SPECIFICATIONS-SPECIAL PROVISIONS RELATIVE COMPACTION:The minimum degree of compaction to be obtained in compacted natural ground, compacted fill,and compacted backfill shall be at least 90 percent. For street and parking lot subgrade, the upper six inches should be compacted to at least 95 percent relative compaction. EXPANSIVE SOILS:Detrimentally expansive soil is defined as clayey soil which has an expansion index of 50 or greater when tested in accordance with the Uniform Building Code Standard 29-C. OVERSIZED MATERIAL: Oversized fill material is generally defined herein as rocks or lumps of soil over 6 inches in diameter. Oversized materials should not be placed in fill unless recommendations of placement of such material are provided by the Geotechnical Engineer. At least 40 percent of the fill soils shall pass through a No. 4 U.S. Standard Sieve. TRANSITION LOTS:Where transitions between cut and fill occur within the proposed building pad, the cut portion should be undercut a* - -F 18 inches below the base of the proposed footings and recompacted as structural backfill. In certain cases that would be addressed in the geotechnical report,. special footing reinforcement or a combination of special footing reinforcement and undercutting may be required. s w CHRISTIAN WHEELER E N G I N E E R I N G G b REPORT OF PRELIMINARY GEOTECHNICAL INVESTIGATION 4 PROPOSED NOMMESEN RESIDENCE 2600 MONTGOMERY AVENUE 3 ENCINITAS, CALIFORNIA 4 t PREPARED FOR: F MR.JOHN NOMMESEN 2540 MONTGOMERY AVENUE ENCINITAS, CALIFORNIA 92007 TEIVED Jr',, CITY OF ENCINITAS BUILDING INSPECTION DIVISION PREPARED BY: CHRISTIAN WHEELER ENGINEERING 4925 MERCURY STREET SAN DIEGO, CALIFORNIA 92111 4925 Mercury Street f San Diego, CA 92111 ♦ 858-496-9760 ♦ FAX 858-496-9758 W CHRISTIAN WHEELER ENGINEERING December 28, 1999 (revised 3-7-00) Mr.John Nommesen CWE 199.099.2 2540 Montgomery Avenue Encinitas, California 92007 SUBJECT: REPORT OF PRELIMINARY GEOTECHNICAL INVESTIGATION, PROPOSED NOMMESEN RESIDENCE,2600 MONTGOMERY AVENUE, ENCINITAS, CALIFORNIA x Dear Mr. Nommesen: l In accordance with your request and our Proposal dated October 27, 1999,we have completed a geotechnical investigation for the subject property. We are presenting herewith our findings and recommendations. In general,we found that the site is suitable for support of the proposed single-family residence,provided the recommendations provided in our report are followed. The most significant geotechnical condition that will affect the construction of the proposed home is the existing moderately to steeply sloping hillside upon which the proposed residence is to be constructed. Our quantitative analyses indicate that the stability of this slope will require that ' a deep foundation system which will not adversely affect the stability of the slope be used for structural support of the proposed structure. If you have any questions after reviewing this report,please do not hesitate to contact our office. This opportunity to be of professional service is sincerely appreciated. ` D Respectfully submitted, RB °�'Cy QPpFESSlON4e CHRISTIAN WHEELER ENGINEERING S H. C Fes,- NO 1090 �� t 1. o CERTIFIEI) a �, rQ ENUNEERING v No.GE ')15 z GEaoaIST Exp.9-30-01 Exp. �p� ` jF�TfCHN���4��� David R. Russell, Staff Geologist f0FCA\0F Charles H. Christian, R.G.E. #00215 Curtis R. Burdett, C.E.G. #1090 CHC:CRB:drr' cc: (4) Submitted 4925 Mercury Street ♦ San Diego, CA 92111 ♦ 858-496-9760 ♦ FAX 858-496-9758 TABLE OF CONTENTS PAGE i Introduction and Project Description..............................................................................................................1 ProjectScope........................................................................................................................................................2 Findings SiteDescription.............................................................................................................................................3 General Geology and Subsurface Conditions..........................................................................................4 Geologic Setting and Soil Description..................................................................................................4 Fill............................. 4 ................................................................................................................. DelmarFormation.................................................................................................................................4 Groundwater.............. 5 TectonicSetting........................................................................................................................................5 GeologicHazards.........................................................................................................................................5 General.......................................................................................................................................................5 GroundShaking...........................................................................................................................:..........5 SeismicDesign Parameters.....................................................................................................................6 Landslide Potential and Slope Stability.................................................................................................7 Liquefaction..............................................................................................................................................7 Flooding.....................................................................................................................................................7 Tsunamis...................................................................................................................................................7 Seiches........................................................................................................................................................7 Groundwater.............................................................................................................................................7 SlopeStability Analysis.....................:..........................................................................................................8 General.............................................................................................................;.........................................8 iMethod of Analysis..................................................................................................................................8 Resultsof Stability Analysis....................................................................................................................8 Conclusions...........................................................................................................................................................9 aRecommendations.............................................................................................................................................10 Gradingand Earthwork.............................................................................................................................10 x General.....................................................................................................................................................10 Observation of Grading .....10 SitePreparation......................................................................................................................................10 ExcavationCharacteristics....................................................................................................................10 Compactionand Method of Filling.....................................................................................................10 ' Surface Drainage GradingPlan Review.............................................................................................................................11 TemporaryCut Slopes...........................................................................................................................12 FoundationSystems............................................................................................................................:......12 General.....................................................................................................................................................12 FoundationDesign.......................................................................................................... ..12 General....................................................................................................................... ....................12 MinimumPier Dimensions.............................................................................................................12 PierReinforcing.................................................................................................................................13 BearingCapacity................................................................................................................................13 LateralPier Capacity.........................................................................................................................13 LateralCreep......................................................................................................................................13 Cleaningof Pier Excavations..........................................................................................................13 Foundation Excavation Observation..................................................................................................13 On-Grade Slabs..........................................................................................................................................14 InteriorFloor Slabs................................................................................................................................14 Moisture Protection for Interior Slabs...............................................................................................14 ExteriorConcrete Flatwork.................................................................................................................14 EarthRetaining Walls................................................................................................................................14 aPassive Pressure............................................. ............................14 Active Pressure for Unrestrained Retaining Walls............................................ At-Rest Pressure for Restrained(Basement)Retaining Walls........................................................15 Backfil...................... ........................ :. ......... ...............................................................................................15 Factorof Safety......................................................................................................................................15 Limitations..........................................................................................................................................................15 Review,Observation and Testing............................................................................................................15 Uniformityof Conditions..........................................................................................................................16 g Change in Scope .............16 ............................................................................................................................ TimeLimitations.........................................................................................................................................16 i Professional Standard.................................................................................................................................16 Client's Responsibility................................................................................................................................17 FieldExplorations..................................:...........................................................................................................17 i Laboratory Testing ................................................................................18 rY g. ........................................................... - ATTACHMENTS TABLES Table I Maximum Bedrock Accelerations,Page 6 Table II Seismic Design Parameters,Page 6 1 FIGURES Figure 1 Site Vicinity Map,Follows Page 1 t PLATES f Plate 1 Site Plan Plates 2-6 Boring Logs Plate 7 Cross Section A A' Plates 8-13 Slope Stability Analysis j Plate 14 Subdrain Detail APPENDICES Appendix A References,Topographic Maps,Photographs Appendix B Recommended Grading Specifications—General Provisions PRELIMINARY GEOTECHNICAL INVESTIGATION PROPOSED NOMMESEN RESIDENCE 2600 MONTGOMERY AVENUE ENCINITAS, CALIFORNIA INTRODUCTION AND PROJECT DESCRIPTION l This report presents the results of a preliminary geotechnical investigation performed for the proposed single family residence to be constructed at 2600 Montgomery Avenue in the City of Encinitas,California. The following Figure Number 1 presents a vicinity map showing the location t of the property. The subject lot is located south of the terminus of Montgomery Avenue and is accessed by a 20-foot- wide driveway easement extending south from the Montgomery Avenue cul-de-sac. We understand l that a three-story single-family residence is proposed for the site. The first floor level will be about ten feet below the driveway grade and will consist of a workroom,bathroom,and sauna. The middle level is to be close to the driveway grade and will consist of a garage,an office,and a bedroom. The upper level will have a living room,kitchen,dining room, and a bedroom. A large outside deck is a also proposed on the upper level. Retaining walls up to about ten feet high will be required for the project Based on the stability characteristics of the moderately to steeply sloping hillside on-site,the proposed residence will need to be supported by a cast-in-place concrete pier and grade beam foundation system. Grading will basically be limited to cutting into a portion of the hillside for the lower level. To aid in the preparation of this report we were provided with a limited preliminary geotechnical report for the site prepared by Barry and Associates, and an untitled site plan for the project. A copy of this site plan was used as the base for our Site Plan and is included herewith as Plate Number 1. This report has been prepared for the exclusive use of Mr.John Nommesen and his design consultants for specific application to the project described herein. Should the project be modified, the conclusions and recommendations presented in this report should be reviewed by Christian Wheeler Engineering for conformance with our recommendations and to determine if any additional 11 ILI 1. ; •�'`�`��'�"'�`a°�'_y"� IN W 32 MIN vg 0e � 9'�,. T� � :-1 1 ,}i � ��}'`�'•'� '�•-�'_� -:5;� +� ®x'' rk v� °7 t � ��.`•- ,! ,'j f f s".3 ��' � � �• '06�'CBHY'3°.. 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X� S v lr s ° t ED ys t t��� T -r a P f 'S'.C s 3...� � - ;, � �,�< ; -��M n_-1:�'a-^I �ro 5•.�� .. a� '4� �.j`,?m' a c.,y. qy az sF' ✓" ,� 3 kr 5 t, NT ;°L�.. _ y Ft'.t:r•5'"$-,• )-�Y`iC 2-N tk.»'l?ir, � _ e CWE 199.099.2 December 28, 1999 Page No. 2 (revised 3-7-00) subsurface investigation,laboratory testing and/or recommendations are necessary. Our professional services have been performed,our findings obtained,and our recommendations J prepared in accordance with generally accepted engineering principles and practices. This warranty is in lieu of all other warranties, expressed or implied. PROJECT SCOPE i The scope of our preliminary investigation included surface reconnaissance,subsurface exploration, i obtaining representative soil samples,laboratory testing, analysis of the field and laboratory data and review of readily available,pertinent geologic and geotechnical literature. In consideration of our past experience in the vicinity of the subject site along with access considerations,an 8-inch diameter boring was advanced within the eastern portion of the proposed building footprint in order to ( explore the subsurface soil conditions,and to obtain representative soil samples for laboratory testing. More specifically, the intent of this investigation was to: a) Explore the subsurface conditions of the site to the depths influenced by the proposed construction. b) Evaluate,by laboratory tests, the engineering properties of the various strata that may influence the proposed construction,including bearing capacities,expansive characteristics and settlement potential. c) Describe the general geology at the site including possible geologic factors that F could have an effect on the site development d) Address potential construction difficulties that may be encountered due to soil conditions,groundwater,or geologic hazards,and provide recommendations concerning these problems. e) Develop soil engineering criteria for site preparation and grading. f) Address the stability of the existing cut slope for Manchester Avenue and determine the foundation setback from this slope. g) Provide design parameters for unrestrained and restrained retaining walls. CWE 199.099.2 December 28, 1999 Page No. 3 (revised 3-7-00) h) Recommend an appropriate foundation system for the type of structure anticipated and develop soil engineering criteria for the recommended foundation design. a i) Present our professional opinions in a report,which will include in addition to our j conclusions and recommendations,a plot plan,exploration logs and a summary of the laboratory test results. It was not within the scope of our services to perform laboratory tests to evaluate the chemical i characteristics of the on-site soils in regard to their potentially corrosive impact to on-grade concrete f and below grade improvements. If desired,we can obtain samples of representative soils and submit them to a chemical laboratory for analysis. Further,it should be understood that Christian Wheeler Engineering does not practice corrosion engineering. If such an analysis is necessary,we recommend that the client retain an engineering firm that specializes in this field to consult with them on this matter. FINDINGS SITE DESCRIPTION 1 The subject site consists of an irregular-shaped parcel of land of less than one-quarter acre in size,which is located south of the terminus of Montgomery Avenue,in Encinitas,California,and is accessed by a t 20-foot-wide driveway easement extending south from the Montgomery Avenue cul-de-sac. The site is bounded to north and southeast by existing single-family residences,to the east by the existing access driveway,and the west by Manchester Avenue. The lot was once part of the adjacent lot to the north, and,as such,supports an observation and parking deck that extends out over the hillside. The deck is supported by continuous footings on the east and by two columns with pier footings on the west. Except for a relatively level area south and east of the deck,the property slopes moderately to steeply to the southwest. Below the deck,the ground slopes at a ratio of between about 4:1 and 2:1,horizontal to vertical. An existing cut slope along Manchester Avenue ranges in height form approximately 20 to 35 feet,increasing in height from west to east,along the southwest portion of the site. The lower approximately ten feet has a slope ratio of about 0.75:1 to 1:1 (H:V). Above this the slope is steeper, varying from about 0.5:1 (H:V) to near-vertical in localized areas. On-site elevations range from approximately 95 feet above sea level within the southeast portion of the site,to approximately 35 feet 0WE 199.099.2 December 28, 1999 Page No. 4 (revised 3-7-00) above sea level along the base of the cut slope along Manchester Avenue. Please refer to the Site j Vicinity Map included herewith as Figure No. 1 and the site plan included herewith as Plate No. 1. f GENERAL GEOLOGY AND SUBSURFACE CONDITIONS GEOLOGIC SETTING AND SOIL DESCRIPTION:The subject site is located in the Coastal Plains Physiographic Province of San Diego County. Based upon the results of our limited exploration jand analysis of readily available,pertinent geologic and geotechnical literature,the site appears to be underlain by a minor amount'of man-made fill materials which overlie formational materials of the j Tertiary-age Delmar Formation(Tan&Kennedy, 1996).These materials are described below: FILL: Approximately eighteen inches of fill material was encountered within our Exploratory Boring B-1. Based on our site reconnaissance,similar or shallower depths of man-placed fill soils can be expected across those portions of the site to receive the proposed single-family residence. The fill was noted to consist of light olive brown,silty sand(SM)which was generally damp and loose in consistency. No documentation as to the placement and compaction of these fill soils has been provided to us at this time. As such,the fill soils are not considered suitable to support settlement-sensitive structures. t Based upon visual observation of the encountered soils,laboratory testing,and experience with . similar soils in the vicinity of the project site,the fill soils are anticipated to possess a"low" expansion potential(based upon UBC Test Method 27-2). f DELMAR FORMATION:As noted within our exploratory boring,the site was observed to be underlain at a depth of V/z feet by Tertiary-age sedimentary deposits of the Delmar Formation. These formational materials were observed to consist of interbedded white,olive, yellowish-brown,and pinkish silty sand and sandstone(SM),clayey sand and sandstone(SC), and sandy clay and claystone(CL). The silty sands (SM) of the Delmar Formation encountered within approximately five feet of the existing ground surface,within the vicinity of our boring location,were noted to be generally moist and medium dense. Below this depth,the sandy portions of the formational materials were noted to be generally moist and very dense,while the clayey portions were noted to be generally moist and hard. Analysis of readily available, pertinent geologic literature indicates that bedding within the Delmar Formation is nearly horizontal within the vicinity of the subject site(Tan&Kennedy,1996). C%VE 199.099.2 December 28, 1999 Page No. 5 (revised 3-7-00) GROUNDWATER No groundwater was encountered in out boring and we do not anticipate any j significant groundwater related problems,either during or after construction. However,it should be recognized that minor groundwater seepage problems might occur after development of a site even where none were present before development. These are usually minor phenomena and are often the 1 result of an alteration in drainage patterns and/or an increase in irrigation water. Based on the permeability characteristics of the soil and the anticipated usage and development,it is our opinion that any seepage problems which will be minor in extent. These potential"nuisance"problems can be mitigated by the use of proper landscaping techniques. 4 l TECTONIC SETTING:No major faults are known to traverse the subject site but it should be noted that much of Southern California,including the San Diego County area,is characterized by a series of Quaternary-age fault zones which typically consist of several individual,en echelon faults that generally strike in a northerly to north-westerly direction. Some of these fault zones(and the individual faults within the zones)are classified as active while others are classified as only potentially active,according to t the criteria of the California Division of Mines and Geology. Active fault zones are those which have shown conclusive evidence of faulting during the Holocene Epoch(the most recent 11,000 years)while potentially active fault zones have demonstrated movement during the Pleistocene Epoch (11,000 to 1.6 million years before the present)but no movement during Holocene time. r A review of available geologic maps indicates that a portion of the Rose Canyon Fault Zone is located approximately two and one-half mile west of the site.Other active fault zones in the region that could t possibly affect the site include the Coronado Bank and San Clemente Fault Zones to the southwest and the Elsinore,San Jacinto,and San Andreas Fault Zones to the northeast. GEOLOGIC HAZARDS GENERAL: No geologic hazards of sufficient magnitude to preclude development of the site as we presently contemplate it are known to exist. In our professional opinion and to the best of our knowledge,the site is suitable for the proposed development. GROUND SHAKING:A likely geologic hazard to affect the site is ground shaking as result of movement along one of the major active fault zones mentioned above. The maximum bedrock accelerations that would be attributed to a maximum magnitude earthquake occurring along the nearest fault segments of selected fault zones that could affect the site are summarized in the following Table I. CWE 199.099.2 December 28, 1999 Page No. 6 (revised 3-7-00) TABLE I Fault Zone Distance Maximum Magnitude Maximum Bedrock Earthquake Acceleration Rose Canyon 2/z miles 6.9 magnitude 0.52 g Coronado Bank 18 miles 7.4 magnitude 0.21 g Elsinore 29 miles 7.1 magnitude 0.12 g San Jacinto 52 miles 7.2 magnitude 0.06 g San Clemente 56 miles 7.3 magnitude 0.06 g Probable ground shaking levels at the site could range from slight to moderate,depending on such factors as the magnitude of the seismic event and the distance to the epicenter. It is likely that the site will experience the effects of at least one moderate to large earthquake during the life of the proposed improvements. SEISMIC DESIGN PARAMETERS:Based on a maximum magnitude(Mmax) earthquake of 6.9 E along the nearest portion of the Rose Canyon Fault Zone,the Maximum Bedrock Acceleration at the site would be approximately 0.52 g. For structural design purposes,a damping ratio not greater than 5 percent of critical dampening,and Soil Profile Type Sc are recommended(UBC Table 16-J). Based upon the location of approximately 4 kilometers from the Rose Canyon Fault(Type B Fault),Near Source Factors Na equal to 1.1 and N,equal to 1.33 are also applicable.These values,along with other seismically related design parameters from the Uniform Building Code(UBC) 1997 edition,Volume R, Chapter 16,utilizing a Seismic Zone 4 are presented in tabular form below. TABLE II UBC—CHAPTER 16 SEISMIC RECOMMENDED TABLE No. PARAMETER VALUE 16-I Seismic Zone Factor Z 0.40 16-j Soil Profile Type Sc 16 Seismic Coefficient Ca (9.40 Na 16-R Seismic Coefficient Co 0.56 No 16-S Near Source Factor N. 1.1 16-T Near Source Factor N„ 1.33 16-U Seismic Source Type. B C`VE 199.099.2 December 28, 1999 Page No. 7 (revised 3-7-00) LANDSLIDE POTENTIAL AND SLOPE STABILITY:The site is identified as being in an area which is considered most susceptible to slope stability hazards due to such factors as the character of the geologic units;the presence of fractures or other planes of weakness;and the presence of steep slopes. The Relative Landslide Susceptibility and Landslide Distribution Map of the Encinitas Quadrangle prepared by the California Division of Mines and Geology indicates that the site is situated within Relative Landslide Susceptibility Area 4-1. Area 4 is considered to be a"most susceptible"to slope failures;Subarea 4-1 includes slopes considered to be outside the limits of known landslides but contains observably unstable materials such as the Delmar Formation. Although most slopes within Subarea 4-1 do not currently contain landslide deposits,they can be expected to fail even in the absence of activities of man. A specific slope stability analysis was performed for the sloping site and that analysis is presented in the"Slope Stability Analysis"section of this report LIQUEFACTION: The soils encountered at the site are not considered susceptible to liquefaction due to such factors as soil density,grain-size distribution and the absence of shallow groundwater conditions. FLOODING: The site is located outside the boundaries of both the 100-year and the 500-pear floodplains according to the maps prepared by the Federal Emergency Management Agency. F TSUNAMIS: Tsunamis are great sea waves produced by submarine earthquakes or volcanic eruptions. Due to the site's setback from the ocean and elevation,the site will not be affected by a tsunami. SEICHES: Seiches are periodic oscillations in large bodies of water such as lakes,harbors,bays or reservoirs. Due to the site's location and elevation,it will not be affected by seiches. GROUNDWATER No groundwater was encountered in our test trenches and we do not anticipate any significant groundwater related problems,either during or after construction. However,it should be recognized that minor groundwater seepage problems might occur after development of a site even where none were present before development. These are usually minor phenomena and are often the result of an alteration in drainage patterns and/or an increase in irrigation water. Based on the permeability characteristics of the soil and the anticipated usage and development,it is our opinion that any seepage problems which will be minor in extent. These potential"nuisance"problems can be mitigated by the use of proper landscaping techniques. CWE 199.099.2 December 28, 1999 Page No. 8 (revised 3-7-00) SLOPE STABILITY ANALYSIS GENERAL:-To analyze the stability of the steepest portion of the existing slope along the western portion of the site,a cross-section of the slope was drawn perpendicular to the face of the slope at the point where the slope is steepest. This cross-section,which shows the site topography and approximate location of the proposed residence,is presented on the attached Plate No. 7. METHOD OF ANALYSIS:The analysis of the stability of the natural hillside slope was performed using the PCSTABL6 computer program developed at Purdue University. The program analyzes circular,block and randomly shaped failure surfaces using the Simplified Bishop,Jambu,and Spencer's Methods. Sted 6.5 PCSTABL6 Editor,developed by Harold W.Van Aller,P.E.,was used in - conjunction with this program for data entry and graphics display.The selected cross-sections were analyzed for both circular and bock-type failures and each failure analysis was programmed to run 100 random failure surfaces. The most critical failure surfaces are accumulated and sorted by value of the Factor-of-safety. After the specified number of failure surfaces are successfully generated and analyzed, the ten most critical surfaces are plotted so that the pattern may be studied. These plots with the fcomputer printout of each run are presented as Plate Nos. 8 through 13. x RESULTS OF STABILITY ANALYSIS:Our quantitative analyses of the slope stability of the existing slope along the western side of the site,have demonstrated a minimum factors-of-safety of 1.31 and 1.32 for block type and rotational slip failures,respectively(see Plate Nos. 8&9). Additionally,the ' minimum factors-of-safety increase only to 1.35 and 1.34 for block type and rotational slip failures, respectively,when the location of the slope failure initiation point is extended from the western edge of the proposed residence towards the east(see Plate Nos. 10&11). Scenarios in which rotational and block type slope failures yield the minimum factor-of-safety considered safe of 1.5 or greater,indicate that the point of slope failure initiation be located at least approximately 46 feet or 40 feet east of the western perimeter of the proposed residence,for block type and rotational slip failures,respectively(see Plate Nos. 12& 13). As such,the proposed residence will need to be supported on a deep foundation system consisting of cast-in-place concrete piers tied together with concrete reinforced grade beams. Such a deep foundation system will need to transmit the loads of the proposed residence to competent formational materials at depths of at least five feet below the slope failure surface that exhibits a minimum factor-of-safety of 1.5. Our analyses indicate that such depths range from 28 feet below existing site grades along the western CWE 199.099.2 December 28, 1999 Page No. 9 (revised 3-7-00) perimeter of the proposed residence to 19 feet below existing site grades along the eastern perimeter of the proposed structure. These depths have been calculated using Plate No. 7,which plots the surfaces of the rotational slip and block type failures,which exhibit minimum factors-of-safety of 1.5. Please refer a to the Foundation Design section of this report for further information regarding the design and depths of such a foundation system. F The potential for slope instability should not be increased by the construction of the proposed residence, t provided the recommendations provided in this report as well as additional sound geotechnical, t construction,and maintenance standards are followed. It can also be noted that the proposed grading, i which involves creating cuts and retaining walls within the slope,will somewhat increase the stability of j the slope from the ungraded condition by removing part of the driving weight,provided sound engineering and construction practices are followed. Furthermore,the construction of the deep j foundation system will help stabilize the hillside by providing additional resistance to lateral movement. z fCare should be taken to ensure the proper drainage of all surface runoff away from the entire slope face. Saturation of the slope caused by excessive or improperly channeled runoff could detrimentally 1 affect the surficial stability of the slope. Irrigation on and adjacent to the slope should be carefully monitored to insure that only the minimum amount necessary to sustain plant life is used. Over- 3 irrigating could not only be erosive but may significantly increase the chance for slope stability problems and should be avoided. i r CONCLUSIONS In general,we found the subject property suitable for the proposed construction,provided the recommendations provided herein are followed. The most significant geotechnical condition that will affect the construction of the proposed residence as proposed,is the stability of the existing moderately to steeply sloping hillside,which extends from the footprint of the proposed residence westward down to Manchester Avenue. As such,the proposed residence will need to be supported on a deep foundation system consisting of cast-in-place concrete piers tied together with concrete reinforced grade beams. CWE 199.699.2 December 28, 1999 Page No. 10 (revised 3-7-00) f RECOMMENDATIONS GRADING AND EARTHWORK GENERAL: No project grading plans have been provided to us at this time.However,it is our understanding that site grading is to be limited to cuts of about ten feet or less into the hillside,to create E the building pad for the lower level of the proposed residence. i OBSERVATION OF GRADING:Observation by the Geotechnical Consultant is essential during the grading operation to confirm conditions anticipated by our investigation,to allow adjustments in 1 design criteria to reflect actual field conditions exposed,and to determine that the grading proceeds in general accordance with the recommendations contained herein. E SITE PREPARATION:Site grading should begin with the removal of all existing improvements and vegetation and other deleterious materials from the portions of site that will be graded and/or will . receive new improvements. This should include all grasses,iceplant,and significant root material. The 1 resulting materials should be disposed of off-site. Any resulting depressions should be cleaned out of loose or disturbed soils and be backfilled with properly compacted soil 1 EXCAVATION CHARACTERISTICS:Based upon the manner of auger penetration,our f experience with similar materials in the vicinity of the site,and review of the referenced geotechnical reports,the subsurface materials at the site appear generally rippable with conventional earthmoving equipment to a depths of at least ten feet below existing site grades. Furthermore,no distinct concretions were observed within the formational materials during our subsurface exploration. However,it should be noted that very dense concretions are sometimes encountered within the Delmar Formation. The contractor is solely responsible for designing and constructing stable,temporary excavations and may need to shore,slope,or bench the sides of trench excavations as required to maintain the stability of the excavation sides where friable sands or loose soils are exposed. The contractor's"responsible person",as defined in the OSHA Construction Standards for Excavations,29 CFR,Part 1926,should evaluate the soil exposed in the excavations as part of the contractor's safety process. In no case should slope height,slope inclination,or excavation depth,including utility trench excavation depth,exceed those specified in local,state,and federal safety regulations. COMPACTION AND METHOD OF FILLING:Any structural fill placed at the site should be compacted to a relative compaction of at least 90 percent of maximum dry density as determined by CWE 199.099.2 December 28, 1999 Page No. 11 (revised 3-7-00) ASTM Laboratory Test D1557-91. Fills should be placed at or slightly above optimum moisture content,in lifts six to eight inches thick,with each lift compacted by mechanical means. Fills should consist of approved earth material,free of trash or debris,roots,vegetation,or other materials determined to be unsuitable by our soil technicians or project geologist. Fill material should be free of i rocks or lumps of soil in excess of twelve inches in maximum dimension.However,in the'upper two ? feet of pad grade,no rocks or lumps of soil in excess of six inches should be allowed. Based upon the results of our sub-surface exploration and laboratory testing,all of the on-site soils appear suitable for ► use as structural fill materiaL 1 Fills should be benched into all temporary slopes and into competent formational materials when the natural slope is steeper than an inclination of 5:1 (horizontal to vertical). Keys should be constructed at the toe of all fill slopes. The keys should extend at least 12 inches into competent formational material and should be sloped back at least two percent into the slope area. Slope keys should have a minimum width of 10 feet. Utility trench backfill within five feet of the proposed structures and beneath driveways,concrete flatwork,and pavements should be compacted to a minimum of 90 percent of its maximum dry density. All grading and fill placement should be performed in accordance with the City of Encinitas Grading Ordinance,the Uniform Building Code,and the attached Recommended Grading Specifications and Special Provisions attached hereto as Appendix B. SURFACE DRAINAGE:Surface runoff into downslope natural areas and graded areas should be minimized. Where possible,drainage should be directed to suitable disposal areas via non-erodible devices such as paved swales,gunited brow ditches,and storm drains. Drainage around the proposed i residence should be designed to collect and direct surface water away from proposed structures and the top of slopes and toward approved drainage areas. GRADING PLAN REVIEW. Once available,the project grading plans should be submitted to this office for review in order to analyze all proposed slopes,cuts,and fills. The final grading plans should be submitted to this office for review in order to ascertain that the recommendations of this report have been implemented,and that no additional recommendations are needed due to changes in the anticipated development plans. CWE 199.099.2 December 28, 1999 (revised 3-7-00) Page No. 12 3 TEMPORARY CUT SLOPES:Unshored temporary cut slopes of up to eight feet in height can be excavated at inclinations of 0.5 to 1.0(horizontal to vertical)or flatter,within competent formational materials. Temporary excavations of between eight and fifteen feet in height can be constructed at inclinations of 0.75 to 1.0 (horizontal to vertical) or flatter,within competent formational materials. 1 , All temporary cut slopes should be observed by the engineering geologist during grading to ascertain that } no unforeseen adverse conditions exist No surcharge loads such as stockpiles,vehicles,etc.should be allowed within a distance from the top of temporary slopes equal to half the slope height. f l FOUNDATION SYSTEMS GENERAL:Based on the calculated factors-of-safety for the existing slope, the proposed residence will need to be supported on a deep foundation system consisting of cast-in-place concrete piers tied together with concrete reinforced grade beams. Such a deep foundation system will need to transmit the loads of the proposed residence to competent formational materials at depths of at least five feet below the slope failure surface that exhibits a minimum factor-of-safety of 1.5. FOUNDATION DESIGN i GENERAL: Augered,cast-in-place concrete piers which are tied together with concrete f reinforced grade beams,are considered suitable for support of the structure loads of the proposed residence. Pier support will be afforded by end bearing within the hard/very dense formational materials. i MINIMUM PIER DIMENSIONS:All drilled,cast-in-place concrete piers should extend at least five feet below the slope failure surface that exhibits a minimum factor-of-safety of 1.5. Our analyses indicate that such depths range from 2.8 feet below existing site grades along the western perimeter of the proposed residence to 19 feet below existing site grades along the eastern perimeter of the proposed structure. These depths have been calculated using Plate No. 7,which plots the surfaces of the block type failures which exhibit minimum factors-of-safety of 1.5. Once the exact location of the piers has been determined by the project structural engineer, we should be contacted to determine the minimum depth requirements for each individual pier. Il;however,we are not contacted to determine the depth of each individual pier,the minimum depth shall.be 28 feet below the existing ground surface for all of the proposed piers. Piers CWVE 199.099.2 December 28, 1999 Page No. 13 (revised 3-7-00) should have a minimum diameter of 24 inches. All pier dimensions should be determined by the project structural engineer. i PIER REINFORCING:Piers should also be reinforced in accordance with the i recommendations of the project structural engineer. The reinforcing cage should extend the i fill height of the pier. , BEARING CAPACITY:Incorporating the minimum dimensions presented above and depths of at least five feet below the slope failure surface that exhibits a minimum factor-of- safety of 1.5,the cast-in-place concrete piers may be designed for an allowable downward axial s bearing capacity of 15 kips per square foot This value may be increased by 500 psf for each i additional foot of pier embedment below the slope failure surface that exhibits a minimum jfactor-of-safety of 1.5,up to a maximum allowable bearing capacity of 25 kips per square foot LATERAL PIER CAPACITY.The passive pressure for the formational materials may be considered to be 450 pounds per square foot per foot of depth,up to a maximum value of 2,500 ps£ These values may be assumed to act on an area equal to twice the pier diameter. LATERAL CREEP:Drilled piers should be designed for a lateral downslope load of 50 pounds per square foot per foot of depth,for a depth of 23 feet This lateral load application is recommended to increase the factor-of-safety of the existing hillside under the house to a t ' minimum of 1.5 against slope failure. CLEANING OF PIER EXCAVATIONS: If 24-inch diameter piers are used,the cleaning of the bottom of the pier excavation may be performed by careful operations of the driller and back-spinning the drill auger under pressure or utilizing a clean-out plate. For larger diameter piers,hand cleaning may be required. This will be determined by the observation of a geologist or engineer from our staff during the excavation of the piers. FOUNDATION EXCAVATION OBSERVATION:All pier foundation excavations should be observed by the Geotechnical Consultant prior to placing concrete to determine if the foundation recommendations presented herein are complied with. All loose or unsuitable material should be removed from the foundation excavations prior to the placement of concrete. CWE 199.099.2 December 28, 1999 Page No. 14 (revised 3-7-00) ON-GRADE SLABS t 3 i INTERIOR FLOOR SLABS:For conventional floor slabs,the minimum slab thickness should be I five inches. Interior floor slabs should be reinforced with at least No.3 bars placed at 12 inches on 7 center each way. The slab reinforcing bars should be turned down to extend at least six inches into the perimeter footings. Slab reinforcing should be positioned on chairs at mid-height in the floor slab. MOISTURE PROTECTION FOR INTERIOR SLABS:Interior concrete on-grade floor slabs ° that will support moisture-sensitive floor covering should be underlain by a moisture barrier. We recommend that the minimum configuration of the subslab moisture barrier consist of a four-inch-thick blanket of coarse clean sand. The moisture barrier material should have less than ten percent and five j percent passing the No. 100 and No.200 sieves,respectively. A visqueen vapor barrier should be placed in the center of the sand blanket. 1 EXTERIOR CONCRETE FLATWORK Exterior slabs should have a minimum thickness of four inches. Reinforcement and control joints should be constructed in exterior concrete flatwork to reduce the potential for cracking and movement Joints should be placed in exterior concrete flatwork to help I control the location of shrinkage cracks. Spacing of control joints should be in accordance with the American Concrete Institute specifications. When patio,walks and porch slabs abut perimeter foundations they should be doweled into the footings. EARTH RETAINING WALLS PASSIVE PRESSURE:The passive pressure for the prevailing soil conditions may be considered to be 400 pounds per square foot per foot of depth. These pressures maybe increased one-third for seismic loading. The lateral pier capacity provided in the Foundation Design section of this report may be utilized for the resistance to lateral movement. ACTIVE PRESSURE FOR UNRESTRAINED RETAINING WALLS: The active soil pressure for the design of unrestrained earth retaining structures with level backfill may be assumed to be equivalent to the pressure of a fluid weighing 35 pounds per cubic foot An additional 13 pounds per cubic foot should be added to said value for 2:1 (horizontal to vertical) sloping backfill. These pressures do not consider any other surcharge. If any are anticipated,this office should be contacted for the necessary increase in soil pressure. These values assume a drained backfill condition. Waterproofing CWE 199.099.2 December 28, 1999 Page No. 15 (revised 3-7-00) details should be provided by the project architect. A suggested wall subdrain detail is provided on the a attached Plate Number 14. We recommend that the Geotechnical Consultant observe all retaining wall subdrains to verify proper construction. t s AT-REST PRESSURE FOR RESTRAINED(BASEMENT)RETAINING WALLS: In the design of wall restrained from movement at the top(non-yielding)such as basement walls,the at-rest soil pressure may be assumed to be equivalent to the pressure of a fluid weighing 50 pounds per cubic foot, 1 provided a level backfill surface. An additional 15 pounds per cubic foot should be added to said value t for 2:1 (horizontal to vertical)sloping backfill. These values assume a drained backfill condition. Waterproofing details should be provided by the project architect A suggested wall subdrain detail is provided on the attached Plate Number 14. We recommend that the Geotechnical Consultant observe all retaining wall subdrains to verify proper construction. 1 BACKFILL: All backfill soils should be compacted to at least 90 percent relative compaction. Expansive or clayey soils should not be used for backfill material. The wall should not be backfilled until the masonry has reached an adequate strength. FACTOR OF SAFETY:The above values,with the exception of the allowable soil friction coefficient, s do not include a factor-of-safety. Appropriate factors-of-safety should be incorporated into the design i to prevent the walls from overturning and sliding. a LIMITATIONS REVIEW,OBSERVATION AND TESTING The recommendations presented in this report are contingent upon our review of final plans and specifications. Such plans and specifications should be made available to the geotechnical engineer and engineering geologist so that they may review and verify their compliance with this report and with the Uniform Building Code. It is recommended that Christian Wheeler Engineering be retained to provide continuous soil engineering services during the earthwork and foundation construction operations. This is to verify compliance with the design concepts,specifications or recommendations and to allow design changes in the event that.subsurface conditions differ from those anticipated prior to start of construction. C%VE 199.099.2 December 28, 1999 Page No. 16 (revised 3-7-00) UNIFORMITY OF CONDITIONS The recommendations and opinions expressed in this report reflect our best estimate of the project 4 requirements based on an evaluation of the subsurface soil conditions encountered at the subsurface s exploration locations and on the assumption that the soil conditions do not deviate appreciably from those encountered It should be recognized that the performance of the foundations and/or cut and fill slopes may be influenced by undisclosed or unforeseen variations in the soil conditions that may occur in the intermediate and unexplored areas. Any unusual conditions not covered in this report that may be 9 encountered during site development should be brought to the attention of the geotechnical engineer so that he may make modifications if necessary. CHANGE IN SCOPE 1 This office should be advised of any changes in the project scope or proposed site grading so that we may determine if the recommendations contained herein are appropriate. This should be verified in writing or modified by a written addendum. 0 TIME LIMITATIONS The findings of this report are valid as of this date. Changes in the condition of a property can,however, occur with the passage of time,whether they be due to natural processes or the work of man on this or i adjacent properties. In addition,changes in the Standards-of-Practice and/or Government Codes may occur. Due to such changes,the findings of this report may be invalidated wholly or in part by changes beyond our control. Therefore,this report should not be relied upon after a period of two years without a review by us verifying the suitability of the conclusions and recommendations. PROFESSIONAL STANDARD In the performance of our professional services,we comply with that level of care and skill ordinarily exercised by members of our profession currently practicing under similar conditions and in the same locality. The client recognizes that subsurface conditions may vary from those encountered at the locations where our borings,surveys,and explorations are made,and that our data,interpretations,and recommendations be based solely on the information obtained by us. We will be responsible for those data,interpretation's,and recommendations,but shall not be responsible for the interpretations by others CWE 199.099.2 December 28, 1999 Page No. 17 (revised 3-7-00) of the information developed. Our services consist of professional consultation and observation only, and no warranty of any kind whatsoever,express or implied,is made or intended in connection with the work performed or to be performed by us,or by our proposal for consulting or other services,or by our furnishing of oral or written reports or findings. CLIENT'S RESPONSIBILITY 'I It is the responsibility of Mr.John Nommesen,or his representatives to ensure that the information and recommendations contained herein are brought to the attention of the structural engineer and architect for the project and incorporated into the project's plans and specifications. It is further their responsibility to take the necessary measures to insure that the contractor and his subcontractors carry j out such recommendations during construction. a FIELD EXPLORATIONS A subsurface exploration was performed at the location indicated on the site plan included herewith as Plate Number 1 on November 16, 1999. This exploration consisted of a small diameter,hollow stem auger advanced with a truck-mounted drill rig. Additionally,the lower portions of the existing 1 moderate to steep slope were examined and logged to determine the stratigraphy within the Delmar Formation. The fieldwork was conducted by or under the observation of our engineering geology ' personnel. The boring logs are presented on the following Plate Numbers 2 through 6.The soils are described in accordance with the Unified Soils Classification. In addition,a verbal textural description,the wet color, s the apparent moisture and the density or consistency are provided.The density of granular soils is given as either very loose,loose,medium dense,dense or very dense. The density of cohesive soils is given as either very soft,soft,medium stiff,stiff,very stiff,or hard. Relatively undisturbed,"ring"samples of typical and representative soils were obtained and returned to the laboratory for testing. The undisturbed samples were obtained by driving a split-tube sampler ahead of the auger,using a 140-pound y hammer free falling a distance of 30 inches. The number of blows to drive the sampler twelve inches is presented on the boring logs as"Penetration Resistance." Bulk samples of disturbed soil from the auger spoil were also collected in bags from the boring location. CWE 199.099.2 December 28 1999 Page No. 18 (revised 3-7-00) g LABORATORY TESTING Laboratory tests were performed in accordance with the generally accepted American Society for Testing and Materials (ASTM) test methods or suggested procedures. A brief description of the tests f performed are presented below: a) CLASSIFICATION: Field classifications were verified in the laboratory by visual 1 examination. The final soil classifications are in accordance with the Unified Soil t ' Classification System. a b) MOISTURE-DENSITY. In-place moisture contents and dry densities were determined for representative soil samples. This information was an aid to classification and permitted recognition of variations in material consistency with depth. The dry unit weight is a determined in pounds per cubic foot,and the in-place moisture content is determined as a percentage of the soil's dry weight. The results of these tests are summarized on the boring logs. c) GRAIN SIZE DISTRIBUTION:The grain size distribution was determined from a representative sample of the Ell in accordance with ASTM D422. The results of this test are presented below. ' Sample Number Boring B-1 @ 15' Sieve Size Percent Passing #4 100 #8 100 #16 99 #30 84 #50 71 t #100 65 #200 65 0.05 mm 56 0.005 mm 31 0.001 mm 4 CWE 199.099.2 December 28, 1999 Page No. 19 (revised 3-7-00) Sample Number Boring B-1 @ 29'/2' Sieve Size Percent Passing 3 #4 100 ' #8 100 #16 99 t #30 92 } #50 74 #100 56 #200 39 Sample Number Boring B-1 @ 441/2' Sieve Size Percent Passing F #4 100 #8 1.00 #16 98 #30 94 #50 85 t #100 71 i #200 54 0.05 mm 46 0.005 mm 20 0.001 mm 4 CWE 199.099.2 December 28, 1999 Page No. 20 (revised 3-7-00) d) DIRECT SHEAR TEST:Direct shear tests were performed to determine the failure P envelope of representative materials based on yield shear strength. The shear box was r designed to accommodate a sample having a diameter of 2.375 inches or 2.50 inches and a a height of 1.0 inch. Samples were tested at different vertical loads and a saturated moisture i content. The shear stress was applied at a constant rate of strain of approximately 0.05 inch per minute. The results of this test are presented below: i iSample Number Boring B-1 @ 8' 1 Description In-place Angle of Friction 341/2 Degrees Apparent Cohesion 100 psf Sample Number Boring B-1 @ 15' Description In-place Angle of Friction 32 Degrees Apparent Cohesion 450 psf s Sample Number Boring B-1 @ 25' Description In-place Angle of Friction 38 Degrees Apparent Cohesion 250 psf 1 Sample Number Boring B-1 @ 391/2' Description In-place Angle of Friction 321/2 Degrees Apparent Cohesion 550 psf Sample Number Boring B-1 @ 50' Description In-place Angle of Friction 29 Degrees Apparent Cohesion 425 psf �o FWr LM N5723'25"E 51.02' p START 4 j YnYW I�i�L / 11A i A �- 6#2 ® 1I you BR#2 A A A ' i A CGA4RA6E �• µ ; ; !/WDlU MT A A O a ; ; a j Dmy B1 -}- PORCH r \ CFFICE O _-- ti1 N49.24A 2 .92' r,r sr v tiz v 2T MIDDLE LEVEL �IIII''A''IIII� W+r- NORTH 'I���IIIh��I' wv LEGEND C IS i N E E R EL R APPROXIMATE BORING LOCATION NOMMESEN RESIDENCE By: CHC DATE 11-17-9 LOG OF TEST BORING NUMBER B-1 Date Excavated: 11/16/99 Equipment CME 55 Logged by DRR _ Surface Elevation: N/A Project Manager. CHC Depth to Water. N/A Hammer Weight 10 pounds Drop of Hammer. 30 inches SAMPLES .� O _ U CaJ p O l� O C� W SUMMARY OF SUBSURFACE CONDITIONS Q � y z O c� x 0 }$ ;''' I• Light olive brown damp,loose,fine to medium .+ grained SILTY SAND(Sn. • � D .T.MA 2 `s T(_r Light olive brown,moist, u^ medium dense, fine to medium grained SILTY SAND(Sn. l y : 3 US 21 5.0 93.8 4 r 5 ..................................................................................................................................................... ...... .. ....... ... .. .. .. .. .. .. .. Olive,moist,hard,SANDY CLAY and claystone (CL),abundant Us 36 13.8 100.4 F 6 .iron stains. *� ............................................................................................................................... ....... ........... .... Olive to white,moist,very dense,fine to medium grained , :: CLAYEY SAND and sandstone(SC) g 7 .:�.{s:%:s:> ,slight iron stains. 8 '•:i:i%#: US 50/6" 7.3 101.0 DS ��rrr�jr ......................................................................................................................................................... Light olive to white,moist,very dense,fine to medium grained SILTY SAND and sandstone (S M),:`••<,<.:•:,• ( M),occasional iron stains. Borine continues on Plate Number 3. NOMMESEN RESIDENCE 2600 Montgomery Avenue,Encinitas CHRISTIAN WHEELER BY: SD DATE: Dec-99 ENGINEERING OB NO. : 199.099 PLATE NO.: 2 LOG OF TEST BORING NUMBER B-1(Continued) Date Excavated: 11/16/99 Logged by: DRR Equipment CME 55 Project Manager. CHC Surface Elevation: N/A Depth to Water. N/A ' Hammer Weight 140 pounds Drop of Hammer. 30 inches SAMPLES a0 W z U t . U p j SUMMARY OF SUBSURFACE CONDITIONS W a E. Oi Q � z o i � Q x. Light olive to white moist very dense fine to medium grained� ry � gr SILTY SAND and sandstone(SM),occasional iron staining. Us 50/a" 11.s 103.7 12 13 $ ~ ..................................................................................................................................................... ... ... ...... ....... ......... ... Light olive,moist,hard,SANDY CLAY and claystone(CL), 14 slight iron stains. . US 76 18.1 1124 DS 15 Grades to pinkish-brown. HA 16 a ' j 17 f 18 < , ..................................................................................................................................................... ... .. ...... ....... ......... ..... • $.�}�{�;{:#>: Yellowish-brown,m moist,very dense,fine to medium grained — 19 �•• :, SILTY SAND(SK,s li g h t iron stains. US 1 50/4" 1123 1 104.1 20 Boring continues on Plate Number 4. NOMMESEN RESIDENCE 2600 Montgomery Avenue,Encinitas CHRISTIAN WHEELER BY: SD DATE: Dec-99 ENGINEERING OBNO. : 199.099 1PLATE NO.: 3 peght7 OG OF TEST BORING NUMBER B-1(Continued) 11/16/99 CME 55 I'Od by DRR Project Manager. CHC NSA Depth to Water. N/A 110 pounds Drop of Hammer: 30 inches SAMPLES _ O 0 04 SUMMARY OF SUBSURFACE CONDITIONS a °a w F cn c7 za a O N � z > i' Yellowish-brown,moist,very dense,fine to medium grained j 21 SILTY SAND(SM),slight iron stains. i 22 23 ......................................................... . ................ ............. ................ . .............. .............. ....... .................. ........... ............. r*, +•i• Light yellowish-brown to olive brown,moist,very dense,fine 24 :•. to medium grained CLAYEY SAND (SC). 3 �•� Y 255 "" US 50/4" 126 111.6 DS s ii:? �• 26 ' :�2 '4WD• 27 ; n ia,y~}v 28 29 } US 50/6 124 1120 SA :ys 30 Boring continues on Plate Number 5. NOMMESEN RESIDENCE 2600 Montgomery Avenue,Encinitas CHRISTIAN WHEELER BY: SD DATE: Dec-99 E N G I N E E R IN G JOB NO. : 199.099 PLATE NO.: 4 LOG OF TEST BORING NUMBER B-1(Continued) Date Excavated: 11/16/99 Logged by. DRR Equipment. CNIE 55 Project Manager. CHC Surface Elevation: NSA Depth to Water. N/A Hammer Weight. 140 pounds Drop of Hammer. 30 inches SAMPLES C7 _ 4i ►1 W z •aJ >" x v 0 '° O ►" U w Ra cn 9 SUMMARY OF SUBSURFACE CONDITIONS W ° A is y v�"i z O P O A Light yellowish-brown to olive brown,moist,very dense,fine 31 to medium grained CLAYEY SAND(SC). 32 ................................................................................................................................._.................. ... ... ...... ....... ........................ 't: White,moist,very dense,fine to medium grained SILTY SAND t ' 33 (SM),abundant iron stains. 34i us 50/4" 11.6 104.6 3 35 ` zt� 36 37 » r 38 YY"s: ..................................................................................................................................................... ... ... ...... ....... ......... ..... Olive,moist,hard,SANDY CLAY and claystone(CL). 39 US 50/3" 14.6 116.6 DS Boring continues on Plate Number 6. NOMMESEN RESIDENCE 'W 2600 Montgomery Avenue,Encinitas CHR]STIAN WHEELER BY: SD DATE: Dec-99 E N G I N E E R I N G OB NO.: 199.099 PLATE NO.: 5 LOG OF TEST BORING NUMBER B-1(Continued) Date Excavated: 11/16/99 Logged by: DRR Equipment; CME 55 Project Manager. CHC Surface Elevation: NSA Depth to Water. N/A Hammer Weight: 140 pounds Drop of Hammer. 30 inches J SAMPLES O .. �4 0 o ,� X U v o 3 W SUMMARY OF SUBSURFACE CONDITIONS aa1 ° E, n Q c4 y v�F"i 2 O N P. x Q Olive,moist,hard,SANDY CLAY and claystone(CL). 41 42 43 1 44 US 50/5" 13.9 111.8 HA 45 I 46 47 Grades to olive to pinkish in color. 48 49 US 50/5" 19.5 97.8 DS 50 Bottom of boring at 50 feet. NOMMESEN RESIDENCE IN . 2600 Montgomery Avenue,Encinitas CHRISTIAN WHEELER. BY: SD DATE: Dec-99 ENGINEERING OB NO.: 199.099 PLATE NO.: 6 L t0 r a t f 1 Ill E � •- CL 4 ON w O N N s t+7 C> ` 1 ON %D a C M O N tC S M w L 2 o+. ,t cr a a`a000000 1 ,Nt -p 3 �v Q ME U m X o L - - 1 N o �e W c.",�000000 tL- Z a ti a th J o W °^��yy pppp pp� 11 » W 4yt7tN7*l")CVN C d t77 -'•t •t-� Z 006 LL U NQ = v-V- V co W .. M + 0 r Z L v --- ♦ � c~n cn -1-. -mss^ ♦ 4- � � L O i O d -N " O V a V),*gn co to I.- LL s t0 v s a UU UU JJ JJ •--i�r e-.--rO.�-r N N Ln Ln%0%D%O %O%C�r r • o u v o ♦ o CD s aN- Ch tp O O to X ^ Q 4- � v ._......... . 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'^ \ \ 4- O U) � a o U F' N N1 vLn%D U- M\0 O\ Cn Ln Ul IA Ln 1!)\0%D%0%0 1�- y N 0 M O O N .r-I X ^ Q 4-) 1 4- r v o 00 r- i T Q Ln j O O N t O +j w I O a Co O 01 ~ CV . 0 N O ~ � m Q C-Z O O Vf „ 10 4-- �^ � a ap n000coo N •.-� 3 o o� x U 0 p L o 0 o 0 0 0 Z � � n O ~ W J ^ e m ] D — � � N In gn 1 (C/) .-- C LLJ 11 p Z c a cn .--I LL- i (w ,� c W r V o ►� p �;�l4�314�lg�Q m 41 a � .. ^ a ornR£dRi4�3� o F � N e L � O (D .-.a _F r F- Lp N M'r U1%0 L) LL • O o � a J ��1NNUU I O O LN Ln In In Ln Ln Ln In Ln Ln in ft a a O 1 OM O N x � a4- i I I I I I 1 I ' 7 LL -�--�% SLOPE MINIMUM __ 6" MIN 1 6" MAX WATERPROOF BACK OF WALL e ° PER ARCHITECT'S SPECIFICATIONS 3/4 INCH CRUSHED ROCK or o .o' . MIRADRAIN 6000 or EQUIVALENT • e ° °•o GEOFABRIC BETWEEN ROCK AND SOIL • e o . o TOP OF GROUND . o . or CONCRETE SLAB 6" MIN MINIMUM 4 INCH DIAMETER a PERFORATED PIPE RETAINING WALL SUBDRAIN DETAIL No Scale Ee: M:A:R r Engineering 99.099 . 2 7 2000 1 14 CWE 199.099 December 28, 1999 Appendix A,Page Al F REFERENCES Anderson,J.G.;Rockwell,R.K.and Agnew,D.C.,1989,Past and Possible Future Earthquakes of Significance to the San Diego Region,Earthquake Spectra,Volume 5,No.2, 1989. 1 Barry And Associates Geotechnical Engineering, 1998,Preliminary Geotechnical Investigation,Proposed Single Family Residence,2600 Montgomery Avenue,Cardiff,California,Parcel 2,of Parcel Map 17367,W.O.P-1639, dated November 16, 1998. 1 3 Jennings,C.W., 1975,Fault Map of California,California Division of Mines and Geology,Map e No. 1,Scale 1:750,000. 1 Maps of Known Active Fault Near Source-Zones in California and Adjacent Portions of Nevada, 1998, i California Division of Mines and Geology. Mualchin,L. and Jones,A.L.,1992,Peak Acceleration from Maximum Credible Earthquakes in California(Rock and Stiff-Soil Sites) California Division of Mines and Geology Open-File Report 92-1. 0 Owen Geotechnical Consultants,1981,Nommesen Condominium Project,Project No. 124.1.1. 1 Tan,Siang S. and Giffen,Desmond G.,1995,Landslide Hazards In The Northern Part Of The San Diego Metropolitan Area,San Diego County,California,Encinitas 7.5'Quadrangle,California Division of Mines and Geology Open-File Report 95-04,scale 1:24,000. Tan,Siang S. and Kennedy,Michael P., 1996, Geologic Map Of The Encinitas and Rancho Santa Fe 7.5' Quadrangles,San Diego County,California,California Division of Mines and Geology Open-File Report 96-02, scale 1:24,000. Wesnousky,S.G., 1986, "Earthquakes,Quaternary Faults,and Seismic Hazards in California",in Journal of Geophysical Research,Volume 91,No.B12,pp 12,587 to 12,631,November 1986. CWE 199.099 December 28, 1999 Appendix A,Page A2 TOPOGRAPHIC MAPS i County of San Diego, 1985, Orthographic Map Sheet 306-1683,Scale. 1 inch=200 feet. U.S. Geological Survey, 1968 (Photo-revised 1975),7'/2 Minute Topographic Map, 1:24,000. p A Quadrangle,scale t 1 AERIAL PHOTOGRAPHS 1 i Aerial FotoBank/Thomas Bros.,Inc.,Aerial Foto-Map Book,San Diego County,1995-96,Sheet 1147,Scale: 1 inch =2000 feet(approximate). Aerial Graphics,Aerial Foto-Map Book,San Diego County,1982,Sheet E-10,Scale:1 inch =2000 feet (approximate). Aerial Graphics,Aerial Foto-Map Book,San Diego County,1984-85,Sheet 10-E,Scale: 1 inch=2000 feet (approximate). Lenska Aerial Images, 1994,The Thomas Guide,Commercial Edition,Page 1147,Scale: 1 inch =2000 feet (approximate). ? San Diego County, 1928,Flight 37B,Photographs 1 and 2;Scale: 1 inch= 1000 feet(approximate). San Diego County, 1953,Flight 8M,Photograph 78,Scale: 1 inch = 1700 feet(approximately). i San Diego County, 1960,Flight 3,Photographs 73 and 74;Scale: 1 inch= 1000 feet(approximate). San Diego County, 1970,Flight 4,Photograph 12;Scale: 1 inch = 1000 feet(approximate). San Diego County, 1974,Flight 33,Photographs 4,5,and 6;Scale: 1 inch = 1000 feet(approximate). San Diego County, 1978,Flight 16B,Photographs 43 and 44;Scale: 1 inch = 1000 feet(approximate). San Diego County, 1983,Photographs 545 and 546;Scale: 1 inch = 1000 feet(approximate). San Diego County, 1989,Photograph 1-209;Scale: 1 inch=2000 feet(approximate). CWE 199.099.1 December 28, 1999 Appendix B,Page BI A PROPOSED NOMMESEN RESIDENCE ' 2600 MONTGOMERY AVENUE ENCINITAS, CALIFORNIA l 3 RECOMMENDED GRADING SPECIFICATIONS- GENERAL PROVISIONS GENERALINTENT 1 i The intent of these specifications is to establish procedures for clearing,compacting natural ground, preparing areas to be filled,and placing and compacting fill soils to the lines and grades shown on the accepted plans. The recommendations contained in the preliminary geotechnical investigation report and/or the attached Special Provisions are a part of the Recommended Grading Specifications and shall supersede the provisions contained hereinafter in the case of conflict These specifications shall only be used in conjunction with the geotechnical report for which they are a part. No deviation from these specifications will be allowed,except where specified in the geotechnical report or in other written communication signed by the Geotechnical Engineer. OBSERVATION AND TESTING Christian Wheeler Engineering shall be retained as the Geotechnical Engineer to observe and test the 1 earthwork in accordance with these specifications. It will be necessary that the Geotechnical Engineer or his representative provide adequate observation so that he may provide his opinion as to whether or not the s work was accomplished as specified. It shall be the responsibility of the contractor to assist the Geotechnical Engineer and to keep him appraised of work schedules, changes and new information and data so that he may provide these opinions. In the event that any unusual conditions not covered by the special provisions or preliminary geotechnical report are encountered during the grading operations, the Geotechnical Engineer shall be contacted for further recommendations. If,in the opinion of the Geotechnical Engineer, substandard conditions are encountered, such as ' questionable or unsuitable soil,unacceptable moisture content,inadequate compaction,adverse weather,etc., construction should be stopped until the conditions are remedied or corrected or he shall recommend rejection of this work CWE 199.099.1 December 2 8' 1999 Appendix B,Page B2 Tests used to determine the degree of compaction should be performed in accordance with American Society for Testing and Materials test methods: the following Maximum Density&Optimum Moisture Content-ASTM D-1557-91 Density of Soil In-Place -ASTM D-1556-90 or ASTM D-2922 All densities shall be expressed in terms of Relative Compaction as determined by the foregoing ASTM testing procedures. ! PREPARATION OF AREAS TO RECEIVE FILL All vegetation, brush and debris derived from clearing operations shall be removed,and legally disposed of. All areas disturbed by site grading should be left in a neat and finished appearance, free from unsightly debris. After clearing or benching the natural ground, the areas to be filled shall be scarified to a depth of 12 inches, brought to the proper moisture content,compacted and tested for the specified minimum degree of e compaction. All loose soils in excess of 6 inches thick should be removed to firm natural ground which is J defined as natural soil which possesses an in-situ density of at least 90 percent of its maximum dry density. When the slope of the natural ground receiving fill exceeds 20 percent(5 horizontal units to 1 vertical unit), the original ground shall be stepped or benched. Benches shall be cut to a firm competent formational soil. The lower bench shall be at least 10 feet wide or 1-1/2 times the equipment width,whichever is greater,and shall be sloped back into the hillside at a gradient of not less than two (2)percent. All other benches should be at least 6 feet wide. The horizontal portion of each bench shall be compacted prior to receivin fill as g specified herein for compacted natural ground. Ground slopes flatter than 20 percent shall be benched when considered necessary by the Geotechnical Engineer. Any abandoned buried structures encountered during grading operations must be totally removed. All underground utilities to be abandoned beneath any proposed structure should be removed from within 10 feet of the structure and properly capped off. The resulting depressions from the above described procedure should be backQed with acceptable soil that is compacted to the requirements of the Geotechnical Engineer. This includes,but is not limited to, septic tanks,fuel tanks, sewer lines or leach lines, storm drains and water lines. Any buried structures or utilities not to be abandoned should be brought to the attention of the Geotechnical Engineer so that he may determine if any special recommendation will be necessary. CWT 199.099.1 December 28, 1999 Appendix B,Page B3 t FILL MATERIAL i Materials to be placed in the fill shall be approved by the Geotechnical Engineer and shall be free of organic matter and other deleterious substances. Granular soil shall contain sufficient fine material to fill the voids. The definition and disposition of oversized rocks and expansive or detrimental soils are covered in the i geotechnical report or Special Provisions. Expansive soils,soils of poor gradation,or soils with low strength characteristics may be thoroughly mixed with other soils to provide satisfactory fill material, but only with the explicit consent of the Geotechnical Engineer. Any import material shall be approved by the Geotechnical Engineer before being brought to the site. i J PLACING AND COMPACTION OF FILL Approved fill material shall be placed in areas prepared to receive fill in layers not to exceed 6 inches in compacted thickness. Each layer shall have a uniform moisture content in the range that will allow the ] compaction effort to be efficiently applied to achieve the specified degree of compaction. Each layer shall be uniformly compacted to the specified minimum degree of compaction with equipment of adequate size to economically compact the layer. Compaction equipment should either be specifically designed for soil compaction or of proven reliability. The minimum degree of compaction to be achieved is specified in either the Special Provisions or the recommendations contained in the preliminary geotechnical investigation report. When the structural fill material includes rocks,no rocks will be allowed to nest and all voids must be carefully filled with soil such that the minimum degree of compaction recommended in the Special Provisions is achieved. The maximum size and spacing of rock permitted in structural fills and in non- ; structural fills is discussed in the geotechnical report,when applicable. Field observation and compaction tests to estimate the degree of compaction of the fill will be taken by the Geotechnical Engineer or his representative. The location and frequency of the tests shall be at the y Geotechnical Engineer's discretion. When the compaction test indicates that a particular layer is at less than the required degree of compaction, the layer shall be reworked to the satisfaction of the Geotechnical Engineer and until the desired relative compaction has been obtained. Fill slopes shall be compacted by means of sheepsfoot rollers or other suitable equipment. Compaction by sheepsfoot roller shall be at vertical intervals of not greater than four feet. In addition, fill slopes at a ratio of two horizontal to one vertical or flatter,should be trackrolled. Steeper fill slopes shall be over-built and cut- CWE 199.099.1 December 28, 1999 Appendix B,Page B4 Y back to finish contours after the slope has been constructed. Slope compaction operations shall result in all fill material six or more inches inward from the finished face of the slope having a relative compaction of at least 90 percent of maximum dry density or the degree of compaction specified in the Special Provisions section of this specification. The compaction operation on the slopes shall be continued until the Geotechnical Engineer is of the opinion that the slopes will be surficially stable. a Density tests in the slopes will be made by the Geotechnical Engineer during construction of the slopes to determine if the required compaction is being achieved. Where failing tests occur or other field problems arise, the Contractor will be notified that day of such conditions by written communication from the 9 Geotechnical Engineer or his representative in the form of a daily field report. If the method of achieving the required slope compaction selected by the Contractor fails to produce the necessary results, the Contractor shall rework or rebuild such slopes until the required degree of compaction is obtained, at no cost to the Owner or Geotechnical Engineer. ` CUT SLOPES The Engineering Geologist shall inspect cut slopes excavated in rock ck or hthtfied formational material during the grading operations at intervals determined at his discretion. If any conditions not anticipated in the preliminary report such as perched water, seepage,lenticular or confined strata of a oten p wally adverse nature,unfavorably inclined bedding,joints or fault planes are encountered during grading, these conditions shall be analyzed by the Engineering Geologist and Geotechnical Engineer to determine if mitigating measures are necessary. s Unless otherwise specified in the geotechnical report,no cut slopes shall be excavated higher or steeper than that allowed by the ordinances of the controlling governmental agency. ENGINEERING OBSERVATION Field observation by the Geotechnical Engineer or his representative shall be made during the filling and i compaction operations so that he can express his opinion regarding the conformance of the grading with acceptable standards of practice. Neither the presence of the Geotechnical Engineer or his representative or the observation and testing shall release the Grading Contractor from his duty to compact all fill material to the specified degree of compaction. CAVE 199.099.1 December 28, 1999 � Appendix B,Page BS SEASON LIMITS 1 j Fill shall not be placed during unfavorable weather conditions. When work is interrupted by heavy rain filling operations shall not be resumed until the proper moisture content and density of the fill materials can be achieved. Damaged site conditions resulting from weather or acts of God shall be repaired before acceptance of work RECOMMENDED GRADING SPECIFICATIONS-SPECIAL PROVISIONS 1 i RELATIVE COMPACTION:The minimum degree of compaction to be obtained in compacted natural ground,compacted fill,and compacted backfill shall be at least 90 percent. For street and parking lot subgrade, the upper six inches should be compacted to at least 95 percent relative compaction.. l EXPANSIVE SOILS:Detrimentally expansive soil is defined as clayey soil which has an expansion 50 or greater when tested in accordance with the Uniform Building Code Standard 29-C. p on index of OVERSIZED MATERIAL:Oversized fill material is generally defined herein as rocks or lumps of soil over 6 inches in diameter. Oversized materials should not be placed in fill unless recommendations of placement of such material are provided by the Geotechnical Engineer. At least 40 percent of the fill soils shall pass through a No. 4 U.S. Standard Sieve. s TRANSITION LOTS:Where transitions between cut and fill occur within the proposed building pad, the cut portion should be undercut a minimum of 18 inches below the base of the proposed footings and recompacted as structural backfill. In certain cases that would be addressed in the geotechnical report, I special footing reinforcement or a combination of special footing reinforcement and undercutting may be 3 required. i y CHRISTIAN WHEELER ENGINEERING December 28, 1999 (revised 3-7-00) Mr.John Nommesen CWE 199.099.2 2540 Montgomery Avenue Encinitas, California 92007 SUBJECT: REPORT OF PRELIMINARY GEOTECHNICAL INVESTIGATION, PROPOSED NOMMESEN RESIDENCE,2600 MONTGOMERY AVENUE,ENCINITAS, CALIFORNIA Dear Mr. Nommesen: In accordance with your request and our Proposal dated October 27, 1999,we have completed a geotechnical investigation for the subject property. We are presenting herewith our findings and recommendations. In general,we found that the site is suitable for support of the proposed single-family residence,provided the recommendations provided in our report are followed. The most significant geotechnical condition that will affect the construction of the proposed home is the existing moderately to steeply sloping hillside upon which the proposed residence is to be constructed. Our quantitative analyses indicate that the stability of this slope will require that a deep foundation system which will not adversely affect the stability of the slope be used for structural support of the proposed structure. If you have any questions after reviewing this report,please do not hesitate to contact our office. This opportunity to be of professional service is sincerely appreciated. Respectfully submitted, CHRISTIAN WHEELER ENGINEERING David R. Russell, Staff Geologist t Charles H.Christian, R.G.E. #00215 Curtis R.Burdett, C.E.G. #1090 CHC:CRB:drr. cc: (4) Submitted 4925 Mercury Street + San Diego, CA 92111 + 858-496-9760 + FAX 858-496-� TABLE OF CONTENTS PAGE Introduction and Project Description..............................................................................................................1 ProjectScope........................................................................................................................................................2 Findings.................................................................................................................................................................3 SiteDescription.............................................................................................................................................3 General Geology and Subsurface Conditions..........................................................................................4 Geologic Setting and Soil Description..................................................................................................4 Fill.............................................................................................................................................................4 DelmarFormation.................................................................................................................................4 Groundwater.............................................................................................................................................5 TectonicSetting........................................................................................................................................5 GeologicHazards.........................................................................................................................................5 General.......................................................................................................................................................5 GroundShaking......................................................................................................................................5 SeismicDesign Parameters.....................................................................................................................6 Landslide Potential and Slope Stability.................................................................................................7 Liquefaction..............................................................................................................................................7 Flooding.....................................................................................................................................................7 Tsunamis...................................................................................................................................................7 Seiches........................................................................................................................................................7 Groundwater.............................................................................................................................................7 SlopeStability Analysis...............................................................................................:................................8 General.......................................................................................................................................................8 Methodof Analysis..................................................................................................................................8 Results of Stability Analysis..................................................... Conclusions...........................................................................................................................................................9 Recommendations.............................................................................................................................................10 Gradingand Earthwork.............................................................................................................................10 General.....................................................................................................................................................10 Observationof Grading........................................................................................................................10 SitePreparation......................................................................................................................................10 ExcavationCharacteristics....................................................................................................................10 Compactionand Method of Filling.....................................................................................................10 SurfaceDrainage....................................................................................................................................11 GradingPlan Review.........................................................................................:......:............................11 TemporaryCut Slopes...........................................................................................................................12 FoundationSystems...................................................................................................................................12 General.....................................................................................................................................................12 FoundationDesign.....................................................................................................................................12 General................................................................................................................................................12 Minimum Pier Dimensions.................... PierReinforcing.................................................................................................................................13 BearingCapacity......................................................................................................:.........................13 Lateral_Pier Capacity ..............................................................................................13 LateralCreep......................................................................................................................................13 Cleaning of Pier Excavations..........................................................................................................13 Foundation Excavation Observation..........................................:.......................................................13 On-Grade Slabs..........................................................................................................................................14 InteriorFloor Slabs................................................................................................................................14 Moisture Protection for Interior Slabs........................................................................:......................14 ExteriorConcrete Flatwork..................................................................................................................14 EarthRetaining Walls................................................................................................................................14 PassivePressure......................................................................................................................................14 Active Pressure for Unrestrained Retaining Walls............................................................................14 At-Rest Pressure for Restrained (Basement)Retaining Walls........................................................15 Backfill.....................................................................................................................................................15 Factorof Safety......................................................................................................................................15 Limitations..........................................................................................................................................................15 Review, Observation and Testing........................................ .....15 ............................................................... Uniformityof Conditions..........................................................................................................................16 Changein Scope.........................................................................................................................................16 TimeLimitations.................:.......................................................................................................................16 ProfessionalStandard.................................................................................................................................16 Client's Responsibility................................................................................................................................17 FieldExplorations..............................................................................................................................................17 LaboratoryTesting.............................................................................................................................................18 ATTACHMENTS TABLES Table I Maximum Bedrock Accelerations,Page 6 Table II Seismic Design Parameters,Page 6 FIGURES Figure 1 Site Vicinity Map,Follows Page 1 PLATES Plate 1 Site Plan Plates 2-6 Boring Logs Plate 7 Cross Section A A' Plates 8-13 Slope Stability Analysis Plate 14 Subdrain Detail APPENDICES Appendix A References,Topographic Maps,Photographs Appendix B Recommended Grading Specifications—General Provisions PRELIMINARY GEOTECHNICAL INVESTIGATION PROPOSED NOMMESEN RESIDENCE 2600 MONTGOMERY AVENUE ENCINITAS, CALIFORNIA INTRODUCTION AND PROJECT DESCRIPTION This report presents the results of a preliminary geotechnical investigation performed for the proposed single family residence to be constructed at 2600 Montgomery Avenue in the City of Encinitas,California. The following Figure Number 1 presents a vicinity map showing the location of the property. The subject lot is located south of the terminus of Montgomery Avenue and is accessed by a 20-foot- wide driveway easement extending south from the Montgomery Avenue cul-de-sac. We understand that a three-story single-family residence is proposed for the site. The first floor level will be about ten feet below the driveway grade and will consist of a workroom,bathroom,and sauna. The middle level is to be close to the driveway grade and will consist of a garage,an office,and a bedroom. The upper level will have a living room,kitchen,dining room, and a bedroom. A large outside deck is also proposed on the upper level. Retaining walls up to about ten feet high will be required for the project Based on the stability characteristics of the moderately to steeply sloping hillside on-site,the proposed residence will need to be supported by a cast-in-place concrete pier and grade beam foundation system. Grading will basically be limited to cutting into a portion of the hillside for the lower level. To aid in the preparation of this report we were provided with a limited preliminary geotechnical report for the site prepared by Barry and Associates, and an untitled site plan for the project. A copy of this site plan was used as the base for our Site Plan and is included herewith as Plate Number 1. This report has been prepared for the exclusive use of Mr.John Nommesen and his design consultants for specific application to the project described herein. Should the project be modified, the conclusions and recommendations presented in this report should be reviewed by Christian . Wheeler Engineering for conformance with our recommendations and to determine if any additional l � ••i �k -. '� s 8 e �d�r p -0•x r%ev. i�� , r ,, . ! 'G .5„ .L'. 't- Y'^_ i''y.l 1 F Gif,•� "16F tYi L`S.' 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I 1 r.,:ra Y I..fir. f b. � c_.,r,,. r ..5 5 F C � }' '+"fa r. k9 x• 1�Z 4= �•i� f'Lt� r#°S fk' 5 > �� 3 � ,, r�p ��,: i a � r}fir J .•� � �£r" z r r# s^� � -, r 1 ` `�'� r e* •,� - �e, .4 `zstYT t �'> � .t. « a tY}�. ry�F �J3„Y.,..•i° i '�i} .f. . t � )k �,. r - r e n �• � S=r] 'Xi`.f! 7 ,.t�� S !ht•'' t �1 ' sit Z 7Z e �` - f• t+ a+4 s T�jSy _ � '° M j t i e - t r } � .: '—j!FSo�i**rs* •t.�%��.!�-r 4 � `� � � �.�T�r'r,•. 3e. Z 7���, ��: iF4�i"aa-J e .f:�tC?�e I.. �t..°SF• '--� 'itr- �5� - w-tl-;,, �"R �;5•J y � n, ��.�ad's r f {} �,, t�+ CjS.'�•a �•r _ -�'' "af �r} G `R 1''�:{3P; •}yW. . !'fps., ,YZL,s�t W'a� �,�. _.i s£. .�., .i x..t �� ..k�f�F _�.+!4i_ � m rti at r'}}�i,•' '`a _ 11:: CWE 199.099.2 December 28, 1999 Page No. 2 (revised 3-7-00) subsurface investigation,laboratory testing and/or recommendations are necessary. Our professional services have been performed,our findings obtained, and our recommendations prepared in accordance with generally accepted engineering principles and practices. This warranty is in lieu of all other warranties,expressed or implied. PROJECT SCOPE The scope of our preliminary investigation included: surface reconnaissance, subsurface exploration, obtaining representative soil samples,laboratory testing, analysis of the field and laboratory-data and review of readily available,pertinent geologic and geotechnical literature. In consideration of our past experience in the vicinity of the subject site along with access considerations, an 8-inch diameter boring was advanced within the eastern portion of the proposed building footprint in order to explore the subsurface soil conditions,and to obtain representative soil samples for laboratory testing. More specifically,the intent of this investigation was to: a) Explore the subsurface conditions of the site to the depths influenced by the proposed construction. b) Evaluate,by laboratory tests,the engineering properties of the various strata that may influence the proposed construction,including bearing capacities, expansive characteristics and settlement potential. c) Describe the general geology at the site including possible geologic factors that could have an effect on the site development. d) Address potential construction difficulties that may be encountered due to soil conditions,groundwater, or geologic hazards,and provide reconunendadons concerning these problems. e) Develop soil engineering criteria for site preparation and grading. Address the stability of the existing cut slope for Manchester Avenue and determine the foundation setback from this slope. g) Provide design parameters for unrestrained and restrained retaining walls. CWE 199.099.2 December 28, 1999 Page No. 3 (revised 3-7-00) h) Recommend an appropriate foundation system for the type of structure anticipated and develop soil engineering criteria for the recommended foundation design. i) Present our professional opinions in a report,which will include in addition to our conclusions and recommendations,a plot plan,exploration logs and a summary of the laboratory test results. It was not within the scope of our services to perform laboratory tests to evaluate the chemical characteristics of the on-site soils in regard to their potentially corrosive impact to on-grade concrete and below grade improvements. If desired,we can obtain samples of representative soils and submit them to a chemical laboratory for analysis. Further,it should be understood that Christian-Wheeler Engineering does not practice corrosion engineering. If such an analysis is necessary,we recommend that the client retain an engineering firm that specializes in this field to consult with them on this matter. FINDINGS SITE DESCRIPTION The subject site consists of an irregular-shaped parcel of land of less than one-quarter acre in size,which is located south of the terminus of Montgomery Avenue,in Encinitas,California,and is accessed by a 20-foot-wide driveway easement extending south from the Montgomery Avenue cul-de-sac. The site is bounded to north and southeast by existing single-family residences,to the east by the existing access driveway,and the west by Manchester Avenue. The lot was once part of the adjacent lot to the north, and,as such,supports an observation and parking deck that extends out over the hillside. The deck is supported by continuous footings on the east and by two columns with pier footings on the west. Except for a relatively level area south and east of the deck,the property slopes moderately to steeply to the southwest. Below the deck,the ground slopes at a ratio of between about 4:1 and 2:1,horizontal to vertical. An existing cut slope along Manchester Avenue ranges in height form approximately 20 to 35 feet,increasing in height from west to east,along the southwest portion of the site. The lower approximately ten feet has a slope ratio of about 0.75:1 to 1:1 (H:V). Above this the slope is steeper, varying from about 0.5:1 (H:V) to near-vertical in localized areas. On-site elevations range from approximately 95 feet above sea level within the southeast portion of the site,to approximately 35 feet CWT_ 199.099.2 December 28, 1999 Page No. 4 (revised 3-7-00) above sea level along the base of the cut slope along Manchester Avenue. Please refer to the Site Vicinity Map included herewith as Figure No. 1 and the site plan included herewith as Plate No. 1. GENERAL GEOLOGY AND SUBSURFACE CONDITIONS GEOLOGIC SETTING AND SOIL DESCRIPTION:The subject site is located in the Coastal Plains Physiographic Province of San Diego County. Based upon the results of our limited exploration and analysis of readily available,pertinent geologic and geotechnical literature,the site appears to be underlain by a minor amount of man-made fill materials which overlie formational materials of the Tertiary-age Delmar Formation(Tan&Kennedy, 1996).These materials are described below. FILL: Approximately eighteen inches of fill material was encountered within our Exploratory Boring B-1. Based on our site reconnaissance,similar or shallower depths of man-placed fill soils can be expected across those portions of the site to receive the proposed single-family residence. The fill was noted to consist of light olive brown,silty sand(SM)which was generally damp and loose in consistency. No documentation as to the placement and compaction of these fill soils has been provided to us at this time. As such,the fill soils are not considered suitable to support settlement-sensitive structures. Based upon visual observation of the encountered soils,laboratory testing,and experience with . similar soils in the vicinity of the project site,the fill soils are anticipated to possess a"low" expansion potential(based upon UBC Test Method 27-2). DELMAR FORMATION:As noted within our exploratory boring,the site was observed to be underlain at a depth of V/z feet by Tertiary-age sedimentary deposits of the Delmar Formation. These formational materials were observed to consist of interbedded white,olive, yellowish-brown,and pinkish silty sand and sandstone(SM),clayey sand and sandstone(SC), and sandy clay and claystone(CL). The silty sands (SM) of the Delmar Formation encountered within approximately five feet of the existing ground surface,within the vicinity of our boring location,were noted to be generally moist and medium dense. Below this depth,the sandy portions of the formational materials were noted to be generally moist and very dense,while the clayey portions were noted to be generally moist and hard. Analysis of readily available, pertinent geologic literature indicates that bedding within the Delmar Formation is nearly horizontal within the vicinity of the subject site(Tan&Kennedy,1996). CWE 199.099.2 December 28, 1999 Page No. 5 (revised 3-7-00) GROUNDWATER:No groundwater was encountered in our boring and we do not anticipate any significant groundwater related problems,either during or after construction. However,it should be recognized that minor groundwater seepage problems might occur after development of a site even where none were present before development These are usually minor phenomena and are often the result of an alteration in drainage patterns and/or an increase in irrigation water. Based on the permeability characteristics of the soil and the anticipated usage and development,it is our opinion that any seepage problems which will be minor in extent. These potential"nuisance"problems can be mitigated by the use of proper landscaping techniques. TECTONIC SETTING:No major faults are known to traverse the subject site but it should be noted that much of Southern California,including the San Diego County area,is characterized by a series of Quaternary-age fault zones which typically consist of several individual,en echelon faults that generally strike in a northerly to north-westerly direction. Some of these fault zones (and the individual faults within the zones)are classified as active while others are classified as only potentially active,according to the criteria of the California Division of Mines and Geology. Active fault zones are those which have shown conclusive evidence of faulting during the Holocene Epoch(the most recent 11,000 years)while potentially active fault zones have demonstrated movement during the Pleistocene Epoch (11,000 to 1.6 million years before the present)but no movement during Holocene tune. A review of available geologic maps indicates that a portion of the Rose Canyon Fault Zone is located approximately two and one-half mile west of the site. Other active fault zones in the region that could possibly affect the site include the Coronado Bank and San Clemente Fault Zones to the southwest and the Elsinore,San Jacinto,and San Andreas Fault Zones to the northeast GEOLOGIC HAZARDS GENERAL: No geologic hazards of sufficient magnitude to preclude development of the site as we presently contemplate it are known to exist In our professional opinion and to the best of our knowledge,the site is suitable for the proposed development. GROUND SHAKING:A likely geologic hazard to affect the site is ground shaking as result of movement along one of the major active fault zones mentioned above. The maximum bedrock accelerations that would be attributed to a maximum magnitude earthquake occurring along the nearest fault segments of selected fault zones that could affect the site are summarized in the following Table I. CWE 199.099.2 December 28, 1999 Page No. 6 (revised 3-7-00) TABLE I Fault Zone Distance Maximum Magnitude Maximum Bedrock Earthquake Acceleration Rose Canyon 21/z miles 6.9 magnitude 0.52 g Coronado Bank 18 miles 7.4 magnitude 0.21 g Elsinore 29 miles 7.1 magnitude 0.12 g San Jacinto 52 miles 7.2 magnitude 0.06 g San Clemente 56 miles 7.3 magnitude 0.06 g Probable ground shaking levels at the site could range from slight to moderate,depending on such factors as the magnitude of the seismic event and the distance to the epicenter. It is likely that the site will experience the effects of at least one moderate to large earthquake during the life of the proposed improvements. SEISMIC DESIGN PARAMETERS:Based on a maximum magnitude (Mmax) earthquake of 6.9 along the nearest portion of the Rose Canyon Fault Zone,the Maximum Bedrock Acceleration at the site would be approximately 0.52 g. For structural design purposes,a damping ratio not greater than 5 percent of critical dampening,and Soil Profile Type Sc are recommended(UBC Table 16-J). Based upon the location of approximately 4 kilometers from the Rose Canyon Fault(Type B Fault),Near Source Factors N.equal to 1.1 and N,equal to 1.33 are also applicable.These values,along with other seismically related design parameters from the Uniform Building Code(UBC) 1997 edition,Volume II, Chapter 16,utilizing a Seismic Zone 4 are presented in tabular form below. TABLE II UBC—CHAPTER 16 SEISMIC RECOMMENDED TABLE No. PARAMETER VALUE 16-1 Seismic Zone Factor Z 0.40 16-j Soil Profile Type Sc 16 Seismic Coefficient C, 0.40 N, 16-R Seismic Coefficient C, 0.56 N, 16-S Near Source Factor N. 1.1 16-T Near Source Factor Nv 1.33 16-U Seismic Source Type B CWE 199.099.2 December 28, 1999 Page No. 7 (revised 3-7-00) LANDSLIDE POTENTIAL AND SLOPE STABILITY:The site is identified as being in an area which is considered most susceptible to slope stability hazards due to such factors as the character of the geologic units;the presence of fractures or other planes of weakness;and the presence of steep slopes. The Relative Landslide Susceptibility and Landslide Distribution Map of the Encinitas Quadrangle prepared by the California Division of Mines and Geology indicates that the site is situated within Relative Landslide Susceptibility Area 4-1. Area 4 is considered to be a"most susceptible"to slope failures;Subarea 4-1 includes slopes considered to be outside the limits of known landslides but contains observably unstable materials such as the Delmar Formation. Although most slopes within Subarea 4-1 do not currently contain landslide deposits,they can be expected to fail even in the absence of activities of man. A specific slope stability analysis was performed for the sloping site and that analysis is presented in the"Slope Stability Analysis"section of this report - - LIQUEFACTION: The soils encountered at the site are not considered susceptible to liquefaction due to such factors as soil density,grain-size distribution and the absence of shallow groundwater conditions. FLOODING: The site is located outside the boundaries of both the 100-pear and the 500-year floodplains according to the maps prepared by the Federal Emergency Management Agency. TSUNAMIS: Tsunamis are great sea waves produced by submarine earthquakes or volcanic eruptions. Due to the site's setback from the ocean and elevation,the site will not be affected by a tsunami. SEICHES: Seiches are periodic oscillations in large bodies of water such as lakes,harbors,bays or reservoirs. Due to the site's location and elevation,it will not be affected by seiches. GROUNDWATER No groundwater was encountered in our test trenches and we do not anticipate any significant groundwater related problems,either during or after construction. However,it should be recognized that minor groundwater seepage problems might occur after development of a site even where none were present before development. These are usually minor phenomena and are often the result of an alteration in drainage patterns and/or an increase in irrigation water. Based on the permeability characteristics of the soil and the anticipated usage and development,it is our opinion that any seepage problems which will be minor in extent. These potential"nuisance"problems can be mitigated by the use of proper landscaping techniques. _ C`'i/E 199.099.2 December 28, 1999 Page No. 8 (revised 3-7-00) SLOPE STABILITY ANALYSIS GENERAL:-To analyze the stability of the steepest portion of the existing slope along the western portion of the site,a cross-section of the slope was drawn perpendicular to the face of the slope at the point where the slope is steepest. This cross-section,which shows the site topography and approximate location of the proposed residence,is presented on the attached Plate No. 7. METHOD OF ANALYSIS:The analysis of the stability of the natural hillside slope was performed using the PCSTABL6 computer program developed at Purdue University. The program analyzes circular,block and randomly shaped failure surfaces using the Simplified Bishop,Jambu,and Spencer's Methods. Sted 6.5 PCSTABL6 Editor,developed by Harold W.Van Aller,P.E.,was used in conjunction with this program for data entry and graphics display.The selected cross-sections were analyzed for both circular and bock-type failures and each failure analysis was programmed to run 100 random failure surfaces. The most critical failure surfaces are accumulated and sorted by value of the factor-of-safety. After the specified number of failure surfaces are successfully generated and analyzed, the ten most critical surfaces are plotted so that the pattern may be studied. These plots with the computer printout of each run are presented as Plate Nos. 8 through 13. RESULTS OF STABILITY ANALYSIS:Our quantitative analyses of the slope stability of the existing slope along the western side of the site,have demonstrated a minimum factors-of-safety of 1.31 and 1.32 for block type and rotational slip failures,respectively(see Plate Nos. 8&9). Additionally,the minimum factors-of-safety increase only to 1.35 and 1.34 for block type and rotational slip failures, respectively,when the location of the slope failure initiation point is extended from the western edge of the proposed residence towards the east(see Plate Nos. 10&11). Scenarios in which rotational and block type slope failures yield the minimum factor-of-safety considered safe of 1.5 or greater,indicate that the point of slope failure initiation be located at least approximately 46 feet or 40 feet east of the western perimeter of the proposed residence,for block type and rotational slip failures,respectively(see Plate Nos. 12& 13). As such,the proposed residence will need to be supported on a deep foundation system consisting of cast-in-place concrete piers tied together with concrete reinforced grade beams. Such a deep foundation system will need to transmit the loads of the proposed residence to competent formational materials at depths of at least five feet below the slope failure surface that exhibits a minimum factor-of-safety of 1.5. Our analyses indicate that such depths range from 28 feet below existing site grades along the western C%VE 199.099.2 December 28, 1999 Page No. 9 (revised 3-7-00) perimeter of the proposed residence to 19 feet below existing site grades along the eastern perimeter of the proposed structure. These depths have been calculated using Plate No. 7,which plots the surfaces of the rotational slip and block type failures,which exhibit minimum factors-of-safety of 1.5. Please refer to the Foundation Design section of this report for further information regarding the design and depths of such a foundation system. The potential for slope instability should not be increased by the construction of the proposed residence, provided the recommendations provided in this report as well as additional sound geotechnical, construction,and maintenance standards are followed. It can also be noted that the proposed grading, which involves creating cuts and retaining walls within the slope,will somewhat increase the stability of the slope from the ungraded condition by removing part of the driving weight,provided sound engineering and construction practices are followed Furthermore,the construction of the deep foundation system will help stabilize the hillside by providing additional resistance to lateral movement. Care should be taken to ensure the proper drainage of all surface runoff away from the entire slope face. Saturation of the slope caused by excessive or improperly channeled runoff could detrimentally affect the surficial stability of the slope. Irrigation on and adjacent to the slope should be carefully monitored to insure that only the minimum amount necessary to sustain plant life is used. Over- irrigating could not only be erosive but may significantly increase the chance for slope stability problems and should be avoided. CONCLUSIONS In general,we found the subject property suitable for the proposed construction,provided the recommendations provided herein are followed. The most significant geotechnical condition that will affect the construction of the proposed residence as proposed,is the stability of the existing moderately to steeply sloping hillside,which extends from the footprint of the proposed residence westward down to Manchester Avenue. As such,the proposed residence will need to be supported on a deep foundation system consisting of cast-in-place concrete piers tied together with concrete reinforced grade beams. CWE 199.099.2 December 28, 1999 Page No. 10 (revised 3-7-00) RECOMMENDATIONS GRADING AND EARTHWORK GENERAL: No project grading plans have been provided to us at this time.However,it is our understanding that site grading is to be limited to cuts of about ten feet or less into the hillside,to create the building pad for the lower level of the proposed residence. OBSERVATION OF GRADING: Observation by the Geotechnical Consultant is essential during the grading operation to confirm conditions anticipated by our investigation,to allow adjustments in design criteria to reflect actual field conditions exposed,and to determine that the grading proceeds in general accordance with the recommendations contained herein. _ SITE PREPARATION:Site grading should begin with the removal of all existing improvements and vegetation and other deleterious materials from the portions of site that will be graded and/or will receive new improvements. This should include all grasses,iceplant,and significant root material. The resulting materials should be disposed of off-site. Any resulting depressions should be cleaned out of loose or disturbed soils and be backfilled with properly compacted soil EXCAVATION CHARACTERISTICS:Based upon the manner of auger penetration,our experience with similar materials in the vicinity of the site,and review of the referenced geotechnical reports,.the subsurface materials at the site appear generally rippable with conventional earthmoving equipment to a depths of at least ten feet below existing site grades. Furthermore,no distinct concretions were observed within the formational materials during our subsurface exploration. However,it should be noted that very dense concretions are sometimes encountered within the Delmar Formation. The contractor is solely responsible for designing and constructing stable,temporary excavations and may need to shore,slope,or bench the sides of trench excavations as required to maintain the stability of the excavation sides where friable sands or loose soils are exposed. The contractor's"responsible person",as defined in the OSHA Construction Standards for Excavations,29 CFR,Part 1926,should evaluate the soil exposed in the excavations as part of the contractor's safety process. In no case should slope height,slope inclination,or excavation depth,including utility,trench excavation depth,exceed those specified in local,state,and federal safety regulations. COMPACTION AND METHOD OF FILLING:Any structural fill placed at the site should be compacted to a relative compaction of at least 90 percent of maximum dry density as determined by CWE 199.099.2 December 28, 1999 Page No. 11 (revised 3-7-00) ASTM Laboratory Test D1557-91. Fills should be placed at or slightly above optimum moisture content,in lifts six to eight inches thick,with each lift compacted by mechanical means. Fills should consist of approved earth material,free of trash or debris,roots,vegetation,or other materials determined to be unsuitable by our soil technicians or project geologist. Fill material should be free of rocks or lumps of soil in excess of twelve inches in maximum dimension.However,in the.upper two feet of pad grade,no rocks or lumps of soil in excess of six inches should be allowed Based upon the results of our sub-surface exploration and laboratory testing,all of the on-site soils appear suitable for use as structural fill material. Fills should be benched into all temporary slopes and into competent formational materials when the natural slope is steeper than an inclination of 5:1 (horizontal to vertical). Keys should be constructed at the toe of all fill slopes. The keys should extend at least 12 inches into competent formational material and should be sloped back at least two percent into the slope area. Slope keys should have a minimum width of 10 feet. Utility trench backfill within five feet of the proposed structures and beneath driveways,concrete flatwork,and pavements should be compacted to a minimum of 90 percent of its maximum dry density. All grading and fill placement should be performed in accordance with the City of Encinitas Grading Ordinance,the Uniform Building Code,and the attached Recommended Grading Specifications and Special Provisions attached hereto as Appendix B. SURFACE DRAINAGE:Surface runoff into downslope natural areas and graded areas should be minimized. Where possible,drainage should be directed to suitable disposal areas via non-erodible devices such as paved swales,gunited brow ditches,and storm drains. Drainage around the proposed residence should be designed to collect and direct surface water away from proposed structures and the top of slopes and toward approved drainage areas. GRADING PLAN REVIEW:Once available,the project grading plans should be submitted to this office for review in order to analyze all proposed slopes,cuts,and fills. The final grading plans should be submitted to this office for review in order to ascertain that the recommendations of this report have been implemented,and that no additional recommendations are needed due to changes in the anticipated development plans. CWE 199.099.2 December 28, 199 9 Page No. 12 (revised 3-7-00) TEMPORARY CUT SLOPES:Unshored temporary cut slopes of up to eight feet in height can be excavated at inclinations of 0.5 to 1.0(horizontal to vertical)or flatter,within competent formational materials. Temporary excavations of between eight and fifteen feet in height can be constructed at inclinations of 0.75 to 1.0 (horizontal to vertical) or flatter,within competent formational materials. All temporary cut slopes should be observed by the engineering geologist during grading to ascertain that no unforeseen adverse conditions exist. No surcharge loads such as stockpiles,vehicles,etc.should be allowed within a distance from the top of temporary slopes equal to half the slope height FOUNDATION SYSTEMS GENERAL:Based on the calculated factors-of-safety for the existing slope, the proposed residence will need to be supported on a deep foundation system consisting of cast-in-place concrete piers tied together with concrete reinforced grade beams. Such a deep foundation system will need to transmit the loads of the proposed residence to competent formational materials at depths of at least five feet below the slope failure surface that exhibits a minimum factor-of-safety of 1.5. FOUNDATION DESIGN GENERAL: Augered,cast-in-place concrete piers which are tied together with concrete reinforced grade beams,are considered suitable for support of the structure loads of the proposed residence. Pier support will be afforded by end beating within the hard/very dense formational materials. MINIMUM PIER DIMENSIONS:All drilled,cast-in-place concrete piers should extend at least five feet below the slope failure surface that exhibits a minimum factor-of-safety of 1.5. Our analyses indicate that such depths range from 28 feet below existing site grades along the western perimeter of the proposed residence to 19 feet below existing site grades along the eastern perimeter of the proposed structure. These depths have been calculated using Plate No. 7,which plots the surfaces of the block type failures which exhibit minimum factors-of-safety of 1.5. Once the exact location of the piers has been determined by the project structural engineer, we should be contacted to determine the minimum depth requirements for each individual pier. If,however,we are not contacted to determine the depth of each individual pier,the minimum depth shall be 28 feet below the existing ground surface for all of the proposed piers. Piers CWE 199.099.2 December 28, 1999 Page No. 13 (revised 3-7-00) should have a minimum diameter of 24 inches. All pier dimensions should be determined by the project structural engineer. PIER REINFORCING:Piers should also be reinforced in accordance with the recommendations of the project structural engineer. The reinforcing cage should extend the full height of the pier. BEARING CAPACITY: Incorporating the minimum dimensions presented above and depths of at least five feet below the slope failure surface that exhibits a minimum factor-of- safety of 1.5,the cast-in-place concrete piers may be designed for an allowable downward axial bearing capacity of 15 kips per square foot. This value may be increased by 500 psf for each additional foot of pier embedment below the slope failure surface that exhibits a minimum factor-of-safety of 1.5,up to a maximum allowable bearing capacity of 25 kips per square foot LATERAL PIER CAPACITY:The passive pressure for the formational materials may be considered to be 450 pounds per square foot per foot of depth,up to a maximum value of 2,500 ps£ These values may be assumed to act on an area equal to twice the pier diameter. LATERAL CREEP:Drilled piers should be designed for a lateral downslope load of 50 pounds per square foot per foot of depth,for a depth of 23 feet This lateral load application is recommended to increase the factor-of-safety of the existing hillside under the house to a minimum of 1.5 against slope failure. CLEANING OF PIER EXCAVATIONS: If 24-inch diameter piers are used,the cleaning of the bottom of the pier excavation may be performed by careful operations of the driller and back-spinning the drill auger under pressure or utilizing a clean-out plate. For larger diameter piers,hand cleaning may he required. This Nvill be determined by the observation of a geologist or engineer from our staff during the excavation of the piers. FOUNDATION EXCAVATION OBSERVATION:All pier foundation excavations should be observed by the Geotechnical Consultant prior to placing concrete to determine if the foundation recommendations presented herein are complied with. All loose or unsuitable material should be removed from the foundation excavations prior to the placement of concrete. CkVE 199.099.2 December 28, 1999 Page No. 14 (revised 3-7-00) ON-GRADE SLABS INTERIOR FLOOR SLABS:For conventional floor slabs,the minimum slab thickness should be five inches. Interior floor slabs should be reinforced with at least No. 3 bars placed at 12 inches on center each way. The slab reinforcing bars should be turned down to extend at least six inches into the perimeter footings. Slab reinforcing should be positioned on chairs at mid-height in the floor slab. MOISTURE PROTECTION FOR INTERIOR SLABS: Interior concrete on-grade floor slabs that will support moisture-sensitive floor covering should be underlain by a moisture barrier. We recommend that the minimum configuration of the subslab moisture barrier consist of a four-inch-thick blanket of coarse clean sand. The moisture barrier material should have less than ten percent and five percent passing the No. 100 and No.200 sieves,respectively. A visqueen vapor barrier should be placed in the center of the sand blanket. EXTERIOR CONCRETE FLATWORK-Exterior slabs should have a minimum thickness of four inches. Reinforcement and control joints should be constructed in exterior concrete flatwork to reduce the potential for cracking and movement joints should be placed in exterior concrete flatwork to help control the location of shrinkage cracks. Spacing of control joints should be in accordance with the American Concrete Institute specifications. When patio,walks and porch slabs abut perimeter foundations they should be doweled into the footings. EARTH RETAINING WALLS PASSIVE PRESSURE:The passive pressure for the prevailing soil conditions may be considered to be 400 pounds per square foot per foot of depth. These pressures maybe increased one-third for seismic loading. The lateral pier capacity provided in the Foundation Design section of this report may be utilized for the resistance to lateral movement. ACTIVE PRESSURE FOR UNRESTRAINED RETAINING WALLS: The active soil pressure for the design of unrestrained earth retaining structures with level backfill may be assumed to be equivalent to the pressure of a fluid weighing 35 pounds per cubic foot An additional 13 pounds per cubic foot should be added to said value for 2:1 (horizontal to vertical)sloping backfill. These pressures do not consider any other surcharge. If any are anticipated,this office should be contacted for the necessary increase in soil pressure. These values assume a drained backfill condition. Waterproofing CWE 199.099.2 December 28, 1999 Page No. 15 (revised 3-7-00) details should be provided by the project architect. A suggested wall subdrain detail is provided on the attached Plate Number 14. We recommend that the Geotechnical Consultant observe all retaining wall subdrains to verify proper construction. AT-REST PRESSURE FOR RESTRAINED(BASEMENT)RETAINING WALLS: In the design of wall restrained from movement at the top (non-yielding)such as basement walls,the at-rest soil pressure may be assumed to be equivalent to the pressure of a fluid weighing 50 pounds per cubic foot, provided a level backfill surface. An additional 15 pounds per cubic foot should be added to said value for 2:1 (horizontal to vertical)sloping backfill. These values assume a drained backfill condition. Waterproofing details should be provided by the project architect A suggested wall subdrain detail is provided on the attached Plate Number 14. We recommend that the Geotechnical Consultant observe all retaining wall subdrains to verify proper construction. BACKFILL: All backfill soils should be compacted to at least 90 percent relative compaction. Expansive or clayey soils should not be used,for backfill material. The wall should not be backfilled until the masonry has reached an adequate strength. FACTOR OF SAFETY:The above values,with the exception of the allowable soil friction coefficient, do not include a factor-of-safety. Appropriate factors-of-safety should be incorporated into the design to prevent the walls from overturning and sliding. LIMITATIONS REVIEW,OBSERVATION AND TESTING The recommendations presented in this report are contingent upon our review of final plans and specifications. Such plans and specifications should be made available to the geotechnical engineer and engineering geologist so that they may review and verify their compliance with this report and with the Uniform Building Code. It is recommended that Christian Wheeler Engineering be retained to provide continuous soil engineering services during the earthwork and foundation construction operations. This is to verify compliance with the design concepts,specifications or recommendations and to allow design changes in the event that subsurface conditions differ from those anticipated prior to start of construction. CWE 199.099.2 December 28, 1999 Page No. 16 (revised 3-7-00) UNIFORMITY OF CONDITIONS The recommendations and opinions expressed in this report reflect our best estimate of the project requirements based on an evaluation of the subsurface soil conditions encountered at the subsurface exploration locations and on the assumption that the soil conditions do not deviate appreciably from those encountered. It should be recognized that the performance of the foundations and/or cut and fill slopes may be influenced by undisclosed or unforeseen variations in the soil conditions that may occur in the intermediate and unexplored areas. Any unusual conditions not covered in this report that may be encountered during site development should be brought to the attention of the geotechnical engineer so that he may make modifications if necessary. CHANGE IN SCOPE This office should be advised of any changes in the project scope or proposed site grading so that we may determine if the recommendations contained herein are appropriate. This should be verified in writing or modified by a written addendum. TIME LIMITATIONS The findings of this report are valid as of this date. Changes in the condition of a property can,however, occur with the passage of time,whether they be due to natural processes or the work of man on this or adjacent properties. In addition,changes in the Standards-of-Practice and/or Government Codes may occur. Due to such changes,the findings of this report may be invalidated wholly or in part by changes beyond our control. Therefore,this report should not be relied upon after a period of.two years without a review by us verifying the suitability of the conclusions and recommendations. PROFESSIONAL STANDARD In the performance of our professional services,we comply with that level of care and skill ordinarily exercised by members of our profession currently practicing under similar conditions and in the same locality. The client recognizes that subsurface conditions may vary from those encountered at the locations where our borings,surveys,and explorations are made,and that our data,interpretations,and recommendations be based solely on the information obtained by us. We will be responsible for those data,interpretations,and recommendations,but shall not be responsible for the interpretations by others CWE 199.099.2 December 28, 1999 Page No. 17 (revised 3-7-00) of the information developed. Our services consist of professional consultation and observation only, and no warranty of any kind whatsoever,express or implied,is made or intended in connection with the work performed or to be performed by us,or by our proposal for consulting or other services,or by our furnishing of oral or written reports or findings. CLIENT'S RESPONSIBILITY It is the responsibility of Mr.John Nommesen,or his representatives to ensure that the information and recommendations contained herein are brought to the attention of the structural engineer and architect for the project and incorporated into the project's plans and specifications. It is further their responsibility to take the necessary measures to insure that the contractor and his subcontractors carry out such recommendations during construction. FIELD EXPLORATIONS A subsurface exploration was performed at the location indicated on the site plan included herewith as Plate Number 1 on November 16,1999. This exploration consisted of a small diameter,hollow stem auger advanced with a truck-mounted drill rig. Additionally,the lower portions of the existing moderate to steep slope were examined and logged to determine the stratigraphy within the Delmar Formation. The fieldwork was conducted by or under the observation of our engineering geology personnel. The boring logs are presented on the following Plate Numbers 2 through 6.The soils are described in accordance with the Unified Soils Classification. In addition,a verbal textural description,the wet color, the apparent moisture and the density or consistency are provided.The density of granular soils is given as either very loose,loose,medium dense, dense or very dense. The density of cohesive soils is given as either very soft,soft,medium stiff,stiff,vety stiff,or hard. Relatively undisturbed,"ring"samples of typical and representative soils were obtained and returned to the laboratory for testing. The undisturbed samples were obtained by driving a split-tube sampler ahead of the auger,using a 140-pound hammer free falling a distance of 30 inches. The number of blows to drive the sampler twelve inches is presented on the boring logs as"Penetration Resistance." Bulk samples of disturbed soil from the auger spoil were also collected in bags from the boring location. CWE 199.099.2 December 28, 1999 Page No. 18 (revised 3-7-00) LABORATORY TESTING Laboratory tests were performed in accordance with the generally accepted American Society for Testing and Materials (ASTM) test methods or suggested procedures. A brief description of the tests performed are presented below: a) CLASSIFICATION: Field classifications were verified in the laboratory by visual examination. The final soil classifications are in accordance with the Unified Soil Classification System. b) MOISTURE-DENSITY: In-place moisture contents and dry densities were determined for representative soil samples. This information was an aid to classification and permitted recognition of variations in material consistency with depth. The dry unit weight is determined in pounds per cubic foot,and the in-place moisture content is determined as a percentage of the soil's dry weight. The results of these tests are summarized on the boring logs. c) GRAIN SIZE DISTRIBUTION:The grain size distribution was determined from a representative sample of the fill in accordance with ASTM D422. The results of this test are presented below. Sample Number Boring B-1 @ 15' Sieve Size Percent Passing #4 100 #8 100 #16 99 #30 84 #50 71 #100 65 #200 65 0.05 mm 56 0.005 mm 31 0.001 mm 4 CkVF- 199.099.2 December 28, 1999 Page No. 19 (revised 3-7-00) Sample Number Boring B-1 @ 291/2' Sieve Size Percent Passing #4 100 #8 100 #16 99 #30 92 #50 74 #100 56 #200 39 _ Sample Number Boring B-1 @ 441/2' Sieve Size Percent Passing #4 100 #8 1.00 #16 98 #30 94 #50 85 #100 71 #200 54 0.05 mm 46 0.005 mm 20 0.001 mm 4 CWE 199.099.2 December 28, 1999 Page No. 20 (revised 3-7-00) d) DIRECT SHEAR TEST:Direct shear tests were performed to determine the failure envelope of representative materials based on yield shear strength. The shear box was designed to accommodate a sample having a diameter of 2.375 inches or 2.50 inches and a height of 1.0 inch. Samples were tested at different vertical loads and a saturated moisture content. The shear stress was applied at a constant rate of strain of approximately 0.05 inch per minute. The results of this test are presented below. Sample Number Boring B-1 @ 8' Description In-place - Angle of Friction 34'/2 Degrees Apparent Cohesion 100 psf Sample Number Boring B-1 @ 15' Description In-place Angle of Friction 32 Degrees Apparent Cohesion 450 psf Sample Number Boring B-1 @ 25' Description In-place Angle of Friction 38 Degrees Apparent Cohesion 250 psf Sample Number Boring B-1 @ 391/2' Description In-place Angle of Friction 32/2 Degrees Apparent Cohesion 550 psf Sample Number Boring B-1 @ 50' Description In-place Angle of Friction 29 Degrees Apparent Cohesion 425 psf moo,. k• N5723'25"E 51.02' u AX 1-' 1 1 I O BR#2 � tI 1 1 1 ,1 11 11 1 14 1 - I GARAGE ! j � r�r. MT 1 i Y I � 1 ENTRY + poRGH B1 A C tb � o N49'24'27"E 78.92 MIDDLE LEVEL vv+r- NORTH LEGEND CE RNts�TIA E E RWHE�R APPROXIMATE BORING LOCATION NOMMESEN RESIDENCE BY: CHC DATE 11-17-9`• JOB NO. 799.099 PLATE NO, 1 LOG OF TEST BORING NUMBER B-1 Date Excavated: 11/16/99 Logged by. DRR Equipment. CME 55 Project Manager. CHC Surface Elevation: N/A Depth to Water. N/A Hammer Weight 140 pounds Drop of Hammer. 30 inches SAMPLES W 2 H U E" o SUMMARY OF SUBSURFACE CONDITIONS W a � a f- W .a :D Q za w Q <' > FILL Qao:Light olive brown,damp,loose,fine to medium a:>n< grained SILTY SAND(SM). DELMAR FORMATION('I'd):Light olive brown moil medium dense,fine to medium grained SILTY SAND(SM). ?'sti Us 21 5.0 93.8 4 �r 5 .................................................................._............................................................I.................... ... ...... ...... ......... ..... Olive,moist,hard,SANDY CLAY and claystone (CL),abundant Us 36 13.8 100.1 6 -iron stains. . ............ ............... ................ Olive to white moist very dense,fine to medium grained 7 CLAYEY SAND and sandstone(SC),slight iron stains. US 50/6" 7.3 101.0 DS 9 . ..................................................................................................................................................... ... .... Light olive to white,moist,very dense,fine to medium grained . "'•.`'` SILTY SAND and sandstone(SM),occasional iron stains. 10 Boring continues on Plate Number 3. NOMMESEN RESIDENCE 2600 Montgomery Avenue,Encinitas CHRISTIAN WHEELER BY: SD DATE: Dec-99 E N G I N E E R A N G OB NO. : 199.099 PLATE NO.: 2 LOG OF TEST BORING NUMBER B-1(Continued) Date Excavated: 11/16/99 Logged by. DRR Equipment CME 55 Project Manager. CHC Surface Elevation: NIA Depth to Water. N/A Hamner Weight: .110 pounds Drop of Hammer: 30 inches SAMPLES v O L W a SUMMARY OF SUBSURFACE CONDITIONS a s w E� Ca w N � . 2 OH O co P. >1 c� Q Light olive to white moist,very dense,fine to medium grained 11 tip;: SILTY SAND and sandstone (SM),occasional iron staining. us 50/4" -11.8 103.7 12 `` 13 �� 3 .................................................................................................................... ... ... ...... ......... .. .. ....... .. .. .. .. ..... .. .. .. .. .. ..... .. Light olive,moist,hard,SANDY CLAY and claystone (CL), 14 slight iron stains. 15 us 76 18.1 1124 DS Grades to pinkish-brown. HA 16 17 18 ....................................................................................................................................................... ... .. <z`€}"> Yellowish-brown,moist,very dense,fine to medium grained — 19 SILTY SAND(SM) slight,sli t iron stains. :';4 >: :z#:>:. •`• US 50/4" 12i 104.1 20 :�::;>.;:�:. Boring continues on Plate Number 4. NOMMESEN RESIDENCE i 2600 Montgomery Avenue,Encinitas CHRISTIAN WHEELER- BY: SD DATE: Dec-99 E N G I N E E R I N G OB NO. : 199.099 IPLATE NO.: 3 LOG OF TEST BORING NUMBER B-1(Continued) Date Excavated: 11/16/99 Logged by: DRR Equipment: CME 55 Project Manager. CHC Surface Elevation: NSA Depth to Water. N/A Hammer Weight 140 pounds Drop of Hamner. 30 inches SAMPLES U' w O I• W o, SUMMARY OF SUBSURFACE CONDITIONS a 0 Q w y z o c7 z w o O a cn c. Z � Q Yellowish-brown,moist,very dense,fine to medium grained —21 >?t SILTY SAND(SM),slight iron stains. 22 >•..:.::: 3tij{iiv y'yjjC�> w! n , 23 � �;,Y: ......................................................................................................................................................... .. .. ....... Light yellowish-brown to olive brown,moist,very dense,fine 24 « : to medium grained CLAYEY SAND(SC). A . 125 -`='• US 50/4" 126 111.6 DS ����_< • l 27 29 US 50/6" 124 11?0 SA L 30 BorinjZ continues on PIate Number 5. NOMMESEN RESIDENCE 2600 Montgomery Avenue,Encinitas CHRISTIAN WHEELER BY: SD DATE: Dec-99 E N G I N E E R I N G OB NO. : 199.099 PLATE NO.: 4 LOG OF TEST BORING NUMBER B-1(Continued) Date Excavated: 11/16/99 Logged by. DRR Equipment. CME 55 Project Manager. CHC Surface Elevation: N/A Depth to Water. N/A Hammer Weight: 1=40 pounds Drop of Hammer: 30 inches SAMPLES C` v O w O h v U u r- o 0O� Q SUMMARY OF SUBSURFACE CONDITIONS W a L n F, W; OP4 PQ z3 a OE- tn � ° }, Q {># Light yellowish-brown to olive brown moist very dense fine 31 > .} to medium grained CLAYEY SAND(SC). 32 f;t ..................................................................................................................................................... ... .. ...... ....... ......... White,moist,very dense,fine to medium grained SILTY SAND 33 #'> (SM),abundant iron stains. 34 z>ti US 50/4" 11.6 104.6 36 38 ::,:<;: ..................................................................................................................................................... ... .. ...... ....... ......... ..... Olive,moist,bard,SANDY CLAY and claystone(CL). 39 L 40 1. 1 1 1 1 1 —� Us 50/3" 14.6 116.6 DS Boring continues on Plate Number 6. NOMMESEN RESIDENCE 2600 Montgomery Avenue,Encinitas '49 - CHRISTIAN WHEELER BY: SD DATE: Dec-99 ENGINEERING OB NO. : 199.099 IPLATE NO: 5 LOG OF TEST BORING NUMBER B-1(Continued) Date Excavated: 11/16/99 Logged by: DRR Equipment CME 55 Project Manager. CHC Surface Elevation: N/A Depth to Water. N/A Hammer Weight. 140 pounds Drop of Hammer. 30 inches SAMPLES U v O w o n o U � U w .. O" w SUMMARY OF SUBSURFACE CONDITIONS a H W z x ' Q Olive,moist,hard,SANDY CLAY and claps tone(CL). 41 42 43 44 Us 50/5" 13.9 111.8 HA 45 46 47 Grades to olive to pinkish in color. 48 49 US 50/5" 19.5 97.8 DS 50 Bottom of boring at 50 feet. NOMMESEN RESIDENCE 2600 Montgomery Avenue,Encinitas CHRJS11AN WHEELER BY: SD DATE: Dec-99 ENGINEERING OB NO.: 199.099 PLATE NO.: 6 0 t 00 1 � 1 1 1 1 1 1 1 1 � e 1 % a O N a 41 m 1 d 1 7 C) T 1 11 si C) I � MI X CNJ 41 -0 O p in 4- N fn 4-- c.. a _ o e a000000 1 x 0 W 3 X O U m W °`o Ion U J �000000 r- ~ Z a O m W d c 0% - °-� a In 'n U •C N� CNI M M A m W ti v N cc 0 r� LL U o n its 8�gq cu 4p CL It U nr M Z c Kii�l0�316�Q ��` °o V) n \ 0 O 10 ,,n-� O C 4-+ U N .. v co F- N►� N co v to�o LL- C> M 0 a a JUU J J �UNN�U M C>C> N M- u1 L-� �k a n v o w w N a% O O e- N •N X ^ ¢ .-r 4- } v 0 00 0 cc o Lr) .0 (n N -1-i CL C ON � w � N o � � ON O `Z N ^ m O a 1 o n +� v o N CL: N e•- N h n000000 -X -0 W avv Q 3 (, A o X m o 7 E -C W o a"000000 N F- U a a° cv M Z J p r m LLJ 11. Cl Cf% W W v N c° C) .--� d' z LL '. n U LLJ V) r-; co v M 5, v Z m� m ++ CD cv�0�3�43l0 Cc c.:) in 4- 0 3'^ o +' M 3 US o F�L ----- Un M L U o 0 o N c ca F- ' o.t in�o � J N FTZ O f") 0 a 1 UU JJ JJ �O N(hf�I�00�e--NNN cnC -4:-4: :ft a v o a w. a O p p M p Cl O� %D N .-I X ^ 4 -+.r `+-- • r v O 00 r a { { { { { lO Q { 1 { a 1 O O uo { 1 O { � ON b r v Oj .+ O c.z o o a N n o N 4J 4- N v •ri c^ - to cr 4 � o c 4000000 .X O 3 C.) A b X N m o c3 a F�- W `o.000 0 0 0 U CL. "' O Z W m c C:l O Ii °,, o.. �p in N cc L.Li C� 1N�MNN •rl i-+ J li<v N cn i--1 Z c Cl. W o dgtVui� = U C/) .-' cs M.. W �+ J En tts v ++ C-) \ \ +% O U) o„�R^IRiR►�OF3� �\ -� N E ~3ry O C 41 U N o t6 �Nm-t N%D LA- O co b d H JU J �D Lnc`•)cnNO%,NwsO%Oc� LNP` std^��InU1 Ul WnUn e-r-••-—•--e-•-•--•--— N fC> O O r N .r-q X ^ Q 4— t v- � v O 0 I 0 Ln E CL o n � t CL C) o C) t Cr CO NN O /1m ON. CC) a y +fie'o o v N CT 4-� o+� Do c n000000 X O W a�" < X 3 C) >' ° X ) W C-) a as Ch Q W c 0% � m 0 v1 pppp in C> Co C/) C'J tv Ih N C) LL d' Z c a+ 7 a U ca Lj z .. 'cvl0�ilOFi3l0 L) 4- 4-J' cn �. �RRRi4R^ � � L O _ -N CL U Z O M m � JJ vv UU JJ JJ LL- -W C/)1') -4: 111 .0 V •O O �- A C +t .••� �o N C>O O r N •r-1 X ^ • � u O 00 e o — —— O � 1 r " ° 1 r 1 O to r CL O L N I -• N O C 1 «S CrIk N o '7 O� O te.iv a o N O ch a Z r' to 4- m . p to �o •r-4 ON - 4- t-Y 7 A_ •rl � (Y y Cy m000000 X O W L�v Q S o t CL U m a W o„,"000000 O A U a ILO m Z J a O W r c O% 11 ° C N Q M �I\ N Q Ln <,- E co LLJ elf Z LL... LL' U a_ co �LL1 W co — m 4,,, .�_.-. U °r ♦ ♦ Q � O z �v------ \\ ♦♦♦ N •+ O uz ORRRlQ� --- N 0 ��v------ c a C U N 1— NM-q-Ln%D L1. N F�L O M v a ° JJ UU .o O N M%O O% .4-r � !U)LA Un 11 f In lA c0 1-4 ft .8 p cr v o a O O O O O O N %D M r In .r.4 X ^ 4 4- } u O 00 r �• O N E '� O �p O N � O a N O � C. O O C O .r N N O i-.m +' C] O d 7 Z M M 4- O � c°c N C7 �- i1 •.1 aa a000000 x W o`' 3 av X C.) >, s LaJ m !000000 O ~ U 8 go-if m Z F- d O e-- w.°.w V) L�v�� c�i�Rv fn csl W C) tL LL Q Z e CL. U W 4 rya-V8� �i V L -4 w J A ca v m 44 .4 RPM L �=> U '^ 4-- ,_,� O . 0RaR,i4�� O Cv.-- -.--- L O O C U �. fn �-N M V'U1%D (y O u a b JUU J J �O 4D "",\0%0%00000 (n U�Ul U)U�Wl U7 N U�Ul Ul r••a--e-a--�r r r�-••- fto a 0 -0 o � a c -.. — v N M O O In .,-4 X ^ Q '6' I N-- I I I 1 I I I I -+—�% SLOPE MINIMUM __ 6" MIN 6" MAX e • o WATERPROOF BACK OF WALL PER ARCHITECT'S SPECIFICATIONS o • 3/4 INCH CRUSHED ROCK or • ° MIRADRAIN 6000 or EQUIVALENT o • ° e GEOFABRIC BETWEEN ROCK AND SOIL . • O '12° e o ; o TOP OF GROUND or CONCRETE SLAB . o ' 6" MIN wall, MINIMUM 4 INCH DIAMETER PERFORATED PIPE RETAINING WALL SUBDRAIN DETAIL No Scale Christian Wheeler Engineering Job Number: 199 - 099- 2 Date:_ MARCH 7, 2000 Plate Number: 14 CWE 199.099 December 28, 1999 Appendi_i A,Page Al REFERENCES Anderson,J.G.;Rockwell,R.K.and Agnew,D.C.,1989,Past and Possible Future Earthquakes of Significance to the San Diego Region,Earthquake Spectra,Volume 5,No.2, 1989. Barry And Associates Geotechnical Engineering, 1998,Preliminary Geotechnical Investigation,Proposed Single Family Residence,2600 Montgomery Avenue,Cardiff,California,Parcel 2,of Parcel Map 17367,W.O.P-1639, dated November 16, 1998. Jennings, C.W., 1975,Fault Map of California,California Division of Mines and Geology,Map No. 1,Scale 1:750,000. Maps of Known Active Fault Near Source-Zones in California and Adjacent Portions of Nevada,1998, California Division of Mines and Geology. Mualchin,L.and Jones,A.L,1992,Peak Acceleration from Maximum Credible Earthquakes in California(Rock and Stiff-Soil Sites)California Division of Mines and Geology Open-File Report 92-1. Owen Geotechnical Consultants, 1981,Nommesen Condominium Project,Project No. 124.1.1. Tan,Siang S.and Giffen,Desmond G., 1995,Landslide Hazards In The Northern Part Of The San Diego Metropolitan Area,San Diego County,California,Encinitas 7.5'Quadrangle,California Division of Mines and Geology Open-File Report 95-04,scale 1:24,000. Tan,Siang S.and Kennedy,Michael P., 1996,Geologic Map Of The Encinitas and Rancho Santa Fe 7.5' Quadrangles,San Diego County, California, California Division of Mines and Geology Open-File Report 96-02, scale 1:24,000. Wesnousky,S.G., 1986, "Earthquakes,Quaternary Faults,and Seismic Hazards in California",in Journal of Geophysical Research,Volume 91,No.B12,pp 12,587 to 12,631,November 1986. CWE 199.099 December 28, 1999 Appendix A,Page A2 TOPOGRAPHIC MAPS County of San Diego,1985,Orthographic Map Sheet 306-1683,Scale: 1 inch=200 feet. U.S. Geological Survey, 1968 (Photo-revised 1975),7'/2 Minute Topographic Map,Encinitas Quadrangle,scale 1:24,000. AERIAL PHOTOGRAPHS Aerial FotoBank/Thomas Bros.,Inc.,Aerial Foto-Map Book,.San Diego County, 1995-96,Sheet 1147,Scale: 1 inch'=2000 feet(approximate). Aerial Graphics,Aerial Foto-Map Book,San Diego County,1982,Sheet E-10,Scale: 1 inch =2000 feet (approximate). Aerial Graphics,Aerial Foto-Map Book,San Diego County,198485,Sheet 10-E,Scale: 1 inch=2000 feet (approximate). Lenska Aerial Images, 1994,The Thomas Guide,Commercial Edition,Page 1147,Scale: 1 inch=2000 feet (approximate). San Diego County,1928,Flight 37B,Photographs 1 and 2;Scale: l inch= 1000 feet(approximate). San Diego County, 1953,Flight 8N� Photograph 78,Scale: 1 inch= 1700 feet(approximately). San Diego County, 1960,Flight 3,Photographs 73 and 74;Scale: 1 inch= 1000 feet(approximate). San Diego County, 1970,Flight 4,Photograph 12;Scale: 1 inch= 1000 feet(approximate). San Diego County, 1974,Flight 33,Photographs 4,5,and 6;Scale: 1 inch= 1000 feet(approximate). San Diego County,1978,Flight 16B,Photographs 43 and 44;Scale: 1 inch= 1000 feet(approximate). San Diego County, 1983,Photographs 545 and 546;Scale: 1 inch= 1000 feet(approximate). San Diego County, 1989,Photograph 1-209;Scale:1 inch=2000 feet(approximate). CWE 199.099.1 December 28, 1999 Appendix B,Page B1 PROPOSED NOMMESEN RESIDENCE 2600 MONTGOMERY AVENUE ENCINITAS, CALIFORNIA RECOMMENDED GRADING SPECIFICATIONS-GENERAL PROVISIONS GENERAL INTENT The intent of these specifications is to establish procedures for clearing,compacting natural ground, preparing areas to be filled,and placing and compacting fill soils to the lines and grades shown on the accepted plans. The recommendations contained in the preliminary geotechnical investigation report and/or the attached Special Provisions are a part of the Recommended Grading Specifications and shall supersede the provisions contained hereinafter in the case of conflict. These specifications shall only be used in conjunction with the geotechnical report for which they are a part. No deviation from these specifications will be allowed, except where specified in the geotechnical report or in other written communication signed by the Geotechnical Engineer. OBSERVATION AND TESTING Christian Wheeler Engineering shall be retained as the Geotechnical Engineer io observe and test the earthwork in accordance with these specifications. It will be necessary that the Geotechnical Engineer or his representative provide adequate observation so that he may provide his opinion as to whether or not the work was accomplished as specified. It shall be the responsibility of the contractor to assist the Geotechnical Engineer and to keep him appraised of work schedules, changes and new information and data so that he may provide these opinions. In the event that any unusual conditions not covered by the special provisions or preliminary geotechnical report are encountered during the grading operations, the Geotechnical Engineer shall be contacted for further recommendations. If,in the opinion of the Geotechnical Engineer,substandard conditions are encountered,such as questionable or unsuitable soil,unacceptable moisture content,inadequate compaction,adverse weather,etc., construction should be stopped until the conditions are remedied or corrected or he shall recommend rejection of this work CWE 199.099.1 December 28, 1999 Appendix B,Page B2 Tests used to determine the degree of compaction should be performed in accordance with the following American Society for Testing and Materials test methods: Maximum Density& Optimum Moisture Content-ASTM D-1557-91 Density of Soil In-Place-ASTM D-1556-90 or ASTM D-2922 All densities shall be expressed in terms of Relative Compaction as determined by the foregoing ASTM testing procedures. PREPARATION OF AREAS TO RECEIVE FILL All vegetation,brush and debris derived from clearing operations shall be removed,and legally disposed of All areas disturbed by site grading should be left in a neat and finished appearance, free from unsightly debris. After clearing or benching the natural ground,the areas to be filled shall be scarified to a depth of 12 inches, brought to the proper moisture content,compacted and tested for the specified minimum degree of compaction. All loose soils in excess of 6 inches thick should be removed to firm natural ground which is defined as natural soil which possesses an in-situ density of at least 90 percent of its maximum dry density. When the slope of the natural ground receiving fill exceeds 20 percent(5 horizontal units to 1 vertical unit), the original ground shall be stepped or benched. Benches shall be cut to a firm competent formational soil. The lower bench shall be at least 10 feet wide or 1-1/2 times the equipment width,whichever is greater,and shall be sloped back into the hillside at a gradient of not less than two (2)percent All other benches should be at least 6 feet wide. The horizontal portion of each bench shall be compacted prior to receiving fill as specified herein for compacted natural ground. Ground slopes flatter than 20 percent shall be benched when considered necessary by the Geotechnical Engineer. Any abandoned buried structures encountered during grading operations must be totally removed. All underground utilities to be abandoned beneath any proposed structure should be removed from within 10 feet of the structure and properly capped off. The resulting depressions from the above described procedure should be backfilled with acceptable soil that is compacted to the requirements of the Geotechnical Engineer. This includes,but is not limited to,septic tanks, fuel tanks, sewer lines or leach lines,storm drains and water lines. Any buried structures or utilities not to be abandoned should be brought to the attention of the Geotechnical Engineer so that he may determine if any special recommendation will be necessary. OWE 199.099.1 December 28, 1999 Appendix B,Page B3 FILL MATERIAL Materials to be placed in the fill shall be approved by the Geotechnical Engineer and shall be free of organic matter and other deleterious substances. Granular soil shall contain sufficient fine material to fill the voids. The definition and disposition of oversized rocks and expansive or detrimental soils are covered in the geotechnical report or Special Provisions. Expansive soils, soils of poor gradation,or soils with low strength characteristics may be thoroughly mixed with other soils to provide satisfactory fill material,but only with the explicit consent of the Geotechnical Engineer. Any import material shall be approved by the Geotechnical Engineer before being brought to the site. J ' PLACING AND COMPACTION OF FILL Approved fill material shall be placed in areas prepared to receive fill in layers not to exceed 6 inches in compacted thickness. Each layer shall have a uniform moisture content in the range that will allow the compaction effort to be efficiently applied to achieve the specified degree of compaction. Each layer shall be uniformly compacted to the specified minimum degree of compaction with equipment of adequate size to economically compact the layer. Compaction equipment should either be specifically designed for soil compaction or of proven reliability. The minimum degree of compaction to be achieved is specified in either the Special Provisions or the recommendations contained in the preliminary geotechnical investigation report. When the structural fill material includes rocks,no rocks will be allowed to nest and all voids must be carefully filled with soil such that the minimum degree of compaction recommended in the Special Provisions is achieved. The maximum size and spacing of rock permitted in structural fills and in non- structural fills is discussed in the geotechnical report,when applicable. Field observation and compaction tests to estimate the degree of compaction of the fill will be taken by the Geotechnical Engineer or his representative. The location and frequency of the tests shall be at the Geotechnical Engineer's discretion. When the compaction test indicates that a particular layer is at less than the required degree of compaction, the layer shall be reworked to the satisfaction of the Geotechnical Engineer and until the desired relative compaction has been obtained. Fill slopes shall be compacted by means of sheepsfoot rollers or other suitable equipment. Compaction by sheepsfoot roller shall be at vertical intervals of not greater than four feet In addition, fill slopes at a ratio of two horizontal to one vertical or flatter,should be trackrolled. Steeper fill slopes shall be over-built and cut- CWE 199.099.1 December 28, 1999 Appendi_Y B,Page B4 • back to finish contours after the slope has been constructed. Slope compaction operations shall result in all fill material six or more inches inward from the finished face of the slope having a relative compaction of at least 90 percent of maximum dry density or the degree of compaction specified in the Special Provisions section of this specification. The compaction operation on the slopes shall be continued until the Geotechnical Engineer is of the opinion that the slopes will be surficially stable. Density tests in the slopes will be made by the Geotechnical Engineer during construction of the slopes to determine if the required compaction is being achieved. Where failing tests occur or other field problems arise, the Contractor will be notified that day of such conditions by written communication from the Geotechnical Engineer or his representative in the form of a daily field report. If the method of achieving the required slope compaction selected by the Contractor fails to produce the necessary results,the Contractor shall rework or rebuild such slopes until the required degree of compaction is obtained,at no cost to the Owner or Geotechnical Engineer. CUT SLOPES The Engineering Geologist shall inspect cut slopes excavated in rock or lithified formational material during the grading operations at intervals determined at his discretion. If any conditions not anticipated in the preliminary report such as perched water, seepage,lenticular or confined strata of a potentially adverse nature,unfavorably inclined bedding,joints or fault planes are encountered during grading, these conditions shall be analyzed by the Engineering Geologist and Geotechnical Engineer to determine if mitigating measures are necessary. Unless otherwise specified in the geotechnical report,no cut slopes shall be excavated higher or steeper than that allowed by the ordinances of the controlling governmental agency. ENGINEERING OBSERVATION Field observation by the Geotechnical Engineer or his representative shall be made during the filling and compaction operations so that he can express his opinion regarding the conformance of the grading with acceptable standards of practice. Neither the presence of the Geotechnical Engineer or his representative or the observation and testing shall release the Grading Contractor from his duty to compact all fill material to the specified degree of compaction. Ck`�E 199.099.1 December 28, 1999 Appendix B,Page B5 SEASON LIMITS Fill shall not be placed during unfavorable weather conditions. When work is interrupted by heavy rain, filling operations shall not be resumed until the proper moisture content and density of the fill materials can be achieved. Damaged site conditions resulting from weather or acts of God shall be repaired before acceptance of work. RECOMMENDED GRADING SPECIFICATIONS- SPECIAL PROVISIONS RELATIVE COMPACTION:The minimum degree of compaction to be obtained in compacted natural ground,compacted fill,and compacted backfill shall be at least 90 percent. For street and parking lot subgrade, the upper six inches should be compacted to at least 95 percent relative compaction. EXPANSIVE SOILS: Detrimentally expansive soil is defined as clayey soil which has an expansion index of 50 or greater when tested in accordance with the Uniform Building Code Standard 29-C. OVERSIZED MATERIAL: Oversized fill material is generally defined herein as rocks or lumps of soil over 6 inches in diameter. Oversized materials should not be placed in fill unless recommendations of placement of such material are provided by the Geotechnical Engineer. At least 40 percent of the fill soils shall pass through a No. 4 U.S. Standard Sieve. TRANSITION LOTS:Where transitions between cut and fill occur within the proposed building pad, the cut portion should be undercut a minimum of 18 inches below the base of the proposed footings and recompacted as structural backfill. In certain cases that would be addressed in the geotechnical report,_ special footing reinforcement or a combination of special footing reinforcement and undercutting may be required. HYDROLOGY CALCULATIONS For RUTHERFORD RESIDENCE APN: 2617191-16 j ENCINITAS, CALIFORNIA r:J d 2004 I" -ONG KRVIGES Prepared For t ,;i of ENCI�ISAS Mr. Kelly Rutherford 2600 Montgomery Avenue Cardiff, CA 92007 PE 966 r PREPARED BY: PASCO ENGINEERING, INC. 535 N. HIGHWAY 101, SUITE A SOLANA BEACH, CA 92075 ,LESS- (858)259-8212 9� A. pq F DATE: 7/5/04 /`� s'P Iru�, No. 29577 M °C F-V.3/31/07 CNI- �@ OF CALW WA A. PASCO, RCE 29577 D TE r' \\ServeNob files\Hydrology& Hydraulics\966 HYDRO REPORT.doc PE#966 10:29 AM 7/1/2004 HYDROLOGY STUDY for RUTHERFORD RESIDENCES PE 966 TABLE OF CONTENTS SECTION DISCUSSION..............................................................................A CONCLUSION.............................................................................B PRE AND POST DEVELOPMENT HYDROLOGY CALCULATIONS.......C POST DEVELOPMENT TREATMENT RUNOFF CALCULATIONS.........D APPENDIX.................................................................................E Isopluvials Intensity Duration Curve Runoff Coefficients Hydrology Map \\Server\job files\Hydrology& Hydraulics\966 HYDRO REPORT.doc PE#966 10:29 AM 7/1/2004 HYDROLOGY STUDY for RUTHERFORD RESIDENCES PE 966 A. INTRODUCTION The purpose of this report is to analyze the storm water runoff produced from the 100 year storm event of the existing and post-developed condition of the Crest Drive development site. The subject property is physically located at 2600 Crest Drive, Cardiff California. The property is geographically located at N 33°00'50" W 117 016'25". Pre-Developed Conditions The existing condition of the project site consists of a vacant lot with an existing asphalt paved driveway and retaining wall. The vacant lot slopes dramatically downhill from the existing asphalt paved driveway and retaining wall westerly to the backyard boundary. Existing slopes of 2:1 and greater exist downhill near the westerly boundary. Some drainage from Montgomery Street, the asphalt driveway and up hill neighbor all drain onto the site. There is an existing ac apron that directs this drainage along the southerly boundary. All drainage runs over the natural steep slope that continues over an on-site open space easement. Eventually the drainage sheet flows over the open space and then reaches Manchester Drive. Post- Development Conditions The proposed development consists of the construction of a single family residence. Part of the existing asphalt paved driveway will be removed and reconstructed to accommodate a garage. The existing retaining wall will be removed in order to accommodate the residence. Existing drainage from the driveway and uphill neighbor will continue pre development runoff conditions. The existing ac apron will be removed and replaced with a channel grate type inlet. The inlet will divert drainage to a rip-rap energy dissipater before it is released onto the open space as sheet flow. The diversion of this drainage will decrease existing runoff that makes its way to the existing cut slope in the backyard. The cut slope is very steep (over 1:1 slope) and is eroding. The proposed drainage system will decrease the amount of runoff going over the cut slope and reduce erosion on it. Drainage from the proposed roof will be collected in downspouts and routed to the northerly boundary where it will be, treated in a grass lined ditch, released onto rip-rap and then return to sheet flow conditions before entering the on-site open space easement. The area at the side and front of the residence near the northerly boundary will be used to treat runoff from the proposed development. A grass lined swale will be used as a treatment facility and then sheet flow across existing natural slope to Manchester Drive. The pre-development and post-development runoff coefficient and area basin remain the same; therefore, there is no increase in runoff from the site. The pre and post runoff is 0.86 cfs. All post-developed drainage, using the 85a'percentile storm calculation, will be \\Server\job files\Hydrology& Hydraulics\966 HYDRO REPORT.doc PE#966 3:16 PM 7/28/2004 HYDROLOGY STUDY for RUTHERFORD RESIDENCES PE 966 treated before released off-site. The treatment runoff is 0.008 cfs and is treated in a grass lined channel near the front of the proposed residence. (See plan) Methodology and Results The hydrologic soil group classification for the site is "D". The methodology used herein to determine Qloo is the rational method. The pre and post-development runoff coefficients, used to analyze the both conditions, were obtained from Table 3-1 of the June 2003 revision of the San Diego County Hydrology Manual. B. CONCLUSION Based on the information and calculations contained in this report it is the professional opinion of Pasco Engineering, Inc. that the storm drain system as proposed on the corresponding Grading Plan will function to adequately intercept, contain and convey Qioo to the appropriate points of discharge. \\ServeNob files\Hydrology& Hydraulics\966 HYDRO REPORT.doc PE#966 3:16 PM 7/28/2004 HYDROLOGY STUDY for RUTHERFORD RESIDENCES PE 966 C. PRE AND POST DEVELOPMENT HYDROLOGY CALCULATIONS \\Server\job files\Hydrology& Hydraulics\966 HYDRO REPORT.doc PE#966 10:29 AM 7/1/2004 HYDROLOGY STUDY for RUTHERFORD RESIDENCES PE 966 PRE-DEVELOPMENT AND POST-DEVELOPMENT RUNOFF: Q =CIA Where, C =0.60(Per Table 3-1 Runoff Coefficients for Urban Areas) Iloo= 5.11 in/hr A= 0.28ac (Existing area where improvements are proposed) Qioo= (0.60)(5.11)(0.28) O,00= 0.86 cfs \\ServeNob files\Hydrology& Hydraulics\966 HYDRO REPORT.doc PE#966 10:29 AM 7/1/2004 HYDROLOGY STUDY for RUTHERFORD RESIDENCES PE 966 D. POST DEVELOPMENT TREATMENT RUNOFF CALCULATIONS \\ServeNob files\Hydrology& Hydraulics\966 HYDRO REPORT.doc PE#966 10:29 AM 7/1/2004 HYDROLOGY STUDY for RUTHERFORD RESIDENCES PE 966 TREATMENT RUNOFF CALCULATION FOR 80u`PERCENTILE STORM Q = CIA Where, C = 0.95 (impervious surfaces) Igo,=0.16 in/hr A= 0.05 ac (Directly connected impervious surface) Q80t,= (0.95)(0.16)(0.05) 080th= 0.008 cfs GRASS TREATMENT CHANNEL SCOUR CALCULATION v=0.04 ft/s (See worksheet next page) <1.0ft/s checks okay for scour GRASS TREATMENT CHANNEL MAXIMUM FLOW CALCULATION Qmax= 0.021cfs (See worksheet on following pages)>0.008cfs checks okay for capacity \\Serverljob files\Hydrology& Hydraulics\966 HYDRO REPORT.doc PE#966 8:45 AM 7/27/2004 GRASS TREATMENT CHANNEL Worksheet for Rectangular Channel Project Description Project File c:lhaestadlacademic\fmw\966.fm2 Worksheet GRASS MOW STRIP BMP AT CARPORT Flow Element Rectangular Channel Method Manning's Formula Solve For Channel Depth Input Data Mannings Coefficient 0.200 Channel Slope 0.1000% Bottom Width 2.00 ft Discharge 0.008 cfs Results Depth 1.1 in Flow Area 0.18 ft2 Wetted Perimeter 2.18 ft Top Width 2.00 ft Critical Depth 0.01 ft Critical Slope 2.954748 ft/ft Velocity 0.04 ftis Velocity Head 0.31 e-4 ft Specific Energy 0.09 ft Froude Number 0.03 Flow is subcritical. 07/27/04 Academic Edition FlowMaster v5.17 08:41:25 AM Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 (203)755-1666 Page 1 of 1 GRASS TREATMENT CHANNEL Cross Section for Rectangular Channel Project Description Project File c:\haestad\academic\fmw\966.fm2 Worksheet GRASS MOW STRIP BMP AT CARPORT Flow Element Rectangular Channel Method Manning's Formula Solve For Channel Depth Section Data Mannings Coefficient 0.200 Channel Slope 0.1000% Depth 1.1 in Bottom Width 2.00 ft Discharge 0.008 cfs 1.1 in 1 2.00 ft V N H 1 NTS 0727/04 Academic Edition FlowMaster v5.17 08:41:39 AM Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 (203)755-1666 Page 1 of 1 GRASS TREATMENT CHANNEL MAX FLOW Worksheet for Rectangular Channel Project Description Project File c:\haestad\academic\fmw\966.fm2 Worksheet GRASS MOW STRIP BMP AT CARPORT Flow Element Rectangular Channel Method Manning's Formula Solve For Discharge Input Data Mannings Coefficient 0.200 Channel Slope 0.1000% Depth 2.0 in Bottom Width 2.00 ft Results Discharge 0.021 cfs Flow Area 0.33 ft2 Wetted Perimeter 2.33 ft Top Width 2.00 ft Critical Depth 0.02 ft Critical Slope 2.397492 ft/ft Velocity 0.06 ft/s Velocity Head 0.64e-4 ft Specific Energy 0.17 ft Froude Number 0.03 Flow is subcritical. 07/27/04 Academic Edition FlowMaster v5.17 08:40:41 AM Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 (203)755-1666 Page 1 of 1 GRASS TREATMENT CHANNEL MAX FLOW Cross Section for Rectangular Channel Project Description Project File c:lhaestaftcademic\fmw1966.fm2 Worksheet GRASS MOW STRIP BMP AT CARPORT Flow Element Rectangular Channel Method Manning's Formula Solve For Discharge Section Data Mannings Coefficient 0.200 Channel Slope 0.1000% Depth 2.0 in Bottom Width 2.00 ft Discharge 0.021 cfs g 2.0 in 1 2.00 ft v H 1 NTS 07/27104 Academic Edition FlowMaster v5.17 08:40:56 AM Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 (203)755-1666 Page 1 of 1 HYDROLOGY STUDY for RUTHERFORD RESIDENCES PE 966 E. APPENDIX \\ServeNob files\Hydrology& Hydraulics\966 HYDRO REPORT.doc PE#966 10:29 AM 7/1/2004 0 0 o . m �n �— _ 133300001E m L N O z a N j m u U ` C+ 1 0 .` m N li. \\ to LL m U N a ✓" a k ,� �► U r O 1 C` l/ U U O U/ c n I ri I w � / C A • A to -- \O C\ N n. O M D\ O\ N %n tr1 r- N M N O C C O C C O C O O O C C O O O � 1. •� a) u � C a) .r ►u. Oo c0 O V1 OG "Ir [l CO 01 00 00 U M M V: 14: n v1 \° V' IT [*- OC OHO OTC OOC O C O O O O O O O O O O C O O •Qj N Cl C O C L) co U a c cm 'a C/J U _ •h N oc h -. er DO t- t- t-•O �f t� 3 _ N M l+1 tf V: h vY %j %.o [- I- 00 00 00 00 C 0. 0 0 0 o d CD d o o d o o •d o o ° u � o V2 W C C �• O - V1 II O l� rt CO 00 N V1 \O %O %O O M •v N N M f! ( 00 00 00 00 .> O C O C O O O O O O O O .O O O •O u W •U r� � u •O h� i► O O �r1 Oti CSS �r1 O vt O O v� O O v1 U U O O N N M rr ,.y o O in � C � H � R 1� V. H N VS � •^"S. •C N N H N W N N N N f0 "U o0 0 0` o` o `0 0 0 v ¢ a a a o w w 0. Q ¢ Q ¢• ¢ a a a � � �, v �; � N N r- .. N �• •y V E � C G C C C C C C G � Lti. •O � p •� H 4U ai u u w u v ai v 0 'u v w E v E s a O .l V a cn ca C _ o R R ° O O U S up,.' C U .0 E ie -R -E aa)i v v u z a v� h 0 0 C C lC 1O of cC C.'. :: .0 C • vl u u u u u u u u u cd u 'D 'G 'b L': 0.� 'b 'd FY S E y .0 t.. •-• a0.' C p ai in U _ �+ �, V ai 'aG •CC D en w Z' 1'' d c p C r z o N ' cC C C ti C �y 4U c u ° ea �° � C C c A A A A C C ` •�. •� 'y •� � c.d 'O z q •- •- a u u Ccc Cd ull O O 0 O u a 0 V U U U Uu 2 San Diego County Hydrology Manual Section: 3 _ Date: June 2003 Page: 12 of 26 Note that the Initial Time of Concentration should be reflective of the general land-use at the upstream end of a drainage basin. A single lot with an area of two or less acres does not have a significant effect where the drainage basin area is 20 to 600 acres. Table 3-2 provides limits of the length (Maximum Length (LM)) of sheet flow to be used in hydrology studies. Initial T; values based on average C values for the Land Use Element are also included. These values can be used in planning and design applications as described below. Exceptions may be approved by the "Regulating Agency" when submitted with a . detailed study. Table 3-2 MAXIMUM OVERLAND FLOW LENGTH (LM) & INITIAL TIME OF CONCENTRATION T; Element* DU/ .5% 1% 2% 3% 5% 10% Acre LM T; LM TT LM T; LM T; IM-FT. LM T; Natural 50113.2 70 12.5 85 10.9 100 10.3 100 8.7 1006.9 LDR 1 50 12.2 70 11.5 85 10.0 100 9.5 100 8.0 100 6.4 LDR 2 50 11.3 70 10.5 85 9.2 100 8.8 100 7.4 100 5.8 LDR 2.9 50 10.7 70 10.0 85 8.8 95 8.1 100 7.01 100 5.6 MDR 4.3 50 10.2 70 9.6 80 8.1 95 7.8 100 6.7 100 5.3 MDR 7.3 50 9.2 65 8.4 80 7.4 95 7.0 100 6.0 100 4.8 MDR 10.9 50 8.7 65 7.91 80 6.9 90 6.4 100 5.7 100 4.5 MDR 14.5 50 8.2 65 7.41 80 6.5 90 6.01 100 5.4 100 4.3 HDR 24 50 6.7 65 6.1 75 5.1 90 4.9 95 4.3 100 3.5 HDR 43 50 5.3 65 4.7 75 4.01 85 3.8 95 3.4 100 2.7 N. Corn 50 5.3 60 4.5 75 4.0 85 3.8 95 3.4 100 2.7 G. Com 50 t3.76O 4.1 75 3.6 85 3.4 90 2.9 100 2.4 O.P./Com 50 3.7 70 3.1 80 2.9 90 2.6 I00 2.2 Limited I. 50 3.7 70 3.1 80 2.9 90 2.6 100 2.2 General I. 50 3.2 70 2.7 80 2.6 90 2.3 100 1.9 *See Table 3-1 for more detailed description 3-12 G:Ir W Y lV a r- C N O + 4- C Or- 4) C1 # (T tb �•L -**-Z T 4) H to b N 5�.. X 2 tt] 4) +•) U Cu L C1 r- C CS .c S- C C U'ZIA C. r A O It O z C) 4- 7•r C)u) r„ L i -r- . G 1 E 41 C- 4-4-- O .0 L # S- 4) ut E— v v C -0 L N +1 (U 4-D r O C •r 1 'C Cu 4)e- b C C1 O O ?1() p -C O C 1- O O C CS. +3 N N r ---j C r to C C •r > O N A +3 L O O C) Cn r 4..1 C 0.C)-C O i to •r r L C ea O ep.0 O O 4-J C) 4.J +3 4) C O 'r• % +3 +.1 r- Q) -r-= to to +1 t•J 11 i r-- 4j C L CL 41 +j +-3 .0 C C ed C L-r--C O •.- •r •r C) •r V1 - N •r \ CO U O O L C -0 U C O. G O C U IZ E C v -r •••-4-•r- r-- Q) C)r-r- •r- O C)r C r •r CL ro (A 4) c` O C i.) 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' f o CN cm cm I cm cm `• � � ✓ �`^�;.•� .0 �` ` �O ' '��-+ � In �� r. o co ., CKX Lo LM ca czc CS LLJ f/1 �• u t� O U x D N 3 co z t.c_ —j Q i t- Z Z O 111 tC1 U < O O O ui u - Ev viper z < o m z a O 4. C) M O „ O W —i �- m UOIL < D z D r M .l v u a N II-A-13 W U o oa ou W 114 1-+ O wZ _ w 0a wiz a o� W W da o F F� w �aaa a� x 0 w z 0 U0 v0 U O W 0 az �a �A w O OU A 0 0 Lm �a w m a �x 0 o� a� gx <U U. O W z O zx .W Q 4` PROJECT DATA: SCOPE OF WORK: NEW SINGLE FAMILY RESIDENCE LEGAL DESCRIPTION: PARCEL 2 OF PARCEL MAP NO. 17367 APN: LOEGAL OWNER: kERRY AND LYNN RUTHERFORD PROJECT ADDRESS: 2600 MONTGOMERY AVE. CARDIFF, CA. 92007 ZONE: RV 11 LOT SIZE: 5374 SQ. FT. LOT COVERAGE: 20% F.A.R.:.27 CONSTRUCTION TYPE: V -N CONSTRUCTION AREA: UPPER FLOOR: 656 SQ. FT. ENTRY LEVEL: 822 SQ. FT. TOTAL LIVING: 1,478 SQ. FT. BASEMENT: 1,115 SQ. FT. (NOT INCLUDED IN F.A.R.) GARAGE: 390 SQ. FT. (NOT INCULDED IN F.A.R.) TOTAL BUILDING AREA: 2.983 SQ. FT. VICINITY MAP LEGEND B -1 APPROXIMATE BORING LOCATION Td DELMAR FORMATION 42 ATTITUDE OF BEDDING Aj,._:..{A1 GEOLOGIC CROSS SECTION SHALLOW SURFICIAL FILLS OF LESS THAN 2' IN THICKNESS WERE NOT MAPPED P' NUALE: I/8" =1 SED p c11/ NON A1TLiN K7 LEY n� y C2736 -• DATE 5105 9� RENEWAL �OF CA��FO CHkISTAN WHE&FR ENGINEERING 4925 Marcury Sunt -Su Diego, CA92111. 358-096.9760 -FAX 85&496.9758 PROPOSED SINGLE FAMILY RESIDENCE BY: DRR /MS DATE: 01 -07 -05 JOB NO.: 2040232 PLATE NO.: 1 P' NUALE: I/8" =1 SED p c11/ NON A1TLiN K7 LEY n� y C2736 -• DATE 5105 9� RENEWAL �OF CA��FO I! i I I; li 4=� o U cd U DRAMN BY: Enter Book Enter Book 6/22/2004 5 CAL E A -1.1 I� i - r ' I 1 --4 c w N 0 0 N U w � z z �j 0 I! i I I; li 4=� o U cd U DRAMN BY: Enter Book Enter Book 6/22/2004 5 CAL E A -1.1 110 a 10 mall 50 .x 30 20 ,sue zo CHRISTIAN WHEELER EN G I N E E R I N G NOMMESEN RESIDENCE BY: DRR /HC A JOB NO: 199.099.2 PLATE Na 7 110 100 MANCHESTER AVENUE 90 �W 80 60' VARI S .70 _ uilY 717 60 s, ,.k 50 40 QL 30 20 - -� 0 10 20 - 30 40 50 mama.. J J 'marl ) - J mama - mama. J ' d �g�$ mama ` `isiY� �. �.... -mama. • . mama . -. mama •..... ,. ,., —.:. � .:ti. .�. ,:mama. w�;:' -., :.:' - -mama ,..5�� �.. _ � _Z{ 4. - mama mama mama 4 t, Y: mama. t { 44 - t � t _ mama mama rt 4 mama , 1 4 t 1_ mama - �1 �1 k - mama ::mama ! -. mama mama mama - - . - - mama mama 110 a 10 mall 50 .x 30 20 ,sue zo CHRISTIAN WHEELER EN G I N E E R I N G NOMMESEN RESIDENCE BY: DRR /HC DATE 03 -07-00 JOB NO: 199.099.2 PLATE Na 7 �� 4