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908, Due slope failure, basement ad, Studies & Reports4 4,,, 4,, • a I 'a ,,,„•..... ' a„,,, l'!,, ..,t„ 4,-/::-- . „. _ „,„„............ -„,,, . ,., 44„, 444. • • 4.44-44- 4 4 444,4444:4 't444,44-44444 , • .„„ ... • ' " ^ „ , .. , -4. ... ..„„ • 4 4 A'. . . , t i ... '' ' ' ' 1, .1. n SOILS AND/G-E0TpC1--INTICAL, CO1S1 4, ,4 ANTTS Feffer { Geological Consulting October 22, 2012 Theresa and Hans Rotter c/o AJ Villanueva, Sons & Associates 500 E Carson Plaza Drive, Suite 201 Carson CA 90746 Attention: Art Villanueva, P.E. Subject: RESPONSE TO COUNTY REVIEW SHEET Building P.C. # 1006030022 Engineering Review Sheet Dated 1/18/12 File No: 895-94 Reference: GEOTECHNICAL REPORT FOR RESIDENCE UNDERPINNING Repair of Existing Residence 2950 Palos Verdes Drive North City of Rolling Hills CA 90274 By Feffer Geological Consulting Dated March 17, 2010 RESPONSE TO COUNTY REVIEW SHEET County Job #B373001/A302 Geologic Review Sheet Dated 7/14/10 Engineering Review Sheet Dated 6/23/10 By Feffer Geological Consulting Dated October 5, 2010 Dear Mr. Villanueva: Enclosed is the response to the referenced County Review Sheet. We appreciate the opportunity to be of service. Should you have any questions regarding the information contained in this report, please do not hesitate to contact us. Sincerely, FEFFER GEOLOGICAL CONSULTING, INC. Joshua R. Feffer Principal Engineering Geologist C.E.G. 2138 Distribution: Addressee— (4) Via Mail y 4th, %ipcir, 0) 207-504,$. ):S26d)1$2, ..,[3) FP' JUN 21 2Q16 City of Hills By Jon A Irvine Principal Engineer G.E. 2891 Page 2 October 22, 2012 Geologic Review Sheet Items No Items were identified for response Soils Engineering Review Sheet File No. 895-94 2950 Palos Verdes Drive North Item 1 Clarify the depth of embedment into competent materials for the proposed pile foundations on the foundation repair plan. Verify that the proposed depth of pile will meet or exceed Los Angeles County setback requirement in the competent embedment material. Provide pile schedule on the building plans. Show and specify depth of proposed piles on the building plans. Response Structural plans were provided to this office. Sheet 2 of 6, Partial Floor Framing and Foundation Plan includes the depths of embedment into the underlying bedrock. Embedment depths range from 9 feet to 16 feet. The depth to bedrock in the proposed pile locations vary between 7-11 feet. Therefore the proposed piles will include the depth to competent bedrock plus the embedment depths and will range between 16 to 27 feet. The base of the soil/bedrock contact has been depicted by both Feffer Geological Consulting and Lockwood -Singh and Associates as a 2.5:1 (horizontal to vertical) surface. The existing slope is approximately 40 feet in height and the required slope setback of 13.33 feet. Piles embedded 9 feet deep will have a 22.5 foot setback from the soil/bedrock contact and therefore exceed the required slope setback. Discussion with Mr. Villanueva indicates that he is aware of the depth to bedrock and has designed the piles accordingly to account for the recommended creep load of 1000 psf for the portion of the pile exposed to fill and soil. Item 2 Address potential effects to the existing residence if fill soils continue to fail down slope between the proposed piles. Pile spacing has increased with the changed location of proposed piles. Provide mitigation measures as necessary. Response Feffer Geological was asked to provide recommendations for underpinning of the residence. The underpinning of the residence will be accomplished using new foundations that derive support in the bedrock. Additional movement or settlement of the fill will not affect the underpinned foundations and will isolate them from the slope. The piles have been designed for creep loading from the fill. The piles are not intended to retain or mitigate additional movement of the fill downslope and are intended to solely support the portion of the foundation that has been affected by the existing slope failure. Based on the site history and the time period between this and the Lockwood Singh investigations, the fill is subject to mostly vertical consolidation and not lateral displacement. Additional movement of the fill will not adversely affect the underpinned portions of the structure. Page 3 October 22, 2012 File No. 895-94 2950 Palos Verdes Drive North The existing foundations that have not been distressed by the slope failure will not be underpinned and are founded within fill. Slight differential movement in the area where the two foundation systems are located should be expected and may cause some cracking of interior surfaces but is not expected to be significant. It is our understanding that the structural loading on the existing foundations will not be changed as a result of the elective remedial repair. If additional loads are to be added to the existing framing, then the footings supporting the framing should be underpinned to bedrock. The homeowner should be aware of the potential for future differential settlement between the dissimilar foundation types, from the dissimilar underlying material, and from slope creep and fill settlement of the portion that is not being underpinned. An architect or structural engineer could design a joint where the two foundations meet to minimize any potential disturbance. Item 3 The soils report shall contain a finding regarding the safety of the proposed construction against hazard from future landsliding, settlement, or slippage and a finding regarding the effect that the proposed construction will have on the geologic stability of property outside of the building site. The finding must be substantiated by appropriate data and analysis. Response The site is within an area including completed housing and building developments. Geotechnical exploration, analyses, experience, and judgment result in the conclusion that the proposed underpinning is suitable, from a geotechnical standpoint, solely as a remedial measure to re -level the distressed portion of the existing building. Based on the findings from the subsurface exploration, laboratory testing, and engineering and geologic evaluation, it is our opinion that the proposed underpinning will provide support to the portion of the building that has been affected by the surficial failure and will establish foundations within competent material. In compliance with the 111 Statement requirement, it is our professional opinion that the proposed Foundation Repair will not be subject to a hazard from landsliding, settlement, or slippage, provided the recommendations of this report are incorporated into the proposed construction. It is also our opinion that the Foundation Repair will not adversely affect the geologic stability of the site or adjacent properties provided the recommendations contained in this report are incorporated into the proposed development. Item 4 Show the following on the building plans: a. Pile schedule that includes the depth, details, etc. for each proposed pile. b. Cross sections that show the depth of piles will meet Los Angeles County setback requirements to competent material slope. c. All recommended mitigation measures. Page 4 October 22, 2012 File No. 895-94 2950 Palos Verdes Drive North Response The pile locations have been shown on the geotechnical map and building plans. The cross section including in the original report and included herein shows the embedment of the pile and the setback. The structural engineer has a pile schedule on sheet 2 of 6 on the building plans that show the depths of piles into the bedrock along with a note indicating that the piles will be 9 to 16 in depth and therefore will extend through 9 to 11 feet of fill and soil before embedment into competent bedrock. Item 5 Add the following notes on the building plans: The Soils Engineer of record shall inspect and approve the foundation excavations before steel or concrete is placed. Response The Civil/Structural Engineer has added the note on sheet 2 of 6 on the plans. Item 6 The Soils Engineer of record must review the building plans and sign and stamp the plans in verification of his recommendations. Original manual signature and wet stamp are required. Response Agreed. When a full set is prepared and provided to us we will review and sign and stamp to acknowledge our review and approval. Item 7 Submit two sets of building plans to the Soils Section for verification of compliance with County codes and policies. Response Agreed. The client or their agent should provide these. Item 8 Requirements of the Geology Section are attached. Response Both the geology and engineering review sheets are attached. Item 9 Include a copy of this review sheet with your response. Response Both the geology and engineering review sheets are attached. Dist. Office 12.02 Sheet 1 of 1 County of Los Angeles Department of Public Works DISTRIBUTION GEOTECHNICAL AND MATERIALS ENGINEERING DIVISION 1 Dist. Office GEOLOGIC REVIEW SHEET 1 Geologist 900' So. Fremont Ave., Alhambra, CA 91803 Soils Engineer TEL. (626) 458-4925 1 GMED File LDD - Grading Tract / Parcel Map 28147 Lot(s) 1 Parent Tract Location Rolling Hills Site Address 2950 Palos Verdes Dr. APN 7569-001-031 Geologist Feffer Geological Consulting Developer/Owner Rotter Soils Engineer Feffer Geological Consulting Engineer/Arch. Mayorga Building P.C. No. 1006030022 For: Foundation Repair with Grade Beam and Piles Geologic Report(s) Dated Soils Engineering Report(s) Dated Geology and Soils Engineering Report(s) Dated 10/5/10, 3/17/10 Additional Reports Reviewed Lockwood -Singh & Assoc.: 5/18/84, 11/24/76 Action: Plan is not recommended for approval for reasons below. Remarks/Conditions: 1. The Soils Engineering review dated 1/19/12 is attached. Prepared by Charles Nestle Reviewed by Date 1/24/12 Please complete a Customer Service Survey at htto://dow.lacountv.aov/ao/amedsurvev P:\Gmepub\Geology Review\Forms\Form08.doc 2/13/08 Address: Telephone: Fax: COUNTY OF LOS ANGELES DEPARTMENT OF PUBLIC WORKS GEOTECHNICAL AND MATERIALS ENGINEERING DIVISION SOILS ENGINEERING REVIEW SHEET 900 S. Fremont Ave., Alhambra, CA 91803 (626) 458-4925 (626) 458-4913 Review No. 3 Revised Foundation Repair Location Developer/Owner Engineer/Architect Soils Engineer Geologist 2950 Palos Verdes Drive North, City of Rolling Hills Estates Hauberg Miles Engineering Feffer Geological Consulting Same as above Building Plan Check No. 1006030022 Review of: Revised Building Plan Dated By Processing Center 1/10/12 Soil Engineering and Geologic Report Dated 10/5/10, 3/17/10 Previous Review Sheet Dated 6/23/10 ACTION: Building plan is not recommended for approval. REMARKS District Office Job Number Sheet 1 of 1 12.03 B373001 / A302 DISTRIBUTION: _ Drainage Grading 1 Geo/Soils Central File 1 District Engineer 1 Geologist 1 Soils Engineer 1 Engineer/Architect The submitted revised foundation plan indicates the number of piles has been reduced from 12 to 6 and location of proposed piles has been changed from the previously approved plans. Therefore address the following and provided revised recommendations as necessary: 1. Clarify the depth of embedment into competent materials for the proposed pile foundations on the foundation repair plan. Verify that the proposed depth of pile will meet or exceed Los Angeles County setback requirement in the competent embedment material. Provide pile schedule on the building plans. Show and specify depth of proposed piles on the building plans. 2. Address potential effects to the existing residence if fill soils continue to fail down slope between the proposed piles. Pile spacing has increased with the changed location of proposed piles. Provide mitigation measures as necessary. 3. The soils report shall contain a finding regarding the safety of the proposed construction against hazard from future Iandsliding, settlement or slippage and a finding regarding the effect that the proposed construction will have on the geologic stability of property outside of the building site. The finding must be substantiated by appropriate data and analysis. 4. Show the following on the building plans: a. Pile schedule that includes the depth, details, etc. for each proposed pile. b. Cross sections that show the depth of piles will meet Los Angeles County setback requirements to competent material slope. c. All recommended mitigation measures. 5. Add the following notes on the building plans: The Soils Engineer of record shall inspect and approve the foundation excavations before steel or concrete is placed. 6. The Soils Engineer of record must review the building plans and sign and stamp the plans in verification of his recommendations. Original manual signature and wet stamp are required. 7. Submit two sets of building plans to the Soils Section for verification of compliance with County codes and policies. 8. Requirements of the Geology Section are attached. 9. Include a copy of this review sheet with your response. NOTES) TO THE PLAN CHECKER/BUILDING AND SAFETY ENGINEER: A. PER THE SOILS ENGINEER, TYPE V CONCRETE SHALL BE USED FOR THE PROPOSED FOUNDATION REPAIR. B. PER THE SOILS ENGINEER, 1. PROPOSED FOUNDATION REPAIR IS INTENDED TO MITIGATE THE AFFECTS OF THE SURFICIAL SLOPE FAILURE AND TO RE - LEVEL THE EXISTING HOME (BY MANOMETER OUT OF LEVEL 11.5"). 2. STRUCTURAL LOADING ON EXISTING FOUNDATIONS WILL NOT =. ED DUE TO ELECTIVE REMEDIAL FOUNDATION REPAIR, 3. IF ADDITIONAL LOADS ARE ADDED TO THE EXISTING F „� ; f�¢ �S SHOULD BE UNDERPINNED INTO BEDROCK. 4. HOMEOWNER SHOULD BE AWARE OF THE POTENTIAL F j,'; <. .,�,Ji L SETTELEMENT BETWEEN DISSIMILAR FOUNDATION TYPES. Reviewed by Yoshiy(•'' Please complete a Customer Service Survey at http://dpw.la unty,gov/gol; NOTICE: Public safety, relative to geotechnical subsurface ex ration, shall be provi.' County Code, Chapter 11.48, and the State of California, Title 8, Construction Safety Ord P:\Yosh\2950 Palos Verdes Dr N, City of Rolling Hills Estates, BP-NA_3 (Foundation Repair) Date 1/18/12 rrent codes for excavations, inclusive of the Los Angeles TOPOFEAIM CENT RPE BEND FAO BEAM , TCPOF (MEIDNRAV4 — 10-i79 VEWEWS TCPOFEDTO( — CIDH PILES MAR( COW COBS a0113 0DH4 COBB OOHS ODIi7 AXISFYURALLFLTO LEETER133S 2SEESCF#311E9 DEFTHOF BEDROCK BELOWTI-E CLOUD SU7FACEVPAES 4 BETWEEN 7 PIZ 11 FL O SUI1IOALEAL i3 • 8 • a to TCPOF IMPTRL PILE FE 94.97 9-6 94.53 9,4 94.0) 194 94.03 164' not mad 95.03 I tea 93.53 lea D ETAI L.1.09 IDISTI GFIG STEMW'LL #5 CarEL B1FG BIB® IN CEEP HQ6 W SET EPDXY INE4S111'G FQ711 PCa GRADE 6 MfM TYP. DEf.1.07 6' -I #4 cm'. EAR 84 LOG Bt8 —#3SRR BIROM Lac Bv3S TYP. SEC. DEF. t08 TI-ESOILS 13CIPEB - CCBDSHAWLINFECT ANDA FFROVE TI-E FOLMAT1ON EXGAVATICB BERME STEH_ AN) CMCFEIE PFE PLACEO 1O"W X 61-I SLIDING ( 1MNBOW DOOR II n RESTROOM I1 IIU HI fl II NG7,10R ROOM" I' li 11 II IIII II11 II PATIO 1 CAR DOOR t3'W % B'F WINDOW HALLWAY 3 CAR GARAIE 2 CR 000R 6Wx6N WINDOW PARTIAL FLOOR FRAMING & FOUNDATION PLAN SCALE- 3ns':I.0' -01 7-6 NOW: REMOVE F AFFECTED BYTIENT3NG - EEBE MS CDH— CAST -IN -DR TP—TCPOFILE SCOPE OF WORK WOFKAREA-1,750 SF -REMOVE FOOTINGS P=FECTED BY CONSTRUCTION OF CDHAND GRADE BEAMS -CONSTRUCT CIDH AN) GRADE BEAMS -REPAIR CRIPPLE STUDS & STUCCO TO MATCH EXISTING FINISH. -RESTORE EXISTING ifFECTED BY NEW CONSTRUCTION. a 83.001P 13-4 PATIO 9350TP '1 aRV F 3081101B 1 II 5 I ffi A G T4y 11'-6 -10(18 1 _-I 26-6 RESTRM H zs • th (7 WARDROVE 01 GE6-1 g9430TP I m� 273) 14'-6 16-2 'aOW 91.25TP 1-OF2 84.50TP a U Ewes macula N WW 4L a 0W W 2 0F6 VICINITY MAP SCALE -rns 3- Prspelty traben melt Asst.-ma/alp: IO: No. 7569-001-031 Site Address; 29Se PAWS VERDES OR N PAWS VERDES EST CA 90274 Ptapen; Type: Single Family Reside =e Refan f Chraer 14 / 14177 Po±perty Boundary Descript dart TRACT NO 2$147 LOT I BuIIdieg Deseliption(R) Impmvem61H 1: Square Footage 3.S22 Year Built / Motive Year Built 1977 / 1977 Bedrooms:' Bathrooms 4 t 4 Units 1 The SITE PATIO 10'W X 6'H SLIDING WINDOW DOOR RESTROOM LIQUOR ROOM 6'W X 6'H WINDOW 8'W X 8'H WINDOW 8'W X 8'H WINDOW 25'-0' 11'-6 PATIO 3'W X 4'H 6'W X 6'H WINDOW WINDOW KITCHEN JVING ROOM RESTROOM1 BEDROOM HALLWAY COI UMN DOUBLE D—DOOR 3 CAR GARAGE 1 CAR DOOR 2 CAR DOOR EXISTING FLOOR PLAN SCALE-ane':1-0" SCOPE OF WORK: SEE SHT 2 OF 6 4'W X 8'H 3.7'W X 8'H HALLWAY WINDOW WINDOW �3 xo 3. Tco 0 HEATER WARDROVE 0 0 0 0 6'W X 6'H WINDOW 30"1x RESTRM z x 523 0"1 0x 33 ■ CIVIL ENGINEER • JOB TITLE ■ SHEET TITLE 0 Z y X W U. Oy re W Zr a. re re FW = F 0 re • Z Cf) W > Wo lY Z 0 W W 0) aew>0 co Le m Z oa < ao = am ao f(7 >R,•JECT NO. 20110623 ^ £ 01/32012 DRAWN 131, FILE NAME: SHEET NO. re •. a��. 1OF6 ...... . ...,...,..... .-...—.... .,,..»..SCALE =NIs.. .,,,....... .aae:%:.�s.�r e..., Iidlili 1. iIIa 1. 1.11, Ili llluli Ai ii/i iili.l 11.1 i Li i 11111,1 II Alla i. si1ill l, i111111.1S L111:.ii.WN.ii ill.Y1, If iHLi 1i1.ii1,1111W4611111..11.61ALli1i1,. Ill iilil 11SSI11:111iiili14i14u1111Jii4611141..14ili i I hi. 1 I AI IiiISnlli1i611S1ii. iil WI111.1 NMI dill i II.I uI ..,Wi111 ii i1W1i1II1ii111111.iluuii11ill 1111i1i SIii11 its.Ifi:WaMaid S1iiiiaiifii.Y:I.W RESIDENCE (E.) RECOMMENDE .v.GpEp ED FOUNDATION F•If•r1 GEOLOGIC MAP 895-94p.COPPERCONST AYH REVISED II/5/10 RNNOS VENDER E'E3/17/10 .i��14a � ERNE NORTH FROMFIELD MEASURE.... GOOGLE EARTH TOPOGRAPHY LEGEND TP-4 LOCATION OF HAND DUG TEST PITS A SECTION LINE 3 STRIKE & DIP OF REGIONAL GEOLOGY jOe SCALE 1" = 40' 53 A 524:, 510..; RESIDENCE (E.) TP2 .s.. . . . . . . . . . . . . . . . . --. L., L. --L. -BEentiFit-tPu"11 . . . L. .• • • 470-- - - 460-- 4502-- 440 430- SILTSTONE & SANDSTONE BEDROCK SECTION A-P. COPPER CONST r19:, 895-94 . FROM GEOLOGIC MAP i< „, YH ''ses'IPET" A -r530 --520 -:--510 -1-500 490 -480 L.- . `-- . . ' . ^-..40 . . . . . . . . . . . . . . . ........ ....... `...... ........ ,.... ,.... "....... ^...... ....... -,.... ....... "....... ........ 1, `....... 1., 1-30 1 CEINREA_TE —C - LLSETTE cktu TO FES 2SETS(F#3TE8 CF BEAM BBNIDNTO ', EVIM..' ..... s,i TO'CF RIE ME FDNRPMM ......./, 1048VERT. BNS _._ . Ni TQ'OF EMITOX !SLRROPLSQ $®ROCK CIDH PIES i TCP CF DEPTHR ^...._ MARC 'PIE ` FT I G0131 i 94.91 ' 9-0 GBH2 I94.1D I91Y 94.m : 194 :'- .._CIDH4...._._94_02 ;16-0 tad c.......1..............._"°t_........ ._. GpHs .__l95 _m . 16-0 ;.._CIDH? ; 93.52 ; 16.0 DETAI L1.09 SMFTG L t STEM VvYL /: I #5CONEL64FS ENB®W %i"etc12"CEEP HO$ W SET ERW11,1EXISTIPG FCOT1 M3 GFNDEBEPM TYP. DE. 1.07 6 Li3'� 4---#4C M-.EE BN2 >\ LONG 8HS c•:..- BaTOM IL1Kz B'1S TYP. SEC. DET. 1.08 THE SOILS ENGINEER OF RECORD SHALL INSPECT AND APPROVE THE FOUNDATION EXCAVATIONS BEFORE STEEL AND CONCRETE ARE PLACED. Ti sur. c 6•4X6.1 IY RE 12130V DP ROC I .._EO/E:l .3 ':rr CD.F sEE ErgcE1DP 2_<3f DR $5 X 50 WINs9N PARTIAL FLOOR FRAMING & FOUNDATION PLAN SCALE-M'1'U7 H 95001P a a6 Aral/ i \L' 6 REMOVE FC11091 3;1 AFFECTED BY TOE DEWG bS a OH —CAST-I µfrt1 1 E TP—TOPOFFLE j SCOPE OF WORK: WORKAREA-1,750 SF -REMOVE FOOTINGS AFFECTED BY CONSTRUCTION OF CIDH AND GRADE BEAMS -CONSTRUCT CIDH AND GRADE BEAMS -REPAIR CRIPPLE STUDS & STUCCO TO MATCH EXISTING FINISH. -RESTORE EXISTING AFFECIE D BY NEW CONSTRUCTION. N 8'-1012'. 20' G'51a18 15,12 a 7:-212. 1H ^.Y Co) 13.4 11'8 k � i Gl$10,18 a E?I-- \. 94507P IF -{i 27'a}2 14,2 162 9 N �.J AI a1x5 91257P -C11]f 94501P n. : al I i 1 2CF6 • • • • • • • • • GEOTECHNICAL INVESTIGATION Proposed Residential Development 2950 Palos Verdes Drive North Rolling Hills Estates, California Lucas Brothers Construction, Inc. 25327 South Normandie Avenue Harbor City, California 90710 Project Number 19510-17 • April 12, 2017 • NorCal Engineering TABLE OF CONTENTS Section Page 1.0 Structural Considerations... 1 1.1 Proposed Development 1 • 2.0 Site Description............ 2 2.1 Location... 2 2.2 Existing Improvements 2 2.3 Drainage/Topography 2 3.0 Field Investigation 2 3.1 Site Exploration 2 3.2 Groundwater 3 4.0 Seismicity Evaluation 3 5.0 Site Geology............ 5 6.0 Liquefaction Evaluation 6 7.0 Laboratory Tests 6 • 7.1 Field Moisture Content 7.2 Maximum Density Tests. 7 7.3 Expansion Index Tests 7 7.4 Atterberg Limits 7 7.5 Direct Shear Tests.. ... 7 ♦ 7.6 Consolidation Tests 7 7.7 Soluble sulfate, pH, Resistivity and Chloride Tests 8 8.0 Conclusions and Recommendations 8 8.1 Site Grading Recommendations 8 8.1.1 Removal and Recompaction Recommendations...... 9 fi 8.1.2 Compacted Fill Blanket 10 8.1.3 Slope Grading Recommendations... 11 8.2 Slope Stability Evaluation............ 11 8.3 Drainage. 12 8:4 Temporary Excavations 12 8.5 Shallow Foundation Design 13 8.5.1 Pile Foundation Design 13 8.6 Settlement Analysis.................... ........... .............. ...... ....... ....... . 14 8.7 Lateral Resistance 14 8.8 Retaining Wall Design Parameters14 8.9 Slab Design... 15 8.10 Expansive Soil... 17 8.11 Corrosion Design Criteria 17 8.12 Utility Trench and Excavation Backfill.. 18 9.0 Closure 18 • • • • • NorCal Engineering SOILS AND GEOTECHNICAL CONSULTANTS 10641 HUMBOLT STREET LOS ALAMITOS, CA 90720 (562)799-9469 FAX (562)799-9459 April 12, 2017 Project Number 19510-17 • Lucas Brothers Construction, Inc. 25327 South Normandie Avenue Harbor City, California 90710 • Attn: Dan Martinez RE: GEOTECHNICAL INVESTIGATION - Proposed Residential Development - Located at 2950 Palos Verdes Drive North, in the City of Rolling Hills Estates, California Dear Mr. Martinez: ✓ Pursuant to your request, this firm has performed a Geotechnical Investigation for the above referenced project. The purpose of this investigation is to evaluate the geotechnical conditions of the subject site and feasibility of development of ✓ the land. This soils engineering report presents the findings of our study along with conclusions and recommendations for development. 0 w 1.0 STRUCTURAL CONSIDERATIONS 1 1 Proposed Development It is proposed to construct new 1-story additions to the east of the existing single family home on the subject site. The addition furthest to the east will include a basement level. Proposed work is depicted on the attached Figure 1. Final building plans shall be reviewed by this firm prior to submittal for city approval to determine the need for any additional study and revised recommendations pertinent to the proposed development, if necessary. s • April 12, 2017 Page 2 Project Number 19510-17 2.0 SITE DESCRIPTION 2.1 Location: The property is located southerly of Palos Verdes Drive North, in the City of Rolling Hills Estates, as shown on the Vicinity Map, Figure 1. A private road provides access to the site along the west side of the property from the street at the north. 2.2 Existing Improvements: The approximately 1.17-acre site is occupied by • an existing single story residence with attached garage, guest house and stable building and other miscellaneous improvements. Concrete driveways, patios, walkways and landscaping cover much of the remainder of the property. f 2.3 Drainage/Topography: The existing building pad area is relatively level with descending slopes along the north and east with inclinations of 2:1 • (horizontal to vertical) or flatter. Land to the south of the existing house slopes up to the property line and then beyond. • • 3.0 FIELD INVESTIGATION 3.1 Site Exploration The purpose of the investigation was to explore the subsurface conditions and to provide preliminary geotechnical engineering design parameters for evaluation of the site with respect to development of the subject parcel. The investigation consisted of the placement of three subsurface exploratory excavations by track -mounted excavator to a maximum depth of 15.5 feet below current ground elevations. The excavations were placed at accessible locations on the site. Existing improvements limited the placement of our excavations. NorCal Engineering • • • • • • April 12, 2017 Page 3 Project Number 19510-17 The explorations were visually classified and logged by a field engineer and geologist with locations of the subsurface explorations shown on the attached Geotechnical Map, Figure 2. The exploratory excavations revealed the existing earth materials to consist of fill and native soil/bedrock zones. A detailed description of the subsurface conditions is given on the excavation logs in Appendix A. It should be noted that the transition from one soil type to another as shown on the borings logs is approximate and may in fact be a gradual transition. The soils encountered are described as. follows: Fill Soils: Fill soils classifying as silty CLAY with some minor debris, roots and rock fragments were encountered in the excavations to depths ranging from 5.5 to 12.5 feet. These soils were noted to be soft to firm and moist. Native Soils: Native colluvial soils classifying as silty CLAY with rock fragments were encountered in the excavations below the existing fill. These soils were noted to be medium stiff and moist. Bedrock: Altamira Siltstone and Shale was encountered below the native soils. The bedrock was noted to be moderately hard to hard and moist. 3.2 Groundwater Groundwater was not encountered in any of our test borings. Research of the California Department of Conservation — Division of Mines and Geology Seismic Hazard Zone Report 035, Plate 1.2, indicates a historic high • groundwater level in excess of 50 feet below ground surface in the vicinity. 0 Cy 4.0 SEISMICITY EVALUATION The proposed development lies outside of any Alquist Priolo Special Studies Zone and the potential for damage due to direct fault rupture is considered unlikely. NorCal Engineering • • • April 12, 2017 Page 4 Project Number 19510-17 The following seismic design parameters are provided and are based upon the 2016 California Building Code (CBC) for the referenced project and were obtained from the website https://earthquake.usas.qov/cn2/designmaps/us/summary. Summary and • detailed reports from the website are included in Appendix B. 0 0 Seismic Design Parameters Site Location — Region 1 Latitude 33.7718° Longitude -118.3378° Seismic Use Group II Site Class D Risk Category I/II/III Maximum Spectral Response Acceleration Ss 1.608g Si 0.619g Adjusted Maximum Acceleration SMS 1.608g SMI 0.929g Design Spectral Response Acceleration Parameters SDS 1.072g SDI 0.619g The Palos Verdes fault zone is located approximately 2.5 kilometers from the site and is capable of producing a Magnitude 7.1 earthquake. Ground shaking originating from earthquakes along other active faults in the region is expected to induce lower horizontal accelerations due to smaller anticipated earthquakes and/or greater distances to other faults. NorCal Engineering • • April 12, 2017 Page 5 Project Number 19510-17 5.0 SITE GEOLOGY • The subject property is situated within the Peninsular Ranges Geomorphic Province. The Peninsular Ranges Geomorphic Province extends from the Los Angeles Basin southeast to Baja California, and from the Pacific Ocean • eastward to the Coachella Valley and Colorado Desert. The province is characterized by a series of northwest -trending valleys, hills and mountains controlled by faults associated with the San Andreas and other major fault • systems. More specifically, the subject property is situated on an elevated marine terrace on northern slope of the Palos Verdes Peninsula. • • 0 M • Geologic mapping by Dibblee (1999) for the regional area indicates that the Altamira Shale Member (upper part) of the Monterey Formation underlies the site. The upper part of the Altamira Shale is of Miocene age, and generally consists of white -weathering, thin -bedded, siliceous and phosphatic shale with interbeds of limestone and siltstone, locally organic and diatomaceous. Our subsurface exploration at the site encountered fill, underlain by a thin mantle of topsoil overlying the Altamira Shale. The bedrock consists of thinly to moderately bedded hard, siliceous siltstone and shale. Bedding planes in the bedrock are oriented dip -slope, striking northwest and dipping to the northeast 28 to 30 degrees, consistent with the mapping by Dibblee. Geologic section A -A' illustrates the underlying soil and rock conditions. The most prominent geologic structural elements in the Palos Verdes Peninsula are the northwest -trending Palos Verdes and Cabrillo faults with reported Holocene offshore surface rupture and Late Quaternary onshore surface rupture. The Palos Verdes fault is mapped northeast of the property. The Cabrillo fault is shown southeast of the site. These faults are considered potentially active and may be capable of generating damaging earthquakes. NorCal Engineering • • • April 12, 2017 Page 6 6.0 LIQUEFACTION EVALUATION Project Number 19510-17 The site lies outside of areas mapped by the State of California Seismic Hazards Mapping Act as potentially liquefiable. In addition, due to the fine grained nature of the soils and historic high groundwater depth in excess of 50 feet below ground surface, the potential for liquefaction at the site is deemed low. Thus, the design of the proposed construction in conformance with the latest Building Code provisions for earthquake design is expected to provide mitigation of ground shaking hazards that are typical to Southern California. 7.0 LABORATORY TESTS Relatively undisturbed samples of the subsurface soils were obtained to perform laboratory testing and analysis for direct shear, consolidation tests, and to determine in -place moisture/densities. These relatively undisturbed 0 ring samples were obtained by driving a thin -walled steel sampler lined with one -inch long brass rings with an inside diameter of 2.42 inches into the undisturbed soils. The sampler was driven a total of 6 inches into undisturbed soils. A • • Bulk bag samples were obtained in the upper soils for expansion index tests, corrosion tests and maximum density tests. Wall loadings on the order of 3,000 lbs./lin.ft. and maximum compression loads on the order of 30 kips were utilized for testing and design purposes. All test results are included in Appendix C, unless otherwise noted. NorCal Engineering • •' • April 12, 2017 Page 7 Project Number 19510-17 7.1 Field moisture content (ASTM:D 2216-10) and the dry density of the ring samples were determined in the laboratory. This data is listed on the logs of explorations. • 7.2 Maximum density tests (ASTM: D-1557-12) were performed on typical samples of the upper soils. Results of these tests are shown on Table I. • 7.3 Expansion index tests (ASTM: D-4829-11) were performed on remolded samples of the upper soils to determine the expansive characteristics and to provide any necessary recommendations for reinforcement of the slabs - on -grade and the foundations. Results of these tests are provided on Table II and are discussed later in this report. • 0 • 7.4 Atterberg Limits (ASTM: D 4318-10) consisting of liquid limit, plastic limit and plasticity index were performed on representative soil samples. Results are shown on Table Ill. 7.5 Direct shear tests (ASTM: D-3080-11) were performed on undisturbed samples of the subsurface soils. These tests were performed to determine parameters for the calculation of the allowable soil bearing capacity. The test is performed under saturated conditions at loads of 1,000 lbs./sq.ft., 2,000 lbs./sq.ft., and 3,000 lbs./sq.ft. with results shown on Plates A and B. 7.6 Consolidation tests (ASTM: D-2435-11) were performed on undisturbed samples to determine the differential and total settlement which may be anticipated based upon the proposed loads. Water was added to the samples at a surcharge of one KSF and the settlement curves are plotted on Plates C and D. NorCal Engineering • • • • • r April 12, 2017 Page 8 Project Number 19510-17 7.7 Soluble sulfate, pH, Resistivity and Chloride tests to determine potential corrosive effects of soils on concrete and metal structures were performed in the laboratory. Test results are given in the attached Tables IV-VII and are discussed later in this report. 8.0 CONCLUSIONS AND RECOMMENDATIONS Based upon our evaluations, the proposed development is acceptable from a geotechnical engineering standpoint. The structures and grading will be safe from future landslides, slippage and settlements under the anticipated design loadings and conditions. The proposed development and grading shall meet all requirements of the City/County Building Ordinance and will not impose any adverse geologic effect on the subject site and existing adjacent land or structures. The following recommendations are based upon soil conditions encountered in our field investigation; these near -surface soil conditions could vary across the site. Variations in the soil conditions may not become evident until the commencement of grading operations for the proposed development and revised recommendations from the soils engineer may be necessary based upon the conditions encountered. • 8.1 Site Grading Recommendations It is recommended that site observations be performed by a representative of this firm during all grading and construction of the development to verify the findings and recommendations documented in this report. Any unusual • conditions which may be encountered in the course of the project development may require the need for additional study and revised recommendations. NorCal Engineering • • • `" • • • • • April 12, 2017 Page 9 Project Number 19510-17 All vegetation shall be removed and hauled from proposed grading areas prior to the start of grading operations. Existing vegetation shall not be mixed or disced into the soils. Any removed soils may be reutilized as compacted fill once any deleterious material or oversized materials (in excess of eight inches) is removed. Grading operations shall be performed in accordance with the attached Specifications for Placement of Compacted Fill. 8.1.1 Removal and Recompaction Recommendations It is recommended that all existing fill soils (5.5 to 12.5 feet) be removed to competent native soils or bedrock, the exposed surface scarified to a depth of 8 inches, brought to within 2-3% of optimum moisture content and compacted to a minimum of 90% of the laboratory standard (ASTM: D- 1557) prior to placement of any additional compacted fill soils, foundations, slabs -on -grade and pavement. Grading shall extend a minimum of 5 horizontal feet outside the edges of foundations or equidistant to the depth of fill placed, whichever is greater, where possible. In areas where raised floor are used or structural slabs supported on foundations embedded in bedrock are installed, removal and recompaction will not be required. Care should be taken to provide or maintain adequate lateral support for all adjacent improvements and structures at all times during the grading operations and construction phase. Adequate drainage away from the structures, pavement and slopes should be provided at all times. NorCal Engineering • • • • • April 12, 2017 Page 1 o Project Number 19510-17 It is possible that isolated areas of undiscovered fill not described in this report are present on site; if found, these areas should be treated as discussed earlier. A diligent search shall also be conducted during grading operations in an effort to uncover any underground structures, irrigation or utility lines. If encountered, these structures and lines shall be removed, properly abandoned or relocated prior to the proposed construction. If placement of slabs -on -grade and pavement is not completed immediately upon completion of grading operations, additional testing and grading of the areas may be necessary prior to continuation of construction operations. Likewise, if adverse weather conditions occur which may damage the subgrade soils, additional assessment by the soils engineer as to the suitability of the supporting soils may be needed. • 8.1.2 Compacted Fill Blanket Due to the potential for differential settlement of structures supported on both compacted fill and native soils/bedrock, it is recommended that all foundations be underlain by a uniform compacted fill blanket at least 3 feet • in thickness. The fill blanket shall extend a minimum of 5 horizontal feet outside the edges of foundations or equidistant to the depth of fill placed, whichever is greater, where possible. In lieu of installing the fill blanket • below foundations, all new foundations may be extended into bedrock materials. • • NorCal Engineering • • • • • • April 12, 2017 Page 1 1 8.1.3 Slope Gradina Recommendations Project Number 19510-17 The grading work would include the regrading of the east descending slope, including installing 5 feet of soil over the existing slope, as shown on Figure 2. A keyway at the toe of proposed slope shall be excavated a minimum of 2 feet into medium stiff soils and at least 10 feet in width with the bottom of keyway sloped at a 2% gradient into slope. The keyway should be observed and approved by the geologist prior to placement of any fill soils. The existing upper loose fill on the slope should be removed and successive benching cut into competent soils during the slope construction procedure, as shown on the attached Figure 4. The graded slope inclination should be 2:1 (horizontal to vertical) or flatter, in accordance with local codes. The need for subdrains along the slope grading area will be evaluated by the geologist during the field work. The slope should be overbuilt and then cut to final grade to assure well compacted soils at the surface. A landscape architect should provide a planting program for the slope to assure long-term surficial stability. 8.2 Slope Stability Evaluation « The descending east and north slopes extend below the house and beyond the property lines with a height of 40 feet or more. A slope stability evaluation was performed for the east descending slope at a 2 to 1 grade • and a total height of 32 feet with our calculations given in Appendix D. A safety factor of 2.0 or greater was computed based on the shear strengths obtained from previous tests on saturated samples. Thus, the existing slope is judged to be grossly stable under the design conditions. All grading • work should be observed by this firm and the consulting geologist throughout construction activities to assure site conditions are consistent with those used in the design. • NorCal Engineering • • April 12, 2017 Page 12 Project Number 19510-17 8.3 Drainage Adequate drainage away from the structures, pavement and slopes should be provided at all times. Ground adjacent to new foundations shall be sloped at a 5% slope for a minimum distance of 10 feet. If the slope for a • distance of 10 feet is not possible, an alternative method of drainage runoff away from the building at the termination of the 5% slope shall be incorporated in the design. Any swales that are located within 10 feet of the building shall be designed with a minimum 2% slope. Pavement adjacent • to the building shall also be sloped at a minimum 2% away from the structure. • • • • • • 8.4 Temporary Excavations Temporary unsurcharcred excavations in on -site soils 5 feet or less in height may be made at vertical inclinations. Any cuts higher than 8 feet shall be further assessed prior to excavation. In areas where soils with little or no binder are encountered, where adverse geological conditions are exposed, or where excavations are adjacent to existing structures, shoring, slot - cutting, or flatter excavations may be required. The temporary cut slope gradients given above do not preclude local raveling and sloughing. All excavations shall be made in accordance with the requirements of the soils engineer, CAL -OSHA and other public agencies having jurisdiction. Temporary shoring design may utilize an active earth pressure of 25 pcf without any surcharge due to adjacent traffic, equipment or structures. The passive fluid pressures of 250 pcf may be doubled to 500 pcf for temporary design. Excavation for the new basement adjacent to the existing 1-story house structure may be designed using an active earth pressure of 60 pcf which includes surcharge from the adjacent structure. NorCal Engineering • • • • April 12, 2017 Page 13 Project Number 19510-17 8.5 Shallow Foundation Design New foundations may be designed utilizing an allowable soil bearing capacity of 2000 psf for a minimum embedded depth of 30 inches below lowest adjacent grade and into compacted fill soils. Footings extended into bedrock shall also be a minimum of 30 inches in overall depth and at least 12 inches into bedrock. Foundations shall not traverse from compacted fill to native soils and/or bedrock. A one-third increase may be used when considering short term loading from wind and seismic forces. All continuous foundations shall be reinforced with a minimum of two #5 bars top and two bottom. A representative of this firm shall inspect all foundation excavations prior to pouring concrete. All foundations near slopes shall maintain a horizontal slope setback equal to or greater than one-third the overall height of slope, but no less than 5 horizontal feet. This distance shall be measured from face of descending slope to bottom outside edge of new foundation. 8.5.1 Pile Foundation Design • Concrete pile foundations shall be a minimum of 18 inches in diameter and embedded a minimum of 5 feet into competent bedrock materials, as verified by the soil engineer. Pile foundations may utilize a skin friction • value of 500 psf along the portion of the pile embedded into competent bedrock. The passive fluid pressure value may be doubled to 500 pcf for isolated pile foundations during temporary loading conditions. The point of fixity should be taken at the soil/bedrock contact depth. Slope setback • requirements are as stated in the above section. • NorCal Engineering • • April 12, 2017 Page 14 Project Number 19510-17 • 8.6 Settlement Analysis Resultant pressure curves for the consolidation tests are shown on Plates C and D. Computations utilizing these curves and the recommended allowable soil bearing capacities reveal that the foundations supported on • bedrock will experience normal settlements on the order of 3/4 inch and differential settlements of less than 1/4 inch. • 8.7 Lateral Resistance The following values may be utilized in resisting lateral loads imposed on the structure. Requirements of the California Building Code should be adhered to when the coefficient of friction and passive pressures are combined. • • • • • a Coefficient of Friction - 0.35 Equivalent Passive Fluid Pressure = 200 lbs./cu.ft. Maximum Passive Pressure = 2,000 lbs./cu.ft. The passive pressure recommendations are valid only for approved compacted fill soils or competent native materials. 8.8 Retaining Wall Design Parameters Active earth pressures against retaining walls will be equal to the pressures developed by the following fluid densities. These values are for granular backfill material placed behind the walls at various ground slopes above the walls. Use of on -site soils for wall backfill will increase the values given. Surface Slope of Retained Materials Equivalent Fluid (Horizontal to Vertical) Density (Ib./cu.ft.) Level 30 5 to 1 35 4 to 1 38 3 to 1 40 2to 1 45 NorCal Engineering 0 • • • • • • • • April 12, 2017 Page 15 Project Number 19510-17 During a local Magnitude 7.1 along the Palos Verdes fault zone, additional lateral pressures will occur along the back of retaining walls. The seismic - induced lateral soil pressure may be computed using a triangular pressure distribution with the maximum value at the top of the wall. The maximum lateral pressure of (20 pcf) H where H is the height of the retained soils above the wall footing should be used in final design of retaining walls. Any applicable short-term construction surcharges should also be added to the above lateral pressure values. A backfill zone of free draining material shall consist of a wedge beginning a minimum of one horizontal foot from the base of the wall extending upward at an inclination of no less than 3/4 to 1 (horizontal to vertical) as shown on the attached Figure 5. All walls shall be waterproofed as needed and protected from hydrostatic pressure by a reliable permanent subdrain system. 8.9 Slab Design Concrete floor slabs -on -grade and any exterior slabs shall be a minimum of 5 inches in thickness and reinforced with #4 bars at 16 inch spacing, each way, positioned in the center of the slab. An effective plasticity index of 60 should also be used in slab design. Soils beneath all exterior and interior slabs shall be brought to approximately 3% above optimum levels to a depth of 18 inches as verified by the soil engineer immediately prior to placement of concrete. NorCal Engineering • • • • • • • • • • • April 12, 2017 Page 16 Project Number 19510-17 If removal and recompaction of all fill soils is not completed, a structural slab should be designed for the building. The upper 12 inches of soil below the slab should be compacted to a minimum of 90% relative compaction and presaturated as described above. The structural slab shall derive support entirely from the foundation system embedded in bedrock materials. Additional reinforcement requirements and an increase in thickness of the slabs -on -grade may be necessary based upon soils expansion potential and proposed loading conditions in the structures and should be evaluated further by the project engineers and/or architect. Design of exterior slabs should take into consideration the information contained in the attached Expansive Soils Guidelines. A vapor retarder should be utilized in areas which would be sensitive to the infiltration of moisture. This retarder shall meet requirements of ASTM E 96, Water Vapor Transmission of Materials and ASTM E 1745, Standard Specification for Water Vapor Retarders used in Contact with Soil or Granular Fill Under Concrete Slabs. The vapor retarder shall be installed in accordance with procedures stated in ASTM E 1643, Standard practice for Installation of Water Vapor Retarders used in Contact with Earth or Granular Fill Under Concrete Slabs. The moisture retarder may be placed directly upon 4 inches of compacted granular, non -expansive soils or gravel; use of sand over the retarder is at the discretion of the structural engineer and if used, should be placed in a dry condition. NorCal Engineering • • April 12, 2017 Page 17 Project Number 19510-17 • 8.10 Expansive Soil The upper on -site soils have a high expansion potential. When soils are expansive, special attention should be given to the project design and maintenance. The attached Expansive Soil Guidelines should be reviewed • by the engineers, architects, owner, maintenance personnel and other interested parties and considered during the design of the project and future property maintenance. • • • • • • • 8.11 Corrosion Design Criteria Representative samples of the surficial soils revealed negligible sulfate concentrations and no special concrete design recommendations are deemed necessary at this time. It is recommended that additional sulfate tests be performed at the completion of rough grading to assure that the as graded conditions are consistent with the recommendations stated in this design. Sulfate test results may be found on the attached Table IV. Tests were also conducted on a random representative sample of soils to determine the potential corrosive effects on buried metallic structures. Tests for pH, resistivity and chloride are included on Tables V — VII. Soil pH indicates a slightly alkaline condition. Resistivity is indicative of a condition which may be considered severely corrosive to metallic structures. Chloride content measured 485 parts per million. Further protection measures against corrosive soils may be provided by a corrosion engineer. NorCal Engineering • • April 12, 2017 Page 18 Project Number 19510-17 8.12 Utility Trench and Excavation Backfill • Trenches from installation of utility lines and other excavations may be backfilled with on -site soils or approved imported soils compacted to a minimum of 90% relative compaction. It is recommended that all utility lines • be properly bedded and shaded with clean sand having a sand equivalency rating of 30 or more to 6 inches above the top of line. This bedding material shall be thoroughly water jetted around the pipe structure prior to placement • of compacted backfill soils. 9.0 CLOSURE The recommendations and conclusions contained in this report are based • upon the soil conditions uncovered in our test excavations. No warranty of the soil condition between our excavations is implied. NorCal Engineering should be notified for possible further recommendations if unexpected or • unfavorable conditions are encountered during construction phase. It is the responsibility of the owner to ensure that all information within this report is submitted to the Architect and appropriate Engineers for the project. • • • • This firm should have the opportunity to review the final plans to verify that all our recommendations are incorporated. (A minimum of 72 hours for the plan review is required by this office.) This report and all conclusions are subject to the review of the controlling authorities for the project. A preconstruction conference should be held between the developer, general contractor, grading contractor, city inspector, architect, and soil engineer to clarify any questions relating to the grading operations and subsequent construction. Our representative should be present during the grading operations and construction phase to certify that such recommendations are complied within the field. NorCal Engineering • • • • • • Andrew S C.E.G. 164 April 12, 2017 Page 19 Project Number 19510-17 This geotechnical investigation has been conducted in a manner consistent with the level of care and skill exercised by members of our profession currently practicing under similar conditions in the Southern California area. No other warranty, expressed or implied is made. We appreciate this opportunity to be of service to you. If you have any further questions, please do not hesitate to contact the undersigned. Respectfully submitted, NORCAL ENGINEERINe Keith D. Tucker Project Engineer R.G.E. 841 • • • • RED GE, R CERTIFIED •nt. ENGINEERING GEOLOGIST OF CA‘-‘() NorCal Engineering Mark A. Burkholder Project Manager • • • April 12, 2017 Page 20 Project Number 19510-17 SPECIFICATIONS FOR PLACEMENT OF COMPACTED FILL Excavation Any existing low -density soils and/or saturated soils shall be removed to competent natural soil under the inspection of the Soils Engineering Firm. After the exposed surface has been cleansed of debris and/or vegetation, it shall be • scarified until it is uniform in consistency, brought to the proper moisture content and compacted to a minimum of 90% relative compaction (in accordance with ASTM: D-1557-12). • • In any area where a transition between fill and native soil or between bedrock and soil are encountered, additional excavation beneath foundations and slabs will be necessary in order to provide uniform support and avoid differential settlement of the structure. Material For Fill The on -site soils or approved import soils may be utilized for the compacted fill provided they are free of any deleterious materials and shall not contain any rocks, brick, asphaltic concrete, concrete or other hard materials greater than eight inches in maximum dimensions. Any import soil must be approved by the Soils Engineering firm a minimum of 72 hours prior to importation of site. O Placement of Compacted Fill Soils The approved fill soils shall be placed in layers not excess of six inches in thickness. Each lift shall be uniform in thickness and thoroughly blended. The fill soils shall be brought to within 2% of the optimum moisture content, unless otherwise specified by the Soils Engineering firm. Each lift shall be compacted • to a minimum of 90% relative compaction (in accordance with ASTM: D-1557-12) and approved prior to the placement of the next layer of soil. Compaction tests shall be obtained at the discretion of the Soils Engineering firm but to a minimum of one test for every 500 cubic yards placed and/or for every 2 feet of compacted fill placed. • • • The minimum relative compaction shall be obtained in accordance with accepted methods in the construction industry. The final grade of the structural areas shall be in a dense and smooth condition prior to placement of slabs -on -grade or pavement areas. No fill soils shall be placed, spread or compacted during unfavorable weather conditions. When the grading is interrupted by heavy rains, compaction operations shall not be resumed until approved by the Soils Engineering firm. NorCal Engineering • April 12, 2017 Page 21 Project Number 19510-17 Grading Observations The controlling governmental agencies should be notified prior to commencement of any grading operations. This firm recommends that the grading operations be conducted under the observation of a Soils Engineering firm as deemed necessary. A 24-hour notice must be provided to this firm prior to the time of our initial inspection. Observation shall include the clearing and grubbing operations to assure that all unsuitable materials have been properly removed; approve the exposed subgrade in areas to receive fill and in areas where excavation has resulted in the desired finished grade and designate areas of overexcavation; and perform field compaction tests to determine relative compaction achieved during fill placement. In addition, all foundation excavations shall be observed by the Soils Engineering firm to confirm that appropriate bearing materials are present at the design grades and recommend any modifications to construct footings. • • • • • NorCal Engineering • April 12, 2017 Page 22 • Project Number 19510-17 EXPANSIVE SOIL GUIDELINES The following expansive soil guidelines are provided for your project. The intent of these guidelines is to inform you, the client, of the importance of proper design and maintenance of projects supported on expansive soils. You, as the owner • or other interested party, should be warned that you have a duty to provide the information contained in the soil report including these guidelines to your design engineers, architects, landscapers and other design parties in order to enable them to provide a design that takes into consideration expansive soils. • In addition, you should provide the soil report with these guidelines to any property manager, lessee, property purchaser or other interested party that will have or assume the responsibility of maintaining the development in the future. • Expansive soils are fine-grained silts and clays which are subject to swelling and contracting. The amount of this swelling and contracting is subject to the amount of fine-grained clay materials present in the soils and the amount of moisture either introduced or extracted from the soils. Expansive soils are divided into five categories ranging from "very low" to "very high". Expansion indices are assigned to each classification and are included in the laboratory testing section • of this report. If the expansion index of the soils on your site, as stated in this report, is 21 or higher, you have expansive soils. The classifications of expansive soils are as follows: • • Classification of Expansive Soil* Expansion Index Potential Expansion 0-20 Very Low 21-50 Low 51-90 Medium 91-130 High Above 130 Very High *From Table 18A-1-B of California Building Code (1988) When expansive soils are compacted during site grading operations, care is taken to place the materials at or slightly above optimum moisture levels and • perform proper compaction operations. Any subsequent excessive wetting and/or drying of expansive soils will cause the soil materials to expand and/or contract. These actions are likely to cause distress of foundations, structures, slabs -on -grade, sidewalks and pavement over the life of the structure. It is therefore imperative that even after construction of improvements, the • moisture contents are maintained at relatively constant levels, allowing neither excessive wetting or drying of soils. NorCal Engineering • April 12, 2017 Page 23 Project Number 19510-17 Evidence of excessive wetting of expansive soils may be seen in concrete slabs, • both interior and exterior. Slabs may lift at construction joints producing a trip hazard or may crack from the pressure of soil expansion. Wet clays in foundation areas may result in lifting of the structure causing difficulty in the opening and closing of doors and windows, as well as cracking in exterior and interior wall surfaces. In extreme wetting of soils to depth, settlement of the • structure may eventually result. Excessive wetting of soils in landscape areas adjacent to concrete or asphaltic pavement areas may also result in expansion of soils beneath pavement and resultant distress to the pavement surface. Excessive drying of expansive soils is initially evidenced by cracking in the surface of the soils due to contraction. Settlement of structures and on -grade • slabs may also eventually result along with problems in the operation of doors and windows. Projects located in areas of expansive clay soils will be subject to more movement and "hairline" cracking of walls and slabs than similar projects situated • on non -expansive sandy soils. There are, however, measures that developers and property owners may take to reduce the amount of movement over the life the development. The following guidelines are provided to assist you in both design and maintenance of projects on expansive soils: • • • • • • Drainage away from structures and pavement is essential to prevent excessive wetting of expansive soils. Drainage shall be designed as stated in Section 7.1.2 of this report. Any "ponding" of water adjacent to buildings, slabs and pavement after rains is evidence of poor drainage; the installation of drainage devices or regrading of the area may be required to assure proper drainage. Installation of rain gutters is also recommended to control the introduction of moisture next to buildings. Gutters should discharge into a drainage device or onto pavement which drains to roadways. • Irrigation should be strictly controlled around building foundations, slabs and pavement and may need to be adjusted depending upon season. This control is essential to maintain a relatively uniform moisture content in the expansive soils and to prevent swelling and contracting. Over -watering adjacent to improvements may result in damage to those improvements. NorCal Engineering makes no specific recommendations regarding landscape irrigation schedules. NorCal Engineering • • • • • • April 12, 2017 Page 24 Project Number 19510-17 • Planting schemes for landscaping around structures and pavement should be analyzed carefully. Plants (including sod) requiring high amounts of water may result in excessive wetting of soils. Trees and large shrubs may actually extract moisture from the expansive soils, thus causing contraction of the fine-grained soils. • Thickened edges on exterior slabs will assist in keeping excessive moisture from entering directly beneath the concrete. A six-inch thick or greater deepened edge on slabs may be considered. Underlying interior and exterior slabs with 6 to 12 inches or more of non -expansive soils and providing presaturation of the underlying clayey soils as recommended in the soil report will improve the overall performance of on -grade slabs. • Increase the amount of steel reinforcing in concrete slabs, foundations and other structures to resist the forces of expansive soils. The precise amount of reinforcing should be determined by the appropriate design engineers and/or architects. • Recommendations of the soil report should always be followed in the development of the project. Any recommendations regarding presaturation of the upper subgrade soils in slab areas should be performed in the field and verified by the Soil Engineer. NorCal Engineering • April 12, 2017 Page 25 • REFERENCES • • 1. California Building Code, 2016. Project Number 19510-17 2. California Division of Mines and Geology, 1997, Guidelines for Evaluating and Mitigating Seismic Hazards in California: Special Publication 117. 3. California Division of Mines and Geology, 1998, Seismic Hazard Zone Report for the Torrance 7.5-Minute Quadrangle, Los Angeles County, California, Seismic Hazard Zone Report 035. 4. State of California Seismic Hazard Zones, Torrance Quadrangle, Official Map Released March 25, 1999, available from California Geological Survey 5. International Conference of Building Officials, Uniform Building Code UBC, 2009. 6. ACI Building Code Requirements for Structural Concrete (ACI 318-05) • and Commentary (ACI 318R-05), 2005. • • • • 7. Geologic Map of the Palos Verdes Peninsula and Vicinity, Redondo Beach, Torrance, and San Pedro Quadrangles, Los Angeles County, California, published by the Dibblee Geologic Foundation, by Thomas W. Dibblee, Jr., 1999 NorCal Engineering • • • • • • • • • • • recinsula Herircge. Stho.71 USPS Collection BOY Ovpplegray Elementary Szhotil 2950 Palos Verdes Dr N. Rolling Hills. CA 90274 SAVO', N r'al Engineeri 11; SOILS AND GEOTECHNICAL CONSULTANTS City cf 6 Roiling 14ills Eztt7fez Sfitre I le, Patin Verdt.s Of"14 ‘5, ^.ZriP1 Gt,cryr I' Cot marine Park and Pe r • " 'l VICINITY MAP 47, 0Rf eet lOOm 2017 HERE • PROJECT 19510-17 IDPITE 4/2017 FIGURE 1 • • • 0I 30' • • • • • SCALE O z. LEGEND: '1` L�._J 16A 63G d=566510• 163. EXISTING HOUSE (60 S.F.) GROUND FLOOR ADDITION (60 S.F.) BASEMENT ADDITION (2,040 S.F.) �¢A Um k v of ;: 142�f'jI it w 1 D nI � .. ant\ j� ? • C4 li 130 oio �� PEE �e .EXIST IN Q ry ,' SERV / YARD d 126' L�� 1 1 STORY UEST HOUSE (530 S.F.) F.F.=131.6 1 AVERAGE EXTERIOR WALL ' NEW ADDITION EASEM NpT TO EXCEE MAXIMUM r s -41:.-;,, ., Ii Io...r......>:. • , 0 1 o / \ 1Do61. pC NorCal Engineering SOILS AND GEOTECHNICAL CONSULTANTS PROJECT 1 9 51 0 —1 7 I DATE 4/ 2 0 1 7 r • ti V Ce I N1213'18 GEOTECHNICAL MAP FIGURE 2 • • • • • • • • • • • A /go - / Z-0 8° - 1 pg.ope.sat> Ex IS T7A/6-- 0.po„seb Otz.oc.34 *7- pet F sat)t,i/vc.,- NorCal Engineering SOILS AND GEOTECHNICAL CONSULTANTS _SO t__ pRf.. eose. _s Lep. SECTION A -A' - 'to - I Z.0 - /00 PROJECT19510-17 IDATE 4/2017 FIGURE 3 • • le 5' MIN. 1- LV 1 BENCHING FILL OVER EXISTING SOILS FILL SLOPE SURFACE OF FIRI,I EARTH MATERIAL O`� SUII TYPICAL 10' TYPICAL 10' MIN. (INCLINED 2% MIN. INTO SLOPE) BENCHING FILL OVER CUT FINISH FILL SLOPE FINISH CUT SLOPE SURFACE OF FIRM EARTH MATERIAL ti 4' TYPICAL ► `S SUtiiI I I ]0' 1 / TYPICAL { { 10' MIN_ OR STABILITY EQUIVALENT PER SOIL ENGINEERING (INCLINED 2% MIN. INTO SLOPE) NorCal Engineering SOILS AND GEOTECHNICAL CONSULTANTS BENCHING FOR COMPACTED FILL • PROJECT 1 9 5 1 0— 1 7 I DATE 4/ 2 0 1 7 FIGURE 4 • • • • • e t1'- 1 H WEEPHOLE n WATERPRPTIONAL)OOFING" (O H/ 2 min •............... 2' min: -- NATIVE OR APPROVED COMPACTED FILL SOILS GRANULAR BACKFILL (SE>30), COMPACTED TO 90% RELATIVE COMPACTION 3/4 TO I MINIMUM BACKCUT SHOULD CONFORM TO CURRENT CAL -OSHA SPECIFICATIONS SUB DRAIN SYSTEM CONSISTING OF ONE CUBIC FOOT PER FOOT MINIMUM GRAVEL, WRAPPED IN FILTER FABRIC WITH A 4 INCH DIAMETER PIPE PERFORATED PVC (PERFORATIONS DOWN) SCHEDULE 40 OR EQUIVALENT, DRAINED AT A MINIMUM SLOPE OF 1% INFORMATION DEPICTED ON THIS DETAIL IS FOR TYPICAL CONDITIONS AND ARE SUBJECT TO CHANGE BY THE GEOTECHNICAL CONSULTANT Nor Cal Engineering SOILS AND GEOTECHNICAL CONSULTANTS RETAINING WALL DETAIL PROJECT 1 9 5 1 0 -1 7 !DATE 4/ 2 01 7 FIGURE 5 April 12, 2017 Project Number 19510-17 • • • • • • APPENDICES (In order of appearance) Appendix A - Logs of Test Explorations *Logs of Test Pits T-1 to T-3 Appendix B — Seismic Design Appendix C - Laboratory Analysis *Table I - Maximum Dry Density Tests *Table II - *Table III - *Table IV - *Table V - *Table VI - *Table VII - Expansion Index Tests Atterberg Limits Tests Sulfate Tests pH Tests Resistivity Tests Chloride Tests *Plates A-B - Direct Shear Tests *Plates C-D - Consolidation Tests Appendix D — Slope Stability Analysis NorCal Engineering • April 12, 2017 Project Number 19510-17 • S • APPENDIX A NorCal Engineering • • Lucas Brothers Construction 19510-17 Boring Location: 2950 PV Drive North, RHE Date of Drilling: 3/22/17 • Drilling Method: Excavator • Hammer Weight: Surface Elevation: Not Measured Depth Lith- (feet) ology Material Description —0 � FILL SOILS CLAY Log of Trench T-1 Groundwater Depth: None Encountered Drop: _ Silty with rock fragments, roots m - � Brown, soft, moist . - g Firm @ 3' —5 • a • —10 E —20 0 — u 3 • cn • —25 ro • - • U _ rn — 30 N — — 35 NATURAL SOILS Silty CLAY Brown, medium stiff, moist BEDROCK Monterey Fm Siliceous siltstone and shale \Yellow -brown to grey, moderately weathered Trench completed at depth of 13.5' NorCal Engineering Samples Laboratory Q. 3 c w • ZN o — I— in •O d o. C.) • 26.2 79.4 ■ 34.9 75.4 • 31.0 78.1 ■ 28.2 86.0 23.2 84.0 1 0 co a E • • Lucas Brothers Construction 19510-17 I Boring Location: 2950 PV Drive North, RHE Date of Drilling: 3/22/17 Drilling Method: Excavator Hammer Weight: Surface Elevation: Not Measured Depth Lith- (feet) ology Material Description — 0 FILL SOILS Log of Trench T-2 Groundwater Depth: None Encountered 1 1 Drop: 1 m Silty CLAY with rock fragments, roots, organics, minor debris Brown, soft, moist 11/ 3 Roots, debris absent below upper 24" - Increased density below 2' — 5//l 0 N _ p,- ! ■ 20.8 83.5 Samples Laboratory w a 8 H m V O �cp re o • 24.9 92.4 e —20 0 - u m 3 - u • d —25 0 I _ t U • 0 —30 a N — — 35 NATURAL SOILS ■ 24.8 91.4 Silty CLAY with rock fragments Brown, medium stiff, moist BEDROCK ■ 31.2 68.9 Monterey Fm Siltstone Grey to grey -brown, moderately weathered Trench completed at depth of 15.5' NorCal Engineering 2 • • • Lucas Brothers Construction 19510-17 Boring Location: 2950 PV Drive North, RHE Date of Drilling: 3/22/17 Drilling Method: Excavator Hammer Weight: Surface Elevation: Not Measured Depth (feet) Lith- ology Material Description Log of Trench T-3 Groundwater Depth: None Encountered I Drop: - 0 FILL SOILS Silty CLAY with rock fragments, roots Brown, soft, moist _ m Firm @ 3' — 5 NATURAL SOILS - Silty CLAY with rock fragments N Brown, medium stiff, moist • a _ o —10 • — 0 — In 1110 o _ a —15 a 0 a - • u - ti E —20 L U C1 N • —25 0 t u F — • :> U of 0 — 30 — 35 BEDROCK Monterey Fm Siliceous siltstone and shale Tan to grey, thinly to moderately bedded, moderately weathered B-N45W, 30NE B-N50W. 27NE Trench completed at depth of 12' NorCal Engineering Samples Laboratory y V. .' N • . 33 3.= w N co I— CaV 5 OQ M • E S ., 39.1 81.3 25.3 92.3 • 22.6 79.6 3 • • April 12, 2017 Project Number 19510-17 • • • APPENDIX B NorCal Engineering 0 4/11/2017 Design Maps Summary Report le MUMS Design Maps Summary Report User -Specified Input Report Title 2950 PV Drive North, RHE Tue April 11, 2017 15:55:45 UTC Building Code Reference Document ASCE 7-10 Standard • (which utilizes USGS hazard data available in 2008) Site Coordinates 33.7718°N, 118.3378°W Site Soil Classification Site Class D — "Stiff Soil" Risk Category I/II/III • USGS-Provided Output • Ss = 1.608 g S1 = 0.619 g SMS = 1.608 g SM1 = 0.929 g SDS = 1.072 g Spl = 0.619 g For information on how the SS and Si values above have been calculated from probabilistic (risk -targeted) and deterministic ground motions in the direction of maximum horizontal response, please return to the application and select the "2009 NEHRP" building code reference document. 1,97 1.70 1..13 1.30 1.19 1)32 cult ac9 a31 a34 a17 l MCEER Response Spectrum ova I I Iwl I I I I OJJ 020 au] aaB] 'Jim 1 1.1+] 1FJ L&iI Period. T (see) 7..03 Design Response Spectrum L10 — a99 — fI A9 a77 — as — , 1 0 1 0 4L a.s3 — 022 — ail — a+b I I I I I I I I I 1 a-]] 0.23 a 4] OJA aB] 1.03 1_23 1. 40 1.03 1.33 2 J73 Penal T (see) For PGA,, TL, C,s, and C, values, please view the detailed reoort. Although this information is a product of the U.S. Geological Survey, we provide no warranty, expressed or implied, as to the accuracy of the data contained therein. This tool is not a substitute for technical subject -matter • knowledge. https://earthquake.usg s.gov/cn2/desig nmaps/us/summaryphp?template=minimal&latitude=33.7718&long itude=-118.3378&siteclass=3&riskcateg ory=0&edition=a .. 1/1 4/11/2017 Design Maps Detailed Report • 02U75 Design Maps Detailed Report ASCE 7-10 Standard (33.7718°N, 118.3378°W) Site Class D - "Stiff Soil", Risk Category I/II/III • Section 11.4.1 — Mapped Acceleration Parameters • • Note: Ground motion values provided below are for the direction of maximum horizontal spectral response acceleration. They have been converted from corresponding geometric mean ground motions computed by the USGS by applying factors of 1.1 (to obtain Ss) and 1.3 (to obtain Si). Maps in the 2010 ASCE-7 Standard are provided for Site Class B. Adjustments for other Site Classes are made, as needed, in Section 11.4.3. From Fiaure 22-1113 From Fiaure 22-2 [21 Section 11.4.2 — Site Class Ss=1.608g S1 = 0.619 g The authority having jurisdiction (not the USGS), site -specific geotechnical data, and/or the default has classified the site as Site Class D, based on the site soil properties in accordance with Chapter 20. Table 20.3-1 Site Classification Site Class vs Nor Tic, s„ A. Hard Rock >5,000 ft/s N/A N/A B. Rock 2,500 to 5,000 ft/s N/A N/A C. Very dense soil and soft rock 1,200 to 2,500 ft/s >50 >2,000 psf • D. Stiff Soil 600 to 1,200 ft/s 15 to 50 1,000 to 2,000 psf E. Soft clay soil <600 ft/s <15 <1,000 psf Any profile with more than 10 ft of soil having the characteristics: • Plasticity index PI > 20, • • Moisture content w >- 40%, and • • F. Soils requiring site response analysis in accordance with Section 21.1 • Undrained shear strength s < 500 psf See Section 20.3.1 For SI: 1ft/s = 0.3048 m/s 11b/ft2 = 0.0479 kN/m2 • https://earthq ual,a.usg s.g ov/cn2/desig nmaps/us/report.php?templ ate=minimal&latitude=33.7718&long itude=-118.3378&siteclass=3&risknateg ory=08,edition=asc... 1/6 4/11/2017 Design Maps Detailed Report • Section 11.4.3 - Site Coefficients and Risk -Targeted Maximum Considered Earthquake (MCER) Spectral Response Acceleration Parameters Table 11.4-1: Site Coefficient Fa Site Mapped MCE R Spectral Response Acceleration Parameter at Short Class Period Ss<_0.25 Ss=0.50 Ss=0.75 Ss=1.00 SS>_1.25 • A 0.8 0.8 0.8 0.8 0.8 B 1.0 1.0 1.0 1.0 1.0 C 1.2 1.2 1.1 1.0 1.0 • D 1.6 1.4 1.2 1.1 1.0 E 2.5 1.7 1.2 0.9 0.9 F See Section 11.4.7 of ASCE 7 Note: Use straight-line interpolation for intermediate values of Ss • For Site Class = D and Ss = 1.608 g, Fa = 1.000 Table 11.4-2: Site Coefficient F Site Class Mapped MCE R Spectral Response Acceleration Parameter at 1-s Period S1<-0.10 S1=0.20 S1 = 0.30 S1=0.40 S1>_0.50 • A 0.8 0.8 0.8 0.8 0.8 B 1.0 1.0 1.0 1.0 1.0 C 1.7 1.6 1.5 1.4 1.3 • D 2.4 2.0 1.8 1.6 1.5 E 3.5 3.2 2.8 2.4 2.4 F See Section 11.4.7 of ASCE 7 • Note: Use straight-line interpolation for intermediate values of S1 • For Site Class = D and Si = 0.619 g, F„ = 1.500 • https://earthq uale.usg s.gov/cn2/desig nmaps/us/report.php?template=minimal&latitude=33.7718&long itude=-118.3378&siteclass=3&riskcateg or�0&edition=asc... 2/6 4/11/2017 • Equation (11.4-1): Design Maps Detailed Report SMs = FaSs = 1.000 x 1.608 = 1.608 g • • • • • • • • • Equation (11.4-2): SM1 = F,S1 = 1.500 x 0.619 = 0.929 g Section 11.4.4 — Design Spectral Acceleration Parameters Equation (11.4-3): Equation (11.4-4): Section 11.4.5 — Design Response Spectrum From Figure 22-12 [3] 0 cn 0 Figure 11.4-1: Sos-1.072 -- Srn-O.619 ---r T,o-O.115 Sips = 2/3 SMS = % x 1.608 = 1.072 g SD1 = % SM1 = % x 0.929 = 0.619 g TL = 8 seconds Design Response Spectrum T<T0:S1=Sps(0.4+0.6T/T0) To5T5Ta:S,=3,34 Ts<TSTL:S,=Sal/T T>TL: S,=SD,TL/Tz 1 Ts - 0,577 1.000 Period. T (see) • https://earthg uale.usg s.gov/cn2/desig nmaps/us/report.php?templ ate=minimal &latitude=33.7718&long itude=-118.3378&siteclass=3&rislcateg or =0&edition=asc... 3/6 4/11/2017 Design Maps Detailed Report • • • Section 11.4.6 — Risk -Targeted Maximum Considered Earthquake (MCER) Response Spectrum The MCER Response Spectrum is determined by multiplying the design response spectrum above by 1.5. sc- 1.608 - -• . -ui 0_929 - _L a To-0.116 Ts • 0.578 1.000 Period. T (sec) • https://earthq ual e.usg s.gov/cn2/desig nmaps/us/report.php?template=minimal&latitude=33.7718&long itude=-118.3378&siteclass=3&rislcateg or�0&edition=asc... 4/6 4/11/2017 Design Maps Detailed Report • Section 11.8.3 - Additional Geotechnical Investigation Report Requirements for Seismic Design Categories D through F • • From Figure 22-7 [4] PGA = 0.654 Equation (11.8-1): PGAM = FPGAPGA = 1.000 x 0.654 = 0.654 g Table 11.8-1: Site Coefficient FPS,, Site Mapped MCE Geometric Mean Peak Ground Acceleration, PGA Class PGA _< PGA = PGA = PGA = PGA >_ 0.10 0.20 0.30 0.40 0.50 • A 0.8 0.8 0.8 0.8 0.8 B 1.0 1.0 1.0 1.0 1.0 C 1.2 1.2 1.1 1.0 1.0 • D 1.6 1.4 1.2 1.1 I 1.0 I E 2.5 1.7 1.2 0.9 0.9 F See Section 11.4.7 of ASCE 7 • Note: Use straight-line interpolation for intermediate values of PGA For Site Class = D and PGA = 0.654 g, F,,,14 = 1.000 Section 21.2.1.1 - Method 1 (from Chapter 21 - Site -Specific Ground Motion Procedures for Seismic Design) • • • ♦ From Figure 22-17 [51 CRS = 0.916 From Figure 22-18 [61 CR1 = 0.923 https://earthq ual.e.usg s.gov/cn2/desig nmaps/us/report.php?template=minimal &latitude=33.7718&long itude=-118.3378&siteclass=3&riskcateg ory0&edition=asc... 5/6 4/11/2017 w Section 11.6 — Seismic Design Category Design Maps Detailed Report Table 11.6-1 Seismic Design Category Based on Short Period Response Acceleration Parameter RISK CATEGORY I or II III IV VALUE OF SDs Sps < 0.167g 0.167g <_ Sps < 0.33g 0.33g <_ Sps < 0.50g • 0.50g 5 SDs For Risk Category = I 41 A A A B B C C C D D D D and SDs = 1.072 g, Seismic Design Category = D Table 11.6-2 Seismic Design Category Based on 1-S Period Response Acceleration Parameter RISK CATEGORY I or II III IV VALUE OF SDl SDl < 0.067g A 0.067g <_ SDI. < 0.133g • 0.133g <_ SDl < 0.20g 0.20g 5 SDI For Risk Category = I III 41 B A A B C C C D D D D and Sm. = 0.619 g, Seismic Design Category = D Note: When Sl is greater than or equal to 0.75g, the Seismic Design Category is E for buildings in Risk Categories I, II, and III, and F for those in Risk Category IV, irrespective of the above. Seismic Design Category = "the more severe design category in accordance with Table 11.6-1 or 11.6-2" = D Note: See Section 11.6 for alternative approaches to calculating Seismic Design Category. References 1. Figure 22-1: https://earthquake.usgs.gov/hazards/designmaps/downloads/pdfs/2010_ASCE-7_ 2. Figure 22-2: https://earthquake.usgs.gov/hazards/designmaps/downloads/pdfs/2010_ASCE-7_ 3. Figure 22-12: https://earthquake.usgs.gov/hazards/designmaps/downloads/pdfs/2010_ASCE-7 12.pdf • 4. Figure 22-7: https://earthquake.usgs.gov/hazards/designmaps/downloads/pdfs/2010_ASCE-7_ 5. Figure 22-17: https://earthquake.usgs.gov/hazards/designmaps/downloads/pdfs/2010_ASCE-7 17.pdf 6. Figure 22-18: https://earthquake.usgs.gov/hazards/designmaps/downloads/pdfs/2010_ASCE-7 18.pdf r Figure_22-1.pdf Figure_22-2.pdf _Fig u re_22- Figure_22-7.pdf _Fig u re_22- _Figure_22- • https://earthq uake.usg s.g ov/cn2/desig nmaps/us/report.php?template=minimal&latitude=33.7718&long itude=-118.3378&siteclass=3&riskcateg orr0&edition=asc... 6/6 • April 12, 2017 Project Number 19510-17 • • APPENDIX C NorCal Engineering • • April 12, 2017 Project Number 19510-17 • TABLE I MAXIMUM DENSITY TESTS (ASTM: D-1557-121 • Optimum Maximum Dry Sample Classification Moisture Density (lbs./cu.ft.) • • • • • • • T-2 @ 2-4' silty CLAY 22.5 100.0 T-3 @ 11-12' Siltstone 24.0 95.0 Sample T-2 @ 2-4' TABLE II EXPANSION INDEX TESTS (ASTM: D-4829-111 Classification silty CLAY TABLE III ATTERBERG LIMITS (ASTM: D-4318-101 Expansion Index 95 Sample Liquid Limit Plastic Limit Plasticity Index T-2 @ 2-4' T-3@11-12' 77 26 51 67 29 38 TABLE IV SOLUBLE SULFATE TESTS (CT 4171 Sulfate Sample Concentration (%) T-2 @ 2-4' .0110 NorCal Engineering • • April 12, 2017 Project Number 19510-17 • TABLE V pH TESTS Sample T-2 @ 2-4' 7.3 TABLE VI RESISTIVITY TESTS (CT 643) Sample Resistivity (ohm -cm) T-2 @ 2-4' 636 TABLE VII CHLORIDE TESTS (CT 422)1 Sample Concentration (ppm) T-2 @ 2-4' 485 NorCal Engineering • • Sample No. T2@4' Sample Type: Undisturbed/Saturated Soil Description: Silty Clay w/ Some Bedrock Fragments 1 2 3 Normal Stress (psf) 1000 2000 3000 Peak Stress (psi) 984 1452 1812 Displacement (in) 0.055 0.085 0.100 • Residual Stress (psf) 756 1368 1776 Displacement (in.) 0.250 0.250. 0.250 In Situ Dry Density (pcf) 92.4 92.4 92.4 In Situ Water Content (%) 24.9 24.9 24.9 Saturated Water Content (%) 30.4 30.4 30.4 Strain Rate (in/min) 0.020 0.020 0.020 • • • • • • Shear Stress (psf) 4000 3500 3000 2500 2000 3000 2500 c 2000 1500 co co 1000 500 0 3 ksf 2 ksf 1 ksf 0.0 2.0 4.0 6.0 8.0 10.0 12.0 Axial Strain (%) • Peak Stress • Residual Stress ,--------- ,......--_,-- 1500 �A 1 1-,-- �r .r 1000 1� I/ / / I 0 (Degree) C (psf) 500 1 l Peak Stress 22 590 C/ Residual Stress 27 280 0 1 I 0 500 1000 1500 2000 2500 3000 3500 4000 Normal Stress (psf) NorCal Engineering DIRECT SHEAR TEST • SOILS AND GEOTECHNICAL CONSULTANTS ASTM D3080 Martinez Plate A PROJECT NUMBER: 19510-17 DATE: 4/7/2017 • • • Sample No. T3@10' Sample Type: Undisturbed/Saturated Soil Description: Diatomaceous Siltstone 1 2 3 Normal Stress (psf) 1000 2000 3000 Peak Stress (psi) 912 1272 1860 Displacement (in.) 0.080 0.125 0.200 • Residual Stress (psi) 756 1272 1848 Displacement (in.) 0.250 0.250 0.250 In Situ Dry Density (pcf) 79.6 79.6 79.6 In Situ Water Content (%) 22.6 22.6 22.6 Saturated Water Content (%) 41.2 41.2 41.2 Strain Rate (in/min) 0.020 0.020 0.020 • • • • • Shear Stress (psf) 4000 I 3500 b 3000 2500 2000 1500 1000 500 Iiii� I / li 0, • 0 500 1000 1500 2000 2500 3000 3500 4000 Normal Stress (psf) 3000 2500 „ 2000 a g1500 2 Ca 1000 500 ii// 0• 0.0 2.0 3 ksf 2 ksf 1 ksf 4.0 6.0 8 0 10.0 12.0 Axial Strain (%) • Peak Stress ■ Residual Stress 0 (Degree) C (psi) Peak Stress 25 400 I Residual Stress 28 200 NorCal Engineering • SOILS AND GEOTECHNICAL CONSULTANTS Martinez PROJECT NUMBER: 19510-17 DATE: 4/7/2017 DIRECT SHEAR TEST ASTM D3080 Plate B • • • Vertical Pressure (kips/sq.ft.) Sample Height (inches) Consolidation (percent) 0.125 1.0000 0.0 0.25 0.9917 0.8 0.5 0.9840 1.6 1 0.9704 3.0 1 0.9662 3.4 .rj » 2 0.9492 5.1 ftt 4 0.9196 8.0 1 8 0.8808 11.9 e 0.25 0.9021 9.8 r M r r • Sample No. T2 1.02 1.01 1.00 -HAL_ 0.99 I \� 0.98 j 0.97 0.96 0.95 0.94 I ai 0.93 Date Tested: 4/3/2017 c Sample: T2 0.92 r Depth: 9' a)= 0.91 a) a E 0.90 m co 0.89 0.88 0.87 0.86 0.85 0.84 Depth Silty Clay w/ Some Bedrock Fragments 0.83 Dry Density: 83.5 pcf Initial Moisture Content: 20.8 % 0.82 • Saturated Moisture Content: 37.4 % Saturated at 1 kip/sq.ft. 0.81 9' Date 4/7/2017 ■ In -Situ Moisture Content O Saturated N\ 0.1 1 10 Vertical Pressure (kips/sq.ft.) NorCal Engineering SOILS AND GEOTECHNICAL CONSULTANTS Martinez PROJECT NUMBER: 19510-17 DATE: 4/7/2017 CONSOLIDATION TEST ASTM D2435 Plate C • Vertical Pressure (bps/sq.ft.) Sample Height (inches) Consolidation (percent) Sample No. T2 Depth 1.01 1.00 0.125 1.0000 0.0 0.99 0.25 0.9924 0.8 0.5 0.9862 1.4 0.98 1 0.9778 2.2 1 0.9287 7.1 ,0.97 � 2 0.8916 10.8 112CS 0.96 4 0.8481 15.2 8 0.8075 19.3 0.95 0.25 0.8325 16.8 Date Tested: 4/4/2017 Sample: T2 Depth: 15' 0.91 0.93 0.92 a, a) t 2 0.91 p� 0.90 m 0.89 fl. E 0.88 0.87 0.86 0.85 0.84 0.83 0.82 Diatomaceous Siltstone 0.81 • Dry Density: 68.9 pcf Initial Moisture Content: 31.2 % 0.80 • Saturated Moisture Content: 52.8 % Saturated at 1 kip/sq.ft. 0.79 15' • Date 4/7/2017 • In -Situ Moisture Content 0 Saturated 0.1 1 10 Vertical Pressure (kips/sq.ft.) NorCal Engineering SOILS AND GEOTECHNICAL CONSULTANTS Martinez PROJECT NUMBER: 19510-17 DATE: 4/7/2017 CONSOLIDATION TEST ASTM D2435 Plate D April 12, 2017 Project Number 19510-17 APPENDIX D NorCal Engineering tio5. n titivt 774 t 11-4444 6�4 Gam. (-360.0.44-2-z-0) 7. F w xy? NorCal Engineering SOILS AND GEOTECHNTCAL CONSULTANTS • • • • LOCATION ecutoIQ' k-A AREA ym W /3 Wsina Wcas SLICE (SQ.(pcf)(kips)�(deg)(kips)(kips)(deg) FT.).CIV"&(.4“- 624116( 41 Vt SHEET OF Ntant15. C I L (kips) (psf) (ft) tt CL (kips) -I-z:4-w1A-A Gi7 61( NorCal Engineering SOILS AND GEOTECHNICAL CONSULTANTS SLOPE STABILITY CALCULATIONS 36 $ I DATE • • • A /yo / Z-0 - /pp Ex I.s r—rNc,- N / bc DI iv NorCal Engineering SOILS AND GEOTECHNICAL CONSULTANTS 1 SECTION A —A' A P `io — /00 PROJECT 1 9 5 1 0— 1 7 IDATE 4/2 0 1 7 FIGURE 3 . , ......,r,..tt..,,,,,y.v..M4"'"''• ;o%'''":o1:'..,,,,,he'r:ll'':' I ....., “.,..,.....,... . .,_..,) ' 0', a.,...),..i...., v..* a....r... - bac.b.";,...g. b ,b,,,,AAbeHAleneb"A"Aebb""Ne"1"4 ki.nee"AA'; •e e" AAA*44,4,0"1,-.1 e,Abeelebblert;.,er,";';;,NOWA'ae;;* bee",b4;e'Z Aeree2:‘e 6 i , ..; i,„, ,,,,,, , ..,,, .,..., I AS„ ; 1, , ', , . ...Kb. b bbernbAe ';;;";e1 be ebbbryArneWee ebrybe., „..e.„,..b, 1 bele,:""6***HW6rnM":47641;*1'. ...... ' .64,7... tee., ee. yb-ba-eparefebre i9.eene,b7...........,,,,,Abbee. Abee,,,,,ebebbe,,,.... "eArn ye" by, , e6 ,e , e" b;". e b4e.,,,m, bee,' . e Ve;" bWARbeeeeee A., , ey Meebey...,.......„,_ .. 7 II ,,,,,,_„ 1: AMMOMVIAMOV ' . 0.".",..rn . re''. - , ,..,...t....,,,m,m.m..,..".".,,,,,,eyAbeib."1„..„...,,, ' ' ""';'"'"* -7,-,,,,.."------.....„„.. A, ,„ -.A.A.A„,,,,,.. 'kb. erne,w...,..:74. , . no, iii.....4.w... 1 "ree..;;;%;;.Keeeebee,,,, b . eebeb4e be "be, ''..";befteAAWAAbObebeebernebeernbeeebbee.eeffiebee.e.e;Vbe,