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2006-409 G - City O(ENGINEERING SERVICES DEPARTMENT Encinitas Capital Improvement Projects District Support Services Field Operations Sand Replenishment/Stormwater Compliance Subdivision Engineering Traffic Engineering November 10, 2008 Attn: Bank of America, N.A. 1000 W. Temple Street 7th Floor, CA9-705-07-05 Los Angeles, CA 90012-1514 RE: Albert and Sandra Bertha 3364 Calle Margarita APN 264-240-20 Grading Permit 409-GI Final release of security Permit 409-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 grading and finaled the project. Therefore, a full release of the security deposited is merited. Letter of Credit 3088430, (in the original amount of$122,219.00), reduced by 75% to $30,554.75, is hereby released in 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, f Debra Geishart i J em ch Engineering Technician ance Manager Subdivision Engineering Financial Services Cc: Jay Lembach,Finance Manager Albert and Sandra Bertha Debra Geishart File Enc. TEL 760-633-2600 / FAX 760-633-2627 505 S. Vulcan Avenue, Encinitas, California 92024-3633 TDD 760-633-2700 �� recycled paper *, City OfENGINEERING SERVICES DEPARTMENT Encinitas Capital Improvement Projects District Support Services Field Operations Sand Replenishment/Stormwater Compliance Subdivision Engineering Traffic Engineering September 25, 2008 Attn: Bank of America, N.A. 1000 W. Temple Street 7t"Floor, CA9-705-07-05 Los Angeles, CA 90012-1514 RE: Albert and Sandra Bertha 3364 Calle Margarita' APN 264-240-20 Grading Perm Partial release Permit 409-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 rough grading. Therefore, a reduction of the security deposited is merited. Letter of Credit 3088430, in the amount of$122,219.00, may be reduced by 75% to $30,554.75. The document original is enclosed. The retention and a separate assignment guarantee completion of finish grading. Should you have any questions or concerns, please contact Debra Geishart at (760) 633- 2779 or in writing, attention this Department. Sincerely, G� Debra Geish " y Le bach Engineering Technician Finance Manager Subdivision Engineering Financial Services Cc: Jay Lembach,Finance Manager Albert and Sandra Bertha 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 e CHRISTIAN WHEELER ENGINEERING UUI_ 31 2007 July 27, 2007 Albert and Sandra Bertha C``(/E 2060364.04 3364 Calle Margarita Encinitas, California 92024 SUBJECT: EXCAVATION OBSERVATION LETTER FOR PROPOSED ACCESSORY UNIT AND GARAGE,3364 CALLE MARGARITA,ENCINITAS,CALIFORNIA. References: 1) Report of Preliminary Geotechnical Investigation,Proposed Accessory Unit and Garage, 3364 Calle Margarita,Encinitas,California,by Christian Wheeler Engineering,Report No. 2060364.01,dated June 23,2006. 2) Revised Preliminary Grading Plans for:Bertha Residence Accessory Unit,3364 Calle Margarita,Encinitas,California,California,by Conway and Associates,Inc.,dated September 28,2006. Dear Mr. and Mrs. Bertha: In accordance with the request of Mr.Dennis Hauswirth of Castillero Design and Construction,we have prepared tlus letter to summarize our observation of the excavation for the proposed accessory unit and garage. Based on our observation, the excavation exposed competent,Tertiary-age materials of the Santiago Formation.We understand that the excavation elevation represents the finish pad grade for the proposed accessory unit and garage and no fills were placed to achieve this grade. If you have any questions after reviewing this letter,please do not hesitate to contact our office. This opportunity to be of professional service is sincerely appreciated. Respectfully submitted, �pFESS/p� ' CHRISTIAN WHEELER ENGINEERING OQ N C. GO C,q`9 t2G' No.C62983 �M L9 Exp.6-30-08 XM Shawn C. Cava, RCE 62983 s C W\- SCC:wm �� OFCA1-1F� cc: (1) Submitted (1) Ston+ook Castles !1 Castillero Design and Construction,Att: Dennis Hauswirth,3536 Dove Hollow Road,Olivenhain,CA 92024 (1) Via Fax:Att: Dennis Haumrth,Fax No. 858-759-1879 4925 Mercury Street + San Diego, CA 92111 + 858-496-9760 + FAX 858-496-9758 Conway & Associates, fom- Clvil Engineers/Surveyors/General-Engineering Contractors AB412412 2525 Pio Pico Drive•Suite 102•Carlsbad,CA 92008•Telephone(760)753-1453•Fax(760)434-5831 July 24, 2007 City of Encinitas f`•1 (� r� Engineering Services I -` 505 South Vulcan Avenue �I I JUL 2 5 2001 Encinitas, CA 92024 L �'! Project: Grading Plan 0409-G /03 -0*ci TPN\ E�1c!!!Er.hnvc S RViCES 3364 Calle Margarita C!TY or Er,Clti!TAS Subject: Engineer's Pad Certification for Release of Building Permit - Provisional To Whom it May Concern: p,,,, 6" Pursuant to section 23.24.3 10 of the Encinitas Municipal Code, this letter is hereby submitted as a Pad Certification Letter for 3364 Calle Margarita, Encinitas, grading permit 0409-G. As the Engineer of Record for the subject project, I hereby state the rough grading for the new building pad was completed in conformance with the approved plans and requirements of the City of Encinitas' codes and standards. VII. The following provides the pad elevations as field verified and shown on the approved grading plan: Pad Elevation Pad Elevation Per Location Per Plan Field Verification Pad-1 330.50 •-' 330.57.E Pad-2 329.00✓ 328.93 Pad-3 331.67 v, 331.72 ' VIII. Constraration of line and grade for-ag-efigineer-ed drainage devices and fetaining walls haA�e been fi verified and are in substantial eenfefmanee with N/A -see note below. IX. The location and inclination of all manufactured slopes and walls have been field verified and are in substantial conformance with the subject grading plan. X. The construction of earthen berms and positive building pad drainage have been field verified and are in substantial conformance with the subject grading plan. The field verification of the pad elevations noted herein was provided by Lorne Da Pron, L.S. 7824 per field data collected on July 20, 2007 as noted in their letter dated July 23, 2007 —see attached. Note: Provision VIII does not apply at this time and the extent of substantial conformance with provisions IX and X are limited as the site is rough graded for building basement wall construction, but the wall construction, backfill and storm drain construction has not yet commenced. The City Engineer will contact the owner if future grade verifications are required. Submitted by, Q,,p F E S S t,y Conway& Associates, Inc. at 1. K. p q� e � Cz No.41022 Michael K. Pasko, P.E. * EXPIRES 3-31-2009 Cr Engineer of Record �qrF OF CA1 cc: Albert Bertha, owner pA06-003 bertha\wordproc\enc07O724-pad_cert.doc GEOCENTRIC N I? MA i' July 23 ,2007 Mike Pasko Conway and Associates, INC. 2525 Pio Pico Drive, Carlsbad, CA 92008 760-753-1453 tel., 760-434-5831 fax Re: Surveyor's Pad Certification for Bertha Residence and Grading Permit No. 0409-G I hereby state that rough grading elevations for the Bertha Residence have been completed_ The following list provides the pad elevation as field verified and shown on the approved grading plan: Pad Elevation Pad Elevation per Location Per Plan field Measurement Proposed Basement 33050 330.57 329.00 323.93 331.67 331.72 71Z 3)0-7 Lorne Da Pron O � Date � Na.7824 LS 7824 * EW 12131/2007 x �k CAt.��'a¢�~� a :C!:7"' ". # 46,. Conway & Associates, Inc. Civil Engineers/Surveyors/General-Engineering Contractors A13412412 2525 Pio Pico Drive•Carlsbad,CA 92008•Telephone(760)753-1453•Fax(760)434-5831 Date: September 26, 2008 City of Encinitas Engineering Services - Permits 505 South Vulcan Ave. Encinitas, CA 92024 Re: Engineer's Final Grading Certification for a Portion of TPM 03-049 and Grading Permit Number 0409-G Bertha Residence — 3364 Calle Margarita — APN 264-240-20 The grading under permit number 0409-G has been performed in substantial conformance with the approved grading plan or as shown on the attached 'As Graded' plan. Final grading inspection has demonstrated that lot drainage conforms with the approved grading plan and that swales drain at a minimum of I%to the street and/or an appropriate drainage system. All the Low Impact Development, Source Control and Treatment Control Best Management Practices as shown on the drawing, and required by the Best Management Practice Manual Part II and as shown on the approved drawing, were constructed and are operational, together with the required maintenance covenant(s). � Q�ppESS/D Engineer of Record �,`�p ja q Dated September 26,2008 No.41022 d EXPIRES 3-31-2009 a �r�rE l V 11 O��Q OF CA1.0F Verification by the Engineering Inspector of this fact is done by the Inspector's signature hereon and will take place only after the above is signed and stamped and will not relieve the Engineer of Record of the ultimate responsibility: Engineering Inspector Dated Miileserver\projects\06-003 bertha\wordproc\0409-g_as_graded-2.doc Conway & Associates, Inc. Civil Engineers/Surveyors/General-Engineering Contractors A13412412 2525 Pio Pico Drive•Suite 102.Carlsbad,CA 92008•Telephone(760)753-1453•Fax(760)434-5831 September 26, 2008 City of Encinitas Engineering Services 505 South Vulcan Avenue Encinitas, CA 92024 Project: Grading Plan 0409-G 3364 Calle Margarita Subject: Engineer's Pad Certification for Release of Building Permit - Final To Whom it May Concern: Pursuant to section 23.24.3 10 of the Encinitas Municipal Code, this letter is hereby submitted as a Pad Certification Letter for 3364 Calle Margarita, Encinitas, grading permit 0409-G. As the Engineer of Record for the subject project, I hereby state the rough grading for the new building pad was completed in conformance with the approved plans and requirements of the City of Encinitas' codes and standards. VII. The following provides the pad elevations as field verified and shown on the approved grading plan: Pad Elevation Pad Elevation Per Location Per Plan Field Verification Pad-1 330.50 330.57 Pad-2 329.00 328.93 Pad-3 331.67 331.72 VIII. Construction of line and grade for all engineered drainage devices and retaining walls have been visually inspected and are in substantial conformance with the subject grading plan. IX. The location and inclination of all manufactured slopes and walls have been field verified and are in substantial conformance with the subject grading plan. X. The construction of earthen berms and positive building pad drainage have been field verified and are in substantial conformance with the subject grading plan. The field verification of the pad elevations noted herein was provided by Lorne Da Pron, L.S. 7824 per field data collected on July 20, 2007 as noted in their letter dated July 23, 2007 —see attached. Submitted by, Conway& Associates, Inc. RG F E S S'o 1. K. Michael K. Pasko, P.E. y Cz No.41022 Engineer of Record d EXPIRES 3-31-2009 lF OF C A O' cc: Albert Bertha, owner \\fileserver\projects\06-003 berth a\wordproc\enc08O926-pad_cert.doc Conway & Associates, l„c. Civil Engineers/Surveyors/General-Engineering Contractors A13412412 2525 Pio Pico Drive•Suite 102•Carlsbad,CA 92008•Telephone(760)753-1453•Fax(760)434-5831 July 24, 2007 ffll City of Encinitas ---_�Engineering Services 505 South Vulcan Avenue Encinitas, CA 92024 JUL 2 5 2007 Project: Grading Plan 0409-G 10 1----- - -- -, ,. 3364 Calle Margarita Subject: Engineer's Pad Certification for Release of Building Permit - Provisional To Whom it May Concern: p,a, 6” Y Pursuant to section 23.24.3 10 of the Encinitas Municipal Code, this letter is hereby submitted as a Pad Certification Letter for 3364 Calle Margarita, Encinitas, grading permit 0409-G. As the Engineer of Record for the subject project, I hereby state the rough grading for the new building pad was completed in conformance with the approved plans and requirements of the City of Encinitas' codes and standards. VII. The following provides the pad elevations as field verified and shown on the approved grading plan: Pad Elevation Pad Elevation Per Location Per Plan Field Verification Pad-1 330.50 330.57 Pad-2 329.00 328.93 Pad-3 331.67 331.72 VIII. cefistrdetion of line and gfade fef all engifleer-ed drainage deviees and fetaining walls have been f4 verified and are in substantia! eenfer-manee with the subjeet grading plan-. N/A -see note below. IX. The location and inclination of all manufactured slopes and walls have been field verified and are in substantial conformance with the subject grading plan. X. The construction of earthen berms and positive building pad drainage have been field verified and are in substantial conformance with the subject grading plan. The field verification of the pad elevations noted herein was provided by Lorne Da Pron, L.S. 7824 per field data collected on July 20, 2007 as noted in their letter dated July 23, 2007 —see attached. Note: Provision VIII does not apply at this time and the extent of substantial conformance with provisions IX and X are limited as the site is rough graded for building basement wall construction, but the wall construction, backfill and storm drain construction has not yet commenced. The City Engineer will contact the owner if future grade verifications are required. Submitted by, Qsp f E S S/0,�, Conway& Associates, Inc. �o pt R. p � �# CIO 4P o No.41022 = rn Michael K. Pasko, P.E. CO EXPIRES 3-31-2009 a Engineer of Record 40 I lF Op CA1.%F�� cc: Albert Bertha, owner pA06-003 bertha\wordproc\enc070724-pad_Cert.doc G E O C E N T R I C July 23 , 2007 Mike Pasko Conway and Associates, INC. 2525 Pio Pica Drive, Carlsbad, CA 92008 760-753-1453 teL 760-434-5831 fax Re: Surveyor's Pad Certification for Bertha Residence and Grading Permit No, 0409-G I hereby state that rough grading elevations for the Bertha Residence have been completed. The following list provides the pad elevation as field verified and shown on the approved grading plan: Pad Elevation Pad Elevation per Location Per Field Measurement Proposed Basement 330.50 330.57 329.00 328.93 331.67 331.72 Lorne Da Pron Date No.7824 p LS 7824 * Exp:1213UM7 W ` CHRISTIAN WHEELER lit! ENGINEERING July 27,2007 Albert and Sandra Bertha CWE 2060364.04 3364 Calle Margarita Encinitas, California 92024 SUBJECT: EXCAVATION OBSERVATION LETTER FOR PROPOSED ACCESSORY UNIT AND GARAGE,3364 CALLE MARGARITA,ENCINITAS,CALIFORNIA. References: 1) Report of Preliminary Geotechnical Investigation,Proposed Accessory Unit and Garage, 3364 Calle Margarita,Encinitas,California,by Christian Wheeler Engineering,Report No. 2060364.01,dated June 23,2006. 2) Revised Preliminary Grading Plans for:Bertha Residence Accessory Unit,3364 Calle Margarita,Encinitas,California,California,by Conway and Associates,Inc.,dated September 28,2006. Dear Mr. and Iv1rs. Bertha: In accordance with the request of Mr.Dennis Hauswirth of Castillero Design and Construction,we have prepared this letter to summarize our observation of the excavation for the proposed accessory unit and garage. Based on our observation, the excavation exposed competent,Tertiary-age materials of the Santiago Formation.We understand that the excavation elevation represents the finish pad grade for the proposed accessory unit and garage and no fills were placed to achieve this grade. If you have any questions after reviewing this letter, please do not hesitate to contact our office. This opportunity to be of professional service is sincerely appreciated. Respectfully submitted, CHRISTIAN WHEELER ENGINEERING QPOFESS/o P�1N C.Cq 0 No.C62983 M <.� Exp.6-30-08 �( Ca a, RCE 62983 cc: (1) SubmittedOFCA�-�F� (1) Ston-book Castles I; Castillero Design and Construction, Att: Dennis Hauswirth,3536 Dove Hollow Road,Olivenhain,CA 92024 Fax: _Att. Dennis Hauswrth, Fax No. 858-759-1879 4925 Mercury Street ♦ San Diego, CA 92111 ♦ 858-496-9760 ♦ FAX 858-496-9758 G-snway & Associates, Inc. Civil Engineers/Surveyors/General-Engineering Contractors AB412412 2525 Pio Pico Drive•Suite 102•Carlsbad,CA 92008•Telephone(760)753-1453•Fax(760)434-5831 MEMORANDUM DATE: November 27, 2006 TO: City of Encinitas Engineering Department 505 S. Vulcan Avenue '1� Encinitas, CA 92024-3633 FROM: Michael Pasko I PROJECT: Grading Plan — Bertha Accessory Unit Replacement !-- 3364 Calle Margarita—APN 264-240-35 t--- SUBJECT: Project Drainage Study This memorandum is presented in lieu of a drainage study for the Bertha accessory unit replacement project. It is my professional opinion that the preparation of a new drainage study for this project site is unnecessary. The proposed Bertha accessory unit replacement project entails the removal and replacement of an existing residential accessory unit constructed under the grading permit for City drawing 3989-G (prepared by this office) as part of the site's original development. It is my professional opinion that the net increase in site runoff to result from the proposed project will be insignificant to the operation of the existing storm drain system as designed in City drawing 3989-G. For reference, the relative change in surface type for the proposed project is tabulated below: Area Description Existing Area Proposed Area Delta s.f.) (s.Q (s.f. Accessory Unit: 1,148 2,168 +1,020 Paving: 2,290 2,231 -59 Impervious Area 3,438 4,399 961 Total: Assuming a design rainfall intensity of 5.0 in/hr., C factors of 0.90 for impervious surfaces and 0.40 pervious surfaces for the project site,the net increase in the proposed site's design runoff is on the order of +0.05 cfs. Q�pf ESs pEL X. � 4 No.41022 d EXPIRES 3-31-2007 m r IVII. 9rE OF CAI.IF�� pA06-003 bertha\hydro\hyd061124.doc Conway & Associates, Inc. Civil Engineers/Surveyors/General-Engineering Contractors AB412412 2525 Pio Pico Drive•Suite 102•Carlbad,CA 92008•Telephone(760)753-1453•Fax(760)434-5831 DRAINAGE STUDY COMPUTATIONS Bertha Residence - 3364 Calle Margarita, Olivenhain City of Encinitas DATE: 11/27/06 ------------------------------------------------------------------------------------------------- ON-SITE TIME OF CONCENTRATION COMPUTATIONS: PRE-DEVELOPMENT Computations based on Figure 3-3, County of San Diego Hydrology Manual, June 2003 C L(ft) S TC (min) 0.0 Initial basin saturation ' 1.0% 0.0 By O/S area 0.0 pipe travel 0.0 min ON-SITE HYDROLOGY DATA 10 YEAR EVENT 100 YEAR EVENT tc(min) min. tc(min) min. P6 (10 YR Return) in. P6 (100 YR Return) in. I, intensity(in/hr) in./hr. I, intensity(in/hr) 5.0 in./hr. P24 (10 YR Return) in. P24 (100 YR Return) in. P6/P24 P6/P24 PRE-DEVELOPMENT CONDITION A Basin SUB AREA AREA "C" Qto Q100 Subtotal BASIN (SF) (ACRES) FACTOR C*A (CFS) (CFS) (CFS) Al 3,438 0.08 ! 0.90 0.07 0.00 0.36 roof/pvmt A2 961 0.02 0.40 0.01 0.00 0.04 i 0.40 yard 4,399 0.10 0.08 0.00 0.40 weighted C value: 0.79 POST-DEVELOPMENT CONDITION "A" Basin SUB AREA AREA "C" Q10 Qioo Subtotal BASIN (SF) (ACRES) FACTOR C*A (CFS) (CFS) (CFS) Al 4,399 0.10 0.90 0.09 0.00 0.45 roof/pvmt A2 0 0.00 0.40 0.00 0.00 0.00 0.45 yard 4,399 0.10 0.09 0.00 0.45 weighted C value: 0.90 Printed 11/27/2006 Page 1 of 1 06-003_Hydro-061127.xis Hydrology CHRISTIAN WHEELER- EN G IN EER- ING July 27, 2007 Albert and Sandra Bertha CWT 2060364.04 3364 Calle Margarita Encinitas, California 92024 SUBJECT: EXCAVATION OBSERVATION LETTER FOR PROPOSED ACCESSORY UNIT AND GARAGE,3364 CALLS MARGARITA,ENCINITAS, CALIFORNIA. References: 1) Report of Preliminary Geotechnical Investigation,Proposed Accessory Unit and Garage, 3364 Calle Margarita,Encinitas,California,by Christian Wheeler Engineering,Report No. 2060364.01, dated June 23,2006. 2) Revised Preliminary Grading Plans for: Bertha Residence Accessory Unit, 3364 Calle Margarita,Encinitas,California,California, by Conway and Associates,Inc.,dated September 28,2006. Dear Mr. and Mrs. Bertha: In accordance with the request of Mr.Dennis Hauswirth of Castillero Design and Construction,we have prepared this letter to summarize our observation of the excavation for the proposed accessory unit and garage. Based on our observation, the excavation exposed competent,Tertiary-age materials of the Santiago Formation. We understand that the excavation elevation represents the finish pad grade for the proposed accessory unit and garage and no fills were placed to achieve this grade. If you have any questions after reviewing this letter,please do not hesitate to contact our office. This opportunity to be of professional service is sincerely appreciated. Respectfully, submitted, CHRISTIAN WHEELER ENGINEERING QPOFESS/o QQr� P�1N C.C9 0 No.C62983 M t Exp.6-30-08 X Shawn C. Cava, RCE 62983 SCC:wm CIV11- - cc: (1) Submitted OFCAI.�F (1) Ston,hook Castles !L, Castillero Design and Construction,.1tt: Dennis Hauswirth,3536 Dove Hollow Road,Obvenhain,C-� 92024 (1) Via Fax: Att: Dennis Hauswirth,Fax No. 858-759-1879 4925 Mercury Street + San Diego, CA 92111 + 858-496-9760 + FAX 858-496-9758 t�c�c.o�v W — F_ ^1G1 vL R JUL 3 0 2007 July ,Ubcrr and 3364 ('ally 1\1.ugarira <AXIL 2(16;7364.04 LrtCinitas, f.allfornt:t 92024 I SUBJECT: EXCAVATION OBSERVATION LETTER FOR PROPOSED ACCESSORY UNIT AND GARAGP-,3364 CALLF MARGARITA,ENCINI fAS, CALIFORNIA. Rcfer,.nccs; 1') Report of Pr elitninatl`Gcoteclztvcal Invesnganon, Proposed Accessorl• Unit and Gunge, 3364(;alle blars,nrira, !?ncirulas,Cal.ifortua ht`Christian Vllecicr Engmccring, Report No, 2106(iM4,01, dated Junc.23, 2006. Rex t,cd'Preliintn:uy Grading flans for' BctYha Residence Accesson; T?nit,336 C i11e 2 farc�rrlra,En i,)itas, Califorrrta, Califar:ua, by Cr)-va,,.and,15sociates, Inc dared 5 2ft, .?1106, cptember [Near RMr. Ind dfr:;, Berrha. In accordance a ith the tcquest of Mr Bennis I Ietl,U,,,'Uth of'C 9stillert Design and Cc;nstntction, we have prepared rills lertc:r to sununari7c our observation of rile excavation for the proposed accessot3-unit and gun r. Bascd orl our observation, the excava [ion exposced competent, `I'er,tiart age tnatecials of the Santiago Formation• 1C'e understand that the excavation rJc��ahon r acce;sor .tnir;md garagc and no fills were placed to achieve this Pta�e r 'h pad grade for the proposed ft}iiu have' an}'i{ucsrions after revi caytig this letter least do no P c hrsttate: tt�contact our !fFce T7iis oppolmn'tr to be of 1�rufessioual ;:rte:ice IS sulc.ercl l APprcx'iarcd, Rc pectfuliq ,ubrn1ttcd, Cf-IRISTIAN W11IsELER ENGINEERINC ��)POFESS < NO.c62983 ` h:,vvn C Ca}a, R( 1, (,2983 Exp.0-30-08 CIV -'-' i r �lll?mlttfd 7 1 Sion hook (A OFCAU�c�` t,rlc, I'. �.,tst111Ctn 1-11 .1 n aril /,nrlstrucdon,.ltt 1-I:.u,t�tirth. 351it !)��-� tin(ic�, Rmr�.i,Oli.- , f)ennts H;tuti�t tfit, Fax \'n, 8511 -jr,,_f 1 Cnhatn, r ., 421124 '}')' S 19ercury yttect ♦ gan Uiei;ci , r � 92 11 I ♦ 85R 196-9;'6 0 ♦ Fq,t g 4 - - SN- 9(�-9 ; 5>i Conway & Associates, Inc. Civil Engineers/Surveyors/General-Engineering Contractors AB412412 2525 Pio Pico Drive•Suite 102•Carlsbad,CA 92008•Telephone(760)753-1453•Fax(760)434-5831 July 24, 2007 City of Encinitas Engineering Services 505 South Vulcan Avenue J U G 2 5 2007 Encinitas, CA 92024 Project: Grading Plan 0409-G� -5-C441 T PN1 3364 Calle Margarita ✓✓ Subject: Engineer's Pad Certification for Release of Building Permit - Provisional To Whom it May Concern: A c,- B Pursuant to section 23.24.3 10 of the Encinitas Municipal Code, this letter is hereby submitted as a Pad Certification Letter for 3364 Calle Margarita, Encinitas, grading permit 0409-G. As the Engineer of Record for the subject project, I hereby state the rough grading for the new building pad was completed in conformance with the approved plans and requirements of the City of Encinitas' codes and standards. VII. The following provides the pad elevations as field verified and shown on the approved grading plan: Pad Elevation Pad Elevation Per Location Per Plan Field Verification Pad-1 330.50 330.57 Pad-2 329.00 328.93 Pad-3 331.67 331.72 VIII. Genstfuction of line and gfade for-all engineered dminage deviees and retaining walls have been fi verified and afe in substantial eenfor-maneewith the subjeet grading p�aw. N/A - see note below. IX. The location and inclination of all manufactured slopes and walls have been field verified and are in substantial conformance with the subject grading plan. X. The construction of earthen berms and positive building pad drainage have been field verified and are in substantial conformance with the subject grading plan. The field verification of the pad elevations noted herein was provided by Lorne Da Pron, L.S. 7824 per field data collected on July 20, 2007 as noted in their letter dated July 23, 2007 — see attached. Note: Provision VIII does not apply at this time and the extent of substantial conformance with provisions IX and X are limited as the site is rough graded for building basement wall construction, but the wall construction, backfill and storm drain construction has not yet commenced. The City Engineer will contact the owner if future grade verifications are required. Submitted by, tO f E S S/0 Conway & Associates, Inc. o Q ` K. �q! 4J,o c y Michael K. Pasko, P.E. No.41022 `� EXPIRES 3-31-2009 d Engineer of Record ��q C/V l 1. y►�Q lF OF CAO"' cc: Albert Bertha, owner pA06-003 bertha\wordproc\enc07O724-pad_cert.doc GEOCENTRIC July 23 ,2007 Mike Pasko Conway and Associates, INC. 2525 Pio Pico Drive, Carlsbad, CA 92008 760-753-1453 tel., 760-434-5831 fax Re: Surveyor's Pad Certification for Bertha Residence and Grading Permit No.0409-G I hereby state that rough grading elevations for the Bertha Residence have been completed. The following list provides the pad elevation as field verified and shown on the approved grading plan: Pad Elevation Pad Elevation per Location Per Plan Field Measurement Proposed Basement 330.50 330.57 329.00 328.93 331.67 331.72 tom'�O Lome Da Pron Date a Ho. O L5 7824 Exp:12131IM7 m � I i ��yyl CHRISTIAN WHEELER E N G I N EERING DAILY REPORT JUt 2 5 2007 - i Project Name --� Project# 01 3-4 Project Address S Permit# Phan File# ` Contractor Architect Subcontractor Engineer ❑Reinforced Concrete ❑Pre-Stressed Concrete ❑Reinforced Masonry ❑Epoxy Anchors ❑Shop Welding ❑Field Welding ❑Fireproofing ❑ Material/Equipment: Weather: Date Time Arrived: Time Departed: Hours Charged: z C_ —Ctom. t )i •{>,,,I_ _ f ".s L y +'� (��S"j`y�' C -•_x .,' ?�. �";""':'� �"�7;Lp ,.., art ?.-- f G't�.,1 t?'r^�� fLa(f _l s 7!'� '�' `� J.•:r �_C'--=},ol ! 'v .t �..-q }._l�_,�) C�f � ,.n � r.�,}Y"y{� t...s.}t, -{:.:.,. s J+ -vf i F _."'� =tom:.-. -4 / �- r ii ✓mot , 7 5 a 4 Unless noted otherise,the Work observed is,to the best of my knowledge,in compliance with a app�ed pl and specifications. /I--- Inspector/Technician's Signatur 1 Reg.# uper' t dentAs • ature Date Ins ector Technician(Print or Type) 4925 Mercury Street + San Diego, CA 92111 + 858-496-9760 + FAX 858-496-9758 w CHRISTIAN WHEELER ENCINF RING v To REPORT OF FIELD OBSERVATIONS AND RELATIVE COMPACTION TESTING ACCESSORY UNIT AND GARAGE 3364 CALLE MARGARITA ENCINITAS, CALIFORNIA PREPARED FOR: ALBERT AND SANDRA BERTHA c/o CASTILLERO DESIGN& CONSTRUCTION 1318 VISTA COLINA SAN MARCOS, CALIFORNIA 92078 PREPARED BY: CHRISTIAN WHEELER ENGINEERING 3980 HOME AVENUE SAN DIEGO, CALIFORNIA 92105 3980 Home Avenue ♦ San Diego, CA 92105 ♦ 619-550-1700 ♦ FAX 619-550-1701 CHRISTIAN WHEELER. E N G I N F E R I N G October 7, 2008 Albert and Sandra Bertha c/o Castillero Design & Construction CWE 2060364.07 1318 Vista Colina San Marcos, California 92078 Attention: Dennis Hauswirth SUBJECT: REPORT OF FIELD OBSERVATIONS AND RELATIVE COMPACTION TESTING,ACCESSORY UNIT AND GARAGE, 3364 CALLE MARGARITA, ENCINITAS, CALIFORNIA. References: 1) Report of Preliminary Geotechnical Investigation,Proposed Accessory Unit and Garage, 3364 Calle Margarita,Encinitas, California, by Christian Wheeler Engineering, dated June 23, 2006. 2) Excavation Observation Letter For Proposed Accessory Unit and Garage,3364 Calle Margarita, Encinitas, California, by Christian Wheeler Engineering, dated July 27,2007. Dear Mr. Hauswirth, In accordance with your request and with the requirements of Section 1701.5.13 of the California Building Code, Christian Wheeler Engineering has prepared this report to summarize our observations of the earthwork operations at the subject site,and to present the results of relative compaction tests performed in the retaining wall backfills that were placed. The observation and testing services addressed by this report were coordinated by representatives of Castillero Design& Construction and were provided during the period of June 28,2007 through December 13, 2007. INTRODUCTION AND PROJECT DESCRIPTION SITE DESCRIPTION: The subject site is a developed,irregular-shaped parcel of land, located at the address of 3364 Calle Margarita, in the Olivenhain area of the city of Encinitas, California. The 3980 Home Avenue ♦ San Diego, CA 92105 ♦ 619-550-1700 f FAX 619-550-1701 CWE 2060364.07 October 7, 2008 Page 2 lot is bounded on the north by Calle Margarita, and on the remaining three sides by residential properties. Prior to the earthwork addressed by this report, the property was characterized by two relatively level graded pads. The upper, northern portion of the property supported a single-family residence,a detached garage/office, a swimming pool, and other associated improvements. The lower, southern portion supported a tennis court, a basketball court and a large grass lawn. The portion of the site addressed by this report is located in the southeastern corner of the upper pad and supported the detached garage/office,which was demolished in order to construct an accessory unit and garage. NEW CONSTRUCTION: The recently constructed accessory unit and garage has three levels consisting of a partial subterranean basement,grade-level parking, and a second-story living area. The structure consists of masonry block construction below grade and wood-frame construction above grade and is supported by conventional foundations with an on-grade concrete floor slab. PLAN REFERENCE: In order to augment our understanding of the designed configuration of the project, our firm was provided with an as-built grading plan for the site prepared by Conway& Associates Inc.,of Carlsbad, California dated September 24,2008. Plate No. 1 of this report is a reproduction of the plan,modified to show the approximate locations of our field tests and the relevant limits of contact with the encountered geologic units. SCOPE OF SERVICE Services provided by Christian Wheeler Engineering during the course of the earthwork consisted of the following: • Observing the foundation excavations of the new structure. • Periodic observation of the retaining wall backfill operations. • Providing field recommendations for elements of the earthwork not specifically addressed by the referenced geotechnical report. • Performing relative compaction tests in the backfills placed. • Performing laboratory maximum density and optimum moisture content determinations on the soils encountered in the earthwork, and, • Preparation of this report. CWE 2060364.07 October 7, 2008 Page 3 SITE PREPARATION GRADING CONTRACTOR: The earthwork addressed by this report was performed by Castillero Design& Construction. The primary equipment utilized by the contractor in the work consisted of an excavator,a skid-steer loader, two manually operated reciprocating compactors and a water hose. CLEARING AND GRUBBING: Prior to the earthwork for the portion of the site addressed by this report, the pre-existing structure and improvements were demolished,stockpiled and removed from the site. This included removing all foundations, slabs, underground utilities as well as any landscape vegetation. SITE PREPARATION:The site preparation consisted of cuts up to 12 feet from the existing grades in order to achieve the excavations necessary to attain the designed elevations.The excavation for the basement associated with the garage exposed competent,Tertiary-age materials of the Santiago Formation and is considered suitable for the support of the structure. RETAINING WALLS FOUNDATION OBSERVATION: Prior to the proposed construction of the basement retaining walls, the foundations excavations for the walls were observed by a representative of our firm. The excavations were found to extend into competent bearing strata. It can be noted, however, that our office was not contacted to observe the foundation excavations for the site retaining walls. SUBDRAINS: Preceding the backfilling of the basement retaining walls, a subdrain system was installed at the base of the walls. The subdram system consisted of a four-inch-diameter perforated PVC pipe set in a matrix of crushed rock,wrapped with geotechnical filter fabric. On our site visit on November 6, 2007, the majority of the subdrain system was installed behind the wall. Our office did not observe the portion of the subdrain behind the southwest portion of the basement wall or the outlet point for the subdrain system. WALL BACKFILL: The basement retaining walls were backfilled using native and imported sandy soils and crushed rock. The crushed rock was wrapped in filter fabric and the elevation of the top of rock is shown on Plate No. 1. The backfills were placed in thin horizontal lifts, which were watered to near optimum conditions and compacted in place bq means of the reciprocating compactors to at CWE 2060364.07 October 7,2008 Page 4 least 90 percent of maximum dry density. Our office did not observe the backfill for the planter areas behind the site walls. FIELD AND LABORATORY TESTING FIELD TESTS: Field tests to measure the relative compaction of the fills were conducted in accordance with ASTM Test Designation D 6938; "Standard Test Methods for Density of Soil and Soil-Aggregate in Place by Nuclear Methods." The locations of the field tests were selected by our technician in areas discerned to exhibit relative compaction that was generally representative of that attained in the fill. The results and approximate locations of the field tests are shown on the attached plates. LABORATORY TESTS:The maximum dry density and optimum moisture content of the soils predominantly encountered in the earthwork were performed in our laboratory by ASTM Test Designation D 1557, "Test Method for Laboratory Compaction Characteristics of Soil Using Modified Effort." The tests were conducted in accordance with the methodology prescribed for the grain-size distribution of the soils tested. The results of these tests are presented on the attached Plate No. 3. CONCLUSIONS GENERAL: It is the opinion of Christian Wheeler Engineering that the earthwork addressed by this report has been performed in accordance with the recommendations presented in the referenced geotechnical report, the grading requirements of the City of Encinitas and the California Building Code. This opinion is based upon our observations of the earthwork operations, the results of the density tests taken in the field, and the maximum density tests performed in our laboratory. It is our further opinion that the site is suitable for the proposed construction. AS-BUILT GEOLOGY: The geologic units encountered during the earthwork operations were generally consistent with those anticipated in our referenced report of geotechnical investigation. The earthwork operations addressed by this report have, in our opinion, satisfactorily mitigated the Potentially adverse conditions described in the referenced report. CWE 2060364.07 October 7, 2008 Page 5 LIMITATIONS The descriptions, conclusions and opinions presented in this report pertain only to the work performed on the subject site during the period from June 28, 2007 through December 13, 2007. As limited by the scope of the services that we agreed to perform, the conclusions and opinions presented herein are based upon our observations of the work and the results of our laboratory and field tests. Our services were performed in accordance with the currently accepted standard of practice in the region in which the earthwork was performed, and in such a manner as to provide a reasonable measure of the compliance of the described work with applicable codes and specifications. With the submittal of this report,no warranty, express or implied,is given or intended with respect to the services performed by our firm, and our performance of those services should not be construed to relieve the grading contractor of his responsibility to perform his work to the standards required by the applicable building codes and project specifications. Christian Wheeler Engineering sincerely appreciates the opportunity to provide professional service on this project. If you should have any questions after reviewing this report,please do not hesitate to contact our firm. Respectfully submitted, CHRISTIAN WHEELER ENGINEERING t pervisor Charles H. Christian,R.G.E. 00215 CHC/CRB/DH:mah Curtis R. Burdett, C.E.G. #1090 cc: (6) Submitted QROFESS/p S�pNAL G� z Cy9�� Q B�qQ Q No.GE215 i a No. 1090 ►Exp.9-30-09 M CERTIFIED ENGIN * * * GEOLOGI TG N:A EX . 10-10 �P ��FaF CAUL 9�F of C A10��Q` o �V W z- s - r R APL / r \\ CJ J `�\ ♦ yn2 r Ir Ld Qo \\ tq + /♦' + • r , \ r lbn \\ �� , b ..+. ♦ \♦, r 64i)"d �� wu h y r. •-pn \\ st air y \ GG" qqq h rc+ \\ I e � \\ i1 YYY��QIII We \\\ r R 3 r t N r A V • r r rr 2 it 7aaa O W i a I r p ' a r j ; a'm w 1-- + W 2 cH x Z } V , c zow , 0 r' r-- r — W — X x >< x >< >< x X s W W IL LL' N r� W ° c =c 0 to IL MQ W 4c M SUMMARY OF TESTS RETAINING WALL Project:Bertha Residence it2Wt a Ca ` action Tests ?' Test No. Date Location ASTM D6938 Elev. Soil Type Moisture Dry Sfax. %Re l. (feet) (°%) Density Density Comp. (pco RWI 11/7/2007 East Wall ................................................. 332.0 2 RW211/7/2007 ..............................................:... 4 2 .......................................:...........:..........;.....1.32.1..... :...............................:........................ East Wall 332 0 141.8 RW3 11/7/2007 ;...... :............................93:2...... ........................ . North East��/all ..... .... .................................... ................:.. RW4 11/7/2007 :. 334.0 ,. .... .... ... North Wall .0 ""' ;. 334.0 2 5 .4 132.4...:... 141.g.....p... 93.4. .. RWS 11 8 2007 / / East Wall North Corner 334.0 2 ............................................... .... .. RW6 11/8/2007..............•East Wall N t... '8.9.. ...;.. .1.38:x.... ;......334...........................................................1.1 :2.....t.....141.8.....x.......82.7...... ..............:...................................................... North Corner 0 RW7 11 8 2007 ................ ......... / / North Wall(a NE Corner 336.0 :........................... ;.. ... .............. .�:6............1. : ....., RW811 8 2007....:................................. 2.. .....141:8...........BS:�. . ............................................:................... / / North Wall�a NE Corner 336.0 .................................... ... : 141. RW9 11/8/2007 :......................:.........2...................... ..........132:�.....ti.....141:8.....;...... 3:6'...... .......:...............................:................... Retest RW6 334.0 RW10 11/8/2007 ...............:......... .... 2 9.8141.8 90.6 ........................................... . Retest RW5 ... .. ................................. :.. .128:4..... RW11 11/8/2007 ........334:0..............2................1�:6i............123:�..... .....141:8.....;......86.7...... >............................................North Side of West Wall...... . ;................. 335.0 ' RW12 € 11/15/2007 ; West Basement Wall North End "' ..............1............................ ... ..... .r..........................:.....336:0....:.........2.........j........7.0.......3.....131.5.....<...... RW13 11/15/2007 € West Basement Wall�a Middle 333.5 2 ...................,...............................1 141.8 92.7 RW14 11/15/2007 • West Ba ` ......:........1... ..91.3 .................:.....129:.......j.....141:8.....;......91.2...... ........................................... Bement Wall South End 332.0 2 RW15 11/15/2007 .......... ..........................:...... . ... 9 7 Retest RW10 ......... .....................:...............125:2............141:8.....1......88.3...... ...............................:..................... 334.0 2 7.6 RW16 :' 11/15/2007 : 130.2 141.8 •' 91.8 Retest RW7 , :................................................................... ` 336.0 2 RW17 11/15/2007 :. :..................200 Retest RW14 ....................... ......:...........North............... ... .......... 332.0 2 • ,128:6....3... 141.8.. RW18 12/3/2007 ...............:......................:.....................1........8.6'.............128.0.....t......141:8............`��:3:.... ...................:.......................................... ...........Wall�NW Corner 338:0 RW19 12/3/2007 North Wall�a NE Corner 338.0 :.. 5 9 139 5 .. .................................:..........>.............:.......<......1 RW20 ...............................:.................................... ............ 2 12 3 2007 ........................:......................I............................. �.............136:4..... .....141:8.....€.......961: ..... / / West Wall(7a Southern End 335.0 RW21 12/3/2007 i North Wall NW Corner 339.0 141.8 1 ...........:..........4.............128:5.....<....... RW22 12/3/2007 . ....... North Wall(fq NE Comer ....... .........2................. :1........:.....1.31:3.....s......141:8.....x.......�2:�...... .................................................................... 339.0 2 RW23 12 4 2007 .......... . ......... / / North Wall(a Mid Portion ;.....341.0.....:............................ .. .................................................... RW24 12/4/2007 ......................s......... .................5: .......3.....129: .....4.....141:8.......... 91 North Wall�a NE Comer 341.0 ................................... ................... .. RW25 12/4/2007 :.....................;......... .................S�.............1?�:5...........141.8.....;....... 1.:3...... :......................................... East Wall..NE Corner 335.5 RW26 ' 12/4/2007 ....... 141.8 1 97.1 East Wall�a North End.....................34.0 2 5.1 :.....................:.....137:7.....:...... RW27 12/5/2007 ...................... East Wall�a North End ; 337.0 :.........2.................6i.:�.............133:2...........141:8............`�3:�...... RW28 12/5/2007 .......... ......... :........................ East Wall�a South End 332.0..... �.. ;.....128:7..... ...13 8.8.....:.......92.7...... RW29 12/5/2007 ............:........ . ........x.........3....................... ......:.....1.30:.....;......138:g............93:7...... ...........................................West Wall..�r.North End 336.5 RW30 12/6/2007 3 :........................... North Wall West Side ..:......... . ......:.. 8.9 :' 127 4 RW31 12/6/2007..................................... 338.5 ; 6.9.. ...E.............:.......x......138 �r.................................:.................................3.........:......................:......1.261:5.....:......138:8.....3.......1.:8...... .......................................... East Wall 4 South End 334.0 RW32 12/6/2007 :............................ West Wall l�tiddle 36:p..... ....... ..... .. .. ;.....3 7.8 127 1 RW3312/10/2007................... ................ 3.. 8.7... ...,.. .........:.......;.....138:8 .............. ......:..............................8...........:.....1.2 6.x.....:......138.8.....'.......91.3...... West Wall(a North End 341.0 .................. ............................................... .......................... 3 RW34 12/1..... West Wall(la South End 336.0 ;.. :..............................:.. ;.........3.................�:2............. 0.....s....... RW35 12/10/2007 . ................................. 8.3 129:.. 138:8............� .. :..................... .....................:......................:.....128:1.....<......138:8.....;....... 2:3...... ......................... ................. East Wall .North End 338.5 RW36 12/10/2007 : . ................................. ...............................3.........:........0:4......:.....1.25:1.....:......138:8...........90..1...... :.......................................... East Walla Middle 337.5 RW37 12/11/2007 ...............................:.......... : ............................................. Westside�a Beam 338.5.....>.....................,........8:4..... RW38 12/11/2007........................................... . 2 7.0 ;.....1.3�:�.....<.. 138:8.... .. ......................:.................................................130:1.....x......138:8.....x.......93.7...... .......................................... Westside�r Beam 337.5 ............................ ................... RW39 121 11/2007 Eastside " :............................ North End RW40 12/12/2007..................................... ...:.. 338.0 ...................8.4........;.. .1.31.:6i.....j.....138 ............:......................:............................................:.....1.30:x.....:......138.8.....x..... 8 West Wall�a North End 340.5 ........................................................................................ .......................... RW41 12/12/2007 i West Wall �i Middle ......339....... ...................:...............................:............ ............................. :6'.............126':�.....t......138:8.....;.......`1:3...... RW42 12/12/2007 ........ ... ...... :........................ . West Wall rt South End 335.5..... .... .....:............. ......................................................................................:3................. 11.......;......127:2.....:......1 RW43 12/13/2007 "' :................................. West Side of Basement ..................... 337.0 5 3 R��'44 12/13/2007 _ �ti'est Sidi of Basement 339.0 1 3 1.� � 138.8.....;... ��:�..... RW45 12/13/200 7 ................................ .... ..... . .........................................:......... .... 3 128 3 0 West Side of Basement "' ' 34L0 � 3 9.4 .......:......138:8.....:. 92.4 131.2 138.8 94.5 21)61)364.07 Plate 2 MAXIMUM IRY �NSI1'Y aid{) PI'IME1M MOISTURE CONTENT ASM 1'A Soil Type Description USCS Optimum!:Moisture Maximum Dry 2 Class (%) Density(pco Medium gray,SILTY SAND with gravel SCI 5.8 141.8 3 I'ellowish brown,SILTI'SAND with gravel and clay S\I 6.3 138.8 ('W'P 2060364 07 I'tatc 3 Ln h Lt:3 �� , CHRA GTiA �N EE R- REPORT OF PRELIMINARY GEOTECHNICAL INVESTIGATION PROPOSED ACCESSORY UNIT AND GARAGE 3364 CALLE MARGARITA ENCINITAS, CALIFORNIA SUBMITTED TO: ALBERT AND SANDRA BERTHA 3364 CALLE MARGARITA ENCINITAS, CALIFORNIA 92024 SUBMITTED BY: CHRISTIAN WHEELER ENGINEERING 4925 MERCURY STREET SAN DIEGO, CALIFORNIA 92111 4925 Mercury Street + San Diego, CA 92111 + 858-496-9760 + FAX 858-496-9758 Ln Wi CHRISTIAN WHEELER ENGINEERING June 23,2006 Albert and Sandra Bertha 3364 Calle Margarita CWE 2060364.01 Encinitas, California 92024 SUBJECT: REPORT OF PRELIMINARY GEOTECHNICAL INVESTIGATION, PROPOSED ACCESSORY UNIT AND GARAGE,3364 CALLE MARGARITA, ENCINITAS, CALIFORNIA Dear Mr. and Mrs.Bertha: In accordance with the request of Storybook Castles and our proposal dated April 11,2006,we have completed a preliminary geotechnical investigation for the proposed accessory unit and garage to be constructed at the subject residential property. We are presenting herewith a report of our findings and recommendations. In general,we found that the project area is suitable to support the proposed accessory unit and garage, provided the recommendations presented herein are followed. We have determined that the project area is underlain by Tertiary-age materials of the Santiago Formation that are overlain by a layer of residual soil (topsoil/subsoil) that is in turn overlain by fill material. We anticipate that the excavations for the proposed basement will remove much of the existing fill and residual soil and expose competent materials of the Santiago Formation at or near the foundation level.As such,it will be possible to extend all building foundations into competent formational material. On the other hand,we anticipate that the proposed slab- on-grade floor will be underlain by fill/residual soil as well as competent formational soil, both of which have a "moderate"to "high"expansion potential.Based on this varying soil condition and to mitigate the possible distress of the lightly loaded slab due to soil expansion, the proposed slab will have to be thickened and heavily reinforced. more The site is located in an area that is relatively free of geologic hazards that will have a significant effect on the _ proposed constriction. The most likely geologic hazard that could affect the site is ground shaking due to seismic activity along one of the regional active faults. However,construction in accordance with the 4925 Mercury Street + San Diego, CA 92111 + 858-496-9760 + FAX 858-496-9758 _ C\XE 2060364.01 une 23,3006 Page\o.2 requirements of the most recent edition of the uniform Building Code and the local governmental agencies should provide a level of life-safety suitable for the type of development proposed. If you have any questions after revie-wing this report,please do not hesitate to contact our office. This opportunity to be of professional service is sincerely-appreciated. Respectfully submitted, CHRISTL-,N WHEELER ENGINEERING r Wail Afokhtar,Staff Engineer Charles H. Christian,RGE#00215 Curtis R.Burdett, C. .G. 1090 CHC:CRB:scc:wm cc: (2) Submitted (4) Storybook Castles .. QPpFESS/p� R D R B�O! A-C `�S U O cPA 2 v No. 1090 N Q CERTIFIED -{ 0 U No.GE215 z rn * ENGINEERING wd Exp.9-30-07 GE OLOGIST * cPJ Exp. 10-06 Q 09 s' � t� Q�' FOF CAL�F�P�\ � cFOcN��P� �P 9� �OF CAL�FC - TABLE OF _ Introduction and Project --' 'z»�ctScone___ ^ -------------------___ ^^s` ^ -------- -------' 1 _ Site Description---------------� .........................................................3 Setting General Geology and Subsurface Conditions Geologic and----^~^�r"""----' ----------`�* Ar��ooP�----.-------------------`^-------------`------------ T«poou-___ -`----------.-,__ Subsoil_. _-----------------_______________._--------'----4 ''---------------- ------------4 _ auouug/F-ozn.-u-�--o-u------------'---------------------------._--_-_-_---------_-_-----`----------`----`. ---------`-- a"",uuuvmaz-- Tectonic Setting Geologic S Ground Shaking----~-------' _--.-----'-' 5 _ Landslide Potential and Slope Stability 6 Liquefaction 7 Flooding 7 Tsunamis Seiches _ C»oclumioum--------' - ___________~ /Recommendations- Grading --- --------------------'--___________ _,~__7 _ General _� '----------'-----_______ _--'------------�8 ----------- ----'----'-'� 8 Observation of '---' ---- Clearing and Grubbing 8 Site_ Temporary Slopes 9 ' ----,-- -----� y Processing of Fill Areas 9 Compaction and Method of- _ ---_ Filling-_-_-_-_-_---.--'---_-_'-_-_-_-_-_-,-_-_-_-._-_--_-�--' ----/" Foundations General .............................10___~___ ____________----_____._____._,_. ----'--------�10 _______ ___________---_________,_____---- .................-----.-'--/0 10 Foundations Bearing Capacity Footing Reinforcement Lateral Load Resistance Settlement Characteristics Expansive� -----^~~^"-------- _ -------. ' --`---------^---~------FouodudouP�oRevicv _,_______~-,--________.____-_--' -_—_-_-__-_-_-_-------. Foundation l�2 x - `~ ~""=^,uuoo-'___-- ----------------------------.l2 Seismic , purxuct�s ___.__ ------------------- '--------- --'�l2 On-Grude8�6 l General Interior Floor Slabs_----------------.---.-___--._____ ^------------13 - Under-Slab Vapor Retarders __-_-_-_--_-_-_-_-_-------_-_-_ -_-. -------- ............- l3 l3 ---------. ---''--------'l]Exterior Cvucce»cFluuvork C\v,'E286l36L01 Proposed Accessory Unit and (�»/»ge 3364CuUc to, 2uc�imo.California u Earth Retaining Walls...................... Foundations Passive Pressure Equivalent Fluid Pressures 14 14 14 Waterproofing and Subdrain..................................................................................................................................15 Backfill Limitations 15 Review,Observation and Testing 15 UnIfOrnlity of Conditions 15 Change in Scope 15 Time Limitations 16 Professional Standard Client's Responsibility .. ...............16 Field Explorations Laboratory Testing 16 17 .....................................................17 ATTACHMENTS TABLES Table I Maximum Ground Acceleration, Page 6 Table II Seismic Design Parameters,Page 12 FIGURES Figure 1 Site Vicinity Map,Follows page 1 PLATES Plate 1 Site Plan. Plates 2-4 Boring Logs Plate 5 Laboratory Test Results Plate 6 Retaining Wall Subdrain Detail APPENDICES Appendix A References Appendix B Recommended Grading Specifications—General Provisions CAVE 2060364.01 Proposed Accessory LTnit and Garage 3364 Calle Margarita, Encinitas,California CHRISTIAN WHEELER ENGINEERING REPORT OF PRELIMINARY GEOTECHNICAL INVESTIGATION PROPOSED CESSnIty 'NIT AND GLRAGF 3364 CALLLS MARG-BRIT ENCINI 'AS CA IFOgNIA INTRODUCTION AND PROJECT DESCRIPTION This report presents the results of our preliminary geotechnical investigation performed for a proposed - accessory unit and garage to be constructed at the residential property located at the address of 3364 Calle Margarita,in the Olivenhain area of the city of Encinitas,California. Figure Number 1 presented on the following page provides a vicinity map showing the location of the property. The subject site consists of a developed,irregular-shaped parcel of land,identified as Assessor's Parcel Number 264-240-20,and is characterized by two relatively level graded pads. The northern pad supports a single-family residence, a detached garage/office, a swimming pool, and other associated improvements. We understand that the existing detached garage/office will be demolished and a new accessory unit and garage will be constructed in its place. This new structure is expected to have three levels consisting of a partial subterranean basement,grade-level parking, and a second-story living area. The structure is expected to be of masonry block construction below grade and wood-frame construction above grade. We also expect that the structure will be supported by conventional shallow foundations and will have an on-grade concrete floor slab. Site retaining walls are also proposed. Grading is expected to consist of cuts of 9 to 12 feet from existing grades to establish the proposed pad elevations. To aid in the preparation of this report,we were provided with a site plan for the subject site prepared by Storybook Castles,dated March 30,2006.A copy of this plan was modified to show our geologic mapping and is included herewith as Plate Number 1. In addition,we were also provided with the following documents: 1) Grading Plan for Parcel 2,Parcel Map 17122,prepared by Conway and Associates,Inc.,dated September 21, 1994,Drawing No. 3989-G. 4925 Mercury Street ♦ San Diego, CA 92111 + 858-496-9760 ♦ FAX 858-496-9758 i I SITE VICINITY MAp (Adapted from Thomas Brothers Maps) NOSED A('('FCcnuv T n ITI AND GAR F � 3364 GA_T.T.F MAR('Atti^re EN INITAS ('Ai iFnu TIA North SITE )0 ��v, "�� —�-•••ten .-1 IVA I �! _. J__ ZAc� A l � Z DWq rERAN CASTxt La s�r ir 0 PANT -", �,lJp � RD `a - �— p( `t PSE0 ti5 ' ST .............. AND ----------- IA CHo V �� I FEl.ICITA a p o A CWE 2060364.01 i 7(1(1/ CWT 3060364.01 June 23,2006 Page No. 2 2) Report of Preliminary Geotechnical Investigation,Proposed Tennis Court, Parcel 2, Parcel Map 17122,3364 Calle Margarita, Olivenhain, California,prepared by Coast Geotechnical,dated,August 2, 1999. 3) Report of Retaining Wall Backfill, Proposed Tennis Court,Parcel 2,Parcel Map 17122,3364 Calle Margarita,Olivenhain, California,prepared by Coast Geotechnical,dated September 7,2000. This report has been prepared for the exclusive use of Albert and Sandra Bertha and their design consultants for specific application to the project described herein. Should the project be changed in any way,the modified plans should be submitted to Christian Wheeler Engineering for review to determine their conformance with our recommendations and to determine if any additional subsurface investigation,laboratory testing and/or recommendations are necessary. Our professional services have been performed,our findings obtained and our recommendations prepared in accordance with generally accepted engineering principles and practices. This warranty is in lieu of all other warranties,express or implied. PROJECT SCOPE Our preliminary geotechnical investigation consisted of surface reconnaissance, subsurface exploration, obtaining representative soil samples,laboratory testing,analysis of the field and laboratory data and review of relevant geologic literature. Our scope of service did not include assessment of hazardous substance contamination,recommendations to prevent floor slab moisture intrusion or the formation of mold within the structure, or any other services not specifically described in the scope of services presented below. More specifically, the intent of this investigation was to: a) Explore the subsurface conditions of the project area to the depths influenced by the proposed construction; b) Evaluate, by laboratory tests and our experience with similar soil types, the engineering properties of the various strata that may influence the proposed construction,including bearing capacities,expansive characteristics and settlement potential; C) Describe the general geology at the site including possible geologic hazards that could have an effect on the proposed construction, and provide the seismic design parameters as required by the most recent edition of the Uniform Building Code; C%XB 306036=1.01 June 23,2006 Page No. 3 d) Address potential construction difficulties that may be encountered due to soil conditions, groundwater or geologic hazards, and provide recommendations concerning these problems; e) Develop soil engineering criteria for site preparation and radin g g,and address the stabilit3-of temporary constriction slopes; Provide design parameters for unrestrained and restrained retaining walls; g) Recommend an appropriate foundation system for the type of structure anticipated and develop soil engineering design criteria for the recommended foundation design; h) Present our professional opinions in this report,which includes in addition to our conclusions and recommendations, a plot plan, exploration logs and a summary of the laboratory test results. It is not within the scope of our services to perform laboratory tests to evaluate the chemical characteristics of the on-site soils in regard to their potentially corrosive impact to on-grade concrete and below grade improvements. If desired,we can submit representative soil samples to a chemical laboratory for analysis. Further,it should be understood Christian Wheeler Engineering does not practice corrosion engineerin I . f such an analysis is necessary,we recommend that the developer retain an engineering firm that this field to consult with them on this matter specializes in - FINDINGS SITE DESCRIPTION The subject site is a developed,irregular-shaped parcel of land,located at the address of 3364 Calle Mar arita in the Olivenhain area of the city of Encinitas,California. The lot is identified as Assessor's Parcel Number ' 264-240-20,and as Parcel 2 of Map 17122. The lot is bounded on the north by Calle Margarita, and on the remaining three sides by residential properties. The property is characterized by two relatively level graded pads. The upper, northern portion of the property supports a single-family residence, a detached garage/office, a swimming pool, and other normally associated improvements. The lower, southern portion supports a tennis court and a basketball court and a large grass lawn. The project area is located in the southeastern corner of the upper pad and currently supports the detached garage/office. The detached garage/office pad is at an elevation of about 341 feet.An approximately 8-foot-high, fill-over-cut slope descends from the pad towards the south and an approximately 5-foot-high fill slope descends from the ad P CWE 2060364.01 June 23,2006 Page No.4 toxvards the east.An approximately 10-foot-high retaining',vall exists at the bottom of the southern slope.A retaining wall ranging from 1 to 4 feet high is located at the bottom of the eastern slope. Vegetation within the project area consists of a grass lawn located to the rear of the existing detached garage/office structure.A planter and a few trees also exist within the project area. PREVIOUS GRADING Based on our review of the referenced grading plan and geotechnical reports,previous grading within the project area consisted of placing about 7 feet of fill to create a level pad for the existing detached garage/office structure and constructing an approximately 8-foot-high fill slope with an inclination of about 2:1 (H:V) to the south of the detached garage/office pad and an approximately 5-foot-high fill slope to th east of the pad.A 3-foot-deep by 15-foot-wide keyway was made along the base of the fill slope.!p a latere date the rear yard area was regarded to create gently sloping to near level terrain. This was accomplished by cutting along the base of the existing fill slope and placing of fill along the southern extend of the rear yard. The 4 to 5 foot-high cut slope along the base of the fill slope has daylighted the keyway and created a 2:1 (H:V) fill-over-cut slope. GENERAL GEOLOGY AND SUBSURFACE CONDITIONS GEOLOGIC SETTING AND SOIL DESCRIPTION:The subject site is located in the Coastal Plains Physiographic Province of San Diego County. Based on the results of our subsurface explorations and review of ry Pertinent,readily available geologic literature,we have determined that the project area is underlain by Tertia age materials of the Santiago Formation that are overlaui by a layer of residual soil(topsoil/subsoil) that is in turn overlain by fill material. Each of the encountered soil units is discussed below. ARTIFICIAL FILL:An approximately 3 to 121/2-foot-thick layer of 611 material was encountered within our exploratory borings. The fill generally consisted of light gray to light yellowish-brown,silty sand-clayey sand(SM-SC),light grayish-brown,clayey sand-sandy clay(SC-CL)and light brownish-gray, sandy clay(CL).The encountered fill material was typically moist and medium dense to dense in the sandy portions and very stiff in the clayey portions.The existing fill is expected to possess a"low"to "medium"expansion index and a low settlement potential. The fill is considered suitable in its present condition to support settlement-sensitive improvements. TOPSOIL:An approximately one-foot-thick layer of topsoil was encountered below the fill material within our test boring B-3,which was drilled in the northern portion of the project area. The C%Y,B 206036=1.01 June 23,2006 Page No. 5 encountered topsoil generally consisted of medium brownish-gray, silty sand (Sl\I) that vas damp and medium dense in consistency. This material is expected to possess a"low"expansion index and a moderate settlement potential. The existing topsoil is considered unsuitable in its present condition to support settlement sensitive improvements. SUBSOIL: An approximately 2 to T/2-foot-thick layer of subsoil was encountered below the fill and topsoil within our test borings B-1 and B-3.The encountered subsoil generally consisted of light brownish-gray to medium reddish-brown,sandy clay(CL) that was typically damp to moist and very stiff in consistency.This material is expected to possess a"low"to "medium"expansion index and moderate settlement potential.The existing subsoil is considered unsuitable in its present condition to support settlement sensitive improvements. SANTIAGO FORMA'T'ION(Tsa):Tertiary-age materials of the Santiago Formation were V encountered below the fill and residual soil (topsoil/subsoil) within each of our test borings, and are expected to underlie the entire project area. The formational materials generally consisted of light grayish-brown to orangish-brown, silty sand-clayey sand (SM-SC),light grayish-brown to light pinkish-gray, sandy clay(CL) and light gray, silty clay(CH). The materials of the Santiago Formation were moist and medium dense to very dense in the sandy portions and very stiff to hard in the clayey portions.The Santiago Formation is expected to possess a "low"expansion index within the sandy Portions. Based on our laboratory tests, the clayey portions of the Santiago Formation were found to possess a "high"expansion index. The formational materials are expected to possess a low settlement potential. The materials of the Santiago Formation are considered suitable in their present condition to support settlement sensitive improvements. GROUNDWATER No groundwater was encountered in our subsurface explorations and we do not expect any groundwater related conditions during or after the proposed construction. However,it should be recognized that minor groundwater seepage problems might occur after construction and landscaping at a site even where none were present before construction.These are usually minor phenomena and are often the result of an alteration in drainage patterns and/or an increase in irrigation water. Based on the anticipated construction and - landscaping,it is our opinion that any seepage problems that may occur will be minor in extent. It is further our opinion that these problems can be most effectively corrected on an individual basis if and when they occur. TECTONIC SETTING:It should be noted that much of Southern California,including the San Diego County area,is characterized by a series of Quaternary-age fault zones that consist of several individual,en echelon faults that generally strike in a northerly to northwesterly direction. Some of these fault zones (and the CWT 2060364.01 June 23,2006 Page No. 6 individual faults within the zone) are classified as "active"according to the criteria of the California Division Mines and Geology. Active fault zones are those that have shown conclusive evidence of faulting during t eof l Holocene Epoch (the most recent 11,000 years). The Division of Mines and Geology used the term"potentially active"on Earthquake Fault Zone maps until 1988 to refer to all Quatema a e (last 1.6 million -ears faults for the purpose of evaluation for possible zonation in accordance with the Alquist ) -Priolo Earthquake Fault Zoning Act and identified all Quaternary-age faults as "potentially active"except for certain faults that were presumed to be inactive based on direct geologic evidence of inactivity during all of Holocene time or longer. Some faults considered to be "potentially active"would be considered to be"active"but lack specific criteria used by the State Geologist, such as J'rriciently active and 2vell-defined. Faults older than Quaternary-age are not specifically defined in Special Publication 42,Fault Rupture Hazard Zones in California,published b the California Division of Mines and Geology. However,it is generally accepted that faults showing n y during he Quaternary g o movement g Q ary period may be considered to be"inactive". The nearest active fault zone is the Rose Canyon Fault Zone,which is located approximately 11 kilometers to the west. Other active fault zones in the region that could possibly affect the site include the Coronado Bank and Fault Zone to the southwest,the Elsinore,and Earthquake Valley Fault Zones to the northeast,and the Newport-Inglewood Fault Zone to the northwest. GEOLOGIC HAZARDS GROUND SHAKING:A likely geologic hazard to affect the site is ground shaking as a result of movement along one of the major active fault zones mentioned above. The maximum ground accelerations that would be attributed to a maximum probable earthquake occurring along the nearest fault segments of selected fault zones that could affect the site are summarized in Table I presented below. TABLE I:MAXIMUM GROUND ACCELERATIONS Fault Zone Distance Max.Magnitude g Maximum Ground Rose Canyon 11 Earth uake Acceleration Newport-Inglewood 22 7.2 magnitude 0.29 g 7.1 Magnitude 0.17 g Coronado Bank 35 km 7.6 Magnitude 0.15 g Elsinore Qulian) 40 km 7.1 Magnitude 0.11 g Earthquake Valley 61 km 6.5 magnitude 0.06 g It is likely that the site will experience the effects of at least one moderate to large earthquake during the life of the proposed improvements. It should be recognized that Southern California is an area that is subject to some degree of seismic risk and that it is generally not considered economically feasible nor technologically CXX'E 2060364.01 June 23,2006 Page No. 7 practical to build structures that are totally resistant to earthquake-related hazards. Construction in accordance with the minimum requirements of the Uniform Building Code should minimize damage due to seismic events. LANDSLIDE POTENTIAL AND SLOPE STABILITY.As part of this investigation we reviewed _ publication, "Landslide Hazards in the Northern Part of the San Diego Metropolitan area"by Tan, 1995.the reference is a comprehensive study that classifies San Diego County into areas of relative landslide susce tibili s The subject site is located in Relative Landslide Susceptibility P ty susceptible"to slope movement;subarea 3-1 classifications are Area 3 is considered to be "generally steep slopes and can be expected to fail locally when adversely modifiededSiteos within hdus classification stability limits due to located outside the boundaries of known landslides but may contain observably unstable a are underlain by weak materials and/or adverse geologic structure.Due to the generally gentle ltopography p of the site and the fact that the on-site fill slopes are well compacted as well as the relatively co etent n underlying formational materials,it is our opinion that the potential for deep-seated lands ding is considered to be low. LIQUEFACTION: The materials at the site are not anticipated to be subject to liquefaction due t factors as soil density,grain-size distribution, and depth to ground water. o such FLOODING:The site is not located within either a 100-year or a 500-year Flood zone accordin to the prepared by the Federal Emergency Management Agency g maps g y(Panel 1051F). TSUNAMIS: Tsunamis are great sea waves produced by submarine earthquakes or volcanic eru tions. upon the location of the site it will not be affected by tsunamis. P Based SEICHES: Seiches are periodic oscillations in large bodies of water such as lakes,harbors, bas or reservoirs. Due to the site's location,it is considered to have a negligible risk potential for seiches. CONCLUSIONS In general,no geotechnical conditions were encountered which would preclude the proposed constriction provided the recommendations presented herein are followed. Based on the results of our investigation we have determined that the project area is underlain by Tertiary-age materials of the Santiago Formation tha overlain by a layer of residual soil (topsoil/subsoil) that is in tur overlain by fill material. tare the excavations for the proposed basement will remove much of the existing fill and residual oil and expose pose C\vv'E 206036 .01 June 23,2006 Page No. 8 competent materials of the Santiago Formation at or near the foundation level.As such,it will be possible to extend all building foundations into competent formational material. On the other hand,we anticipate that the proposed slab-on-grade floor will be underlain by fill/residual soil as well as competent formational soil, both of which have a "moderate" to "high"expansion potential. Based on this varying soil condition and to mitigate the possible distress of the lightly loaded slab due to soil expansion, the proposed slab will have to be thickened and more heavily reinforced. Also, due to the depth of the proposed excavation for the basement, the existing foundations at the southeastern corner of the existing residence will be undermined.Therefore, temporary shoring of the excavations or temporary support of the southeastern corner of the existing residence will be necessary during the construction of die basement.Both the shoring and/or temporary supports stem will designed and constructed b an en Y need to be y engineer/contractor experienced in this area. The design will need to be reviewed by our firm prior to construction in order to verify that the geotechnical recommendations presented in this report have been incorporated into the design. The site is located in an area that is relatively free of geologic hazards that will have a significant effect on the - proposed construction. The most likely geologic hazard that could affect the site is ground shaking due to seismic activity along one of the regional active faults. However,construction in accordance with the requirements of the most recent edition of the Uniform Building Code and the local governmental agencies should provide a level of life-safety suitable for the type of development proposed. RECOMMENDATIONS GRADING AND EARTHWORK GENERAL;All grading should conform to the guidelines presented in Appendix Chapter A33 of the Uniform Building Code,the minimum requirements of the city of Encinitas,and the recommended Grading Specifications and Special Provisions attached hereto,except where specifically superseded in the text of this report. Prior to grading,a representative of Christian Wheeler Engineering should be present at the pre- construction meeting to provide additional grading guidelines,if necessary, and to review the earthwork- schedule. OBSERVATION OF GRADING;Continuous observation by the Geotechnical Consultant is essential during the grading operation to confirm conditions anticipated by our investigation, to allow adjustments in C%K,'E 2060364.01 June 23,2006 Page No. 9 design criteria to reflect actual field conditions exposed, and to determine that the grading proceeds in general accordance with the recommendations contained herein. CLEARING AND GRUBBING:Site preparation should begin with the removal of the existing improvements that are designated for removal. This removal should include all existing foundations,slabs and above grade and underground utilities,as well as any vegetation and other deleterious materials,including all significant root material. The resulting organic materials and construction debris should be disposed of in an appropriate off-site facility. SITE PREPARATION:After clearing and grubbing,site grading is expected to consist of cuts of 9 to 12 feet from existing grades to establish the proposed pad elevations. Our firm will need to observe the bottom of the excavations to make sure that all unsuitable materials (residual soil) have been removed by the planned cuts. If any unsuitable soils were found at the bottom of the excavation they will need to be removed replaced as structural fill. The removals should extend to the contact with the competent materials of the Santiago Formation.The removals should extend to include all areas that will receive fill and/or improvements. The bottom of the excavations should be approved by our project geologist,engineer,or technician supervisor prior to placing fills or constructing improvements. TEMPORARY SLOPES:Temporary slopes will be required during the construction of the proposed basement. Temporary slopes for the basement of up to 15 feet in height can be excavated vertically bottom 4 feet and at an inclination of 1.0 to 1.0 (horizontal to vertical) above. Our firm should be contacted to observe all temporary cut slopes during grading to ascertain that no unforeseen adverse conditions exist. No surcharge loads such as adjacent building foundations,soil or equipment stockpiles,vehicles,etc. should be allowed within a distance from the top of temporary slopes equal to half the slope height. Where there is not room to construct temporary slopes in accordance with the above recommendations, such as in the area adjacent to the southeast corner of the existing residence, temporary shoring of the excavation sides ' necessary. Shoring should be designed using the following soil parameters: wtll be Angle of internal friction: 25 degrees Apparent cohesion: 250 psf Total Unit weight. 120 pcf It should be noted that the contractor is solely responsible for designing and constructing stable, temporary excavations and may need to shore, slope, or bench the sides of trench excavations as required to maintain the stability of the excavation sides. The contractor's "competent person", as defined in the OSHA CkX'E 2060364.01 June 23,2006 Page No. 10 Construction Standards for Excavations,29 CFR, Part 1926, should evaluate the soil exposed in the excavations as part of the contractor's safety process. Temporary cut slopes should be constructed in accordance with the recommendations presented in this section. In no other case should slope height, slope inclination, or excavation depth,including utility trench excavation depth,exceed those specified ui local, state, and federal safety regulations. PROCESSING OF FILL AREAS: Prior to placing any new fill soils or constructing any new improvements in areas that have been cleaned out and approved to receive fill, the exposed soils should be scarified to a depth of 12 inches,moisture conditioned,and compacted to at least 90 percent relative compaction. No other special ground preparation is anticipated at this time. COMPACTION AND METHOD OF FILLING:All structural fill placed at the site should be compacted to a relative compaction of at least 90 percent of maximum dry density as determined by ASTM Laboratory Test D1557. Fills should be placed at or slightly above optimum moisture content,in lifts six to eight inches thick, with each lift compacted by mechanical means. Fills should consist of approved earth material, free of trash o debris,roots,vegetation,or other materials determined to be unsuitable by our soil technicians or project r geologist. Fill material should be free of rocks or lumps of soil in excess of twelve inches in maximum dimension. However,in the upper two feet of pad grade,no rocks or lumps of soil in excess of six inches should be allowed. Utility trench backfill within five feet of the proposed structure and beneath driveways,concrete flatwork,and pavements should be compacted to a minimum of 90 percent of its maximum dry density. SURFACE DRAINAGE: The ground around the proposed structure should be graded so that surface flows rapidly away from the structure without ponding. In general,we recommend that the ground adjacent to the structure slope away at a gradient of at least two percent. Densely vegetated areas where runoff can be impaired should have a minimum gradient of at least five percent within the first three feet from the structure. Gutters and downspouts should discharge into controlled drainage devices. FOUNDATIONS GENERAL: Based on our findings and engineering judgments, the proposed accessory unit and garage ma y be supported by conventional continuous and isolated spread footings.The following recommendations are considered the minimum based on anticipated soil conditions after site grading and are not intended to be lieu of structural considerations. All foundations should be designed by a qualified structural engineer. C\X'E 2060364.01 June 23,2006 Page No. 11 CONVENTIONAL,FOUNDATIONS: Spread footings supporting the three-story stricture should extend through any fill or residual soil and be embedded at least 6 inches into the underlying competent materials o Santiago Formation and have a f the minimum embedment depth of 24 inches. Continuous footings should have a minimum width of 18 inches. Isolated and retaining wall footings should have a minimum width of 24 inches. Site retaining walls footings should extend through any fill or residual soil and be embedded at least 6 inches into the underlying competent materials of the Santiago Formation and have a minimum embedment of 18 inches below the lowest adjacent grade. BEARING CAPACITY. Conventional footings with a minimum embedment of 6 inches into formational materials may be designed for an allowable soil bearing pressure of 3,000 pounds per square foot.This value T may be increased by 700 pounds per square foot for each additional foot of embedment depth and 300 pounds per square foot for each additional foot of width,up to a maximum of 5,000 psf. This value may be increase by one-third for combinations of temporary loads such as those due to wind or seismic loads. d FOOTING REINFORCEMENT:The project structural engineer should provide reinforcement requirements for foundations. However,based on soil conditions,we recommend that the minimum reinforcing for the proposed residence continuous footings should consist of at least two No. 5 bars positioned three inches above the bottom of the footing and two No. 5 bars positioned two inches below the top of the footing. Where new footings abut existing house foundations, they should be doweled together as per the recommendations of the project structural engineer. LATERAL LOAD RESISTANCE:Lateral loads against foundations may be resisted by friction between the bottom of the footing and the supporting soil,and by the passive pressure against the footing. The coeffici of friction between concrete and soil may be considered to be 0.30. The passive resistance may be consideredt to be equal to an equivalent fluid weight of 350 pounds per cubic foot. This assumes the footings are tight against undisturbed soil. If a combination of the passive pressure and friction is used, the ftictio P value should be reduced by one-third. SETTLEMENT CHARACTERISTICS:The anticipated total and differential settlement is expected to be less than about 1 inch and 1 inch in 40 feet,respectively,provided the recommendations presented in this report are followed. It should be recognized that minor cracks normally occur in concrete slabs and foundations due to shrinkage during curing or redistribution of stresses, therefore some cracks may be anticipated. Such cracks are not necessarily an indication of excessive vertical movements. CWE 3060364.01 June 23,2006 Page No. 12 EXPANSIVE CHARACTERISTICS: We expect the soils within the foundation to consist of materials of the Santiago Formation.The formational materials are comprised of interbedded layers of sandstones siltstones and claystones. As stated in the "Geology"section above, the Santiago Formation is expected to - possess a "low"expansion index within the sandy portions and a "high"expansion index within the clayey portion. This condition has been incorporated in these foundation recommendations. FOUNDATION PLAN REVIEW. The foundation plans should be submitted to this office for review in order to ascertain that the recommendations of this report have been implemented,and that no additional recommendations are needed due to changes in the anticipated construction. FOUNDATION EXCAVATION OBSERVATION:All foundation excavations should be o Geotechnical Consultant prior to placing formwork or reinforcing steel in order to determine if the foundation e recommendations presented herein are followed. All footing excavations should be excavated neat level a square. All loose or unsuitable material should be removed prior to the placement of concrete. nd SEISMIC DESIGN PARAMETERS Based on our Deterministic Seismic Hazard Analysis,the Maximum Ground acceleration at the site is estimated to be 0.29 g(based upon a Maximum Magnitude Seismic Event of 7.2 Magnitude along the Rose Canyon Fault). For structural design purposes,a damping ratio not greater than 5 percent of critical dampening,a ) Type Sc;are recommended (UBC Table 16-J). Based upon the location of the site at approximately 11 0�Profile kilometers from the Rose Canyon Fault(Type B Fault),Near Source Factors Na equal to 1.0 and N.equal are also applicable. These values,along with other seismically related design parameters from the Uniform to 1.0 Building Code (UBC) 1997 edition,Volume II,Chapter 16,utilizing a Seismic Zone 4 are presented in tabular form below. TABLE II: SEISMIC DESIGN PARAMETERS - UBC Chapter 16 Seismic Design Recommended Table No. Parameter Value 16-1 Seismic Zone Factor Z 16-1 Soil Profile T e 0.40 Sc. 16-Q Seismic Coefficient Ca 0.40 Na 16-R Seismic Coefficient C, 16-S N 0.56N,. Near Source Factor Na 1.0 16-T Near Source Factor N 1.0 Seismic Source T e B C`XT 2060364.01 June 23,2006 Page No. 13 ON-GRADE SLAB GENERAL: It is our understanding that the proposed structure will have a concrete slab-on-grade. The following recommendations are considered the minimum slab requirements based on the soil conditions and are not intended in lieu of structural considerations. INTERIOR FLOOR SLABS: The minimum floor slab thickness should be five inches (actual) and the floor slab should be reinforced with at least No. 4 reinforcing bars placed at 12 inches on center each way. Slab reinforcement should be supported on chairs such that the reinforcing bars are positioned at mid-height in the floor slab. The slab reinforcement should extend into the perimeter foundations at least six inches. UNDER-SLAB VAPOR RETARDERS:Steps should be taken to minimize the transmission of moisture vapor from the subsoil through the interior slabs where it can potentially damage the interior floor coverings. Local industry standards typically include the placement of a vapor retarder,such as visqueen, between two, 2-inch-thick layers of coarse sand placed directly beneath the concrete slab. This is the most common under- slab vapor retarder system used in San Diego County. The vapor retarder should be at least 15 mil visqueen with sealed seams and should extend at least 12 inches down the sides of the interior and perimeter footings. The sand should contain less than 10%passing the Number 100 sieve and less than 5%passing the Number 200 sieve. Although the system described above has historically performed adequately,national standards for the installation of vapor retarders below interior slabs are changing as evidenced in currently published standards including ACI 302, "Guide to Concrete Floor and Slab Construction"and ASTM E1643, "Standard Practice for Installation of Water Vapor Retarder Used in Contact with Earth or Granular Fill Under Concrete Slabs". Rather than placing the vapor retarder between the two sand layers, both of these standards recommend placing the sand capillary break layer onto the subgrade with a vapor retarder placed above the sand and th e concrete placed directly onto the vapor retarder. There are advantages and disadvantages to each of these - installation procedures. An advantage to placing concrete directly onto a vapor retarder is that it eliminates the layer of sand between the slab and vapor retarder. This layer of sand typically contains moisture prior to the placement of concrete and can receive more moisture during the curing and construction processes. This moisture can be retained in the sand layer for an extended period of time until the concrete moisture decreases to the point at which the excess sand moisture is absorbed by the concrete and transmitted up through the slab. This process can take many months depending upon the environmental conditions. C\X'E 2060364.01 June 23,2006 Page No. 14 One disadvantage to placing concrete directly onto a vapor retarder is that removing the sand layer from directly beneath the concrete restricts the ability of the concrete to lose moisture on both the top and bottom surfaces during the initial curing period. Variations in the drying rate between the top and bottom surfaces can result in increased concrete cracking,curling,and other finishing issues. The drying rate differences and their potential side effects can be minimized,however,with suitable finishing and curing procedures. Recognizing the stated benefits and limitations of these standard below-slab vapor retarder systems, the owner and designer should select the system that they believe is most suitable for this project considering the construction schedule and planned floor coverings. It should be understood that neither of the described systems provides a "waterproof barrier". It should also be understood that slab concrete contains free water and should be allowed to reach equilibrium in an environment similar to that anticipated in the completed structure prior to installing floor coverings. We recommend that the flooring installer perform standard moisture vapor emission tests prior to the installation of all moisture-sensitive floor coverings in accordance with ASTM F1869"Standard Test Method for Measuring Moisture Vapor Emission Rate of Concrete Subfloor Using Anhydrous Calcium Chloride". EXTERIOR CONCRETE FLATWORK Exterior slabs should have a minimum thickness of five inches. - Reinforcement should be placed in exterior concrete flatwork to reduce the potential for cracking and movement. Control joints should be placed in exterior concrete flatwork to help control the location of _ shrinkage cracks. Spacing of control joints should be in accordance with the American Concrete Institute specifications. Where patio slabs,walkways and porch slabs abut perimeter foundations, they should be doweled into the footings. It should be noted that due to the expansive potential of the existing soils,minor cosmetic distress might occur. EARTH RETAINING WALLS FOUNDATIONS: Foundations for proposed retaining walls should be constructed in accordance with t recommendations for shallow foundations presented previously in this report. he PASSIVE PRESSURE:The passive pressure for the anticipated foundation soils may be considered to be 350 pounds per square foot per foot of depth. This pressure may be increased by one-third for seismic loading. The coefficient of friction for concrete to soil may be assumed to be 0.35 for the resistance to lateral movement. kyAien combining frictional and passive resistance, the friction should be reduced by one-third. EQUIVALENT'FLUID PRESSURES: The equivalent fluid pressure for the design of"unrestrained"and "restrained"earth retaining structures with level backfill may be assumed to be 40 and 60 pounds per cubic foot, CYX'E 2060364.01 June 23,2006 Page No. 15 respectively. These pressures do not consider any surcharge. If any are anticipated, this office should be contacted for the necessary increase in soil pressure. This value assumes a drained,moderately expansive (E.I<90) backfill condition. WATERPROOFING AND SUBDRAIN: Waterproofing details should be provided by the project architect. A suggested wall subdrain detail is provided on the attached Plate Number 6. \Y,'e recommend that the Geotechnical Consultant be requested to observe all retaining wall subdrains to verify proper constriction. BACKFILL: All backfill soils should be compacted to at least 90 percent relative compaction. Expansive or clayey soils should not be used for backfill material. The wall should not be backfilled until the masonry has reached an adequate strength. LIMITATIONS REVIEW, OBSERVATION AND TESTING The recommendations presented in this report are contingent upon our review of final plans and specifications. Such plans and specifications should be made available to the Geotechnical Engineer and Engineering Geologist so that they may review and verify their compliance with this report and with the Uniform Building Code. It is recommended that Christian Wheeler Engineering be retained to provide continuous soil engineering services during the earthwork operations. This is to verify compliance with the design concepts,specifications or recommendations and to allow design changes in the event that subsurface conditions differ from those anticipated prior to start of construction. -- UNIFORMITY OF CONDITIONS The recommendations and opinions expressed in this report reflect our best estimate of the project requirements based on an evaluation of the subsurface soil conditions encountered at the subsurface exploration locations and on the assumption that the soil conditions do not deviate appreciably from those encountered. It should be recognized that the performance of the foundations and/or cut and fill slopes may be influenced by undisclosed or unforeseen variations in the soil conditions that may occur in the intermediate and unexplored areas. Any unusual conditions not covered in this report that may be encountered during site development should be brought to the attention of the Geotechnical Engineer so that he may make modifications if necessary. CX'E 2060364.01 June 23,2006 Page No. 16 CHANGE IN SCOPE This office should be advised of any changes in the project scope or proposed site grading so that we may determine if the recommendations contained herein are appropriate. It should be verified in writing if the recommendations are found to be appropriate for the proposed changes or our recommendations should be modified by a written addendum. TIME LIMITATIONS The findings of this report are valid as of this date. Changes in the condition of a property can,however,occur with the passage of time,whether they are due to natural processes or the work of man on this or adjacent properties. In addition,changes in the Standards-of-Practice and/or Government Codes may occur. Due to such changes, the findings of this report may be invalidated wholly or in part by changes beyond our control. Therefore,this report should not be relied upon after a period of two years without a review by us verifying the suitability of the conclusions and recommendations. PROFESSIONAL STANDARD In the performance of our professional services,we comply with that level of care and skill ordinarily exercised by members of our profession currently practicing under similar conditions and in the same locality. The client recognizes that subsurface conditions may vary from those encountered at the locations where our borings, surveys,and explorations are made,and that our data,interpretations,and recommendations are based solely on the information obtained by us. We will be responsible for those data,interpretations,and recommendations, but shall not be responsible for the interpretations by others of the information developed. Our services consi st of professional consultation and observation only,and no warranty of any kind whatsoever,express or implied is made or intended in connection with the work performed or to be performed by us,or by our proposal for consulting or other services,or by our furnishing of oral or written reports or findings. CLIENT'S RESPONSIBILITY It is the responsibility of the Client,or their representatives, to ensure that the information and recommendations contained herein are brought to the attention of the structural engineer and architect for the project and incorporated into the project's plans and specifications. It is further their responsibility to take the necessary measures to insure that the contractor and his subcontractors carry out such recommendations during construction. CA`G'E 2060364.01 June 23,2006 Page No. 17 FIELD EXPLORATIONS Three subsurface explorations were made on May 16,2006 at the locations indicated on the attached Plate Number 1.These explorations consisted of borings drilled using a limited access tripod rig. The fieldwork was conducted under the observation of our engineering geology personnel. The explorations were carefully logged when made. The boring logs are presented on the following Plate Numbers 2 through 4. The soils are described in accordance with the Unified Soils Classification System. In addition,a verbal textural description, the wet color, the apparent moisture and the density or consistency are provided.The density of granular soils is given as 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. Relatively undisturbed drive samples were collected using a modified California sampler. The sampler,with an external diameter of 3.0 inches,is lined with 1-inch long, thin, brass rings with inside diameters of approximately 2.4 inches.The sample barrel was driven into the ground with the weight of a 140-pound hammer falling 30 inches in general accordance with ASTM D 3550-84. The driving weight is permitted to fall freely. The number of blows per foot of driving, or as indicated,are presented on the boring logs as an index to the relative resistance of the sampled materials.The samples were removed from the sample barrel in the brass rings, and sealed. Bulk samples of the encountered earth materials were also collected. Samples were transported to our laboratory for testing. LABORATORY TESTING Laboratory tests were performed in accordance with the generally accepted American Society for Testing and Materials (ASTM) test methods or suggested procedures.A brief description of the tests erformed is presented below. P a) CLASSIFICATION: Field classifications were verified in the laboratory by visual examination. The final soil classifications are in accordance with the Unified Soil Classification System. b) MOISTURE-DENSITY: In-place moisture contents and dry densities were determined for representative soil samples. This information was an aid to classification and permitted recognition of _ variations in material consistency with depth. The dry unit weight is determined in pounds per cubic foot,and the in-place moisture content is determined as a percentage of the soil's dry weight. The results are summarized in the boring logs. CNXT-2060364.01 June 23,2006 Page No. 18 c) DIRECT SHEAR TEST: Direct shear tests were performed on a representative sample of the on-site soils to determine the failure envelope based on yield shear strength. The shear box was designed to accommodate a sample having a diameter of 2.375 inches or 2.50 inches and a height of 1.0 inch. The samples were saturated and tested at different vertical loads.The shear stress was applied at a constant rate of strain of approximately 0.05 inch per minute. The results of this test are presented on Plate No. 5. d) EXPANSION INDEX TEST:An expansion Index test was performed on remolded sample of a representative sample. The test was performed on the portion of the sample passing the#4 standard sieve. The sample was brought to optimum moisture content and then dried back to constant moisture content for 12 hours at 230±9 degrees Fahrenheit. The specimen was then compacted in a 4-inch- diameter mold in two equal layers by means of a tamper, then trimmed to a final height of 1 inch and brought to a saturation of approximately 50 percent. The specimen was placed in a consohdometer with Porous stones at the top and bottom, a total normal load of 12.63 pounds was placed (144.7 psf),and the sample was allowed to consolidate for a period of 10 minutes. The sample was saturated, and the change in vertical movement was recorded until the rate of expansion became nominal. The expansion index is reported on Plate No. 5 as the total vertical displacement times 1000. GRAIN SIZE DISTRIBUTION:The grain size distributions were determined from representative soil samples in accordance with ASTM D422. The results of these tests are presented on Plate No. 5. I.FGAL 'f?f& 5ANMA 13 `W MAP,GA lm FNCINIfA5 / 10- 2 -o ' � o 1_- . R P NCF;6700 5Q,Ff, z F to be removed;982 50,Ff. U j 5FMEW. 274150,Ff, z /' u•e �AGF; 1000 5Q,Ff. o z xisr MA/ OFFICE; 542 5Q,Ff, `* 00 15OPY UNIT: 748 50,Ff, � N 'K; 1280 5Q•Ff, l� 5Q,Ff.AMOK i "COVFZA6F; 10.7% K5i . v 71 , nL 7<I 6 2s L06 1 n I �1 I 1�h I I $, 1. 5fowo0K — CAV5 cAL�� 1�1fJ6Y; MAP?GA?ITA MWIMM 16(�g19.00y0 3/30/2006 Aug. � 34AL' I-INV- of Pf"Crof 13A5I;MF-M" / GAP.A Al ESSORY UNIT& GARAGE JOB NO.: 2060364.01 CI-IRISTIAN Wl IE-ELER PLATE NO.: 1 C N (; I N c t 1( I N (; LOG OF TEST BORING NUMBER B-1 Date Excavated: 5/16/3006 Equipment: LA Tri Tripod Logged by: AN P Project Manager: CHC Existing Elevation: 341 feet Finish Elevation: 331 feet Depth to Water: N/A Drive Weight: 140 lbs./30" v O v U W (D o Wa SUMNL-1RY OF SUBSURFACE CONDITIONS T �1 Z A a � z o _ � 7 o o W _ a � A 6-inch layer of Sod and Associated To soil. 2 Artifici Ft_(Oat),Light gray to light brown to orangish-yellowish- - brown,moist,medium dense,SILTY SAND-CLAYEY SAND(SM-SC). Cal 33 17.13 101.2 4 Abundant roots present in upper 1 foot. Cal 33 20.3 99.6 .......................................... ................................................................ """"' ............ ...........................Li g ht brownish-gray,moist,very stiff,SANDY CLAY(CL). . 8 Contact'at T/z feet. Subsoil•Light to medium grayish-brown,moist,very stiff,SANDY 10 SILTY CLAY(CL),mottled,with trace rootlets. Contact at 9'/2 feet. Cal i1 25.2 93.7 12 Santiago Formation al Light grayish-brown to medium orangish- brown,moist,very stiff,SANDY CLAY(CL) .... ......• , 14 very fine to fine: rained. Contact at 11'/z feet: Light gray to light brownish-gray to light orangish-brown,moist,dense, ('al 50/6" 17.2 lob 7 SILTY SAND-CL.-IYEY SAND (SM-SC),fine-grained,with iron staining. I)ti At 14 feet becomes very dense. 18 Cal 5t1/5" 20 Test borin terminated at 19'/z feet.No roundwater. PROPOSED ACCESSORY UNIT AND GARAGE 3364 Calle Margarita,Encinitas, California =CHR1_S_fl.kN ELER BY: �It� t ry �: D ATE: une 2006 OB NO. : 2060364 PLATE NO.: 2 LOG OF TEST BORING NUMBER B-2 Date Excavated: 5/16/2006 - Equipment: Lr1 Tripod Logged by: AKN Existing Elevation: 341 feet Project Manager: CHC Finish Elevation: 2 9.5 Feet Depth to Water: N/A 331/3 Drive Weight: 1401bs./30" (� SAMI'Ll"S v C x o � o W SUMMARY OF SUBSURFACE CONDITIONS W �� O H pq z 2 O W rificl— a— 1—Fl_'11 fQaQ�Light gray to light brown and medium brown, 2 moist,medium dense,SILTY SAND-CLAYEY SAND(SM-SC). 4 6 Cal 28 12.8 103.8 _.. �..'� .................................... """"' ............""..""" ............................I'g grayish-brown, very stiff,SANDY C L S (CL). 10 Cal 42 23.4 99.4 12 Contact at 12'/2 feet. 14 Santiago FormaN.,., i'r Light gray to light grayish-brown to light orangish-brown,moist,dense,SILTY SAND-CL.-k 1,EY SAND(SM-SC), Ca] 72 16 fine-grained,with iron staining. 16.2 1n7.8 At 14 feet becomes very dense. 18 Ca] su/5" 20 Test borin terminated at 19'/2 feet.No oundwater. giPROPOSED ACCESSORY UNIT AND GARAGE CHRISTIAN WHEELER BI': 3364 Calle Margarita, Encinitas, California _ �IW N (; I N is 1. it 1 N r; DATE: June 2006 OB NO. : 2060364 PLATE NO.: 3 LOG OF TEST BORING NUMBER B-3 Date Excavated: 5/16/2006 Equipment: L N Tripod Logged by: AKN Existing Elevation: 341 feet Project Dlanager: CHC Finish Elevation: 332 feet Depth to Water: N/A Drive Weight: 140 lbs./30" C7 s:�nml,l:s O v ~x W SUMMARY OF SUBSURFACE CONDITIONS � c 1-r r� O Q a4 Cn O 6-inch laver of Sod and Associated To soil. 2 Artificial Fi 1 Oafl Light gray to light yellowish-brown to medium - brown,moist,medium dense,SILTY SAND-CLA1YEy SAND(SNI-SC). Cal 58 10.11 103.8 4 .fit 2 feet becomes dense. - Ton oil•Medium brownish-gray,damp,medium dense,SILTY 6 SAND Sly ,with sli ht inhole ores and trace shell fra ents. Cal 64 11'7 116.8 Subsoil Medium reddish-grayish-brown,damp to moist,very stiff, 8 SANDY CL. Y(CL),mottled,well rounded,with abundant rootlets and trace ravels. Contact at 7'/2 feet. 10 •, SaniagF „ T Li g ht greenish-gray,moist,hard,SILTY C with a sli ht wax ....... (:al CLAY 711.......6.5 95S ^............•... � • t ................... feet. . ........ " 12 Li g ht pinkish-gray,moist,hard,SANDY CLAY(CL).............. Is.l Contact at 12'/z feet.Ex .P......ion Index= 115 ans...... j """"'" ........................ .14 Li g ht grayish-brown, hard,SANDY with abundant iron staining and gypsum layers up to 1/8"thick. Cad 511/3 SA .5" 16 Exapnsion Index= 100(high) n.S / Contact at 17'/z feet. 1$ ...... Light brown to ............................................................................................ purplish-grayish-brown,moist,very dense,SILTY SAND- y CLAYEY SAND SCI-SC ........ very fine to fine- aired,with iron stai>un .............._ (:al 511/5" ?5.7 'I8.4 20 Test boring terminated at 19'/z feet. No groundwater. PROPOSED ACCESSORY UNIT AND GARAGE 3364 Calle Margarita, Encinitas, California FCHN Rl-' TI,A,N WHEELER BY: (. I NI. I: It IN (I �AV DATE: OB NO.: 2 June 2006 060364 PL_-1TE NO.: 4 LABORATORY TEST RESULTS PROPOSED��CCESS(�RY UNIT AND 3364 C-1I T E N�G�R TT a ENC- _11yIT�S ( �LIFORNi DIRECT SHEAR(ASTM D3080) Sample Location: Boring B-1 @ 14.5' Boring B-3 @ 14.5' Sample Type: Remolded to 90% o Friction Angle: 170 Remolded to 90 /o 28 Cohesion: 600 psf 500 psf GRAIN SIZE DISTRIBUTION(ASTM D422) Sample Location Boring B-3 @ 14'-18.5' Sieve Size Percent Pass nS #4 100 #8 99 #16 98 #30 96 #50 94 #100 90 #200 70 0.05 mm 57 0.005 mm 30 0.001 mm 18 EXPANSION INDEX(ASTM D4829) Sample Location Boring B-3 @ 9,5'-13,5' Boring B-3 @ 14'-18 Initial Moisture 13.5 Initial Dry Density 100.0 cf 12.6 .5' Final Moisture 30.0% 100.3 pcf Expansion Index 29'3 115 (high) 100 (high) CWE 2060364.01 June 23,2006 Plate No. 5 I j 1� �— V/6 Slope Minimum vxx�� ✓,r iy x � x ——— G-inch Nfar 6-inch Minimum v a 3/4 inch Crushed Rock or D Mirafi G100N or Equivalent A Waterproof Back of Wall Per Architect's Specifications GGGa i w ! v Top of Ground 9 or Concrete Slab v Geofabric Completely I` Wrapped Around Rock a 0.- YNXJ� yYyy� 6-inch x tifinimum �vx; Minimum 4-inch Diameter Perforated Pipe X PVC Schedule 40 RETAINING WALL SUBDRAIN DETAIL No Scale PROPOSED ACCESSORY UNIT AND GARAGE CHRISTIAN WHEELER 3364 Calle Margarita,Encinitas,California BY: I IC 4725,�II(R(;l'Rl'til'RI•;If L)-1l'li: �unc2006 TIT.�:1..Iassl 49r,-976n SAN 1)II GU,(;.1J II ORN1.1 9'1 I I rAX.(SSA)469-979x JOB NO.: 2060364.01 > CWE 2060364.01 June 23, 2006 Appendix A,A_1 REFERENCES Anderson,J.G.;Rockwell,R.K. and Agnew,D.C., 1989,Past and Possible Future Earthquakes of Significance to the San Diego Region,Earthaulke Snectra,Volume 5,No. 2, 1989. Blake,T.F.,2000,EQFALTLT,A Computer Program for the Estimation of Peak Horizontal Acceleration from 3-D Fault Sources,Version 3.0,Thomas F.Blake Computer Services and Software,Thousand Oaks,California. Boore,David M.,Joyner,WUiam B.,and Fumal,Thomas E., 1997,"Empirical Near-Source Attenuation Relationships for Horizontal and Vertical Components of Peak Ground Acceleration,Peak Ground Velocity, and Pseudo-absolute Acceleration Response Spectra",in Seismological Research Letters,Volume 68,Number 1,January/February 1997. Grading Plan for Parcel 2,Parcel Map 17122,prepared by Conway and Associates,Inc.,dated September 21, 1994,Drawing No.3989-G. - Report of Preliminary Geotechnical Investigation,Proposed Tennis Court,Parcel 2,Parcel Map 17122 3364 Calle Margarita,Olivenhain,California,prepared by Coast Geotechnical,dated August 2, 1999 ' Report of Retaining Wall Backfill,Proposed Tennis Court,Parcel 2,Parcel Map 17122, 3364 Calle Margarita, Olivenhain, California,prepared by Coast Geotechnical,dated September 7,2000. California Division of Mines and Geology, 1998,Maps of Known Active Fault Near Source-Zones in California and Adjacent Portions of Nevada. California Division of Mines and Geology, 1997,Guidelines for Evaluating and Mitigating Seismic Hazards in California,Special Publication 117. Countywide Flood Insurance Rate Map,Map No.06073C1051F(panel 1051 of 2375),prepared by the Federal Emergency Management agency,effective date June 19, 1997. California Division of Mines and Geology, 1995,Landslide Hazards in the Northern Part of the San Diego Metropolitan Area. CWE 2060364.01 June 23, 2006 Appendix A,A-2 Hart,E.W., 1994,Fault-Rupture Hazard Zones in California,California Division of Mines and Geology Special Publication 42. Jennings,C.W., 1975, Fault Map of California, California Division of Mines and Geology,Map No. 1,Scale 1:750,000. Kern, P., 1989,Earthquakes and Faults in San Diego County,Pickle Press,73 pp. Wesnousky,S.G., 1986, "Earthquakes,Quaternary Faults, and Seismic Hazards in California",in Journal of Geophysical Research,Volume 91,No.B12,pp 12,587 to 12,631,November 1986. CWE 2060364.01 June 23, 2006 Appendix B,B-1 RECOMMENDED GRADING SPECIFICATIONS- GENERAL PROVISIONS PROPOSED ACCESSORY UNIT AND GARAGE 3364 CALLS MA I? -1RIT� ENCINIT�AS, CAT LIFORNI A GENERAL INTENT The intent of these specifications is to establish procedures for clearing,compacting natural ground, preparing areas to be filled,and placing and compacting fill soils to the lines and grades shown on the accepted plans. The recommendations contained in the preliminary geotechnical investigation report and/or the attached Special Provisions are a part of the Recommended Grading Specifications and shall supersede the provisions contained hereinafter in the case of conflict. These specifications shall only be used in conjunction with the geotechnical report for which they are a part. No deviation from these specifications will be allowed, except where specified in the geotechnical report or in other written communication signed by the Geotechnical Engineer. OBSERVATION AND TESTING Christian Wheeler Engineering shall be retained as the Geotechnical Engineer to observe and test the earthwork in accordance with these specifications. It will be necessary that the Geotechnical Engineer or his representative provide adequate observation so that he may provide his opinion as to whether or not the _ work was accomplished as specified. It shall be the responsibility of the contractor to assist the Geotechnical Engineer and to keep him appraised of work schedules,changes and new information and data so that he may provide these opinions. In the event that any unusual conditions not covered by the special provisions or preliminary geotechnical report are encountered during the grading operations, the Geotechnical Engineer shall be contacted for further recommendations. If,in the opinion of the Geotechnical Engineer, substandard conditions are encountered, such as questionable or unsuitable soil,unacceptable moisture content,inadequate compaction,adverse weather,etc., construction should be stopped until the conditions are remedied or corrected or he shall recommend rejection of this work. _ Tests used to determine the degree of compaction should be performed in accordance with the followin American Society for Testing and Nfaterials test methods: g CA`G'E 2060364.01 June 23,2006 Appendix B,B-2 Maximum Density& Optimum Moisture Content-AST",L%I D-1557-91 Density of Soil In-Place-ASThI D-1556-90 or ASTM D-2922 - All densities shall be expressed in terms of Relative Compaction as determined by the foregoing ASTNI testing procedures. PREPARATION OF AREAS TO RECEIVE FILL All vegetation, brush and debris derived from clearing operations shall be removed,and legally disposed of. All areas disturbed by site grading should be left in a neat and finished appearance, free from unsightly debris. After clearing or benching the natural ground, the areas to be filled shall be scarified to a depth of 6 inches, brought to the proper moisture content,compacted and tested for the specified minimum degree of compaction. All loose soils in excess of 6 inches thick should be removed to firm natural ground which is defined as natural soil which possesses an in-situ density of at least 90 percent of its maximum dry density. - When the slope of the natural ground receiving fill exceeds 20 percent(5 horizontal units to 1 vertical unit), the original ground shall be stepped or benched. Benches shall be cut to a firm competent formational soil. _. The lower bench shall be at least 10 feet wide or 1-1/2 times the equipment width,whichever is greater,and shall be sloped back into the hillside at a gradient of not less than two (2) percent. All other benches should be at least 6 feet wide. The horizontal portion of each bench shall be compacted prior to receiving fill as specified herein for compacted natural ground. Ground slopes flatter than 20 percent shall be benched when considered necessary by the Geotechnical Engineer. Any abandoned buried structures encountered during grading operations must be totally removed. All underground utilities to be abandoned beneath any proposed structure should be removed from within 10 feet of the structure and properly capped off. The resulting depressions from the above described procedure should be backftlled with acceptable soil that is compacted to the requirements of the Geotechnical Engineer. This includes, but is not limited to, septic tanks, fuel tanks, sewer lines or leach lines, storm drains and water lines. Any buried structures or utilities not to be abandoned should be brought to the attention of the Geotechnical Engineer so that he may determine if any special recommendation will be necessary. All water wells which will be abandoned should be backfilled and capped in accordance to the requirements set forth by the Geotechnical Engineer. The top of the cap should be at least 4 feet below finish grade or 3 CXX'E 2060364.01 June 33, 2006 Appendix B,B-3 feet below the bottom of Footing whichever is greater. The type of cap will depend on the diameter of the well and should be determined by the Geotechnical Engineer and/or a qualified Structural Engineer. FILL MATERIAL Materials to be placed in the fill shall be approved by the Geotechnical Engineer and shall be free of vegetable matter and other deleterious substances. Granular soil shall contain sufficient Fine material to fill the voids. The definition and disposition of oversized rocks and expansive or detrimental soils are covered in the geotechnical report or Special Provisions. Expansive soils, soils of poor gradation, or soils with low strength characteristics may be thoroughly mixed with other soils to provide satisfactory fill material, but only with the explicit consent of the Geotechnical Engineer. Any import material shall be approved by the Geotechnical Engineer before being brought to the site. PLACING AND COMPACTION OF FILL Approved fill material shall be placed in areas prepared to receive fill in layers not to exceed 6 inches in compacted thickness. Each layer shall have a uniform moisture content in the range that will allow the compaction effort to be efficiently applied to achieve the specified degree of compaction. Each layer shall be uniformly compacted to the specified minimum degree of compaction with equipment of adequate size to economically compact the layer. Compaction equipment should either be specifically designed for soil compaction or of proven reliability. The minimum degree of compaction to be achieved is specified in either the Special Provisions or the recommendations contained in the preliminary geotechnical investigation report. When the structural fill material includes rocks,no rocks will be allowed to nest and all voids must be carefully filled with soil such that the minimum degree of compaction recommended in the Special Provisions is achieved. The maximum size and spacing of rock permitted in structural fills and in non- structural fills is discussed in the geotechnical report,when applicable. Field observation and compaction tests to estimate the degree of compaction of the fill will be taken by the Geotechnical Engineer or his representative. The location and frequency of the tests shall be at the Geotechnical Engineer's discretion. When the compaction test indicates that a particular layer is at less than the required degree of compaction, the layer shall be reworked to the satisfaction of the Geotechnical Engineer and until the desired relative compaction has been obtained. CWE 2060364.01 June 23,2006 _appendix B,B-4 Fill slopes shall be compacted by means of sheepsfoot rollers or other suitable equipment. Compaction by sheepsfoot roller shall be at vertical intervals of not greater than four feet. In addition, fill slopes at a ratio of two horizontal to one vertical or flatter, should be trackrolled. Steeper fill slopes shall be over-built and cut- - back to finish contours after the slope has been constructed. Slope compaction operations shall result in all fill material six or more inches inward from the finished face of the slope having a relative compaction of at least 90 percent of maximum dry density or the degree of compaction specified in the Special Provisions section of this specification. The compaction operation on the slopes shall be continued until the Geotechnical Engineer is of the opinion that the slopes will be surficially stable. Density tests in the slopes will be made by the Geotechnical Engineer during construction of the slopes to determine if the required compaction is being achieved. Where failing tests occur or other field problems arise, the Contractor will be notified that day of such conditions by written communication from the Geotechnical Engineer or his representative in the form of a daily field report. If the method of achieving the required slope compaction selected by the Contractor fails to produce the necessary results, the Contractor shall rework or rebuild such slopes until the required degree of compaction is obtained, at no cost to the Owner or Geotechnical Engineer. CUT SLOPES The Engineering Geologist shall inspect cut slopes excavated in rock or lithified formational material during the grading operations at intervals determined at his discretion. If any conditions not anticipated in the preliminary report such as perched water,seepage,lenticular or confined strata of a potentially adverse nature,unfavorably inclined bedding,joints or fault planes are encountered during grading, these conditions shall be analyzed by the Engineering Geologist and Geotechnical Engineer to determine if mitigating measures are necessary. Unless otherwise specified in the geotechnical report,no cut slopes shall be excavated higher or steeper than that allowed by the ordinances of the controlling governmental agency. CWE 2060364.01 June 23,2006 Appendix B,B-5 ENGINEERING OBSERVATION Field observation by the Geotechnical Engineer or his representative shall be made during the filling and compaction operations so that he can express his opinion regarding the conformance of the grading with acceptable standards of practice. Neither the presence of the Geotechnical Engineer or his representative or the observation and testing shall release the Grading Contractor from his duty to compact all fill material to the specified degree of compaction. SEASON LIMITS Fill shall not be placed during unfavorable weather conditions. When work is interrupted by heavy rain, filling operations shall not be resumed until the proper moisture content and density of the fill materials can be achieved. Damaged site conditions resulting from weather or acts of God shall be repaired before acceptance of work. RECOMMENDED GRADING SPECIFICATIONS- SPECIAL PROVISIONS RELATIVE COMPACTION:The minimum degree of compaction to be obtained in compacted natural ground, compacted fill,and compacted backfill shall be at least 90 percent. For street and parking lot subgrade, the upper six inches should be compacted to at least 95 percent relative compaction. EXPANSIVE SOILS: Detrimentally expansive soil is defined as clayey soil which has an expansion index of 50 or greater when tested in accordance with the Uniform Building Code Standard 29-2. OVERSIZED MATERIAL: Oversized fill material is generally defined herein as rocks or lumps of soil over 6 inches in diameter. Oversized materials should not be placed in fill unless recommendations of placement of such material is provided by the Geotechnical Engineer. At least 40 percent of the fill soils shall pass through a No. 4 U.S. Standard Sieve. TRANSITION LOTS: Where transitions between cut and fill occur within the proposed building pad, the cut portion should be undercut a minimum of one foot below the base of the proposed footings and recompacted as structural backfill. In certain cases that would be addressed in the geotechnical report, special footing reinforcement or a combination of special footing reinforcement and undercutting may be required. CHRISTIAN WHEELER E N G I N E E K I N G REPORT OF PRELIMINARY GEOTECHNICAL INVESTIGATION PROPOSED ACCESSORY UNIT AND GARAGE 3364 CALLE MARGARITA ENCINITAS, CALIFORNIA n � SUBMITTED TO: ALBERT AND SANDRA BERTHA 3364 CALLE MARGARITA ENCINITAS, CALIFORNIA 92024 SUBMITTED BY: CHRISTIAN WHEELER ENGINEERING 4925 MERCURY STREET SAN DIEGO,CALIFORNIA 92111 4925 Mercury Street + San Diego, CA 92111 + 858-496-9760 + FAX 858-496-9758 CHRISTIAN WHEELER ENGINEERING June 23, 2006 Albert and Sandra Bertha CWE 2060364.01 3364 Calle Margarita Encinitas,California 92024 SUBJECT: REPORT OF PRELIMINARY GEOTECHNICAL INVESTIGATION, PROPOSED ACCESSORY UNIT AND GARAGE,3364 CALLE MARGARITA, ENCINITAS, CALIFORNIA Dear Mr. and Mrs.Bertha: In accordance with the request of Storybook Castles and our proposal dated April 11,2006,we have completed a preliminary geotechnical investigation for the proposed accessory unit and garage to be constructed at the subject residential property. We are presenting herewith a report of our findings and recommendations. In general,we found that the project area is suitable to support the proposed accessory unit and garage, provided the recommendations presented herein are followed. We have determined that the project area is underlain by Tertiary-age materials of the Santiago Formation that are overlain by a layer of residual soil (topsoil/subsoil) that is in turn overlain by fill material. We anticipate that the excavations for the proposed basement will remove much of the existing fill and residual soil and expose competent materials of the Santiago Formation at or near the foundation level.As such,it will be possible to extend all building foundations into competent formational material. On the other hand,we anticipate that the proposed slab- on-grade floor will be underlain by fill/residual soil as well as competent formational soil, both of which have a "moderate" to "high"expansion potential. Based on this varying soil condition and to mitigate the possible distress of the lightly loaded slab due to soil expansion, the proposed slab will have to be thickened and more heavily reinforced. The site is located in an area that is relatively free of geologic hazards that will have a significant effect on the proposed constriction. The most likely geologic hazard that could affect the site is ground shaking due to seismic activity along one of the regional active faults. However,construction in accordance with the 4925 Mercury Street + San Diego, CA 92111 + 858-496-9760 + FAX 858-496-9758 C\\'E 3060364.01 )tine 33,3006 Page\n.3 requirements of the most recent edition of the Uniform Building Code and the local governmental agencies should provide a level of life-safety suitable for the type of development proposed. If you have any questions after revie«ing this report,please do not hesitate to contact our office. This opportunity to be of professional service is sincerer-appreciated. Respectfully-submitted, CHRISTIAN WHEELER ENGINEERING Wail Nfokhtar,Staff Engineer 'g�:2' Charles H. Christian,RGE # 00215 Curtis R.Burdett,C. G. 1090 CHC:CRBacc:wm cc: (2) Submitted (4) Storybook Castles S ��p E D GF� Q�pFES o, R. B C'".Cy J No. 1090 �1 U CERTIFIED -� Q- (D c=> No.GE215 z m k ENGINEERING Exp.9-30-07 G_oLOGIST cPJ Ex . 10-06 P GF�TECNNyr�\Q 9�FGF CAI�FOP�� OF CAI TABLE OF CONTENTS Introduction and Project Description.......................................................................................................... Project Scope......................... ag1 Findings......................................... ................................................................................. Site Description...................................................................... 3 Previous Grading............................. . ..3 . .............................................................................................. General Geology and Subsurface Conditions........................ ""' Geologic Setting and Soil Description...................................................................................................................... ArtificialFill............................................................................ ......................4 Topsoil...................... Subsoil............................. Santiago Formation................................................ Groundwater............................. .........5 Tectonic Setting ................................5 ................................... ................................................................................................. Geologic Hazards................................................... 5 GroundShaking............................................................................................. Landslide Potential and Slope Stability.............................. ..............................................................6 ............................ ........................................................7 ............................................... Floodin ...................................... . ....................................... ......................................................... 7 Tsunamis........................ ..................................................................................... ..................... 7 .. Seiches ................................................................................................................................................ 7 Conclusions....................... ............................................................ Recommendations............................... 7 ......................................................... Grading and Earthwork 8 General............................................ 8 ........................................................8 Observation of Grading.................................................................... Clearing and Grubbing................................................. 8 Site Preparation 9 Temporary Slopes..................................................... 9 Processing of Fill Areas.................. .........' ............................................................................... Compaction and Method of Filling """""" 10 SurfaceDrainage........................................................................ 10 Foundations.................................... ......................................... ............................................................................ General............................ ................................................ 10 Conventional Foundations..................... ..................................................... 11 Bearing Capacity.............................................. 11 Footing Reinforcement......................................................................... 11 Lateral Load Resistance..................... ................................................................................................... Settlement Characteristics................................................ 11 Expansive Characteristics........................ ..........11 .............................................................................................................. Foundation Plan Review....................... ..12 Foundation Excavation Observation................................................................................................ Seismic Design Parameters........................................................................................... 12 On-Grade Slab............... 12 Genera]....................................................... ..13 ............................................................................. Interior Floor Slabs................................................. .............13 Linder-Slab Vapor Retarders ......................... 13 ................................................................................. Exterior Concrete Flatwork....... ............................................................................................................................ 14 CkY,'E 2060364.01 Proposed Xccessory Unit and Garage 3364 Calle Margarita,Encinitas, California Earth Retaining W alls............................................ Foundations................................................ 14 Passive Pressure......................... EquivalentFluid Pressures...................................................................................................................................... 14 \Vaterproofing and Subdrain................................ Backfill 15 Limitations 1� Review,Observation and Testing..................................................................................................... ChUniformityof Conditions.............................................................................................................................................15 ange in Scope.................................................................................................................................... Time Limitations........................ ........................16 Professional Standard .............................................................16 ..................................................................... Client's Responsibility............................................................... FieldExplorations................................................... ....................................................................................16 Laboratory ............................................................17 oratory Testing......................... ...................................................................................................................................................... ......17 ATTACHMENTS TABLES Table I Maximum Ground Acceleration, Page 6 Table II Seismic Design Parameters,Page 12 FIGURES Figure 1 Site Vicinity 1\Iap, Follows Page 1 PLATES Plate 1 Site Plan. Plates 2-4 Boring Logs Plate 5 Laboratory Test Results Plate 6 Retaining Wall Subdrain Detail APPENDICES Appendix A References Appendix B Recommended Grading Specifications—General Provisions C\`G'E 2060364.01 Proposed i\ccessory C'nit and Garage 336.1 Calle Nfargarita, Encinitas,California CHRISTIAN WHEELER ENGINEERING REPORT OF PRELIMINARY GEOTECHNICAL INVESTIGATION PROPOSED ACCESSORY UNIT AND GARAGE 3364 CALLE MARGARITA ENCINITAS C ALIFORNLI INTRODUCTION AND PROJECT DESCRIPTION This report presents the results of our preliminary geotecht ical investigation performed for a proposed accessory unit and garage to be constructed at the residential property located at the address of 3364 Calle Margarita,in the Olivenhain area of the city of Encinitas,California. Figure Number 1 presented on the following page provides a vicinity map showing the location of the property. The subject site consists of a developed,irregular-shaped parcel of land,identified as Assessor's Parcel Number 264-240-20, and is characterized by two relatively level graded pads. The northern pad supports a single-family residence, a detached garage/office, a swimming pool,and other associated improvements. We understand that the existing detached garage/office will be demolished and a new accessory unit and garage will be constructed in its place. This new structure is expected to have three levels consisting of a partial subterranean basement,grade-level parking, and a second-story living area. The structure is expected to be of masonry block construction below grade and wood-frame construction above grade. We also expect that the structure will be supported by conventional shallow foundations and will have an on-grade concrete floor slab. Site retaining walls are also proposed. Grading is expected to consist of cuts of 9 to 12 feet from existing grades to establish the proposed pad elevations. To aid in the preparation of this report,we were provided with a site plan for the subject site prepared by Storybook Castles,dated March 30,2006.A copy of this plan was modified to show our geologic mapping and is included herewith as Plate Number 1. In addition,we were also provided with the following documents: 1) Grading Plan for Parcel 2,Parcel Map 17122,prepared by Conway and Associates,Inc.,dated September 21, 1994,Drawing No. 3989-G. 4925 Mercury Street + San Diego, CA 92111 + 858-496-9760 + FAX 858-496-9758 I T i SITE VICINITY MAP (Adapted from Thomas Brothers Maps) i PROPOSED ACCESSO RY NIT AND GARAGE 3364 CAL LE MAR wARl TA ENCINITAS.CALIFORNIA i I I i North SITE )0 "AJ .. r +...lam- y r'ERANZA �r �li_ CASTI l.'(} -.._..,4�. Z p A P ANA EP ao �4 `C <) co i 5 AND i i i p,N C HO �. , - VIA , P D1 FELICITA o --.- r),)nnr Thnm i CWE 3060364.01 June 2006 CXXTE 2060364.01 June 23,2006 Page No. 2) Report of Preliminary-Geotechnical Investigation,Proposed Tennis Court, Parcel 2, Parcel I lap 17122, 3364 Calle Margarita,Olivenhain,California,prepared by Coast Geotechnical,dated august 2, 1999. 3) Report of Retaining Wall Backfill,Proposed Tennis Court, Parcel 2,Parcel Map 17122,3364 Calle Margarita,Olivenhain, California,prepared by Coast Geotechnical,dated September 7,2000. This report has been prepared for the exclusive use of Albert and Sandra Bertha and their design consultants for specific application to the project described herein. Should the project be changed in any way, the modified plans should be submitted to Christian Wheeler Engineering for review to determine their conformance with our recommendations and to determine if any additional subsurface investigation, laboratory testing and/or recommendations are necessary. Our professional services have been performed,our findings obtained and our recommendations prepared in accordance with generally accepted engineering principles and practices. This warranty is in lieu of all other warranties,express or implied. PROJECT SCOPE Our preliminary geotechnical investigation consisted of surface reconnaissance, subsurface exploration, obtaining representative soil samples, laboratory testing, analysis of the field and laboratory data and review of relevant geologic literature. Our scope of service did not include assessment of hazardous substance contamination,recommendations to prevent floor slab moisture intrusion or the formation of mold within the structure,or any other services not specifically described in the scope of services presented below. More specifically, the intent of this investigation was to: a) Explore the subsurface conditions of the project area to the depths influenced by the proposed construction; b) Evaluate, by laboratory tests and our experience with similar soil types, the engineering properties of the various strata that may influence the proposed construction,including bearing capacities,expansive characteristics and settlement potential; C) Describe the general geology at the site including possible geologic hazards that could have an effect on the proposed constriction, and provide the seismic design parameters as required by the most recent edition of the Uniform Building Code; C% 'E 3060364.01 June 23, 1006 Page No. 3 d) Address potential construction difficulties that mat be encountered due to soil conditions, groundwater or geologic hazards, and provide recommendations concerning these problems; e) Develop soil engineering criteria for site preparation and grading, and address the stability of temporary-constriction slopes; Provide design parameters for unrestrained and restrained retaining walls; g) Recommend an appropriate foundation system for the type of structure anticipated and develop soil engineering design criteria for the recommended foundation design; h) Present our professional opinions in this report,which includes in addition to our conclusions and recommendations,a plot plan,exploration logs and a summary of the laboratory test results. It is not within the scope of our services to perform laboratory tests to evaluate the chemical characteristics of the on-site soils in regard to their potentially corrosive impact to on-grade concrete and below grade improvements. If desired,we can submit representative soil samples to a chemical laboratory for analysis. Further,it should be understood Christian Wheeler Engineering does not practice corrosion engineering. If such an analysis is necessary,we recommend that the developer retain an engineering firm that specializes in this field to consult with them on this matter FINDINGS SITE DESCRIPTION The subject site is a developed,irregular-shaped parcel of land,located at the address of 3364 Calle Margarita, in the Olivenhain area of the city of Encinitas,California. The lot is identified as Assessor's Parcel Number 264-240-20,and as Parcel 2 of Map 17122. The lot is bounded on the north by Calle Margarita,and on the remaining three sides by residential properties. The property is characterized by two relatively level graded pads. The upper,northern portion of the property supports a single-family residence, a detached garage/office, a swimming pool, and other normally associated improvements. The lower, southern portion supports a tennis court and a basketball court and a large grass lawn. The project area is located in the southeastern corner of the upper pad and currently supports the detached garage/office. The detached garage/office pad is at an elevation of about 341 feet.An approximately 8-Foot-high, fill-over-cut slope descends from the pad towards the south and an approximately 5-foot-high fill slope descends from the pad M CWE 2060364.01 June 23,2006 Page No. 4 towards the east. An approximately 10-foot-high retaining wall exists at the bottom of the southern slope. A retaining wall ranging from 1 to 4 feet high is located at the bottom of the eastern slope. Vegetation within the project area consists of a grass lawn located to the rear of the existing detached garage/office structure.A planter and a few trees also exist within the project area. PREVIOUS GRADING Based on our review of the referenced grading plan and geotechnical reports,previous grading within the project area consisted of placing about 7 feet of fill to create a level pad for the existing detached garage/office structure and constructing an approximately 8-foot-high fill slope with an inclination of about 2:1 (H:V) to the south of the detached garage/office pad and an approximately 5-foot-high fill slope to the east of the pad. A 3-foot-deep by 15-foot-wide keyway was made along the base of the fill slope. At a later date the rear yard area was regarded to create gently sloping to near level terrain.This was accomplished by cutting along the base of the existing fill slope and placing of fill along the southern extend of the rear yard. The 4 to 5 foot-high cut slope along the base of the fill slope has daylighted the keyway and created a 2:1 (H:V) fill-over-cut slope. GENERAL GEOLOGY AND SUBSURFACE CONDITIONS GEOLOGIC SETTING AND SOIL DESCRIPTION:The subject site is located in the Coastal Plains Physiographic Province of San Diego County. Based on the results of our subsurface explorations and review of pertinent,readily available geologic literature,we have determined that the project area is underlain by Tertiary- age materials of the Santiago Formation that are overlain by a layer of residual soil (topsoil/subsoil) that is in turn overlain by fill material. Each of the encountered soil units is discussed below. ARTIFICIAL FILL:An approximately 3 to 121/2-foot-thick layer of fill material was encountered within our exploratory borings. The fill generally consisted of light gray to light yellowish-brown,silty sand-clayey sand (SM-SC),light grayish-brown,clayey sand-sandy clay(SC-CL) and light brownish-gray, sandy clay(CL).The encountered fill material was typically moist and medium dense to dense in the sandy portions and very stiff in the clayey portions.The existing fill is expected to possess a"low"to "medium"expansion index and a low settlement potential. The fill is considered suitable in its present condition to support settlement-sensitive improvements. _ TOPSOIL:An approximately one-foot-thick layer of topsoil was encountered below the fill material within our test boring B-3,which was drilled in the northern portion of the project area. The CWE 2060364.01 June 23,2006 Page No. 5 encountered topsoil generally consisted of medium brow nish-gra}', silty sand (SAI) that was damp and medium dense in consistency. This material is expected to possess a"low"expansion index and a moderate settlement potential. The existing topsoil is considered unsuitable in its present condition to support settlement sensitive improvements. SUBSOIL: An approximately 2 to T/2-foot-thick layer of subsoil was encountered below the fill and topsoil within our test borings B-1 and B-3.The encountered subsoil generally consisted of light brownish-gray to medium reddish-brown,sandy clay(CL) that was typically damp to moist and very stiff in consistency.This material is expected to possess a"low"to "medium"expansion index and moderate settlement potential.The existing subsoil is considered unsuitable in its present condition to support settlement sensitive improvements. SANTIAGO FORMATION (Tsa):Tertiary-age materials of the Santiago Formation were encountered below the fill and residual soil(topsoil/subsoil) within each of our test borings,and are expected to underlie the entire project area.The formational materials generally consisted of light grayish-brown to orangish-brown, silty sand-clayey sand (SM-SC),light grayish-brown to light pinkish-gray, sandy clay(CL) and light gray, silty clay(CH). The materials of the Santiago Formation were moist and medium dense to very dense in the sandy portions and very stiff to hard in the clayey portions. The Santiago Formation is expected to possess a"low"expansion index within the sandy portions. Based on our laboratory tests, the clayey portions of the Santiago Formation were found to possess a "high"expansion index.The formational materials are expected to possess a low settlement potential. The materials of the Santiago Formation are considered suitable in their present condition to support settlement sensitive improvements. GROUNDWATER:No groundwater was encountered in our subsurface explorations and we do not expect any groundwater related conditions during or after the proposed construction. However,it should be recognized that minor groundwater seepage problems might occur after construction and landscaping at a site even where none were present before construction.These are usually minor phenomena and are often the result of an alteration in drainage patterns and/or an increase in irrigation water. Based on the anticipated construction and landscaping,it is our opinion that any seepage problems that may occur will be minor in extent. It is further our opinion that these problems can be most effectively corrected on an individual basis if and when they occur. TECTONIC SETTING:It should be noted that much of Southern California,including the San Diego County area,is characterized by a series of Quaternary-age fault zones that consist of several individual,en echelon faults that generally strike in a northerly to northwesterly direction. Some of these fault zones (and the CNXTE 2060364.01 June 23,2006 Page No. 6 individual faults within the zone) are classified as"active"according to the criteria of the California Division of Mines and Geology. Active fault zones are those that have shown conclusive evidence of faulting during the Holocene Epoch (the most recent 11,000 years). The Division of Mines and Geology used the term"potentially active"on Earthquake Fault Zone maps until 1988 to refer to all Quaternary-age (last 1.6 mullion years) faults for the purpose of evaluation for possible zonation in accordance with the Alquist-Priolo Earthquake Fault Zoning Act and identified all Quaternary-age faults as "potentially active"except for certain faults that were presumed to be inactive based on direct geologic evidence of inactivity during all of Holocene time or longer. Some faults considered to be "potentially active"would be considered to be"active"but lack specific criteria used by the State Geologist,such as�rr(jiiient_),addve and svell-defined. Faults older than Quaternary-age are not specifically defined in Special Publication 42,Fault Rupture Hazard Zones in California,published by the California Division of Mines and Geology. However,it is generally accepted that faults showing no movement during the Quaternary period may be considered to be"inactive". The nearest active fault zone is the Rose Canyon Fault Zone,which is located approximately 11 kilometers to the west. Other active fault zones in the region that could possibly affect the site include the Coronado Bank and Fault Zone to the southwest,the Elsinore,and Earthquake Valley Fault Zones to the northeast,and the Newport-Inglewood Fault Zone to the northwest. GEOLOGIC HAZARDS GROUND SHAKING:A likely geologic hazard to affect the site is ground shaking as a result of movement along one of the major active fault zones mentioned above. The maximum ground accelerations that would be attributed to a maximum probable earthquake occurring along the nearest fault segments of selected fault zones that could affect the site are summarized in Table I presented below. TABLE I:MAXIMUM GROUND ACCELERATIONS Fault Zone Distance Max.Magnitude Maximum Ground Earthquake Acceleration Rose Canyon 11 km 7.2 magnitude 0,29 g Newport-Inglewood 22 km 7.1 Magnitude 0.17 Coronado Bank g 35 km 7.61�fagnitude 0.15 g V_Isinore Qulian) E61 km 7.1 Magnitude 0.11 g Earthquake Valley km 6.5 magnitude 0.06 g It is likely that the site will experience the effects of at least one moderate to large earthquake during the life of the proposed improvements. It should be recognized that Southern California is an area that is subject to some degree of seismic risk and that it is generally not considered economically feasible nor technologically CWE 2060361.01 June 23,2006 Page No. 7 practical to build strictures that are totally resistant to earthquake-related hazards. Construction in accordance with the minimum requirements of the Uniform Building Code should minimize damage due to seismic events. LANDSLIDE POTENTIAL AND SLOPE STABILITY:As part of this investigation we reviewed the publication, "Landslide Hazards in the Northern Part of the San Diego Metropolitan Area"by Tan, 1995. This reference is a comprehensive study that classifies San Diego County into areas of relative landslide susceptibility. The subject site is located in Relative Landslide Susceptibility Area 3-1. Area 3 is considered to be "generally susceptible"to slope movement;subarea 3-1 classifications are considered at or near their stability limits due to steep slopes and can be expected to fail locally when adversely modified. Sites within this classification are located outside the boundaries of known landslides but may contain observably unstable slopes that may be underlain by weak materials and/or adverse geologic structure.Due to the generally gentle topography of the site and the fact that the on-site fill slopes are well compacted as well as the relatively competent nature of the underlying formational materials,it is our opinion that the potential for deep-seated landsliding is considered to be low. LIQUEFACTION: The materials at the site are not anticipated to be subject to liquefaction due to such factors as soil density,grain-size distribution, and depth to ground water. FLOODING:The site is not located within either a 100-year or a 500-year flood zone according to the maps - prepared by the Federal Emergency Management Agency(Panel 1051 F). TSUNAMIS: Tsunamis are great sea waves produced by submarine earthquakes or volcanic eruptions. Based upon the location of the site it will not be affected by tsunamis. SEICHES: Seiches are periodic oscillations in large bodies of water such as lakes, harbors, bays or reservoirs. Due to the site's location,it is considered to have a negligible risk potential for seiches. CONCLUSIONS In general, no geotechnical conditions were encountered which would preclude the proposed constriction provided the recommendations presented herein are followed. Based on the results of our investigation,we have determined that the project area is underlain by Tertiary-age materials of the Santiago Formation that are overlain by a layer of residual soil (topsoil/subsoil) that is in turn overlain by fill material. We anticipate that the excavations for the proposed basement will remove much of the existing fill and residual soil and expose CWE 2060364.01 June 33,2006 Page No. 8 competent materials of the Santiago Formation at or near the foundation level.As such, it will be possible to extend all building foundations into competent formational material. On the other hand,we anticipate that the proposed slab-on-grade floor dill be underlain by fill/residual soil as well as competent formational soil, both of which have a"moderate" to "high"expansion potential. Based on this var�_ing soil condition and to mitigate the possible distress of the lightly loaded slab due to soil expansion, the proposed slab will have to be thickened and more heavily reinforced. Also,due to the depth of the proposed excavation for the basement, the existing foundations at the southeastern corner of the existing residence will be undermined. Therefore, temporary shoring of the excavations or temporary support of the southeastern corner of the existing residence will be necessary during the construction of the basement. Both the shoring and/or temporary support system will need to be designed and constructed by an engineer/contractor experienced in this area.The design will need to be reviewed by our firm prior to construction in order to verify that the geotechnical recommendations presented in this report have been incorporated into the design. The site is located in an area that is relatively free of geologic hazards that will have a significant effect on the proposed construction. The most likely geologic hazard that could affect the site is ground shaking due to seismic activit3-along one of the regional active faults. However,construction in accordance with the requirements of the most recent edition of the Uniform Building Code and the local governmental agencies should provide a level of life-safety suitable for the type of development proposed. RECOMMENDATIONS GRADING AND EARTHWORK GENERAL:All grading should conform to the guidelines presented in Appendix Chapter X33 of the Uniform Building Code,the minimum requirements of the city of Encinitas,and the recommended Grading Specifications and Special Provisions attached hereto,except where specifically superseded in the text of this report. Prior to grading,a representative of Christian Wheeler Engineering should be present at the pre- construction meeting to provide additional grading guidelines,if necessary,and to review the earthwork schedule. OBSERVATION OF GRADING: Continuous observation by the Geotechnical Consultant is essential during the grading operation to confirm conditions anticipated by our investigation, to allow adjustments in _., C%X'E 2060364.01 June 23,2006 Page No. 9 design criteria to reflect actual Field conditions exposed,and to determine that the grading proceeds in general accordance with the recommendations contained herein. CLEARING AND GRUBBING: Site preparation should begin with the removal of the existing improvements that are designated for removal. This removal should include all existing foundations,slabs and above grade and underground utilities,as well as any vegetation and other deleterious materials,including all significant root material. The resulting organic materials and construction debris should be disposed of in an appropriate off-site facility. SITE PREPARATION:After clearing and grubbing,site grading is expected to consist of cuts of 9 to 12 feet from existing grades to establish the proposed pad elevations. Our firm will need to observe the bottom of the excavations to make sure that all unsuitable materials (residual soil) have been removed by the planned cuts. If any unsuitable soils were found at the bottom of the excavation they will need to be removed and replaced as structural fill. The removals should extend to the contact with the competent materials of the Santiago Formation.The removals should extend to include all areas that will receive fill and/or improvements. The bottom of the excavations should be approved by our project geologist,engineer,or technician supervisor prior to placing Fills or constructing improvements. TEMPORARY SLOPES:Temporary slopes will be required during the construction of the proposed basement. Temporary slopes for the basement of up to 15 feet in height can be excavated vertically for the bottom 4 feet and at an inclination of 1.0 to 1.0 (horizontal to vertical) above. Our firm should be contacted to observe all temporary cut slopes during grading to ascertain that no unforeseen adverse conditions exist. No surcharge loads such as adjacent building foundations, soil or equipment stockpiles,vehicles,etc. should be allowed within a distance from the top of temporary slopes equal to half the slope height. Where there is not room to constrict temporary slopes in accordance with the above recommendations,such as in the area adjacent to the southeast corner of the existing residence, temporary shoring of the excavation sides will be necessary. Shoring should be designed using the following soil parameters: Angle of internal friction: 25 degrees Apparent cohesion: 250 psf Total Unit weight: 120 pcf It should be noted that the contractor is solely responsible for designing and constructing stable, temporary excavations and may need to shore, slope,or bench the sides of trench excavations as required to maintain the stability of the excavation sides. The contractor's "competent person", as defined in the OSHA C%VE 2060364.01 June 23,3006 Page No. 10 Construction Standards for Excavations,29 CFR, Part 1926, should evaluate the soil exposed in the excavations as part of the contractor's safety process. Temporary-cut slopes should be constructed in accordance with the recommendations presented in this section. In no other case should slope height, slope inclination,or excavation depth,including utility trench excavation depth,exceed those specified in local, state,and federal safety regulations. PROCESSING OF FILL AREAS: Prior to placing any new fill soils or constructing any new improvements in areas that have been cleaned out and approved to receive fill, the exposed soils should be scarified to a depth of 12 inches,moisture conditioned,and compacted to at least 90 percent relative compaction. No other special ground preparation is anticipated at this time. COMPACTION AND METHOD OF FILLING:All structural fill placed at the site should be compacted to a relative compaction of at least 90 percent of maximum dry density as determined by ASIM Laboratory Test D1557. Fills should be placed at or slightly above optimum moisture content,in lifts six to eight inches thick, with each lift compacted by mechanical means. Fills should consist of approved earth material, free of trash or debris,roots,vegetation,or other materials determined to be unsuitable by our soil technicians or project geologist. Fill material should be free of rocks or lumps of soil in excess of twelve inches in maximum dimension. However,in the upper two feet of pad grade,no rocks or lumps of soil in excess of six inches should be allowed. Utility trench backfill within five feet of the proposed structure and beneath driveways,concrete flatwork,and pavements should be compacted to a minimum of 90 percent of its maximum dry density. SURFACE DRAINAGE: The ground around the proposed structure should be graded so that surface water flows rapidly away from the structure without ponding. In general,we recommend that the ground adjacent to the structure slope away at a gradient of at least two percent. Densely vegetated areas where runoff can be impaired should have a minimum gradient of at least five percent within the first three feet from the structure. Gutters and downspouts should discharge into controlled drainage devices. FOUNDATIONS GENERAL: Based on our findings and engineering judgments,the proposed accessory unit and garage may be supported by conventional continuous and isolated spread footings.The following recommendations are considered the minimum based on anticipated soil conditions after site grading and are not intended to be lieu of structural considerations. All foundations should be designed by a qualified structural engineer. CWE 2060364.01 June 23,2006 Page No. 11 CONVENTIONAL FOUNDATIONS: Spread footings supporting the three-story stricture should extend through any fill or residual soil and be embedded at least 6 inches into the underlying competent materials of the Santiago Formation and have a minimum embedment depth of 24 inches. Continuous footings should have a minimum width of 18 inches. Isolated and retaining wall footings should have a minimum width of 24 inches. Site retaining walls footings should extend through any fill or residual soil and be embedded at least 6 inches into the underlying competent materials of the Santiago Formation and have a minimum embedment of 18 inches below the lowest adjacent grade. BEARING CAPACITY: Conventional footings with a minimum embedment of 6 inches into formational materials may be designed for an allowable soil bearing pressure of 3,000 pounds per square foot.This value may be increased by 700 pounds per square foot for each additional foot of embedment depth and 300 pounds per square foot for each additional foot of width,up to a maximum of 5,000 psf. This value may be increased by one-third for combinations of temporary loads such as those due to wind or seismic loads. FOOTING REINFORCEMENT:The project structural engineer should provide reinforcement requirements for foundations. However,based on soil conditions,we recommend that the minimum reinforcing for the proposed residence continuous footings should consist of at least two No. 5 bars positioned three inches above the bottom of the footing and two No. 5 bars positioned two inches below the top of the footing. Where new footings abut existing house foundations, they should be doweled together as per the recommendations of the project structural engineer. LATERAL LOAD RESISTANCE:Lateral loads against foundations may be resisted by friction between the bottom of the footing and the supporting soil,and by the passive pressure against the footing. The coefficient of friction between concrete and soil may be considered to be 0.30. The passive resistance may be considered to be equal to an equivalent fluid weight of 350 pounds per cubic foot. This assumes the footings are poured tight against undisturbed soil. If a combination of the passive pressure and friction is used, the friction value should be reduced by one-third. SETTLEMENT CHARACTERISTICS:The anticipated total and differential settlement is expected to be less than about 1 inch and 1 inch in 40 feet,respectively,provided the recommendations presented in this report are followed. It should be recognized that minor cracks normally occur in concrete slabs and foundations due to shrinkage during curing or redistribution of stresses, therefore some cracks may be anticipated. Such cracks are not necessarily an indication of excessive vertical movements. CWT-3060364.01 June 23, 2006 Page No. 12 EXPANSIVE CHARACTERISTICS: We expect the soils within the foundation to consist of materials of the Santiago Formation. The formational materials are comprised of interbedded layers of sandstones, siltstones and clay-stones. As stated in the "Geology"section above, the Santiago Formation is expected to possess a "low"expansion index within the sandy portions and a "high"expansion index within the clayey portion. This condition has been incorporated in these foundation recommendations. FOUNDATION PLAN REVIEW: The foundation plans should be submitted to this office for review in order to ascertain that the recommendations of this report have been implemented,and that no additional recommendations are needed due to changes in the anticipated construction. FOUNDATION EXCAVATION OBSERVATION:All foundation excavations should be observed by the Geotechnical Consultant prior to placing formwork or reinforcing steel in order to determine if the foundation recommendations presented herein are followed. All footing excavations should be excavated neat,level,and square. All loose or unsuitable material should be removed prior to the placement of concrete. SEISMIC DESIGN PARAMETERS Based on our Deterministic Seismic Hazard Analysis,the Maximum Ground Acceleration at the site is estimated to be 0.29 g(based upon a Maximum Magnitude Seismic Event of 7.2 Magnitude along the Rose Canyon Fault). For structural design purposes,a damping ratio not greater than 5 percent of critical dampening,and Soil Profile Type Sc are recommended (UBC Table 16-J). Based upon the location of the site at approximately 11 kilometers from the Rose Canyon Fault(Type B Fault),Near Source Factors N„equal to 1.0 and N,,equal to 1.0 are also applicable.These values, along with other seismically related design parameters from the Uniform Building Code (UBC) 1997 edition,Volume II,Chapter 16,utilizing a Seismic Zone 4 are presented in tabular form below. TABLE II: SEISMIC DESIGN PARAMETERS UBC Chapter 16 Seismic Design Recommended Table No. Parameter Value 16-I Seismic Zone Factor Z 0.40 16-j Soil Profile T e Sc 16-Q Seismic Coefficient C, 0.40 N, 16-R Seismic Coefficient C,. 0.56N, 16-S Near Source Factor N;, 1.0 16-T Near Source Factor N,. 1.0 16-U Seismic Source T e B CXX'E 2060364.01 June 23,2006 Page No. 13 ON-GRADE SLAB GENERAL: It is our understanding that the proposed structure will have a concrete slab-on-grade. The folloxving recommendations are considered the minimum slab requirements based on the soil conditions and are not intended in lieu of structural considerations. INTERIOR FLOOR SLABS: The minimum floor slab thickness should be five inches (actual) and the floor slab should be reinforced with at least No.4 reinforcing bars placed at 12 inches on center each way. Slab reinforcement should be supported on chairs such that the reinforcing bars are positioned at mid-height in the floor slab. The slab reinforcement should extend into the perimeter foundations at least six inches. UNDER-SLAB VAPOR RETARDERS: Steps should be taken to minimize the transmission of moisture vapor from the subsoil through the interior slabs where it can potentially damage the interior floor coverings. Local industry standards typically include the placement of a vapor retarder, such as visqueen,between two, 2-inch-thick layers of coarse sand placed directly beneath the concrete slab. This is the most common under- slab vapor retarder system used in San Diego County. The vapor retarder should be at least 15 mil visqueen with sealed seams and should extend at least 12 inches down the sides of the interior and perimeter footings. The sand should contain less than 10%passing the Number 100 sieve and less than 5%passing the Number 200 sieve. Although the system described above has historically performed adequately,national standards for the installation of vapor retarders below interior slabs are changing as evidenced in currently published standards including ACI 302, "Guide to Concrete Floor and Slab Construction"and ASTM E1643, "Standard Practice for Installation of Water Vapor Retarder Used in Contact with Earth or Granular Fill Under Concrete Slabs". Rather than placing the vapor retarder between the two sand layers, both of these standards recommend placing the sand capillary break layer onto the subgrade with a vapor retarder placed above the sand and the concrete placed directly onto the vapor retarder. There are advantages and disadvantages to each of these installation procedures. An advantage to placing concrete directly onto a vapor retarder is that it eliminates the layer of sand between the slab and vapor retarder. This layer of sand typically contains moisture prior to the placement of concrete and can receive more moisture during the curing and construction processes. This moisture can be retained in the sand layer for an extended period of time until the concrete moisture decreases to the point at which the excess sand moisture is absorbed by the concrete and transmitted up through the slab. This process can take many months depending upon the environmental conditions. C\NT-206036=1.01 June 23,2006 Page No. 14 One disadvantage to placing concrete directly onto a vapor retarder is that removing the sand laN-er from directly beneath the concrete restricts the ability of the concrete to lose moisture on both the top and bottom surfaces during the initial curing period. Variations in the drying rate between the top and bottom surfaces can result in increased concrete cracking,curling, and other finishing issues. The drying rate differences and their potential side effects can be minimized,however,with suitable finishing and curing procedures. Recognizing the stated benefits and limitations of these standard below-slab vapor retarder systems, the owner and designer should select the system that they believe is most suitable for this project considering the construction schedule and planned floor coverings. It should be understood that neither of the described systems provides a "waterproof barrier". It should also be understood that slab concrete contains free water and should be allowed to reach equilibrium in an environment similar to that anticipated in the completed structure prior to installing floor coverings. We recommend that the flooring installer perform standard moisture vapor emission tests prior to the installation of all moisture-sensitive floor coverings in accordance with ASTM F1869 "Standard Test Method for Measuring Moisture Vapor Emission Rate of Concrete Subfloor Using Anhydrous Calcium Chloride". EXTERIOR CONCRETE FLATWORK Exterior slabs should have a minimum thickness of five inches. Reinforcement should be placed in exterior concrete flatwork to reduce the potential for cracking and movement. Control joints should be placed in exterior concrete flatwork to help control the location of shrinkage cracks. Spacing of control joints should be in accordance with the American Concrete Institute specifications. Where patio slabs,walkways and porch slabs abut perimeter foundations, they should be doweled into the footings. It should be noted that due to the expansive potential of the existing soils,minor cosmetic distress might occur. EARTH RETAINING WALLS FOUNDATIONS: Foundations for proposed retaining walls should be constructed in accordance with the recommendations for shallow foundations presented previously in this report. PASSIVE PRESSURE:The passive pressure for the anticipated foundation soils may be considered to be 350 pounds per square foot per foot of depth. This pressure may be increased by one-third for seismic loading. The coefficient of friction for concrete to soil may be assumed to be 0.35 for the resistance to lateral movement. kMien combining frictional and passive resistance, the friction should be reduced by one-third. EQUIVALENT FLUID PRESSURES: The equivalent fluid pressure for the design of"unrestrained"and "restrained"earth retaining structures with level backfill may be assumed to be 40 and 60 pounds per cubic foot, CWE 3060364.01 June 33,2006 Page No. 15 respectively. These pressures do not consider any surcharge. If any are anticipated, this office should be contacted for the necessary increase in soil pressure. Tlus value assumes a drained,moderately expansive (E.I<90) backfill condition. WATERPROOFING AND SUBDRAIN: Waterproofing details should be provided by the project architect. A suggested wall subdrain detail is provided on the attached Plate Number 6. We recommend that the Geotechnical Consultant be requested to observe all retaining wall subdrains to verifti.proper construction. BACKFILL: All backfill soils should be compacted to at least 90 percent relative compaction. Expansive or clayey soils should not be used for backfill material. The wall should not be backfilled until the masonry has reached an adequate strength. LIMITATIONS REVIEW, OBSERVATION AND TESTING The recommendations presented in this report are contingent upon our review of final plans and specifications. Such plans and specifications should be made available to the Geotechnical Engineer and Engineering Geologist so that they may review and verify their compliance with this report and with the Uniform Building Code. It is recommended that Christian Wheeler Engineering be retained to provide continuous soil engineering services during the earthwork operations. This is to verify compliance with the design concepts, specifications or recommendations and to allow design changes in the event that subsurface conditions differ from those anticipated prior to start of construction. UNIFORMITY OF CONDITIONS The recommendations and opinions expressed in this report reflect our best estimate of the project requirements based on an evaluation of the subsurface soil conditions encountered at the subsurface exploration locations and on the assumption that the soil conditions do not deviate appreciably from those encountered. It should be recognized that the performance of the foundations and/or cut and fill slopes may be influenced by undisclosed or unforeseen variations in the soil conditions that may occur in the intermediate and unexplored areas. Any unusual conditions not covered in this report that may be encountered during site development should be brought to the attention of the Geotechnical Engineer so that he may make modifications if necessary. CXXE 2060364.01 June 23,2006 Page No. 16 CHANGE IN SCOPE This office should be advised of any changes in the project scope or proposed site grading so that we may determine if the recommendations contained herein are appropriate. It should be verified ui writing if the recommendations are found to be appropriate for the proposed changes or our recommendations should be modified by a written addendum. TIME LIMITATIONS The findings of this report are valid as of this date. Changes in the condition of a property can,however,occur with the passage of time,whether they are due to natural processes or the work of man on this or adjacent properties. In addition,changes in the Standards-of-Practice and/or Government Codes may occur. Due to such changes, the findings of this report may be invalidated wholly or in part by changes beyond our control. Therefore,this report should not be relied upon after a period of two years without a review by us verifying the suitability of the conclusions and recommendations. PROFESSIONAL STANDARD In the performance of our professional services,we comply with that level of care and skill ordinarily exercised by members of our profession currently practicing under similar conditions and in the same locality. The client recognizes that subsurface conditions may vary from those encountered at the locations where our borings, surveys,and explorations are made,and that our data,interpretations,and recommendations are based solely on the information obtained by us. We will be responsible for those data,interpretations,and recommendations, but shall not be responsible for the interpretations by others of the information developed. Our services consist of professional consultation and observation only,and no warranty of any kind whatsoever,express or implied, is made or intended in connection with the work performed or to be performed by us,or by our proposal for consulting or other services,or by our furnishing of oral or written reports or findings. CLIENT'S RESPONSIBILITY It is the responsibility of the Client,or their representatives, to ensure that the information and - recommendations contained herein are brought to the attention of the structural engineer and architect for the project and incorporated into the project's plans and specifications. It is further their responsibility to take the necessary measures to insure that the contractor and his subcontractors carry out such recommendations during construction. CWE 2060364.01 June 23,2006 Page No. 17 FIELD EXPLORATIONS Three subsurface explorations were made on May 16,2006 at the locations indicated on the attached Plate Number 1.These explorations consisted of borings drilled using a limited access tripod rig.The fieldwork was conducted under the observation of our engineering geology personnel. The explorations were carefully logged when made. The boring logs are presented on the following Plate Numbers 2 through 4. The soils are described in accordance with the Unified Soils Classification System. In addition, a verbal textural description, the wet color, the apparent moisture and the density or consistency are provided.The density of granular soils is given as 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. Relatively undisturbed drive samples were collected using a modified California sampler.The sampler,with an external diameter of 3.0 inches,is lined with 1-inch long, thin,brass rings with inside diameters of approximately 2.4 inches. The sample barrel was driven into the ground with the weight of a 140-pound hammer falling 30 inches in general accordance with ASTM D 3550-84.The driving weight is pernitted to fall freely.The number of blows per foot of driving,or as indicated,are presented on the boring logs as an index to the relative resistance of the sampled materials.The samples were removed from the sample barrel in the brass rings,and sealed. Bulk samples of the encountered earth materials were also collected. Samples were transported to our laboratory for testing. LABORATORY TESTING Laboratory tests were performed in accordance with the generally accepted American Society for Testing and Materials (ASTM) test methods or suggested procedures.A brief description of the tests performed is presented below: a) CLASSIFICATION: Field classifications were verified in the laboratory by visual examination. The final soil classifications are in accordance with the Unified Soil Classification System. b) MOISTURE-DENSITY: In-place moisture contents and dry densities were determined for representative soil samples. This information was an aid to classification and permitted recognition of variations in material consistency with depth. The dry unit weight is determined in pounds per cubic foot,and the in-place moisture content is determined as a percentage of the soil's dry weight. The results are summarized in the boring logs. CWE 2060364.01 June 23,2006 Page No. 18 c) DIRECT SHEAR TEST: Direct shear tests were performed on a representative sample of the on-site soils to determine the failure envelope based on yield shear strength. The shear box was designed to accommodate a sample having a diameter of 2.375 inches or 2.50 inches and a height of 1.0 inch. The samples were saturated and tested at different vertical loads.The shear stress was applied at a constant rate of strain of approximately 0.05 inch per minute.The results of this test are presented on Plate No. 5. d) EXPANSION INDEX TEST:An expansion Index test was performed on remolded sample of a representative sample. The test was performed on the portion of the sample passing the #4 standard sieve. The sample was brought to optimum moisture content and then dried back to constant moisture content for 12 hours at 230 + 9 degrees Fahrenheit. The specimen was then compacted in a 4-inch- diameter mold in two equal layers by means of a tamper, then trimmed to a final height of 1 inch, and brought to a saturation of approximately 50 percent. The specimen was placed in a consolidometer with porous stones at the top and bottom, a total normal load of 12.63 pounds was placed(144.7 pso,and the sample was allowed to consolidate for a period of 10 minutes. The sample was saturated, and the change in vertical movement was recorded until the rate of expansion became nominal. The expansion index is reported on Plate No. 5 as the total vertical displacement times 1000. f) GRAIN SIZE DISTRIBUTION:The grain size distributions were determined from representative soil samples in accordance with ASTM D422. The results of these tests are presented on Plate No. 5. N z 5d1INIDNA b11dy� I Iy� pug 1INn �doss Hd gNys ld�fl� o " cv �Q co --I cn x � o Go \ a �6 I a I o ��'� W CO �1 0 / I � U JWA ~ im vlaG F //I oT 11= LL1 M FIA Rl- -13 lu a / U W 11 0 \ LV, - I ._..• !. 2 ��AP YAII� S TI3ACK==�� ———————- 1 � _ — — r' N87'03 23 E 292.78 LOG OF TEST BORING NUMBER B-1 Date Excavated: 5/16/2006 Logged by: AKN Equipment: LA Tripod Project NIanager: CHC Existing Elevation: 341 feet Depth to Water: N/_1 Finish Elevation: 331 Feet Drive W'eight: 140 lbs./30" SAMPLES C (� SUNINLkRY OF SUBSURFACE CONDITIONS a �4 z 6-inch layer of Sod and_associated Topsoil. 2 Artificial Fill(Oat)•Light gray to light brown to orangish-yellowish- brown,moist,medium dense,SILTY SAND-CLAYEY SAND(STNI-SC). Cal 33 17.8 101.2 4 Abundant roots present in upper 1 foot. Cal 33 20.3 99.6 6 ........................................................................................................................................................................... ......... ........................ ............................ Light brownish-gray,moist,very-stiff,SANDY CLAY(CL). 8 Contact at T/z feet. Subsoil:Light to medium grayish-brown,moist,very stiff,SANDY 10 SILTY CLAY(CL),mottled,with trace rootlets. Contact at 9'/z feet. -al 31 25.2 93.7 12 0//////// Santiago Formation Light grayish-brown to medium orangish- ......... ........................ ............................ brown,moist,very stiff,SANDY CLAY(CL), e' 14 ; verj:fine to fine- rained. Contact at 11'/z feet. ...................................................................................................................... Light gray to light brownish-gray to light orangish-brown,moist,dense, Cal 50/6 17.2 108.7 16 ' SILTY SAND-CL-k 1T3Y SAND(Sli-SC),fine-grained,with iron staining. 1�s At 14 feet becomes very dense. 18 (-al 111 50/5" 20 1 1 Test borina terminated at 19'/ feet. No jzroundwater. PROPOSED ACCESSORY UNIT AND GARAGE W3364 Calle Margarita,Encinitas, California CI IRISTI:= N WHEELER BY: �fW EDAT7E: June 2006 I N r, I N 1 I It I N r; OB NO. : 2060364 O.: 2 LOG OF TEST BORING NUMBER B-2 F�Date av ated: 5/16/2006 Logged b5-: .�ItN qupment: Iv-k Tripod Project Manager: CHC Existing Elevation: 341 feet Finish Elevation: � Depth to Water: N/A -. 331/3_9.5 feet Drive Weight 1401bs./30. s.V%IP1.I:S u C P. SUMN'LkRY OF SUBSURFACE CONDITIONS w a z W a a v Q � z Cn ( Artificial Fill(Qaf),Light gray to light brown and medium brown, 2 moist,medium dense,SILTY SAND-CLAYEY SAND(SM-SC). 4 Cal 28 12.8 113.8 6 8 . ........................ Light grayish-brown,moist,very stiff,SANDY CLA i'(CL). 10 Cal 42 23.4 99.4 12 / _ Contact at 12'/2 feet. 14 Santiago Formation (T )-Light gray to light grayish-brown to light orangish-brown,moist,dense,SILTY SAND-CLAYEY SAND(S2%1-SC), Cal 72 16 fine-grained,with iron staining. 16.2 107.8 At 14 feet becomes very dense. 18 (A 1 50/5" 20 Test boring terminated at 19'/2 feet. No groundwater. W PROPOSED ACCESSORY UNIT AND GARAGE 3364 Calle Margarita, Encinitas, California CHRISTIAN WHEELER BY: �11� i N r. i N i i it I N r. DATE: June 2006 OB NO. c 2060364 PLATE NO.: 3 EE LOG OF TEST BORING NUMBER B-3 Date Excavated: 3/16/2006 Logged by: AKN Equipment: LA Tripod Project Manager: CHC Existing Elevation: 341 feet Depth to Water: N/A Finish Elevation: 332 feet Drive Weight: 140 lbs./30" ti.\\Il'1.1•a Q w z C W c �x SUNIM-kRY OF SUBSURFACE CONDITIONS 7 � M Z E~ H Q o E-4 � Q 6-inch layer of Sod and Associated Topsoil. 2 Artificial Fill(O� at):Light gray to light yellowish-brown to medium brown,moist,medium dense,SILTY SAND-CLAYEY SAND(SM-SC). Cal 58 10.0 103.8 4 At 2 feet becomes dense. Topsoil:-Medium.brownish-gray,damp,medium dense,SILTY Cal 64 11.7 116.8 6 SAND ST ,with sli ht inhole ores and trace shell fra ents. Subsoil:Medium reddish-grayish-brown,damp to moist,very stiff, 8 SANDY CLAY(CL),mottled,well rounded,with abundant rootlets and trace ravels. Contact at T/z feet. 10 Santiago Formation(Ts.)-Light greenish-gray,moist,hard,SILTY ....::'... 711 36.5 95.5 CL�Y(CI�,with a sli ht waxy texture. Contact at 9'/z feet. :` ................................I............................................................................................ I•;.I 12 Light pinkish-gray,moist,hard,SANDY CLAY(CL). Contact at 12'/z feet.Ex ansion Index= 115 ............................................P................. .....�;ah)................................................. ............. 14 j Light grayish-brown,moist,hard,SANDY CLAY(CL), SA with abundant iron staining and gypsum layers up to 1/8" thick. Cal 50/3.5' 16 Exapnsion Index= 100(high) I) Contact at 17'/2 feet. . ........................................................ 18 :. Light brown to purplish-grayish-brown,moist,very dense,SILTY SAND- ......... ........................ ...... ...................... CLAYEY SAND(SM-SC),very fine to fine-grained,with iron staining. Cal 50/5" 25.7 98.3 20 1 Test boring terminated at 19!'�,feet.No groundwater. PROPOSED ACCESSORY UNIT AND GARAGE f op 3364 Calle Margarita, Encinitas, California CHRISTIAN WHEELER BY: �I\7G' �DATE: June 2006 I N 1 I. It I N OB NO. : 3060364 E NO.: 4 LABORATORY TEST RESULTS PROPOSED ACCESSORY UNIT AND GARAGE 336=1 -ALLE MARGARITA ENCINITAS C ALIFORNIA DIRECT SHEAR(ASTM D3080) Sample Location: Boring B-1 @ 14.5' Boring B-3 @ 14.5' Sample Type: Remolded to 90 9/0 Remolded to 90% Friction Angle: 17 0 28 0 Cohesion: 600 psf 500 psf GRAIN SIZE DISTRIBUTION(ASTM D422) Sample Location Boring B-3 @ 14'-18.5' Sieve Sitie Penent Pasjing #4 100 #8 99 #16 98 #30 96 #50 94 #100 90 #200 70 0.05 mm 57 0.005 mm 30 0.001 mm 18 EXPANSION INDEX(ASTM D4829) Sample Location Boring B-3 @ 9.5'-13.5' Boring B-3 @ 14'-18.5' Initial Moisture 13.5 % 12.6% Initial Dry Density 100.0 pcf 100.3 pcf Final Moisture 30.0% 29.3 Expansion Index 115 (high) 100 (high) CWE 2060364.01 June 23,2006 Plate No. 5 I I - j L --w 1° Slope Minimum 6-inch 6-inch\linimum D v 3/4 inch Crushed Rock or D _ Mirafi G100N or Equivalent A Waterproof Back of Wall Per Architect's Specifications a i v 211 a ` Top of Ground '9 or Concrete Slab a i Geofabric Completely a Wrapped Around Rock � YN�V4 r�yy� 7 6-inch Mlinimum Minimum 4-inch Diameter X Perforated Pipe X PVC Schedule 40 '/,YN RETAINING WALL SUBDRAIN DETAIL No Scale ' PROPOSED ACCESSORY UNIT AND GARAGE CHRISTIAN W HEELER 3364 Calle Margarita,Encinitas,California 4925:\u.R(:L RV s I ItruCr �unc_006 (xsx)496-976(1 <nry DI 11 c>RNI.\rr r r OB NO.: 3060364.01 � 1.\x.(xix)469-97.58 1 1..\'1'I:NO.: 6 CWE 2060364.01 June 23, 2006 Appendix A,A-I REFERENCES Anderson,J.G.;Rockwell,R.K. and Agnew,D.C., 1989,Past and Possible Future Earthquakes of Significance to the San Diego Region,Earth°U1ke.— SSpectra,Volume 5,No. 2, 1989. Blake,T.F.,2000,EQFAULT,A Computer Program for the Estimation of Peak Horizontal Acceleration from 3-D Fault Sources,Version 3.0,Thomas F.Blake Computer Services and Software,Thousand Oaks,California. Boore,David M.,Joyner,William B.,and Fumal,Thomas E., 1997,"Empirical Near-Source Attenuation Relationships for Horizontal and Vertical Components of Peak Ground Acceleration, Peak Ground Velocity, and Pseudo-Absolute Acceleration Response Spectra",in Seismological Research Letters,Volume 68,Number 1,January/February 1997. Grading Plan for Parcel 2,Parcel Map 17122,prepared by Conway and Associates,Inc.,dated September 21, 1994,Drawing No. 3989-G. Report of Preliminary Geotechnical Investigation, Proposed Tennis Court,Parcel 2,Parcel Map 17122,3364. Calle Margarita,Olivenhain,California,prepared by Coast Geotechnical,dated August 2, 1999. Report of Retaining Wall Backfill,Proposed Tennis Court,Parcel 2,Parcel Map 17122, 3364 Calle Margarita, Olivenhain, California,prepared by Coast Geotechnical,dated September 7,2000. California Division of Mines and Geology, 1998,Maps of Known Active Fault Near Source-Zones in California and Adjacent Portions of Nevada. California Division of Mines and Geology, 1997, Guidelines for Evaluating and Mitigating Seismic Hazards in California,Special Publication 117. Countywide Flood Insurance Rate Map,Map No. 06073C1051F(panel 1051 of 2375),prepared by the Federal Emergency Management Agency,effective date June 19, 1997. California Division of Mines and Geology, 1995,Landslide Hazards in the Northern Part of the San Diego Metropolitan Area. _ C%VE 2060364.01 June 23, 2006 Appendix A,A_2 Hart, E.W., 1994, Fault-Rupture Hazard Zones in California,California Division of Mines and Geology Secial Publication 42. p Jennings,C.\!'., 1975,Fault Map of California,California Division of Mines and Geology-,Map No. 1,Scale 1:750,000. Kern, P., 1989,Earthquakes and Faults in San Diego County,Pickle Press, 73 pp. Wesnousky,S.G., 1986, "Earthquakes,Quaternary Faults,and Seismic Hazards in California",in Journal of Geophysical Research,Volume 91,No.B12,pp 12,587 to 12,631,November 1986. CX 'E 3060364.01 June 23, 2006 Appendix B,B-1 RECOMMENDED GRADING SPECIFICATIONS- GENERAL PROVISIONS PROPOSED ACCESSORY UNIT AND GARAGE 3364 CALLS M LARGARITA ENCINITA0 CALIFORNIA GENERAL INTENT The intent of these specifications is to establish procedures for clearing,compacting natural ground, preparing areas to be filled,and placing and compacting fill soils to the lines and grades shown on the accepted plans. The recommendations contained in the preliminary geotechnical investigation report and/or the attached Special Provisions are a part of the Recommended Grading Specifications and shall supersede the provisions contained hereinafter in the case of conflict. These specifications shall only be used in conjunction with the geotechnical report for which they are a part. No deviation from these specifications will be allowed,except where specified in the geotechnical report or in other written communication signed by the Geotechnical Engineer. OBSERVATION AND TESTING Christian Wheeler Engineering shall be retained as the Geotechnical Engineer to observe and test the earthwork in accordance with these specifications. It will be necessary that the Geotechnical Engineer or his representative provide adequate observation so that he may provide his opinion as to whether or not the work was accomplished as specified. It shall be the responsibility of the contractor to assist the Geotechnical Engineer and to keep him appraised of work schedules,changes and new information and data so that he may provide these opinions. In the event that any unusual conditions not covered by the special provisions or preliminary geotechnical report are encountered during the grading operations, the Geotechnical Engineer shall be contacted for further recommendations. If,in the opinion of the Geotechnical Engineer, substandard conditions are encountered, such as questionable or unsuitable soil, unacceptable moisture content,inadequate compaction, adverse weather,etc., construction should be stopped until the conditions are remedied or corrected or he shall recommend rejection of this work. Tests used to determine the degree of compaction should be performed in accordance with the following American Society for Testing and Nfaterials test methods: CWE 2060364A1 June 23, 2006 Appendix B, B-2 Maximum Density& Optimum l%foisture Content-ASTM D-1557-91 Density of Soil In-Place-_-1STINI D-1556-90 or ASTM D-2922 All densities shall be expressed in terms of Relative Compaction as determined by the foregoing ASTiVI testing procedures. PREPARATION OF AREAS TO RECEIVE FILL All vegetation, brush and debris derived from clearing operations shall be removed, and legally disposed of. All areas disturbed by site grading should be left in a neat and finished appearance, free from unsightly debris. After clearing or benching the natural ground, the areas to be filled shall be scarified to a depth of 6 inches, brought to the proper moisture content,compacted and tested for the specified minimum degree of compaction. All loose soils in excess of 6 inches thick should be removed to firm natural ground which is defined as natural soil which possesses an in-situ density of at least 90 percent of its maximum dry density. When the slope of the natural ground receiving fill exceeds 20 percent (5 horizontal units to 1 vertical unit), the original ground shall be stepped or benched. Benches shall be cut to a firm competent formational soil. The lower bench shall be at least 10 feet wide or 1-1/2 times the equipment width,whichever is greater,and shall be sloped back into the hillside at a gradient of not less than two (2) percent. All other benches should be at least 6 feet wide. The horizontal portion of each bench shall be compacted prior to receiving fill as specified herein for compacted natural ground. Ground slopes flatter than 20 percent shall be benched when considered necessary by the Geotechnical Engineer. Any abandoned buried structures encountered during grading operations must be totally removed. All underground utilities to be abandoned beneath any proposed structure should be removed from within 10 feet of the structure and properly capped off. The resulting depressions from the above described procedure should be backfilled with acceptable soil that is compacted to the requirements of the Geotechnical This includes, but is not limited to, septic tanks, fuel tanks, sewer lines or leach lines, storm drains d w tern lines. Any buried structures or utilities not to be abandoned should be brought to the attention of the Geotechnical Engineer so that he may determine if any special recommendation will be necessary. All water wells which will be abandoned should be backfilled and capped in accordance to the requirements set forth by the Geotechnical Engineer. The top of the cap should be at least 4 feet below finish grade or 3 C WE 2060364.01 June 33,3006 .Appendix B,B-3 feet below the bottom of footing whichever is greater. The type of cap will depend on the diameter of the well and should be determined by the Geotechnical Engineer and/or a qualified Structural Engineer. FILL MATERIAL Materials to be placed in the fill shall be approved by the Geotechnical Engineer and shall be free of vegetable matter and other deleterious substances. Granular soil shall contain sufficient fine material to fill the voids. The definition and disposition of oversized rocks and expansive or detrimental soils are covered in the geotechnical report or Special Provisions. Expansive soils, soils of pooatis r gradation,or soils with low strength characteristics may be thoroughly mixed with other soils to provide f actory fill material,but only with the explicit consent of the Geotechnical Engineer. Any import material shall be approved by the Geotechnical Engineer before being brought to the site. PLACING AND COMPACTION OF FILL Approved fill material shall be placed in areas prepared to receive fill in layers not to exceed 6 inches in compacted thickness. Each layer shall have a uniform moisture content in the range that will allow the compaction effort to be efficiently applied to achieve the specified degree of compaction. Each layer shall be uniformly compacted to the specified minimum degree of compaction with equipment of adequate size to economically compact the layer. Compaction equipment should either be specifically designed for soil compaction or of proven reliability. The minimum degree of compaction to be achieved is specified in either the Special Provisions or the recommendations contained in the preliminary geotechnical investigation report. When the structural fill material includes rocks,no rocks will be allowed to nest and all voids must be carefully filled with soil such that the minimum degree of compaction recommended in the Special Provisions is achieved. The maximum size and spacing of rock permitted in structural fills and in non- structural fills is discussed in the geotechnical report,when applicable. Field observation and compaction tests to estimate the degree of compaction of the fill will be taken by the Geotechnical Engineer or his representative. The location and frequency of the tests shall be at the Geotechnical Engineer's discretion. When the compaction test indicates that a particular layer is at less than the required degree of compaction, the layer shall be reworked to the satisfaction of the Geotechnical - Engineer and until the desired relative compaction has been obtained. CWE 206036 .01 June 23, 2006 -appendix B,B-4 Fill slopes shall be compacted by means of sheepsfoot rollers or other suitable equipment. Compaction by sheepsfoot roller shall be at vertical intervals of not greater than four feet. In addition, Fill slopes at a ratio of two horizontal to one vertical or flatter, should be trackrolled. Steeper fill slopes shall be over-built and cut- back to finish contours after the slope has been constructed. Slope compaction operations shall fill material sic or more inches inward from the finished face of the slope having ar elative compaction of at least 90 percent of maximum dry density or the degree of compaction specified in the Special Provisions section of this specification. The compaction operation on the slopes shall be continued until the Geotechnical Engineer is of the opinion that the slopes will be surficially stable. Density tests in the slopes will be made by the Geotechnical Engineer during construction of the slopes to determine if the required compaction is being achieved. Where failing tests occur or other field problems arise, the Contractor will be notified that day of such conditions by written communication from the Geotechnical Engineer or his representative in the form of a daily field report. If the method of achieving the required slope compaction selected by the Contractor fails to produce the necessary results, the Contractor shall rework or rebuild such slopes until the required degree of compaction is obtained,at no cost to the Owner or Geotechnical Engineer. CUT SLOPES The Engineering Geologist shall inspect cut slopes excavated in rock or lithifred formational material durin the grading operations at intervals determined at his discretion. If any conditions not anticipated in the g Preliminary report such as perched water, seepage, lenticular or confined strata of a potentially adverse nature, unfavorably inclined bedding,joints or fault planes are encountered during grading, these conditions shall be analyzed by the Engineering Geologist and Geotechnical Engineer to determine if mitigatin measures are necessary. g Unless otherwise specified in the geotechnical report, no cut slopes shall be excavated higher or steeper than that allowed by the ordinances of the controlling P - g governmental agency. _ CWE 2060364.01 June 23,2006 Appendix B,B-5 ENGINEERING OBSERVATION Field observation by the Geotechnic g al Engineer or his representative shall be made durin the tilling and compaction operations so that he can express his opinion regarding the conformance of the grading with acceptable standards of practice. Neither the presence of the Geotechnical Engineer or his representative or the observation and testing shall release the Grading Contractor from his duty-to compact all fill material to the specified degree of compaction. SEASON LIMITS Fill shall not be placed during unfavorable weather conditions. Wien work is interrupted by heavy rain, filling operations shall not be resumed until the proper moisture content and density of the fill materials can be achieved. Damaged site conditions resulting from weather or acts of God shall be repaired before acceptance of work. RECOMMENDED GRADING SPECIFICATIONS- SPECIAL PROVISIONS RELATIVE COMPACTION:The minimum degree of compaction to be obtained in compacted natural ground, compacted fill, and compacted backfill shall be at least 90 percent. For street and parking lot subgrade, the upper six inches should be compacted to at least 95 percent relative compaction. EXPANSIVE SOILS: Detrimentally expansive soil is defined as clayey soil which has an expansion index of 50 or greater when tested in accordance with the Uniform Building Code Standard 29-2. OVERSIZED MATERIAL: Oversized fill material is generally defined herein as rocks or lumps of soil over 6 inches in diameter. Oversized materials should not be placed in fill unless recommendations of placement of such material is provided by the Geotechnical Engineer. At least 40 percent of the fill soils shall pass through a No. 4 U.S. Standard Sieve. TRANSITION LOTS: Where transitions between cut and fill occur within the proposed building d cut portion should be undercut a minimum of one foot below the base of the proposed footings and 'the recompacted as structural backfill. In certain cases that would be addressed in the geotechnical report, special footing reinforcement or a combination of special footing reinforcement and undercutting may be required. y