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2002-7219 G 1 e8 J � �\ \ ` . � $�' °mac "Q►n. l v � c / p 1 N 1 / - t / > � o Rose WAY I P `\ r IQ � N soft am V � U I i I a �t U N 1 \ X -C,: N ps yy y 1n3 P� _ o a I', --- $, • Civil Engineering • Land Planning • Structural • Surveying June 2, 2001 , 1 OF g j L s zu S HYDROLOGY STUDY FOR HERITAGE RIDGE II DESCRIPTION: 5 -LOT GRADING PLAN & DESIGN REVIEW VIA DI FELICITA, OLIVENHAIN A.P.N.'s .264 - 151 -36, 38 -41 Q R�F ESS /p,� APPLICANT: E. l��Fyy VENTURE PACIFIC DEVELOPMENT C :0i.'.S P.O. BOX 231639 Exp. 12 -31-01 ENCINITAS, CA 92023 -1639 760 - 632 -5609 'lF OF C ^ `F p2� P 1 D E. L AN DATE R.C.E. 39726 EXPIRES 12 -31 -01 Office; 16236 San Dieguito Road, #3 -1 1 • Rancho Santa Fe Mailing; PMB -N • 132 N. El Camino Real • Encinitas, CA 92024 Phone 858 -756 -8696 • Fax 858 -756 -8698 Co(j o c- 600rz9 MAAukt- C %4 MIA To w& -'P 5 t l 6 I2' W EST C R -j4O(L . e - PrLA W Jk6 E % - 1 �E � tt' � %f Uri ryt P' TZ-E�Qu ICL E Me 13 \1 1,A WA(tJA&E c44 ArAl.-IS . C P1 A tti 'hO 13C VE 7:DE VJ I VA PROJECT: Heritage Ridge II Brow Ditch DATE: PIPE FLOW TIME: Diameter (inches) ... 24 Mannings n 016 Slope (ft /ft) ....... 0.0200 Q (cfs) ........... 12.20 C �Y depth (ft) .......... 0.96 depth /diameter ... 0.48 Velocity (fps) ...... 8.14 Velocity head .... 1.03 Area (Sq. Ft.) ...... 1.50 Critical Depth ...... 1.25 Critical Slope ... 0.0085 Critical Velocity ... 5.88 Froude Number .... 1.66 Te s - - - - -- - -- - - - -- -- -- - - - - ` _ -� TABLE 2 - RUNOFF COEFFICIENTS (RATIONAL METHOD) • DEVELOPED AREAS (URBAN) URBAN Coeffic C Soil Group (1) ' Lan. A 8 C — D Residential: - -Single Fa mily .40 .45 .50 .55 Multi -Units .45 .50 .60 .70 Mobile homes .45 .50 _955 ..65 Rural (lots greater than 1/2 acre) .30 .035 .40 .45 Commereia](2) .70 .75 `. .80 .85 80% Impervious Industrial ( . .80 .85 .90 ..95 90% Impervious NOTES: (l) Soil'Grouo mans are available at the offices of the Department of Public Works. ( actual conditions. deviate significantly from the tabulated impervious- ness values of 80% or 90%. the values given for coefficient C. may be revised by multiplying 80% or 90% by the ratio of actual imperviousness to the tabulated imperviousness. However, in no case shall the final coefficient be less than 0.50. For example Consider commercial property on D soil.liroup- Actual imperviousness 50 Tabulated imperviousness 80% • Revised C —0 x 0.85 0.53 • • • so A: 9 APPENDIX Seal H EQLIAT /ON r //. 9L 1 • Feef Tc ( SOOD T • Tune Of tv174enfi12f1;" \ 4000 L • Leng/h of waf «shed H • 011?e-eMce in e%vafion a/oeg 3000 c1/ccfire s/voe 1117 lSce fooe7dlx X•w T L .01*5 Fee/ 11,04& Afim/feJ Z ODO 4 2�0 3 /BO /O /DDO \ 900 sloe ? /20 MO /DD 600 \ \ S 90 300 \ BO 400 4 7D 200 • \\ 2 QO \ 30 • O / � SODD �4rQD0 20 \\ /B 3000 \ Ac SO 40 Jw NOTE /CDO g :a araa R NATURAL WATERSI�D /10o B FOR ZD ADD TEN MIMUTES TO 9 D y CON M RATIO TIME OF CON C�NTRATION_ BOO O a� sp _ Al 6 S ¢DO 300 JT 5 200 SAN DIEGO COUNTY NOMOGRAPH FOR DETERMINATION DEPARTMENT OF SPECIAL DISTRICT SERVICES OF TIME OF CONCENTRATION (Tc) FOR NATURAL WATERSHEDS DESIGN MANUAL APPROVED ' Y e DATE n 6 APPENDIX X -A L-A-10 Rev. 5/81 4- t O an O +1 4- # C O -r a) a7 L �- r = \9 C X , L 117 227 b u 1t� 'O C >1 r- to aJ r-- r-- Cs 1.0 G7 ij u Cu L r A O U • C3 W Q' a7 4 C - a7 unp CZ. C �V N CQ d a # 0. CL �►.1 + IMP QJ u JC E C T7 • O G7 sJ r G7 C -r- 1 "a ` Q a7 r•- r0 C C. • O a. % N O N � • VI Y C Y to C C !n r O 1.l C a a7 - 0 C i 1a L •� • . .0 C to O to= 1L1 O 41 d 41 4J iJ a7 C O 4.11 4.1 . - G7 •r- t to .0 4J to C L Y T7 O -•-- - - •. - C1 -r- Q7 u u O O L C t.7 C t1 G O O r .*-• -.- r- 4J u L = u u L .0 a a a to 1n w C O G++ CU CJ N cr , C U� a_ N L 0. O H O - 0 ,C N L O C -r- - � O La_ Q'' O 0 E ar• C r L L .0 - r 0 4 L7- � N O 4- d r0 A ••� tp t L JC u r C e Z N a r C -. •cr of to a7 10 a7 r O O 4j C L Q! ra Q7 N N a) -C 4-j r ' u N O E JC N� •r O� D 4J � y 4J N i a7 11 O a _ •r, a •LJ L. zr t to d -v .0 .0 O .- 4-- L r•- t t u al tp Z7 u r-•. . {-+ d-•+ 4- d O G] G 1- V -r- N 0. C + d r L a CL CL O r N cn s7 Ln C O r N <') �! j. V z 6 -Hour Precipitation (inches) c7 C) to O to C LO C to C�O • in C I i to vi llf s7 v- cv7 c•7 N .- .-- to n CO —• . -_ — - - .7 _i��/ T'-"._ • v-` V) s7 I-� _..1__�_.L_ �- .l - .�. -• . . r in X -� 1 `i - r' 1 v , �- I' � •'1 7• .1 1 111 1 1 I 1•+ C I 1, I r _ _ l 1 s E'_ • 1 I 1 i ! 1 Cj °• an ," - =-� - Y - - — - -j- 1 . r• 17:11 7 I i I I Hill I I I n h 1 %p A - Oe a a n -_ . � n _ - - -_ -- - - s«1 s a 0. A — _ - — - -- / JI ,�f�— C O Q - - -_ - _ -- -- —r O RI w r { —_ - -_ _ — _ _ _ M CDO 4. t —�— I! I 1 I 1 ! r r APPENDIX XI IV -A - (.moll /tayoui} X;Isua4uI fit Li o ILI CD co cn R=ah cm in LJ6 LC n. CD 1 - 1 w (j • W cm CD u = try CN cn Ln a cm y' /• %o ` lY � LY x ~ W . r I •� V j. O_ to • j •� U W � < S Q O _ CV7 x ZO '' �• Y , o pa: zo LLI IL Q h • 1 < v Z LL. -3 M 1 W , , ' o o �o ou C)bi0 .3 ac ( zQ P " �d0 : <�'� O C3 t�0LL. t 1 M 0. II-A-7 CD cmi •••_ L t _ LL cm cal o 1 .°—. ' '� ;� 1:�� = •'� r �_ 1 - ,r o '� o ell N .•. `� . 7 p �� C= cc 1 (. I o ° V. I O I ✓ o v L1. Z t: • < O vy 1 N U ^ W< .-� t Z s =c y v Dih tv� - 2 tL J Q } O e'"1 tL SC O W O ' <Y F X%j xs V O lip � M u r s NGINEERING SERVICES DEPARTMENT '* Cityo� Encinitas Capital Improvement Projects District Support Services Field Operations Sand Replenishment/Stormwater Compliance Subdivision Engineering Traffic Engineering February 27, 2003 Attn: San Diego National Bank 1420 Kettner Boulevard San Diego, California 92101 -4232 RE: Heritage Ridge II Grading Permit 7219 -G Camino Di Felicita APN 264 - 151- 36,38 -41 Final release of security Permit 7219 -GI authorized earthwork, storm drainage, site retaining wall, and erosion control, all as necessary to build the described project. The Field Inspector has approved the project. Therefore, a full release of the security deposited is merited. Letter of Credit 1662, in the amount of $297,710.00, is hereby released in its entirety. The document original is enclosed. Should you have any questions or concerns, please contact Debra Geishart at (760) 633- 2779 or in writing, attention this Department. Sincerely, L� Masih Maher J embach Senior Civil Engineer F ance Manager Field Operations Financial Services CC: Jay Lembach, Finance Manager Olivenhain Colony VIII Debra Geishart File TEL 760 - 633 -2600 / FAX 760 - 633 -2627 505 S. Vulcan Avenue, Encinitas, California 92024 -3633 TDD 760- 633 -2700 � recycled paper i City o NGINEERING SERVICES DEPARTMENT Encinitas Capital Improvement Projects District Support Services Field Operations Sand Rep lenishment /Stormwater Compliance Subdivision Engineering Traffic Engineering JLily 7, 2004 Attn: San Diego National Bank 1420 Kettner Boulevard San Diego, California 92101 -4232 RE: Heritage Ridge 11 Grading Permit 7219 -G Camino Di Felicita APN 264 -151- 36,38 -41 Final release of security Permit 7219 -GI authorized earthwork, stone drainage, site retaining wall, and erosion control, all as necessary to build the described project. The Field Inspector has approved the project and has accepted the project after the one -year warranty inspection. Therefore, a full release of the remaining security deposited is merited. Letter of Credit 1663, in the remaining amount of $6,500.00, is hereby released in its entirety. The original amount was $26,000.00. The document original is enclosed. Should you have any questions or concerns, please contact Debra Geishart at (760) 633- 2779 or in writing, attention this Department. Sincerely, Masih Maher . y Le� bach Senior Civil Engineer Finance Manager Field Operations Financial Services CC: Jay Lembach, Finance Manager Olivenhain Colony Vill Debra Geishart File TEL 760- 633 -2600 / FAX 760- 633 -2627 505 S. Vulcan Avenue, Encinitas, California 92024 -3633 TDD 760- 633 -2700 recycled paper 0 City o rGINEERING SERVICES DEPARTMENT Encinitas Capital Improvement Projects District Support Services Field Operations Sand Replenishment/Stormwater Compliance Subdivision Engineering Traffic Engineering February 27, 2003 Attn: San Diego National Bank 1420 Kettner Boulevard San Diego, California 92101 -4232 RE: Heritage Ridge II Grading Permit 7219 -G Camino Di Felicita APN 264 - 151- 36,38 -41 Partial release of security Permit 7219 -GI authorized construction of the public sewer, all as necessary to build the described project. The Field Inspector has approved the project. Therefore, a full release of the security deposited is merited. Letter of Credit 1663, in the amount of $26,000.00, is hereby reduced by 75% to a remainder amount of $6,500.00. The remainder will be released in one year after the final warranty inspection. Should you have any questions or concerns, please contact Debra Geishart at (760) 633- 2779 or in writing, attention this Department. Sincerely, Masih Maher Jay mbach Senior Civil Engineer Finance Manager Field Operations Financial Services CC: Jay Lembach, Finance Manager Olivenhain Colony VIII Debra Geishart File TEL 760- 633 -2600 / FAX 760 - 633 -2627 505 S. Vulcan Avenue, Encinitas, California 92024 -3633 TDD 760- 633 -2700 � recycled paper FROM WESTERN SOIL & FOUNDDION ENG. PHONE N0. : 760 746 4912 Mar. 07 2002 12 :25PM P2 UPDATE GEOTECHNICAL REPORT HERITAGE RIDGE TI PREVIOUSLY REVAIFELICTTA PARCEL MAP VIA DI FELICITA ENCINITAS, CALIFORNIA JOB NO. W54 MARCH 6, 2002 WESTERN SOIL AND FOUNDATION ENGINEERING, INC. FROM : WESTERN SOIL & FOU4ION ENG. PHONE NO. : 760 746 4912 Mar. 07 2002 12:25PM P3 • WESTERN SOIL AND FOUNDATION ENGINEERING, INC. PHONE: (760) 748.3558 423 HALE AVENUE FAX: (760) 740 -4912 F.Sr-ONDima, CALIFORNIA 92029 March 6, 2002 Mr. Bob Booker Venture Pacific Development P.O. Box 231639 Encinitas, CA 92023 -1639 Project: Job No. 00 -54 Heritage Ridge H Previously Reva/Felicita Parcel Map Via Di Felicita Encinitas, California Subject: Update Geotechnical Report Dear Mr. Booker: In accordance with your request, we are preserving this Update Geotechnical Report for the above referenced project. The purpose of this Update Geotechnical Report is to evaluate the current site conditions, the applicability of previous recommendations to theproposed project, and to provide additional recommendations as necessary. The results of prior investigations are presented in our report titled "Geoteclhnical Investigation, Reva/Felicita Parcel Map, Via Di Fclicita, Encinitas, California ", dated August 28, 2000. In addition, this Update Report addresses comments specifically relating to our original report that were submitted by Geopacifica, Inc. on October 16, 2001. In summary, our services for this "Update Geotechnical Report" consisted of the following: 1) Review of the previous referenced report; 2) Review of the preliminary grading plans provided by Logan Engineering; 3) Review of the memo provided by Geopacifica, Inc, dated October 16, 2001; FROM : WESTERN SOIL & FOUNW ON ENG. PHONE NO. : 760 746 4912 • Mar. 07 2002 12 : 25PM P4 Update Geotechnical Report .lab No. 00 -54 'March 6, 2002 Page 2 4) Performance of a visual surface reconnaissance of the site by our engineering and geology staff; and 5) Preparation of this report. The conclusions and recommendations presented in this report are based in part on data developed and documented during our previous investigations on the site. We also relied upon our surficial observations and our experience with the soil and geologic conditions in the site vicinity. No additional laboratory'testing or subsurface exploration was performed for this update. This report has been prepared for Venture Pacific Development to be used solely in the evaluation and design of the proposed project, This report has not been prepared for use by other parties, and may not contain sufficient information for purposes of other parties or other uses. The information in this report represents professional opinions that have been developed using that degree of we and skill ordinarily exercised, under similar circumstances, by reputable geotechnical consultants practicing in this or similar localities. No other warranty, express or implied, is made as to the professional advice included in this report. 1r NTDINGS Existing Site Conditions: Based on our visual observations, the surface conditions of the property appear to be generally similar to those documented in our original referenced report. The maj ority of the site is currently vacant and supports vegetation consisting of wild grasses and native chaparral. Proposed Development: Based on the drawings provided by Logan Engineering, the proposed project Will be the development of five residential lots. The earthwork is expected to result in maximum cuts and fills on the order of 16 feet and 14 feet, respectively, WESTERN SOIL AND FOUNDATION ENGINEERING, INC. FROM : WESTERN SOIL & FOU4ON ENG. PHONE NO. : 760 746 4912 � Mar. 07 2002 12:26PM PS Update Geotechnical Report Job No. 00 -54 March 6, 2002 Page 3 CONCLUSTONS AND RECOMMENDATIONS With the exception of those items listed below, it is our opinion that the recommendations presented in the referenced geotechnical report are, in general, applicable to the proposed development of the site as we understand it. We recommend that the items noted below be incorporated into the final design. Grading Plan Review: We have reviewed the grading plan provided by Logan Engineering dated March 6, 2002. It is our professional opinion that this grading plan is in general conformance with the recommendations presented in our referenced report. This grading plan now depicts typical removal depths, keyway widths and subdrains. Removal of Incompetent Soil: All landslide debris, colluvium and existing fill occurring within the project boundaries should be mmoved to firm naturally occurring sedimentary bedrock (siltstone or sandstone). However, backeuts for these removal areas are not anticipated to encroach into adjacent properties. The recommendations presented on page 11 or our referenced report should be followed when working near the adjacent property lines. Fill Slopes: At the time our original report was issued, the height and inclination of the proposed fill slopes were not known. We had anticipated that fill slopes would have inclinations of 2 :1 (horizontal :vertical) and vertical heights up to 25 feet. After reviewing the referenced grading plans, it is apparent that many of the slopes have inclinations of 2 and 3:1. In addition, the. vertical height of these slopes is less than the anticipated 25 feet. WESTERN SOIL AND FOUNDATION ENGINEERING, INC. FROM : WESTERN SOIL & FOU4ION ENG. PHONE NO. 760 746 4912 Mar. 07 2002 12:26PM P6 Update Geoteehnical Report Job No. 00-54 March G, 2002 Page 4 .Additional slope stability and analysis were performed using the new slope configurations and the physical engineering properties (unit weight, internal angle of friction and cohesion intercept) of the on -site soils. Our analysis indicated that fill slopes constructed with the best available on -site soil materials would exceed the generally accepted minimum safety factor of 1.5. Retaining Wall Foundations; Retaining will foundations should be entirely embedded into dense natural ground or compacted fill. The foundations should not be allowed to cross any transition (cut/fill) line. If foundations are supported in compacted fill, then grading and site preparation must Wend 5 feet horizontally beyond all sides of the foundation. If grading cannot be performed at least 5 feet beyond the wall, then the footings should be extended to dense natural soil. LIMFTATIONS 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 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 are encountered during site development should be brought to the attention of the geotechnical consultant so that they may make modifications, if necessary. WESTERN SOIL. AND FOUNDATION ENGINEERING, INC. ' FROM : WESTERN SOIL & FOU4ON ENG. PHONE NO. ; 760 746 4912 Mar. 07 2002 12:26PM P7 Update Geotechnical Report ,lob No. 00 -54 March 6, 2002 Page 5 This office should be advised of any changes in the project scope so that it maybe determined if the recommendations contained herein are appropriate. This should be verified in writing or modified by a written addendum. It is recommended that Western Soil and Foundation Engineering, Inc. be retained to provide continuous geotechnical engineering services during the earthwork operations. This is to observe 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. Western Soil and Foundation Engineering, Inc. and/or our consultants, will not be held responsible for earthwork of any kind performed without our observation, inspection and testing. 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 State -of -the -Ark 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 one year without a review by us verifying the suitabiUty of the conclusions and recommendations. We will be responsible for our data, interpretations, and recommendations, but shall not be responsible for the interpretations by others of the information developed. Our services consist of professional consultation and observation only, ad 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. WESTERN SOIL AND FOUNDATION ENGINEERING, INC. FROM : WESTERN SOIL & FOU6ION ENG. PHONE NO. : 760 746 4912 Mar. 07 2002 12:27PM P9 Update Geotechnical R.eport Job No. 00 -54 March G, 2002 Page 6 It is the responsibility of the Client or the Client's representative to ensure that the information and recommendations contained herein are brought to the attention of the enginecr and architect for the project and incorporated into the projects plans and specifications. It is further the responsibility of the Client to take the necessary measures to ensure that the contractor and sub- contractors carry out such recommendations during construction. Respectfully submitted, WFSTERN SOIL AND FOUNDATION ENGINEERING, INC. • C7 7 V 4 No 1755 * �a �k GWLOQIST Vincent W. Gaby, CEG 1755, Expires 7131/03a� Engineering Geologist t oQ �pF ESS10 No. 928 2 T Dennis E. Zimmerman, C 26676, GE 928, Expires 3/31/04 " Geotechnical Engineer Distribution: (3) Addressee (3), Logan Engineering OF CA1,1E� VWG:DEZ/lung WESTERN SOIL AND FOUNDATION ENGINEERING, INC. r ;.: L001 i GEOTECHNICAL INVESTIGATION REVA/FELICITA PARCEL MAP VIA DI FELICITA ENCINITAS, CALIFORNIA JOB NO. 00-54 AUGUST 28, 2000 I ✓r. ?GEC tlz.iV i i I I I , i i WESTERN SOIL AND FOUNDATION ENGINEERING, INC. WESTERN SOIL AND FOUNDATION ENGINEERING, INC. PHONE: (760) 746 -3553 423 HALE AVENUE FAX: (760) 746 -4912 ESCONDIDO, CALIFORNIA 92029 August 28, 2000 i I Mr. Bob Booker Venture Pacific Development P.O. Box 231639 Encinitas, CA 92023 -1639 Project: Job No. 00 -54 Reva/Felicita Parcel Map Via Di Felicita Encinitas, California i Subject: Report of Geotechnical Investigation Dear Mr. Booker: I I In accordance with your request, we have completed a geotechnical investigation for the i proposed project. We are presenting to you, herewith, our findings and recommendations for the j development of this site. The findings of this study indicate that the site is suitable for development if the recommendations provided in the attached report are incorporated into the design and construction of this project. i I Reva/Felicita Parcel Map Our Job No. 00 -54 August 28, 2000 Page 2 If you have any questions after reviewing the findings and recommendations contained in the attached report, please do not hesitate to contact this office. This opportunity to be of professional service is sincerely appreciated. Respectfully submitted, WESTERN SOIL AND FOUNDATION ENGINEERING, INC. ,G - LIJ Flo. 1755 EX ; - 3 1-01 FryGl€�' �tlidt3 ` \GE0L0Gj Vincent W. Gaby, CEG 1755 Expires 7/31/01 0 A Engineering Geologist � _ /fi:, J �� r• cr Dennis E. Zimmerman, C 26676, GE 928, Expires 3/31/04 Geotechnical Engineer .J rY Y• ; ;' f Y'' Attachments r C Distribution: (4) Addressee j VWG/DEZ:kmg WESTERN SOIL AND FOUNDATION ENGINEERING, INC. GEOTECHNICAL INVESTIGATION REVA/FELICITA PARCEL MAP VIA DI FELICITA ENCINITAS, CALIFORNIA I j Prepared For: Mr. Bob Booker Venture Pacific Development P.O. Box 231639 Encinitas, CA 92023 -1639 i i JOB NO. 00 -54 AUGUST 28, 2000 WESTERN SOIL AND FOUNDATION ENGINEERING, INC. w Table of Contents Page Introduction and Project Description ................ ............................... 1 ! Project Scope ................................... .............................. i Findings ....................................... .............................. Site Description ........................... .............................. Subsurface Conditions ...................... .............................. Santiago Formation ........................ .............................. Landslide .......................... .............................. i Colluvium ............................... ................... Rippability .................. ............................... ........... .6 Groundwater ............................. .............................. Geologic Hazards ................................ .............................. � Faults and Seismic Hazards ............... ............................... . .7 Seismicity of Major Faults ................ ............................... . 8 Liquefaction .............................. .............................. Landslides and Slope Stability ............... ............................... 9 Recommendations and Conclusions ................ ............................... 9 Site Preparation ........................... .............................. General ............................ .............................. Excavation and Shoring ............... .............................11 Expansive ...................... .............................11 Imported ....................... .............................11 Earthwork .......................... ............................. Cut Slopes ......................... ............................. Fill Slopes ............................... .............................13 Buttress Fill Slopes ........................ .............................1 Surface Drainage .................... .............................15 Subdrains .......................... ............................. WESTERN SOIL AND FOUNDATION ENGINEERING, INC. 1 Table of Contents — Cont. Page i Foundation Recommendations .............. ............................... 16 Seismic Site Categorization .......... ............................... 16 Footings........................... ............................. Concrete Slabs -On -Grade ........... ............................... 18 Post Tensioned Foundations ........... ............................. Transition Areas .................................................. 20 Lateral Resistance ................. ............................... 21 Lateral Resistance Values ........... ............................... 21 Footing Observations ............... ............................... 21 RetainingWalls ........................... ............................. Lateral Pressures .................. ............................... 22 Drainage and Waterproofing ......... ............................... 22 Backfill............................ ............................. Field Explorations ............................................................ 23 Laboratory Testing ............................... ............................. PlanReview .................................... ............................. Limitations..................................... ............................. I WESTERN SOIL AND FOUNDATION ENGINEERING, INC. I ATTACHMENTS i Plate Number 1 Site Plan (In back pocket) Plate Number 2 Unified Soil Classification Chart Plate Numbers 3 through 13 Exploratory Excavation Logs Plate Numbers 14 and 15 Laboratory Test Results Plate Number 16 Table I i Plate Number 17 Fill Slope Key APPENDIX I Specifications for Construction of Controlled Fills APPENDIX II References I � I I I I WESTERN SOIL AND FOUNDATION ENGINEERING, INC. GEOTECHNICAL INVESTIGATION REVA/FELICITA PARCEL MAP VIA DI FELICITA ENCINITAS, CALIFORNIA Introduction and Project Description This report presents the results of our geotechnical investigation performed on the above referenced site. The purpose of this investigation was to evaluate the existing surface and subsurface conditions from a geotechnical perspective and to provide recommendations for grading, foundation design, floor slab support and retaining wall design. The proposed project will be the development of a four lot parcel map with a fifth remainder lot. Building plans have not been prepared, however, it is anticipated that a one- or two -story single family residence will be constructed on each lot. We have not been provided with grading plans as of i i the date of this report. For the purposes of this evaluation, we are estimating cuts and fills on the order of 25 feet. It should be recognized that re- evaluation of our analysis may be necessary as construction documents are produced. We should be provided the opportunity to amend our recommendations if necessary, once the grading and improvement plans are finished. The site configuration and the approximate locations of our subsurface explorations are shown on the enclosed Site Plan, Plate No 1. Project Scope This investigation consisted of a surface reconnaissance coupled with a subsurface f exploration. Representative samples of soil material were obtained from the site and returned to our laboratory for observation and testing. The results of the field and laboratory data collected are presented in this report. I WESTERN SOIL AND FOUNDATION ENGINEERING, INC. I Reva/Felicita Parcel Map Our Job No. 00 -54 August 28, 2000 Page 2 Specifically, the intent of this investigation was to: a) Explore the subsurface conditions to the depths that could be influenced by the proposed construction; b) Evaluate, by laboratory tests, the pertinent static physical properties of the various soil and rock stratigraphic units which could influence the development of this project; C) Describe the site geology, including potential geologic hazards and their effect upon the proposed development; d) Provide recommendations for site preparation and grading; e) Present recommendations for foundation and retaining wall design, including bearing capacity, estimated settlements, lateral pressures, and expansion potential of the on -site soils. This report has been prepared for Venture Pacific Development to be used in the evaluation of the referenced site. This report has not been prepared for use by other parties, and may not contain sufficient information for purposes of other parties or other uses. The information in this report represents professional opinions that have been developed using that degree of care and skill ordinarily exercised, under similar circumstances, by reputable geotechnical consultants practicing in this or similar localities. No other warranty, express or implied, is made as to the professional advice included in this report. WESTERN SOIL AND FOUNDATION ENGINEERING, INC. Reva/Felicita Parcel Map Our Job No. 00 -54 August 28, 2000 Page 3 Findings Site Description: The project site is located on the south side of the east end of Via Di Felicita, I in the community of Olivenhain, in the city of Encinitas, California. The site vicinity can be found in the northeast quarter of grid A -5, Page 1148, of the Thomas Brothers Guide for San Diego County, 1999 edition. The subject property is nearly rectangular in configuration and encompasses approximately 6 acres. It is bounded to the east, west and south by residential property. Approximately 386 feet front Via Di Felicita along the northern property line. A private road/utility easement straddles the I property's east boundary. The majority of the site is situated on the north facing hillside of an eastwardly trending ridge. The terrain varies from gently inclined to moderately steep. Elevations range from approximately 270 feet above mean sea level (m.s.l.) on top of the ridge to 140 feet m.s.l. at the northwest property corner. No improvements were observed on the site at the time of our investigation. The site was vacant and covered with scattered wild grasses. Subsurface Conditions: The subject site is underlain by Eocene age lagoonal sediments that have been mapped by Tan and Kennedy (1996) as the Santiago Formation. The formational materials are covered with recent and older landslide deposits. The surface of the site is mantled with a thin to moderately thick layer of colluvium. Each unit is described below beginning with the oldest. I WESTERN SOIL AND FOUNDATION ENGINEERING, INC. Reva/Felicita Parcel Map Our Job No. 00 -54 , August 28, 2000 Page 4 Santiago Formation: The Santiago Formation is represented on site by dark green, clayey to sandy siltstone with interbedded lenses of silty, fine grained sandstone. Individual beds vary from 2 to 6 feet in thickness and dip gently (0 to 5 degrees) to the southwest. The siltstone is moderately fissle and varies from poorly to moderately well cemented. The Santiago Formation was encountered in our exploratory excavations at depth ranging I from 6 to 33 feet. Near the contact with overlying soil materials, the Santiago Formation exhibits fractures, dessication cracks and zones of white caliche precipitate. These are indications that the weathered siltstone may be prone to creep and slope failure. i Landslide Debris: Geomorphic features associated with landsliding are observable on the site. i These features include bulging lobe - shaped topography within the northern one -third of the site, head scarps within the southern portion of the site, tension cracks on the slope face, closed depressions and a damaged roadway. Based on the field evidence, it is apparent that at least two episodes of significant movement have occurred on this site. The first involved the development of original landslide debris and is identified on the attached Site Plan, Plate No. 1, as older I landslide deposits (QLSO)• It appears that a reactivation along a portion of the original slide plane i occurred approximately 20 years ago. This reactivated landslide created the most obvious topographic features described at the beginning of this section. The resulting deposits are mapped on our referenced site plan as recent landslide deposits (QLSR)• WESTERN SOIL AND FOUNDATION ENGINEERING, INC. i I Reva/Felicita Parcel Map Our Job No. 00 -54 August 28, 2000 Page 5 1 In general, the two landslide units are similar in character. Both consist of grayish -green to dark green with orange mottling, sandy to very clayey silt. Bedding is obscured or severely contorted. In addition, the older landslide deposits contain discontinuous wedges of intact but rotated stratigraphy. The recent landslide deposits appear to be significantly more fractured and contain trapped lenses of colluvial soil. The landslide debris is very moist, poorly consolidated i and ranges from soft to stiff in apparent consistency. The results of laboratory tests performed on i samples of the landslide debris indicate that it has an expansion potential that varies from low to very high. In its present condition, it is not considered suitable to support foundations, fill or constructed embankments. I Colluvium: At the locations explored, poorly consolidated colluvium ranging from 1 1 /2 to 5 feet in thickness was observed mantling the landslide and formational materials. It generally consisted of dark brown, very silty, fine grained sand that graded with depth to dark brown, clayey silt. At the time of our investigation, it varied from damp to very moist and was porous. The results of laboratory testing performed on samples of the colluvium indicated that it had a high expansion potential. In its present condition, the colluvium is not considered suitable for the support of foundations or fill. i I I I i WESTERN SOIL AND FOUNDATION ENGINEERING, INC. Reva/Felicita Parcel Map Our Job No. 00 -54 August 28, 2000 Page 6 i i y Recommendations for the removal and recompaction of existing soils are presented I within this report. Thicker or poorer quality materials may be encountered at locations that were not explored. I Rippability: The exploratory trenches were excavated with moderate to little difficulty by a JD 410E backhoe. These trenches ranged from 11 to 16 feet in depth. The exploratory borings were excavated with little difficulty to depths of approximately 35 feet. Based on our field observations, it appears that the majority of the materials to be exposed during grading may be excavated with I conventional earthmoving equipment. It is possible that resistant bedrock and/or boulders may be encountered at locations that were not explored. 1 I Groundwater: Free groundwater was observed as slow seepage in our exploratory borings. This seemed to occur near the contact of the landslide debris and Santiago Formation. There were no observable indications of perched water in the shallow exploratory trenches. It should be noted that fluctuations of subsurface water will be affected by variations in i annual precipitation and local irrigation. Moreover, it has been our experience that periodic j events of seepage will occur in areas of significant "cut" or any "below- grade" structures. Therefore, consideration must be given to appropriate surface and subsurface drainage systems such as underdrains and swales as recommended further in this report. i I WESTERN SOIL AND FOUNDATION ENGINEERING, INC. Reva/Felicita Parcel Map Our Job No. 00 -54 August 28, 2000 Page 7 Geologic Hazards Faults and Seismic Hazards: The numerous fault zones in southern California include active, potentially active, and inactive faults. Active faults are those which display evidence of movement within Holocene time (from the present to approximately 11 thousand years). Faults that have I ruptured geologic units of Pleistocene age (11 thousand to 2 million years) but not Holocene age materials, are considered potentially active. Inactive faults are those which exhibit movement that is older than 2 million years. According to available published information, there are no known active or potentially active faults which intercept the project site. The site is not located i within an Alquist -Priolo Special Studies Zone. Therefore, the potential for ground rupture at this site is considered low. There are, however, several faults located in close proximity that movement I associated with them could cause significant ground motion at the site. The table below presents the maximum credible earthquake magnitudes and estimated peak accelerations anticipated at the site. These accelerations are based on the assumption that I the maximum credible earthquake occurs on specific faults at the closest point on that particular fault to the site. The maximum credible earthquake is defined as the maximum earthquake that appears to be reasonably capable of occurring under the conditions of the presently known geologic framework. The probability of such an earthquake occurring during the lifetime of this project is considered low. The severity of ground motion is not anticipated to be any greater at i this location than in other areas of San Diego County. , WESTERN SOIL AND FOUNDATION ENGINEERING, INC. Reva/Felicita Parcel Map Our Job No. 00 -54 August 28, 2000 Page 8 Seismicity of Major Faults Maximum Estimated Credible Bedrock Distance Magnitude Acceleration (1) Fault (Miles) (Richter) (g) Coronado Banks 23 7.6L (2) 0.25 Elsinore 25 7.5 L(3) 0.23 1 Rose Canyon 8 7.0 L (2) 0.41 I San Andreas 74 8.3L (3) 0.07 San Jacinto 49 7.8L (3) 0.12 L = Local Magnitude (1) Seed and Idriss, 1982 (2) Slemmons, 1979 (3) Greensfelder, C.D.M.G. Map Sheet 23, 1994 Liquefaction: The potential for seismically induced liquefaction is greatest where shallow ground- water and poorly consolidated, well sorted, fine grained sands and silts are present. Liquefaction potential decreases with increasing density, grain size, clay content and gravel content. Conversely liquefaction potential increases as the ground acceleration and duration of seismic shaking increase. j Although minor subsurface seepage was observed within our explorations, the site is underlain by stiff sediments with significant clay content. Based on the consistency of the underlying materials and the anticipated recompaction of overburden soils, the potential for generalized liquefaction in the event of a strong to moderate earthquake on nearby faults is considered low. WESTERN SOIL AND FOUNDATION ENGINEERING, INC. Reva/Felicita Parcel Map Our Job No. 00 -54 August 28, 2000 Page 9 Landslides and Slope Stability: Landslide deposits and topographic features typical of landsliding were observed on the site and the site vicinity. At the locations explored, landslide debris extended to depths as great as 33 feet. The base of the landslide debris is typically represented by shear zones ranging from thin ( /z inch or less) fractured clayey, silt seams to a 2 -inch thick slide plane consisting of wet, remolded clay. In addition to the landslide debris, the weathered formational materials are fractured and contain discontinuous sheared clay seams. This suggests that these materials are prone to shallow 4 failure and soil creep. Observation of the cut slopes during and after grading will be important to identify potential shallow slope failures. It is anticipated that any incompetent soil materials encountered during the earthwork may be i mitigated as recommended fiarther in this report. It is our opinion that the potential for slope failure on this project is low if grading is performed in accordance with the recommendations contained in this report. Recommendations and Conclusions Site Preparation General: The poorly consolidated overburden soils ( colluvium and landslide debris) encountered during our subsurface exploration are not considered suitable for the support of foundations, floor slabs i or new fill in their present condition. To provide more uniform support for the proposed structures and prior to the placement of any new fill, we recommend that any existing fill, colluvium, landslide debris or otherwise unsuitable material be completely removed to firm undisturbed natural ground. I i WESTERN j SOIL AND FOUNDATION ENGINEERING, INC. i f Reva/Felicita Parcel Map Our Job No. 00 -54 August 28, 2000 Page 10 The horizontal limits of removal and recompaction shall include the entire areas of proposed structures, fill or any proposed fill slopes. All soil removal and replacement should extend at least 5 feet beyond the footprint of any structures and shall be accomplished in accordance with the earthwork and foundation recommendations presented in this report. ` Based on the results of our field explorations, it appears that the depth of removal will range from 10 to 35 feet. Table I (Plate No. 16) of this report presents anticipated removal depths in the area of our subsurface explorations. Thicker and/or less competent materials may be encountered at locations that were not explored. Unsuitable soils that occur beneath areas to receive retaining walls, asphalt or concrete pavements, driveways, patio slabs, sidewalks or any other improvements shall be treated similarly. i The on -site soils minus any debris or organic material may be used as controlled fill. j Selective grading and fill placement is recommended further in this report for critical areas such as slope construction and building pad capping. All fill shall be compacted to at least 90% of its I maximum dry density as determined by ASTM D1557 -91. The moisture content at the time of compaction should be within 2% of optimum for non - expansive soils and between 2% and 4% over optimum for the clayey materials. All debris, organic matter or oversized materials (greater I than 6 inches in maximum dimension) encountered must be removed and legally disposed of at a i I, licensed disposal site. If groundwater is encountered during the removal and recompaction of the soil, or if difficulty is experienced in achieving the minim of 90% relative compaction (ASTM D1557 -91), I then this office shall be consulted for further recommendations. WESTERN SOIL AND FOUNDATION ENGINEERING, INC. Reva/Felicita Parcel Map Our Job No. 00 -54 August 28, 2000 Page 11 Excavation Adjacent to Property Lines: As currently proposed, improvements may occur within 5 feet of property line. Removal depths adjacent to existing off site structures should be evaluated by the Soil Engineer or Engineering Geologist during construction. Depending on the soil conditions encountered, one or more of the following recommendations may be implemented: • Maintain a set -back of at least 50 feet from the top of the removal excavation to the adjacent property line; • Perform the removal and recompaction in a series of slots with an approximate width of 20 feet (measured parallel to the affected property line). The recompacted slots should be at least 25 feet long as measured perpendicular to the affected property line; • Install shoring designed by a structural engineer registered in the state of California. These are general recommendations provided without the benefit of having reviewed a preliminary grading plan. These recommendations will likely be subject to modification after the grading plan has been prepared. I i Expansive Soil: Detrimentally expansive soils (Expansion Index of 21 or greater) were encountered I during our subsurface exploration. These materials occurred within the colluvium, landslide debris I and formational materials. We recommend that these soils be placed within the deeper proposed fill areas or legally exported from the site. Potentially expansive soil should not be placed within 4 feet of finish grade for conventional foundations, or 2 feet of finish grade when post tensioned foundations are j used. Expansive soils should not be used as wall backfill, within 4 feet of finish subgrade in paved or hard- scaped areas, or within 15 feet of the face of any constructed slope. i WESTERN SOIL AND FOUNDATION ENGINEERING, INC. Reva/Felicita Parcel Map Our Job No. 00 -54 August 28, 2000 Page 12 Imported Fill: Imported fill, if required at this site, shall be approved by our office prior to i importing. We should be given ample time to sample and test potential import soil prior to its delivery to this site. Imported fill material shall have an Expansion Index of 20 or less with not more than 25 percent passing the No. 200 U.S. standard sieve. It shall have an internal angle of friction of not less than 28 degrees, and a cohesion intercept between 200 and 400 psf when compacted to 90 percent of maximum dry density (ASTM D1557 -91). Earthwork: All earthwork performed on -site must be accomplished in accordance with the attached Specifications for Construction of Controlled Fills (Appendix 1). All special site preparation recommendations presented in the sections above will supersede those in the Standard Specifications for Construction of Controlled Fills. All embankments, structural fill, and utility trench backfill j shall be compacted to no less than 90% of its maximum dry density. The moisture content of the granular fill soils should be within 2% of optimum moisture content at the time of compaction. The moisture content of the clayey soil materials should be maintained between 2% and 4% over optimum moisture content. The maximum dry density of each soil type shall be determined in accordance with ASTM D1557 -91. Prior to commencement of the brushing operation, a pregrading meeting shall be held at the site. The Developer, Surveyor, Grading Contractor, and Soil Engineer should attend. Our firm should be given at least 3 days notice of the meeting time and date. I Cut Slopes: It is our opinion that cut slopes excavated completely within competent unfractured natural soil or rock materials at an inclination of 2:1 (horizontal to vertical) or flatter would be stable to a maximum height of 15 feet. WESTERN SOIL AND FOUNDATION ENGINEERING, INC. i Reva/Felicita Parcel Map Our Job No. 00 -54 August 28, 2000 Page 13 Proposed cut slopes that occur in colluvium, landslide debris, adversely fractured formation materials, or any proposed slopes cut into incompetent soil material shall be evaluated by the Soils Engineer or Engineering Geologist. Additional remedial actions may be required to mitigate the effects of detrimental slope conditions. When feasible this would likely include complete removal of all incompetent soil and then reconstruction of the slope as a fill slope in accordance with the recommendations below. Temporary shoring may be necessary for the support of adjacent properties. If complete removal is deemed not feasible then a buttress fill shall be constructed. Recommendations for buttress fill slopes are presented on page 14. Fill Slopes: It is our opinion that fill slopes constructed at an inclination of 2:1 (horizontal to i vertical) or flatter will be stable to a maximum height of 25 feet. Fill slopes shall be keyed into dense natural ground. The key shall extend through all incompetent soil and be established at least 2 feet into dense competent material. The key shall be a minimum of 2 feet deep at the toe of slope and fall with 5% grade toward the interior of the proposed fill areas. The bottom of the key shall have a width of at least 15 feet (Plate No. 17). i All keys must be inspected by the Soil Engineer, Engineering Geologist or their representative in the field. �I The soil material placed within the outer 15 feet of any fill slope, as measured inward horizontally from the face of the slope, should consist of on -site or imported granular soil material within an expansion index of 20 or less. Fill slopes constructed with clayey or expansive soils may experience creep and/or surficial failure. I WESTERN SOIL AND FOUNDATION ENGINEERING, INC. t Reva/Felicita Parcel Map Our Job No. 00 -54 August 28, 2000 Page 14 i We recommend that slopes be compacted by backrolling with a loaded sheepsfoot roller at vertical intervals not to exceed 4 feet and should be track walked at the completion of each slope. The face of the slopes should be compacted to no less than 90 % relative compaction (ASTM D1557 -91). This can best be accomplished by overbuilding the slope at least 4 feet and trimming to design finish slope grade. Buttress Fill Slopes: Buttress fill slopes shall be constructed in general conformance with the I recommendations for fill slopes above with the following exceptions. • The keyway shall be excavated no less than five (5) feet into competent formational material. • Backdrains shall be installed at the heel of the keyway and on alternating benches. Backdrains will utilize similar dimensions and materials as described in this report under the heading subdrains. Backdrains shall connect to non - perforated down drains at a maximum spacing of 100 feet. • The width of the buttress fill shall be between 30 and 20 feet, measured horizontally inward from face of slope. • From bottom of the keyway at the toe of the slope to a vertical height of 10 feet above toe elevation the buttress fill should have a width of no less than 35 feet. • From a vertical height of 10 feet to 20 feet above the toe of slope, the buttress should have a width that gradually decreases from 35 to 20 feet. The soil materials used in construction of the buttress may consist of import or best i available on -site soil material. Buttress soil should have an internal angle of friction equal to or greater than 28 degrees and a cohesion intercept between 200 and 400 psf when compacted to 90 percent of its maximum dry density (ASTM 1557 -91). WESTERN i SOIL AND FOUNDATION ENGINEERING, INC. i I Reva/Felicita Parcel Map Our Job No. 00 -54 August 28, 2000 Page 15 Surface Drainage: Surface drainage shall be directed away from structures and paved areas. The ponding of water or saturation of soils should not be allowed adjacent to any of the foundations. We recommend that planters be provided with drains and low flow irrigation systems. Gutter, roof drains and other drainage devices shall discharge water away from the structure into surface drains and storm sewers. i Surface water must not be allowed to drain in an uncontrolled manner over the top of any slope or excavation. I The exterior grades should be sloped to drain away from the structures to minimiz ponding I of water adjacent to the foundations. Minimum site gradients of at least 2% in the landscaped areas and of I% in the hardscaped areas are recommended in the areas surrounding buildings. i These gradients should extend at least 10 feet from the edge of the structure. i To reduce the potential for erosion, the slopes shall be planted as soon as possible after grading. Slope erosion, including sloughing, rilling, and slumping of surface soils may be I anticipated if the slopes are left unplanted for a long period of time, especially during rainy seasons. Swales or earth berms are recommended at the top of all permanent slopes to prevent surface water runoff from overtopping the slopes. Animal burrows should be controlled or eliminated since they can serve to collect normal sheet flow on slopes, resulting in rapid and i destructive erosion. Erosion control and drainage devices must be installed in compliance with the requirements of the controlling agencies. I I WESTERN SOIL AND FOUNDATION ENGINEERING, INC. i i i Reva/Felicita Parcel Map Our Job No. 00 -54 Page 16 August 28, 2000 I led at the toe of slopes Subdrains: A subdrain system shall be instal es draining into the property, P ! within buttress or stability fills or where fill is proposed over canyons or drainage areas. The final determination for the location of the subdrains shall be made by the Soil Engineer or Engineering Geologist during the site grading. i The subdrain shall consist of a trench at least 36 inches deep and 18 inches wide. Mirafi 140N or Amoco 4547 non -woven geotextile fabric, or an approved equivalent, shall line the bottom and sides of the trench. Four inches of 3/4 -inch rock bedding shall be placed on the geotextile at the bottom of the trench. A 4 -inch diameter perforated pipe shall be placed in the trench with the perforations down. The pipe shall be ABS schedule 40 (ASTM- D1785) or SDR 26 (ASTM- D2241) or approved equal. The drainpipe shall have a minimum 1% gradient and shall be centered within the trench horizontally. The subdrain should be attached to clean -out risers at intervals not to exceed 100 feet. A minimum of 3 cubic feet of 3/4 -inch rock per linear foot of subdrain shall be placed over and around the pipe within the geotextile lined trench. The i geotextile shall lap at least 12 inches over the top of the rock. The subdrain shall outlet away from any structures or slopes in an approved legal manner. I Foundation Recommendations Seismic Site Categorization: The following seismic site categorization parameters may be used for foundation design. These design parameters are based on the information provided in Chapter 16 of the 1997 Uniform Building Code. WESTERN i SOIL AND FOUNDATION ENGINEERING, INC. I . j Reva/Felicita Parcel Map Our Job No. 00 -54 August 28, 2000 Page 17 Soil Profile Type = S Near Source Factor N = 1.0 Near Source Factor N„ = 1.0 Seismic Source Type = B l Footings: The on -site overburden soils (colluvium and landslide debris) are not considered i suitable for foundation or floor slab support. To provide more uniform support we recommend i that proposed structures be entirely supported on compacted fill. Conventional footings should be underlain by at least 2 feet of compacted soil that has an expansion index of 20 or less. Footings shall be designed with the minimum dimensions and allowable dead plus live load soil bearing values given in the following table: I Footings Established on Compacted Fill Minimum Minimum Allowable ' Building Depth Width Soil Bearing Height (inches) (inches) Value (p.s.£) One Story 12 12 1,500 Two Story 18 15 2,000 The minimum depth given shall be below lowest adjacent finish subgrade. If I foundations are proposed adjacent to the top of any slope, we recommend that the footings be deepened to provide a horizontal distance of 8 feet between the outer edge of the footing and the adjacent slope face. WESTERN SOIL AND FOUNDATION ENGINEERING, INC. Reva/Felicita Parcel Map Our Job No. 00 -54 August 28, 2000 Page 18 The soil load bearing values presented above may be increased by one -third for short term loads, including wind or seismic. The soil load bearing values of any imported soil should be determined after its selection but prior to its delivery on -site. All continuous footings shall be reinforced in accordance with recommendations provided I by a Structural Engineer. Settlements under building loads are expected to be within tolerable limits for the proposed structure. Concrete Slabs -On- Grade: If the soils are prepared as recommended in this report, concrete slabs -on -grade may be supported entirely on compacted fill. Soil material placed within 4 feet of I finish floor should have an expansion index of 20 or less. No cut/fill transitions should be allowed to occur beneath the structure. ( To provide protection against vapor or water transmission through the building and floor slabs, we recommend that the slabs -on -grade be underlain by a 4 -inch layer of Caltrans Class 2 i i permeable material or gravel. A suggested gradation for the gravel layer is as follows: I Sieve Size Percent Passim 3/4" 90 -100 No. 4 0 -10 i No. 100 0 -3 WESTERN 1 SOIL AND FOUNDATION ENGINEERING, INC. i Reva/Felicita Parcel Map Our Job No. 00 -54 August 28, 2000 Page 19 If the slab -on -grade is underlain by at least 4 feet of granular compacted fill, the gravel layer may be replaced by 4 inches of clean sand. An impermeable membrane as described below { should be placed at the midpoint of the sand layer. I In areas where vinyl or other moisture - sensitive floor coverings are planned or where moisture may be detrimental to the structure's contents, we recommend that the 4- inch -thick gravel layer be overlain by a 10 -mil -thick impermeable plastic membrane to provide additional protection against water vapor transmission through the slab. The vapor barrier should be i installed in accordance with the manufacturer's instructions. We recommend that the edges be sealed. To protect the membrane during later concrete work, to facilitate curing of the concrete, and to reduce slab curling, a 2- inch -thick layer of clean sand shall be placed over the membrane. If sand bedding is used, care should be taken during concrete placement to prevent displacement of the sand. A low -slump concrete (4 -inch maximum slump) should be used to fizrther minimize possible curling of the slabs. The concrete slabs should be allowed to cure properly before placing vinyl or other moisture- sensitive floor covering. j Slab reinforcing and thickness shall be designed in accordance with the anticipated use i and loadings on the slab and as recommended by the Structural Engineer. Construction joint spacing and placement shall be provided by the Structural Engineer. I WESTERN SOIL AND FOUNDATION ENGINEERING, INC. Reva/Felicita Parcel Map Our Job No. 00 -54 August 28, 2000 Page 20 ` Post Tensioned Foundations: Post tensioned foundations should be designed using the following I parameters: Thornthwaite Moisture Index: -20 { Edge Moisture Variation Distance; e n , Edge Lift Loading Conditions: 2.6 Center Lift Loading Conditions: 5.3 I Percent of Clay: 50 Predominant Clay Mineral: Montmorillonite Depth to Constant Soil Suction: 5 Feet Constant Soil Suction, pF: 3.6 Velocity of Moisture Flow: 0.5 inches /month Differential Swell, y n j Center Lift: 1.36 inches Edge Lift: 0.32 inches I i Transition Areas: Any proposed structures should not be allowed to straddle a cut -fill transition line. Footings and floor slabs should be entirely supported on cut or entirely on fill. The tendency of cut and fill soils to compress differently can frequently result in differential settlement, cracking to portions of the structure and in severe cases structural damage. To reduce the potential for damage due to differential settlement in transition areas, we recommend that on pads where the i maximum fill thickness is less than 15 feet, cut areas be over - excavated to a depth of at least 2 j feet below the bottom of the deepest footing and replaced with very low expansive soil material I compacted to at least 90% of its maximum dry density (ASTM D1557 -91). If the fill thickness exceeds 15 feet (including removal and recompaction of incompetent soil) the cut portion should be over - excavated 4 feet below the bottom of the deepest footing. The compacted fill should extend at least 5 feet beyond the building floor plan. WESTERN SOIL AND FOUNDATION ENGINEERING, INC. i Reva/Felicita Parcel Map Our Job No. 00 -54 August 28, 2000 Page 21 f Lateral Resistance: Resistance to lateral loads may be provided by friction at the base of the I footings and floor slabs and by the passive resistance of the supporting soils. Allowable values of frictional and passive resistance are presented for the fill soils in the table below. The frictional resistance and the passive resistance of the materials may be combined without reduction in f determining the total lateral resistance. i Lateral Resistance Values I Allowable Coefficient Passive Pressure Soil Type of Friction (psf/ft of depth) Compacted Fill 0.20 225 (Expansion Index 0 -20) Footing Observations: Prior to the placement of reinforcing steel and concrete, all foundation excavations shall be inspected by the Soil Engineer, Engineering Geologist or their representative. Footing excavations shall be cleaned of any loosened soil and debris before i placing steel or concrete. Footing excavations should be observed and probed for soft areas. Any soft or disturbed soils shall be over - excavated prior to placement of steel and concrete. Over - excavation of soils should not be performed in locations that were undercut for transition I areas. This would compromise the thickness of the soil supporting the footings. In undercut transition areas loose soils should be recompacted. WESTERN SOIL AND FOUNDATION ENGINEERING, INC. • Reva/Felicita Parcel Map Our Job No. 00 -54 August 28, 2000 Page 22 Retaining Walls Lateral Pressures: We are providing these recommendations in the event that retaining walls are constructed on site. Our analysis anticipated retaining walls constructed to a maximum height of 10 feet. These recommendations should be reviewed and updated as needed once wall I heights and types are determined. For the design of cantilevered retaining walls where the backfill consists of well drained; very -low expansive soil, the equivalent fluid pressures for both active and at -rest conditions are presented below. l Backfill Active Pressure At -rest Pressure Inclination (p c f) - P .c. L) I Level 40 55 2:1 slope 55 70 I Drainage and Waterproofing: If the backfill is placed and compacted as recommended herein and good surface drainage is provided, the infiltration of water into the wall backfill may be reduced. Adequate drainage of adjacent planters should likewise be provided to reduce water infiltration into wall backfills. To limit the entrapment of water in the backfill behind the proposed walls, backdrains or other drainage measures should be installed. Drainage should consist of vertical gravel drains about 12 inches wide connected to a 4- inch - diameter perforated pipe. The pipe shall be ABS schedule 40 (ASTM- D1785) or SDR 26 (ASTM- D2241) or approved equal. The perforated pipe should be I placed with the perforations down and should be surrounded by at least 1 foot of filter gravel or uniformly graded gravel or Caltrans Class 2 permeable material wrapped in geosynthetic filter fabric, such as Mirafi 140N or approved equivalent. Care should be taken to select a filter fabric compatible i with the backfill materials as clogging of the filter material may occur. WESTERN SOIL AND FOUNDATION ENGINEERING, INC. Reva/Felicita Parcel Map Our Job No. 00 -54 August 28, 2000 Page 23 The drain pipe should be located near the base of the wall and should discharge into a storm drain or onto a surface draining away from the structure. As an alternative to the vertical gravel drains, a drainage geocomposite such as Miradrain, or an approved equivalent, may be used with a 4 inch - diameter perforated pipe collector drain. Backfill: The exterior grades should be sloped to drain away from the structures to minimize I ponding of water adjacent to the foundations and retaining walls. Compaction of the backfill as I recommended herein will be necessary to reduce settlement of the backfill and associated settlement of the overlying walks, paving, and utilities. All backfill should be compacted to at least 90% of the maximum dry density (ASTM D1557 -91). i Some settlement of the backfill should be anticipated, and any utilities supported therein should be designed to accept differential settlement, particularly at the points of entry to buildings. Also, provisions should be made for some settlement of concrete walks on -grade and other hardscapes supported on fill. Field Explorations Subsurface conditions were explored by excavating eight backhoe trenches on July 18, I 2000 and three borings on July 25, 2000. The exploratory trenches were 24- inches in width, approximately 15 feet long and extended to depths ranging from 11 to 16 feet. The exploratory borings were approximately 30 inches in diameter and reached maximum depths of 35 feet. No caving occurred in the excavation walls. Groundwater was observed in the deep borings at approximately 28 to 30 feet below the surface. The locations of the exploratory excavations are depicted on the Site Plan, Plate No. 1, in the back pocket of this report. I WESTERN i SOIL AND FOUNDATION ENGINEERING, INC. i Reva/Felicita Parcel Map Our Job No. 00 -54 August 28, 2000 Page 24 The surface reconnaissance and subsurface exploration were conducted by our geology and soil engineering personnel. The soils are described in accordance with the Unified Soil Classification System as illustrated on the attached simplified chart (Plate No. 2). In addition, a I verbal textural description, the wet color, the apparent moisture and the density or consistency are presented. The density of granular material is given as either very loose, loose, medium dense, dense or very dense. The consistency of silts or clays is given as either very soft, soft, medium stiff, stiff, very stiff or hard. The sampling and logging of our exploratory excavations were performed using standard geotechnical methods. The logs are presented on Plate No. 3 through Plate No. 13. Samples of typical and representative soils were obtained and returned to i our laboratory for observation and testing. Laboratory Testing Laboratory tests were performed in accordance with the American Society for Testing and Materials (ASTM) test methods or suggested procedures. Test results are shown on Plate No. 14 and Plate No. 15. j Plan Review Western Soil and Foundation Engineering, Inc. should review the final grading and building plans for this project. i WESTERN SOIL AND FOUNDATION ENGINEERING, INC. f Reva/Felicita Parcel Map Our Job No. 00 -54 August 28, 2000 Page 25 Limitations i The recommendations presented in this report are contingent upon our review of final plans and specifications. The geotechnical consultant should review and verify the compliance of the final plans with this report. It is recommended that Western Soil and Foundation Engineering, Inc. be retained to provide continuous geotechnical engineering services during the earthwork operations. This is to observe 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. Western Soil and Foundation Engineering, Inc. and/or our consultants, will not be held responsible for earthwork of any kind performed without our observation, inspection and testing. 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 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 are encountered during site development should be brought to the attention of the geotechnical consultant so that they may make modifications, if i necessary. WESTERN SOIL AND FOUNDATION ENGINEERING, INC. i Our Job No. 00 -54 Reva/Felicita Parcel Map Page 26 August 28, 2000 1 This office should be advised of any changes in the project scope so that it may be determined if the recommendations contained herein are appropriate. This should be verified in writing or modified by a written addendum. f 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 C or the work of man on this or adjacent properties. In addition, changes in the State -of -the -Art V and/or Government Codes may occur. Due to such changes, the findings of the 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 one year without a review by us verifying the suitability of the p conclusions and recommendations. We will be responsible for our data, interpretations, and recommendations, but shall not be responsible for the interpretations by others of the information developed. Our services consist of professional consultation and observation only, and no warranty of any kind I 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. I i I WESTERN SOIL AND FOUNDATION ENGINEERING, INC. Reva/Felicita Parcel Map Our Job No. 00 -54 August 28, 2000 Page 27 It is the responsibility of the Client or the Client's representative to ensure that the information and recommendations. contained herein are brought to the attention of the engineer and architect for the project and incorporated into the project's plans and specifications. It is further the responsibility of the Client to take the necessary measures to ensure that the contractor and sub - contractors carry out such recommendations during construction. Respectfully submitted, WESTERN SOIL AND FOUNDATION ENGINEERING, INC. t�D 0 A. No. 1755 � 4=�eP .7- 31-ol EFsl iFIED ENGINEEPING GEOLOGIST� \�° Vincent W. Gaby, CEG 1755 Expires 7/31/01 9 o�C -� Engineering Geologist � i�F E r; No 928 Dennis E. Zimmerman, C 26676, GE 928, Expires 3/31/04 Geotechnical Engineer �' q �� VWG/DEZ:kmg If` C i i I WESTERN SOIL AND FOUNDATION ENGINEERING, INC. i I i ATTACHMENTS I i I I i I 'i I WESTERN SOIL AND FOUNDATION ENGINEERING, INC. i i SITE PLAN (Plate No. 1) In Back Pocket i I i i WESTERN j SOIL AND FOUNDATION ENGINEERING, INC. _ Z TRENCH NO. T -1 Z z\ w �•- a O ELEVATION 250± w F- v w QN �~ W� U)Z HU W v SAMPLING N v w g Q = a N N METHOD JD 410E BACKHOE a 0 a z a O w N Q Q V O U O D V DESCRIPTION v SM = COLLUVIUM - Dark Brown, Very Silty, Fine Damp Loose _1 1- — Grained Sand _ = To - - grades to 2- B MH -2 Dark Brown, Sandy, Clayey Silt Very Stiff _ - - Moist 3- -3 4- i ML_ LANDSLIDE DEBRIS - Mottled Dark Green and Moist Soft _4 _ Orange, Clayey, Sandy Silt To To H Very - Moist -5 5 - - _ grades to 6- - -6 ML _ Discontinuous Beds of Fractured, Very Medium 7- To Dark Green Siltstone with Moist Stiff -7 - SPS Interbedded, Pale Green, Fine to and and _ .. Medium Grained Sandstone Moist Medium 8- \ Dense -8 9- -10 10- _ ML = SANTIAGO FORMATION - Dark Green, Clayey Very Very To Siltstone with Moist Stiff - • Interbedded and and -11 11- MFI.:� Yellowish- Green, Moist Medium and Silty, Fine to Medium Dense _ - - Grained Sandstone =SM - -12 12- 1 ' ' -13 3- 14- C -14 Bedding Dipping Gently to the Southwest 115.4 19.0 15- — -15 BOTTOM OF TRENCH @ 15 FEET 16- -16 SAMPLE LEGEND B = Bulk Sample - 17- C = Chunk Sample -17 JOB NUMBER DATE LOGGED LOGGED BY 00 -54 REVAIFELICITA PARCEL MAP 7 - - VWG SUBSURFACE EXPLORATION LOG Plate No.3 Z TRENCH NO. T- 2 r w a 0 ELEVATION 265± z W Z z j p w W an � U) W LL U) Z � I LL W - LL SAM a y p U N g a = CL N METHOD JD 410E BACKHOE CL O a z a O w Uj g a� ao p U o p p DESCRIPTION U U { — T. _ =.SM COLLU - Brown, Very Silty, Fine Grained Sand Damp Loose _ _ LANDSLIDE DEBRIS - Pale Green, Silty, Very Damp Loose - = Fine to Fine Grained Sandstone, 2- ; _ Extremely Fractured _2 3- _• • COLLUVIUM - Brown, Very Silty, Fine Grained Sand Damp Loose -3 -4 4- = F �L _ LTo LANDSLIDE DEBRIS - Dark Green, Clayey, Very Soft - Siltstone, Fractured with Caliche Moist To 5- _ MH Precipitate, Clods of Pale Yellow, Silty Sand Medium _5 Stiff 6 _ MH SHEAR ZONE - Dark Green, Sheared, Fractured, Very Medium -6 Clayey Siltstone Moist Stiff -7 7- MH SANTIAGO FORMATION - Green, Clayey Siltstone Very Stiff l _ rt 8- � grades to - -8 _ _ -9 9- — ML• Dark Green, Sandy Siltstone, Moist Very _ - - Moderately Cemented Stiff 10- C J To 136.3 9.9 -10 Hard 11- -11 BOTTOM OF TRENCH @ 11 FEET -12 12- -13 13- -14 14- -15 15- i 16- - -16 - 17- 17 JOB NUMBER DATE LOGGED LOGGED BY 00 - 54 REVA/FELICITA PARCEL MAP 7 -18 -00 VwG SUBSURFACE EXPLORATION LOG Plate No.4 j z TRENCH NO. T 3 v w e w z � - j w w a ELEVATION 245± z Z z N > O w > U. r aN a ay SAMPLING zLL i �.z t-� LL , - F =. U_ w JU a0 az >a 0z WC a a N METHOD JD 410E BACKHOE a a p o O O e N g DESCRIPTION U - SM = COLLUVIUM - Dark Brown, Very Silty, Fine Damp Loose - _ Grained Sand -1 1- To - _:'• grades to MH - -2 2- Dark Brown, Clayey Silt Very Medium Moist Stiff - 3- _ -3 4 -4 - Caliche Precipitate Forming in Lower 2 Feet -5 5- - ML LANDSLIDE DEBRIS - Mottled Dark Brown and Very Medium -6 6- -- r Yellowish- Brown, Clayey, Sandy Silt Moist Stiff - C 91.7 14.3 -7 7- -- _ MH LANDSLIDE DEBRIS - Mottled Pale Green and Very Soft _ Orange, Sandy, Very Clayey, Silt Moist To -8 Medium 8- B T Stiff 9 - -9 _ -10 10- 11- 12- 7 Plane N50 °E /45 °NW -12 Pale Green, -13 7. 13- — Remolded, Sheared, - - _ Clay y Silt -14 14- H - SANTIAGO FORMATION - Dark Green, Very Stiff -15 15- - To Clayey Siitstone, Fractured Moist Very - Stiff -16 16- BOTTOM OF TRENCH @ 16 FEET -17 17- JOB NUMBER DATE LOGGED LOGGED BY 00 -54 REVA/FELICITA PARCEL MAP 7 -18 -00 VWG SUBSURFACE EXPLORATION LOG Plate No.5 _ Z TRENCH NO. T -4 �- a O ELEVATION 230± F- w �- Z ~ W Lu =r v SAMPLING Q DU tA� JQ 2 a y N METHOD JD 410E BACKHOE a 0 a z a O w 0 Q� Q� U O DES G v CRIPTION U SM COLLUVIUM - Dark Brown, Silty Sand Damp Loose - 1 _ ' -To grades to -1 Very Medium M T- Moist Stiff - Dark Brown, Clayey Silt 2- -2 M_ H LANDSLIDE DEBRIS - Green, Fractured, Clayey Very Soft _ Silt Moist 3- -3 grades to - 4 - - -4 - P Fractured, Clayey, Sandy Siltstone Very Loose _ _M .= Moist 6- F Caliche Filled Shear Dipping North 200 _g 7- —_ __ -7 g_ - ML= SANTIAGO -$ To - FORMATION - Dark Green, _ - - = Clayey Siltstone Very Hard 9 _ = Moist -9 - grades to � 1 -10 0- Moist Dense SM • -; Green, Very Silty, Very Fine to Fine Grained 11- %� • Sandstone, Moderately Cemented -11 -.- 12- Moderately Fractured with Caliche Filling -12 BOTTOM OF TRENCH @ 12 FEET 13- -13 14- -14 15- -15 i 16- -16 17- -17 JOB NUMBER DATE LOGGED LOGGED BY 00 -54 REVA /FELICITA PARCEL MAP 7.18 -00 VwG i SUBSURFACE EXPLORATION LOG Plate No .6 Z TRENCH NO. T- 5 } l w O 2171 East -� � w f- V w° w Z w W a F ELEVATION Z Z Z Lu > O w Lu ��- Qy �y ZLL HZ HH U. E SAMPLING a- U a N W w a U. J J U U gQ CL N METHOD JD 410E BACKHOE Q a 0" 2 0 2 w g QU U 0 U) DESCRIPTION U - _ ML COLLUVIUM - Dark Brown, Very Sandy Silt Moist Soft - 1- To To -1 - 77 grades to - T MH . _ Very Stiff _2 2- -_ � Dark Brown, Sandy, Clayey Silt Moist - 3 _ -3 - _ - ML -: LANDSLIDE DEBRIS - Green with Orange Very Soft - To Mottling, Sandy, Clayey Silt Moist -4 Sheared, Clayey Silt, Dark Green -5 5 =7 �_ -6 6- - B LANDSLIDE LANDSLIDE Very Soft 7- DEBRIS - DEBRIS - Moist _7 Pale Yellow, , Dark Green, Green, Very Clayey Clayey, Silt -8 8- — Sandy Silt 9- _ ML- LANDSLIDE F 2' t - - To - DEBRIS - -10 i 10- MH - Dark Green, _ Clayey Siltstone, - Moderately Fractured -11 11- grades to _ 12- Green, Very Silty, Very Very -12 -- Fine to Fine Grained Moist - Sandstone Soft -13 13- BOTTOM OF TRENCH @ 13 FEET _ -14 14- -15 15- -16 16- I -17 17- JOB NUMBER DATE LOGGED LOGGED BY 00 -54 REVA/FELICITA PARCEL MAP 7.18.00 VwG SUBSURFACE EXPLORATION LOG Plate No.7 Z TRENCH NO. T- 6 >- o w a ELEVATION 175± Z Z Z - W\ > O W H W= W~ ZLL �Z HF- LL W -1 - SAMPLING a CO X W V CO w g Q = (L U) in METHOD JD 410E BACKHOE a O a s Z °.: O Z a a w a g CL 4: 2 O n W W < a� a° o V o 0 L) DESCRIPTION -: SM COLLUVIUM - Dark Brown, Very Silty, Fine Grained Sand Damp Loose - "- grades to -1 1- '• .:. Dark Brown, Sandy, Clayey Silt Moist Medium - 2- = -2 ^ ML.- LANDSLIDE DEBRIS- Green, Clayey, Sandy Silt with Very Soft - T Pockets of Brown, Silty, Fine Grained Moist - 3- Sand -3 grades to _4 4- -� MH= Dark Green, Clayey Silt with Very Soft 5- Convoluted, Interbedded Lenses of Moist and _5 _ Yellowish- Brown, Silty, Fine to Loose - — Medium Grained Sand -6 6 •SM 7- C 90.8 28.5 -7 8- -8 _ Well - Developed -g 9 - - - Precipitate Nearly Horizontal to Dipping into Slope 5° SW Layer on - _ = r Shear Plane -10 10- 1= - CH - - - 1 SHEAR PLANE - Dark Green Sheared Clay, Approx. 2" ThickVe Moist Soft ML _ SANTIAGO FORMATION - Dark Green, Clayey Siltstone _ Moist 13- M Very Hard -11 11- To Moderately Fractured with M Oxidation Staining - 12- - -12 -13 - 14- BOTTOM OF TRENCH @ 14 FEET -14 - 15- 15 16- -16 17- -17 JOB NUMBER DATE LOGGED LOGGED BY 00 -54 REVA /FELICITA PARCEL MAP 7 - - VWG i SUBSURFACE EXPLORATION LOG Plate No. s Z TRENCH NO. T- 7 >- w a ELEVATION 165± z z Z -�- j p w F QN W~ W L% I ~ U W -� LL SAMPLING Q V) o a n a. U) (n METHOD JD 410E BACKHOE Q a 0 O It 2 w Q O U 0 N V DESCRIPTION Mhi - COLLUVIUM - Dark Brown, Sandy, Clayey Silt Moist Medium Stiff _ 2- '— -2 Very Medium - MH LANDSLIDE DEBRIS - Dark Grayish - Brown, Moist Stiff 3- Clayey Silt -3 4- grades to _4 5- _� Dark Grayish- Green, Clayey Silt, Very Soft -5 MH � _ Very Fractured with Caliche Moist To Precipitate Medium - _ Stiff -6 -7 7- _ Becomes Sheared with Caliche Lined Fractures -8 MH SANTIAGO FORMATION - Dark Green, Clayey Very Stiff _ - To = Siltstone Moderately Fractured Moist -9 9 - - ML grades to y `- -10 10- �. Very Hard -- Greenish- Brown, Sandy, Clayey Siltstone Moist - - -11 BOTTOM OF TRENCH @ 11 FEET -12 12- - -13 13- -14 14- -15 15- - 16- 16 -17 j 17- JOB NUMBER DATE LOGGED LOGGED BY 00 -54 REVA /FELICITA PARCEL MAP 7 -18 -00 VWG SUBSURFACE EXPLORATION LOG Plate No.9 Z TRENCH NO. T- 8 W } a ELEVATION 160± z Z Z Z �° j p W UJ Qy Xy uj HZ h-H LL SAMPLING a- v N Q = a (L y U) METHOD JD 410E BACKHOE a n 0 a g O W g w 5 a o U O en DES o U CRIPTION - = MH - LANDSLIDE DEBRIS - Dark Grayish -Green Very Soft and - Siltstone with Contourted Moist To _ 1- SM = Interbedded Lenses of Pale Yellow Medium Sandstone Extremely Fractured Stiff - 2- 3- -3 Very Undulating Contact _ 4- _ - = 4 - MH - COLLUVIUM - Dark Grayish- Brown, Clayey Silt Very Medium Moist Stiff -5 - ML LANDSLIDE DEBRIS - Dark Grayish- Green, Very Medium _ 6= -.To -_ Slightly Sandy Clayey Silt Moist Stiff _ M HO grades to -7 7- - - H Green, Clayey Silt, Very Fractured and Very Soft _g To g_�_ _ Desiccated Moist Medium _ - - grades to Stiff 9- -9 - MH� Dark Green, Clayey Siltstone, Fractured � -10 10- Very Very _ MH rt SANTIAGO FORMATION - Dark Green, Clayey -_ T Siltstone Moderately Fractured with Moist Stiff 11- Oxidation Staining To -11 Hard a grades to -12 12- H = Grayish -Green with Red Mottling, Slightly Very Stiff — Waxy, Clayey Siltstone, Fractured Moist -13 i 13- _ = grades to Very Very = ML - Green, Sandy Siltstone Moist Stiff 1 -14 14- BOTTOM OF TRENCH @ 14 FEET _ -15 15- -16 16- -17 17- JOB NUMBER DATE LOGGED LOGGED BY 00 - 54 REVA /FELICITA PARCEL MAP 7 -18 -00 VWG SUBSURFACE EXPLORATION LOG Plate No. 10 Z BORING NO. B-1 F- H w ELEVATION 210 ± w z w m D f- p 0 u W V SAMPLING a N a Cn o v N~ v _ Uj lu = oJ. O LL METHOD 30 INCH DIAMETER AUGER a - o- m a O Z w a CL 2 mCn a� ap � �O _jn. w w N g DESCRIPTION a v o v m o U -Z- MH _ COLLUVIUM - Dark Brown, Sandy, Clayey Silt Damp Medium _ To Stiff _ Very To - Moist Stiff - - -5 5- _ - ML LANDSLIDE DEBRIS - Pale Green with Orange, Very Medium _ - To. Mottling, Sandy, Clayey Silt Moist Stiff _ MH grades to -10 10- — • T - = MH_ Pale Yellowish- Green, Very Clayey Silt Very Medium -15 15- Moist Stiff _ — - To grades to Stiff 20- B MH= Pale Yellowish -Green with Orangish- Very Medium -20 Brown Mottling Very Clayey Silt Moist Stiff _ To Stiff - grades to - _ -25 25- _ MH _ Dark Green, Very Fractured, Clayey Silt Very Stiff with Caliche Precipitate Moist - - B NCH _ SLIDE PLAN - Dark Green, Sheared Clay Wet Soft - r (Fractured Near Contact) 30- -ML SANTIAGO FORMATION - Dark Green, Slightly Very Very -30 To Clayey, Sandy Siltstone Moist Stiff _ To MH ••_ •. Hard - _ o Hard Groundwater Seepage @ 33 Feet - - - .glyj SANTIAGO FORMATION - Orange, Silty, Fine to Very Dense - Medium Grained Sandstone, Moderately Moist 35- -35 Well Cemented - I � - BOTTOM OF BORING @ 37 FEET -40 40- JOB NUMBER DATE LOGGED LOGGED BY 00 - 54 REVA /FELICITA PARCEL MAP 7 -25 -00 VWG SUBSURFACE EXPLORATION LOG Plate No 11 Z BORING NO. B-2 >' i- LU a ELEVATION 222 t z w t_ z�- = w H ~ W LL H W V z IL SAMPLING a N - 00 y = LU _ -� J V METHOD 30 INCH DIAMETER AUGER a _ a N a. p 1- a. 2 U) U) Q� a0 � 2 0 �a w W N g DESCRIPTION a o 0 m o U = ML= COLLUVIUM - Dark Brown, Sandy, Clayey Silt Damp Medium = To Stiff � MH, Very To - Moist Stiff r -5 5- SC' LANDSLIDE DEBRIS - Brownish- Orange, Clayey, Very Medium - - Fine to Medium Grained Sand Moist Dense _ t�E_ � To �`- grades to Dense 10- ML Pale Green, Sandy, Clayey Silt Very Medium -10 To Moist Stiff MH - - - MH Dark Green, Very Clayey Silt, Very Very Medium _ Fractured Moist Stiff 15- -15 Contact Dips West - I - _CH LANDSLIDE DEBRIS - Dark Brown, Sandy Clay Wet Soft - _ To with with Fragments of Dark Green To j 20 7 -20 Medium .SC 7 Siltstone with Contorted Interbeds - _ ; � o T of Brownish - Orange, Clayey Sand Stiff _ f MH and Dark Green, Clayey Silt - ' grades to 25- - MH - Dark Green, Clayey Silt with Caliche Very Medium -25 — Precipitate Moist Stiff - CH -7 - - SLIDE PLANE - Dark Green Clay Wet Soft - _ =y : Groundwater @ 29 Feet = - 30 - ML SANTIAGO FORMATION - Dark Green, Sandy Very Very - _ Siltstone, Fractured with Fractured Moist Stiff - T ' Clayey Silt Seams To To - Wet Hard _ - grades to _ = Very Very - . 4 35 Pale Green, Sandy, Clayey Siltstone Moist Stiff -35 - BOTTOM OF BORING @ 35 FEET - i 4 -40 40- DATE LOGGED LOGGED BY JOB NUMBER REVA /FELICITA PARCEL MAP 7 -25 -00 VWG 00 -54 SUBSURFACE EXPLORATION LOG Plate No. 12 i w z BORING NO. B -3 v w Z w P ELEVATION 225 t SOUTH -� Z Z w m == w J J V SAMPLING Q y y w v v W V CL a. N U) METHOD 30 INCH DIAMETER AUGER Q Q O a 0 O a w w N g DESCRIPTION V m V m U = i- MH = COLLUVIUM - Dark Brown, Sandy, Clayey Silt Damp Medium = To Stiff Moist To __ - - grades to Stiff - i. MH. Brown, Very Clayey Silt Very - 5 5- Moist Stiff i ML LANDSLIDE DEBRIS - Yellowish- Brown, Sandy, Very Medium ? To• Clayey Silt Moist Stiff MH = with Sheared, Contorted - Interbeds of Pale _10 10- Yellowish- Green, _ _ Clayey Silt - = MH Very Medium _ Moist Stiff To - 15- = — Stiff -15 _ SM •. OLDER LANDSLIDE DEBRIS - Pale Yellow, Silty, Moist Medium _ Fine to Medium Grained Sandstone Dense _ To Dense - �� -20 20- _ Dark Green, Slightly Clayey, Very Stiff - Sandy Silt with Caliche Moist - Precipitate _ Qr ' ' �•.. Very Medium -25 25- , _ _ Pale Gray, Clayey, Fine to Moist Dense : _ Medium Grained Sandstone To - _ Dense - _ s' MH _ - Dark Green, Clayey Silt, Very Very Medium - 30- Fractured, Large Caliche Zones Moist Stiff -30 To To _ — Wet Stiff _ — Thin, Caliche Lined Shear Zone _ v_ M H SANTIAGO FORMATION - Dark Green, Fractured, Very Very - Clayey Siltstone Moist ry t St ff 35- — Groundwater Seepage @ 35 Feet -35 To � Wet _ BOTTOM OF BORING @ 37 FEET I - -40 40 — _ JOB NUMBER DATE LOGGED LOGGED BY 00 -54 REVAIFELICITA PARCEL MAP 7 -25-00 VWG SUBSURFACE EXPLORATION LOG Plate No 13 LABORATORY TEST RESULTS f Maximum Density /Optimum Moisture Maximum Optimum Dry Moisture Sample Density Content Lo cation Description (pcfl (percent) T -3 @ 8' Pale Green, Sandy, Clayey Silt 113.0 17.0 T -5 @ 8' Yellowish- Green, Clayey, Sandy Silt 116.5 15.0 B -1 @ 20' Green, Clayey Silt 114.5 17.0 i Direct Shear Angle of Apparent Internal Sample Cohesion Friction Location (Psf) (deg rees) * T -3 @ 8' 500 24 * T -5 @ 8' 525 23 ** B -1 @ 28' 155 19 * Sample remolded to 90 percent of maximum dry density and 3 percent over optimum moisture content. Sample was saturated prior to testing. ** Sample remolded to in -place moisture and density. Plate No. 14 WESTERN SOIL AND FOUNDATION ENGINEERING, INC. LABORATORY TEST RESULTS - Cont. Expansion Index Initial Final Sample Moisture Moisture Expansion Expansion Lo cation Content ( %) Content ( %) Index Potenti T -1 @ 2' 12.4 31.5 121 High T -5 @ 8' 12.4 25.0 48 Low B -1 @ 20' 14.8 39.9 158 Very High 1 In -Place Density and Moisture Sample Dry Density Moisture Location (pcfl percent T -1 @14' 115.4 19.0 T -2 @ 10' 136.3 9.9 T -3 @ 6% 91.7 14.3 T -6 @ 7' 90.8 28.5 B -1 @ 28' 89.3 35.1 I i Plate No. 15 WESTERN SOIL AND FOUNDATION ENGINEERING, INC. I FILL SLOPE KEY PROJECTED PLANE 1 TO 1 MAXIMUM FROM TOE OF NATURAL GROUND SLOPE TO APPROVED GROUND FILL � . 00 � TOE OF SLOPE .0 00 00 00 40 � . P ��NM P 00 0- '.wo �� E .00 00 00 � � • NSO'C ..0 0. 0-.000 8' MINIMUM BENCH 00 COMPETENT EARTH / 0 MATERIAL �0- 00 � 2' S% MINIMUM � � I TYPICAL BENCH MINIMUM BASE KEY WIDTH (HEIGHT VARIES) 15' MINIMUM DOWNSLOPE BACKDRAINS MAY BE REQUIRED PER KEY DEPTH RECOMMENDATIONS OF SOILS ENGINEER I REVA/FELICITA PARCEL MAP JOB NO. 00 -54 DATE: 08 -25 -00 Plate No. 17 WESTERN SOIL AND FOUNDATION ENGINEERING, INC. l I APPENDIX I I I I I I I i 1 i WESTERN j SOIL AND FOUNDATION ENGINEERING, INC. 1. SPECIFICATIONS FOR CONSTRUCTION OF CONTROLLED FILLS I General Description: The construction of controlled fills shall consist of adequate geotechnical J investigations, and clearing, removal of existing structures and foundations, preparation of land to be filled, excavation of earth and rock from cut area, compaction and control of the fill, and all other work necessary to complete the grading of the filled area to conform with the lines, grades, and slopes as shown on the accepted plans. Clearing And Preparation Of Areas To Be Filled: (a) All fill control projects shall have an investigation or a visual examination, depending upon the nature of the job, performed by a qualified soil engineer prior to grading. (b) All timber, trees, brush, vegetation, and other rubbish shall be removed, piled and burned, or otherwise disposed of to leave the prepared area with a finished appearance free from unsightly debris. (c) Any soft, swampy or otherwise unsuitable areas, shall be corrected by drainage or removal of compressible material, or both, to the depths indicated on the plans or as directed by the soil engineer. j(d) The natural ground which is determined to be satisfactory for the support of the filled ground shall then be plowed or scarified to a depth of at least six inches (6 ") or deeper as specified by the soil engineer, and until the surface is free from ruts, hummocks, or other uneven features which would tend to prevent uniform compaction by the equipment to be used. I (e) No fill shall be placed until the prepared native ground has been approved by the soil j engineer. (f) Where fills are made on the hillsides with slopes greater than 5 (horizontal) to 1 (vertical), horizontal benches shall be cut into firm undisturbed natural ground to provide lateral and vertical stability. The initial bench at the toe of the fill shall be a least 10 feet in width on firm undisturbed natural ground at the elevation of the toe stake. The soil engineer shall determine the width and frequency of all succeeding benches which will vary with the soil conditions and the steepness of slope. (g) After the natural ground has been prepared, it shall be brought to the proper moisture content and compacted to not less than 90% of maximum density, A.S.T.M. D1557 -91. l WESTERN SOIL AND FOUNDATION ENGINEERING, INC. (h) Expansive soils may require special compaction specifications as directed in the report of geotechnical investigation by the soil engineer. (i) The cut portions of building pads may require excavation and recompaction for density compatibility with the fill as directed by the soil engineer. Materials: The fill soils shall consist of select materials graded so that at least 40 percent of the material passes the No. 4 sieve. The material may be obtained from the excavation, a borrow pit, or by mixing soils from one or more sources. The material used shall be free from vegetable matter, and other deleterious substances, and shall not contain rocks or lumps greater than 6 inches in diameter. If excessive vegetation, rocks, or soils with unacceptable physical characteristics are encountered, these materials shall be disposed of in waste areas designated on the plans or as directed by the soil engineer. If soils are encountered during the grading operation which were not reported in the report of geotechnical investigation, further testing will be required to ascertain their engineering properties. Any special treatment recommended in the preliminary or subsequent soil reports not covered herein shall become an addendum to these specifications. No material of perishable, spongy, or otherwise unstable nature shall be used in the fills. Placing, Spreading And Compacting Fill Material: (a) The selected fill material shall be placed in layers which shall not exceed six inches (6 ") when compacted. Each layer shall be spread evenly and shall be thoroughly blade -mixed during the spreading to insure uniformity of material and moisture in each layer. (b) When the moisture content of the fill material is below that specified by the soil engineer, water shall be added until the moisture content is near optimum as determined by the soil engineer to assure thorough bonding during the compacting process. (c) When the moisture content of the fill material is above that specified by the soil engineer, the fill material shall be aerated by blading and scarifying, or other satisfactory methods until i the moisture content is near optimum as determined by the soils engineer. (d) After each layer has been placed, mixed and spread evenly, it shall be thoroughly compacted to not less than the specified maximum density in accordance with A.S.T.M. D1557 -91. I Compaction shall be by means of tamping or sheepsfoot rollers, multiple -wheel pneumatic - tired rollers, or other types of rollers. Rollers shall be of such design that they will be able to compact the fill to the specified density. Rolling of each layer shall be continuous over its entire area and the roller shall make sufficient passes to obtain the desired density. The entire area to be filled shall be compacted to the specified density. WESTERN SOIL AND FOUNDATION ENGINEERING, INC. i (e) Fill slopes shall be compacted by means of sheepsfoot rollers or other suitable equipment. Compacting operations shall be continued until the slopes are stable and until there is no appreciable amount of loose soil on the slopes. Compacting of the slopes shall be accomplished by backrolling the slopes in increments of 3 to 5 feet in elevation gain or by other methods producing satisfactory results. i (f) Field density tests shall be made by the soil engineer for approximately each foot in elevation gain after compaction, but not to exceed two feet in vertical height between tests. The location of the tests in plan shall be spaced to give the best possible coverage and shall be taken no farther than 100 feet apart. Tests shall be taken on comer and terrace lots for each two feet in elevation again. The soil engineer may take additional tests as considered necessary to check on the uniformity of compaction. Where sheepsfoot rollers are used, the tests shall be taken in the compacted material below the disturbed surface. No additional layers of fill shall be spread until the field density tests indicate that the specified density has been obtained. (g) The fill operation shall be continued in six inch (6 ") compacted layers, as specified above, until the fill has been brought to the finished slopes and grades as shown on the accepted plans. Supervision: Supervision by the soil engineer shall be made during the filling and compacting operations so that he /she can certify that the fill was made in accordance with accepted specifications. The specifications and soil testing of subgrade, subbase, and base materials for roads, or other public property shall be done in accordance with specifications of the governing agency. i Seasonal Limits: No fill material shall be placed, spread, or rolled during unfavorable weather conditions. When the work is interrupted by heavy rain, grading shall not be resumed until field i tests by the soil engineer indicate that the moisture content and density of the fill are as previously specified. In the event that, in the opinion of the engineer, soils unsatisfactory as foundation material i are encountered, they shall not be incorporated in the grading, and disposition will be made at the engineer's discretion. 1 i WESTERN i SOIL AND FOUNDATION ENGINEERING, INC. i I I APPENDIX H I I I I I i i I i r I WESTERN I SOIL AND FOUNDATION ENGINEERING, INC. w REFERENCES CITED Greensfelder, R.W., 1974, Maximum Credible Rock Accelerations from Earthquakes in California: CDMG Map Sheet 23. Seed, H.B. and Idriss, I.M., 1982, Ground Motions and Soil Liquefaction During Earthquakes, EERI Monograph Series. Slemmons, D.B., 1979, 'Evaluation of Geomorphic Features of Active Faults for Engineering Design and Siting Studies ", Association of Engineering Geologists Short Course. Tan, S. and Kennedy, M.P., 1996, Geologic Maps of the Northwestern Part of San Diego County, California: CDMG Open -File Report 96 -02. Weber, Harold F. Jr., 1982, Recent Slope Failures, Ancient Landslides, and Related Geology of The North - Central Coastal Area, San Diego County, California: CDMG Report 82 -12. Wilson, Kenneth L., 1972 Eocene and Related Geology of a Portion of the San Luis Rey and Encinitas Quadrangles San Diego County, California: Masters Thesis, U.C. Riverside. I I I i WESTERN SOIL AND FOUNDATION ENGINEERING, INC.