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HomeMy WebLinkAbout1980 LA COSTA AVE; SOILS; CB120241; PermitSOILS REPORT . FOR CB120241 1980 LA c·osTA AVE i (: ~ ) ; '<: , J ' ~ ... :·;· ::; ~', \.' l ... :. -•, '•/ _.-,,. ,, ,-::,. ·\~ . ._. ,~. \. ,, , ... _..,_, ..;: ! ,,.- ' ·' !,'. 1 • :. ' .... ,, . -:~·-. .:•• ,, : ', .. : ' ,,_,, :·. '.,., ... {i:., .,\ • C •. ' I ~'• , I .·-"t._.,. -,1, . '. , .. · .. -,• --:,-.,-' •. :) J,' • : ~ :, :<-•• ·" I ,' .. , . '.'.i· i .. \)t ... ' ··t· :l -·~ ..... ' ,[' ' . ·: .. ~-. . .· . -· --: .. ,} ' .. --~ .. ; -;.., . .·. ;~ . ·' ' '~ " ,-,·-·,J ., :.,_,, ',i;,.•'./,.; )_.:·;· . •{•. ··-: . . -;, ~ -=-,-~-~ ~ . ' \ '• · .. -. ; ,._ ··:, ... ·. ,_ .... ' ' ~ ;, , ~ : .. :/ ·· .. - ' .. ~ ' I r • ~. ,·i' ',. -::- -.'\, ... ';_,1.·, .''',~ .. ' ', .,, . · .. · ', ~-1' ,-•:, ... ' ·;..·,· ·,-:.·'·· ,··" ,, .. '. ·~ ~ . ,, ,,.,,· '' '·' ,'•,' ·~' - I ,l -' ''.1 • .... ,, ,- ! .:, ;_ , •• '•. ,, \ ,·. ~-- ·, -':."..11, :·'' ' ,• ' ;,..: ~" ~· .. -'·,: ~ : ,', ' , ' • ~ ' ,' ! : I ) •' ,' ', f ' r, ·, .'•"',· . ' '-.,'.~, ~ , ,·'· ·- .. ,; . ' ,,-·\ 'r .: ., ~-' .~, ' ' ». •' .. ~.,., /i,,' '-;:,··· '· ·.:;_:. ' : t ' I , I' )' . '~-' . ,-·,,,. .. i' .--...... ,, ' ,· ' '·~ . I ~ • i . • •·,' . ' :,·, . , ',. . /:·\_· '; /1 <-- \ ' '1' ,~, '. : l ' -~ . ,' ·"1' ). ' ' ' \ ' ' I ' , ,l ,! ' ' / ', ' ,: ' 'GEOTECHNIC.A:L UPDATE EVA(UATION PROPOSED JEWISH COMMUN-ITV COMPLEX , 1980· LA. COSTA .A V,ENIJ.E __ ' cMtLSBAD, ·sAN'. DIEGO COUNTY, CALIFORNIA -· ' FOR CHABAD At LA COSTA C/0 K:ARNAK PLANNING AND DESIGN 2525 ·p10· PICO)WENUE, SUITE 102 CARLSBAD, ,~ALIFORN_IA 92008' W.O. 6304-A-SC DECEMaER 15, 20.11 ( - ) ',\' ( • Geotechnical •Geologic• Coastal• Environmental 5741 PalmerWay • Carlsbad,California92010 • (760)438-3155 • FAX(760)931-0915•www.geosoilsinc.com December 15, 2011 Chabad at La Costa, Dr. Michael Galperin c/o Karnak Planning and Design 2525 Pio Pico Avenue, Suite 102 Carlsbad, California 92008 Attention: Mr. Robert Richardson W.O. 6304-A-SC Subject: Geotechnical Update Evaluation, Proposed Jewish Community Complex, 1980 La Costa Avenue, Carlsbad, San Diego County, California · Dear Mr. Richardson: In accordance with the request and authorization of Dr. Michael Galperin, GeoSoils, Inc. (GSI), is providing this geote~hnical update evaluation for the currently proposed development at the subject site. Previous site and near-site geotechnical investigations were performed by Heatherington Engineering, Inc. ([HEl]1999, 2010a, and 2010b ), Diaz Yourman and Associates ([DY&A] 2005), M&T Agra, lnc./Agra Earth and Environmental, Inc. ([Agra]1994a and 1994b), and GSI (1997). Copies of the HEI, DY&A, Agra, and GSI reports are provided on the compact disc, included inside the back cover of this report. These reports are also briefly summarized herein . . The purpose of this update was to evaluate the onsite and near-site geologic conditions specific to the currently proposed development shown on Karnak Planning and Design ([KP&D] 2011) and Conway and Associates, Inc. ([C&A] 2011). This update provides supplemental analyses regarding the stability of the slope upon which the site is located, as well as recommendations for earthwork construction and geotechnical design parameters for foundations, temporary shoring, walls, and pavements. The geotechnical analyses and recommendations, provided herein, consider current building code requirements outlined in the 201 o California Building Code {[201 O CBC], California Building Standards Commission [CBSC], 2010). Unless specifically superceded herein, the conclusions and recommendations provided in HEI (1999, 201 Oa and 201 Ob) remain valid and applicab!e and should be appropriately implemented in project planning, design, and construction. EXECUTIVE SUMMARY Based on our review of the available data (see Appendix A), field exploration, laboratory testing, and geologic, and engineering analyses, the proposed development of the property appears to be feasible from a geotechnical viewpoint, provided the recommendations presented in the text of this report are properly incorporated into the design and construction of the project. The most significant elements of this study are summarized below: • Based on a review of the architectural and civil engineering plans prepared by KP&D (2011) and C&A (2011 }, it is our understanding that proposed site development will consist of removing the existing building and associated improvements, and preparing the site for the construction of a new two-story Synagogue with associated underground utility, wall, and pavement improvements. The proposed building will incorporate a below-grade floor level. • Based on the subsurface data GSI acquired during our recent field exploration program and our review of HEI (1999, 2010a, and 2010b), onsite earth materials primarily consist of sedimentary rock belonging to the Tertiary Delmar Formation. These earth materials are locally mantled by undocumented fill, and colluvium (topsoil). • Undocumented artificial fill, colluvium and near-surface weathered Delmar Formation are considered potentially compressible in their existing state. As such, these earth materials should not be relied upon for support of the proposed settlement-sensitive improvements (buildings, walls, underground utilities, pavements, etc.) and/or planned fill. In areas to receive the planned settlement- sensitive improvements/fill, all undocumented artificial fill, topsoil/colluvium, and weathered Delmar Formation should be removed to expose dense, unweathered Delmar Formation. The removed materials may be re-used as engineered fill provided that major concentrations of organic and/or deleterious materials are removed prior to their re-use. Potentially compressible earth materials should be removed below a 1 :1 (horizontal:vertical [h:v]) projection down from the bottom, outboard edge of settlement-sensitive improvements and/or planned fill areas. Based on the available data, the depth of excavations required to remove potentially compressible earth materials are anticipated to be approximately ¼-foot to 6 feet below the existing grade. However, locally deeper excavations cannot be precluded, and should be anticipated. GSI anticipates that dense Delmar Formation will be exposed at the bottom of the planned excavation for the building. • It should be noted that the 2010 CBC (CBSC, 2010) indicates that removals of unsuitable soils be performed across all areas under the purview of the grading permit, not just within the influence of the proposed building. Relatively deep removals may also· necessitate a special zone of consideration on perimeter/confining areas. This zone would be approximately equal to the depth Chabad at La Costa File:wp12\6300\6304a.gue GeoSoils, Ine. W.O. 6304-A-SC Page Two of removals, if removals cannot be performed onsite or offsite. Thus, any settlement-sensitive improvements (walls, flatwork, etc.), constructed within this zone may require deepened foundations, reinforcement, etc., or will retain some potential for settlement and associated distress. The presence of existing, offsite improvements may limit remedial earthwork along property boundaries. Should unmitigated soils remain within the property boundaries at the conclusion of grading, the potential for settlement-sensitive improvements, constructed within the influence of these soils, to experience settlement-related distress should be anticipated and be properly disclosed to all interested/affected parties. • On a preliminary basis, temporary slopes should conform to CAL-OSHA and/or OSHA requirements for Type "B" soils. Temporary construction slopes, up to a maximum height of +20 feet, may be excavated at a 1 :1 (horizontal to vertical [h:vff gradient, or flatter, provided groundwater and/or running sands are not present. All temporary excavations should be observed by a licensed engineering geologist or geotechnical engineer prior to worker entry. Stockpiled soils and building materials, equipment, etc., should not be located within 'H' of the slope, where 'H' is the height of the slope. • Expansion index (E.I.) testing by HEI (1999) indicates that the near-surface soils exhibit expansion indices ranging between 35 arid 39. GSI testing on soils located near the finish grade of the planned building indicate expansion indices ranging between 21 and 51. Atterberg limits testing by GSI indicates that plasticity indices (P .I.) of these soils are greater than 15. Thus, site soils meet the criteria outlined in Section 1803.5.2 of the 2010 CBC (CBSC, 2010) for expansive soils. In addition, swell pressure testing by GSI indicates that relatively undisturbed sample of claystone, located within approximately 12 feet of pad grade, exerts a swell pressure of 4,000 pounds per square foot (psf). Foundations within the influence of expansive soils should be designed and constructed in accordance with the minimum guidelines presented herein, and as presented in Sections 1808.6.1 or 1808.6.2 of the 2010 CBC. Foundation systems used for the mitigation of expansive soils typically incorporate the Post-Tension Institute (PTI) and/or Wire Reinforcement Institute (WRI) methodologies. Preliminary recommendations for the design and construction of WRI mat foundations are included herein. Final foundation design will be provided at the conclusion of grading, based on the E.I. and P.1. of soils exposed near pad grade. Earthwork mitigation of expansive soils does not appear feasible at this site due to limited space. • Soil pH, saturated resistivity, and soluble sulfate, and chloride testing, performed on samples of site soils collected from our recent subsurface exploration, indicates that the site soils are medium acid to neutral with respect to soil acidity/alkalinity, are severely corrosive to exposed buried metals when saturated, present moderate to severe sulfate exposure to concrete (per Table 4.2.1 of ACI 318-08), and contain non-detectable amounts of soluble chlorides. Soluble sulfate testing performed by HEI (1999) indicates that the tested sample of onsite soils presents severe sulfate Chabad at La Costa File:wp12\6300\6304a.gue GeoSoils, Ine. W.O. 6304-A-SC Page Three • • • exposure to concrete. Therefore, GSI recommends that reinforced concrete mix design conform to "Exposure Class S2" in Table 4.3.1 of ACI 318-08. This implies the use of lype V concrete with a maximum water to cement ratio of 0.45 and a minimum compressive strength of 4,500 pounds per square inch (psi). GSI does not consult in corrosion engineering. Additional comments and recommendations may be obtained from a corrosion engineer based on the required level of corrosion protection for the project, as determined by the structural engineer and/or architect for the project. Groundwater was not encountered in any of the GSI and HEI subsurface explorations performed within the property-. Based on our experience with the neighboring site to the west and north (GSI, 1997), groundwater is generally coincident With Mean Sea Level (MSL) or approximately 37 feet below the lowest planned grade. Our review indicates that regional groundwater should generally not significantly affect site development, based on the available data. However, due to the nature of the site materials, seepage and/or perched groundwater conditions may develop throughout the site in the future, both during and subsequent to development, especially along boundaries of contrasting permeabilities (i.e., clayey and sandy fill lifts, fill/formational contacts, joints/fractures, discontinuities, etc.), and should be anticipated. This potential should be disclosed to all interested/affected parties. Thus, more onerous slab design is necessary for any new slab-on-grade floor (State of California, 201 O}. Recommendations for reducing the amount of water and/or water vapor through slab-on-grade floors are provided in the "Soil Moisture Considerations" sections of this report. It should be noted that these recommendations should be implemented if the transmission of water or water vapor through the slab is undesirable. Should these mitigative measures not be implemented, then the potential for water or vapor to pass through the foundations and slabs and resultant distress cannot be precluded, and would need to be disclosed to all interested/affected parties. Our evaluation indicates that the site currently has a low potential for liquefaction, due to the relatively dense nature of the Delmar Formation that underlies the site at a shallow depth and the depth to the regional water table below existing grade. Our liquefaction evaluation also considers that low-density surficial soils will be removed and re-compacted within the limits of the site and the influence of the new planned building foundations. Settlements (static and seismic) of the building components are not anticipated to be significant based on the anticipated building loads, depth of foundations, and primary supporting earth materials (i.e., Delmar Formation). Some vertical deformation may occur due to: a) settlement of basement wall backfill; b) expansion of earth materials below the basement slab-on-grade; and c) creep or lateral movement of surficial soils on the adjoining property slope that may induce both vertical and horizontal deformations, and influence fills (i.e., backfills) and improvements along the property line. Chabad at La Costa File:wp12\6300\6304a.gue W.O. 6304-A-SC Page Four GeoSoils, Inc. • Excavations into the Delmar Formation ranged from easy to very difficult to the depths explored during our field exploration with a rubber-tire backhoe. Discontinuous, highly cemented concretionary zones were encountered within the sandstone member of the Delmar Formation. This resulted in practical refusal at a depth of approximately 12½ feet below the existing grade. In addition, practical refusal was encountered within the interbedded member of the Delmar Formation at an approximate depth of 15½ feet below the existing grade. Further, 3-sack sand-cement slurry was used to backfill GSI test pits to the approximate bottom-of-footing elevation. However, elevation control was unavailable during placement. To that end, it is possible that the slurry may be encountered slightly above this elevation and require a chipping hammer to excavate the footings properly. The potential for encountering very difficult excavation and the need for specialized excavation equipment (i.e., rock breaker attachment, chipping hammer, etc.) should be considered during project planning and construction. Concretionary zones may generate oversize material, which may require special handling during grading. Excavation equipment should be appropriately sized to facilitate the basement excavation. • The seismic acceleration values and design parameters provided herein should be considered during the design of the proposed development. The adverse effects of seismic shaking on the structure(s) will likely be wall cracks, some foundation/slab distress, and some seismic settlement. This potential should be disclosed to all interested/affected parties. Provided that the recommendations in this report are incorporated into project design arid construction, catastrophic failure is unlikely, and it is anticipated thatthe structure will be repairable in the event of the design seismic event. • Our evaluation indicates there are no known active faults crossing the site. In addition, other than strong seismic shaking produced from an earthquake on a nearby active fault, other geologic hazards have a low potential to affect the proposed site development. • Adverse geologic featu.res that would preclude project feasibility were not encountered. • The recommendations presented in this report should be incorporated into the design and construction considerations of the project. Chabad at La Costa File:wp12\6300\6304a.gue GeoSoils, Inc. W.O. 6304-A-SC Page Five The opportunity to be of service is greatly appreciated. If you have any questions concerning this report, or if we may be of further assistance, please do not hesitate to contact any of the undersigned. Respectfully submitted, RBB/JPF/ATG/jh Distribution: (4) Addressee (1) Chabad at La Costa, Attention: Dr. Michael Galperin (1) Conway and Associates, Inc., Attention: Mr. Michael Pasko (via email) (1) Sun Structural Engineering, Inc., Attention: Mr. Changua Sun (via email) Chabad at La Costa File:wp12\6300\6304a.gue GeoSoils, Inc. W.O. 6304-A-SC Page Six TABLE OF CONTENTS SCOPE OF SERVICES ................................................... 1 SITE DESCRIPTION AND PROPOSED DEVELOPMENT ......................... 1 SUPPLEMENTAL FIELD STUDIES .......................................... 2 PROJECT BACKGROUND ................................................ 2 NEAR-SITE GEOTECHNICAL STUDIES ...................................... 3 DY&A {2005) ...................................................... 3 GSI (1997) ........................................................ 4 Agra (1994a and 1994b) ............................................ 4 REGIONAL GEOLOGY ................................................... 5 SITE GEOLOGIC UNITS .................................................. 5 Artificial Fill -Undocumented (Map Symbol-Afu) ......................... 6 Quaternary Colluvium (Not Mapped) ................................... 6 Tertiary Delmar Formation (Map Symbol -Td) ........................... 6 GEOLOGIC STRUCTURE ................................................. 6 GROUNDWATER ........................................................ 7 MASS WASTING/LANDSLIDE SUSCEPTIBILITY ............................... 8 UPDATED FAULTING AND REGIONAL SEISMICITY ............................ 8 Regional Faults ................ · .................................... 8 Local Faulting ..................................................... 9 Seismicity ........................................................ 9 Deterministic Maximum Credible Site Acceleration .................. 9 Historical Site Acceleration ..................................... 9 Probabilistic Site Acceleration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 O Seismic Shaking Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 o Liquefaction and Seismic Densification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Liquefaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Seismic Densification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Summary ............ · ...................................... 12 Other Geologic/Seismic Hazards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 LABORATORY TESTING ................................................. 13 General ......................................................... 13 Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Moisture-Density Relations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Laboratory Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Expansion Index (E.1.) Testing ....................................... 14 GeoSoils, Inc. Atterberg Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Swell Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Particle-Size Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Shear Testing ........ : ........................................... 15 Unconsolidated, Undrained Triaxial Test (UU, Q) ........................ 15 Saturated Resistivity, pH, and Soluble Sulfates, and Chlorides ............. 15 Corrosion Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 SLOPE STABILITY ANALYSIS ............................................. 16 Gross Stability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Surficial Stability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 ROCK HARDNESS ..................................................... 18 UPDATE PRELIMINARY CONCLUSIONS AND RECOMMENDATIONS ............ 18 EARTHWORK CONSTRUCTION RECOMMENDATIONS ....................... 21 General ......................................................... 21 Demolition/Grubbing .............................................. 22 Remedial Removals (Removal of Potentially Compressible Surficial Materials) 22 temporary Slopes ....................•........................... 22 Er.igineered Fill Placement .......................................... 23 Import Fill Materials ............................................... 23 Excavation Observation (All Excavations) .............................. 23 SHORING DESIGN AND CONSTRUCTION .......... : ....................... 24 Shoring of Excavations ............................................. 24 Shoring ......................................................... 26 Lateral Pressure -Shoring ........................................... 26 Shoring Vertical Bearing ........................................... 27 Shoring Construction Recommendations .............................. 28 Monitoring of Shoring .............................................. 29 Monitoring of Structures ...................................... 30 PRELIMINARY FOUNDATION DESIGN RECOMMENDATIONS .................. 31 General ......................................................... 31 General Foundation Design ......................................... 32 DESIGN OF FOUNDATIONS WITHIN THE INFLUENCE OF EXPANSIVE SOILS USING THE WIRE REINFORCEMENT INSTITUTE (WRI) METHODOLOGY ............. 33 Perimeter Cut-Off Walls ............... , ............................ 34 Foundation Settlement ............................................. 35 POST-TENSIONED FOUNDATIONS ........................................ 35 Chabad at La Costa File:e:\wp12\6300\6304a.gue GeoSoils, Inc. Table of Contents Page ii SOIL MOISTURE TRANSMISSION CONSIDERATIONS ........................ 35 WALL DESIGN PARAMETERS CONSIDERING EXPANSIVE SOILS ............... 38 Conventional Retaining Walls ....................................... 38 Restrained Walls ............................................ 38 Cantilevered Walls ........................................... 38 Earthquake Loads (Seismic Surcharge) ............................... 39 Retaining Wall Backfill and Drainage .................................. 39 Wall/Retaining Wall Footing Transitions ............................... 43 TOP-OF-SLOPE WALLS/FENCES/IMPROVEMENTS AND EXPANSIVE SOILS ...... 44 Expansive Soils and Slope Creep .................................... 44 Top of Slope Walls/Fences ......................................... 44 EXPANSIVE SOILS, DRIVEWAY, FLATWORK, AND OTHER IMPROVEMENTS ...... 45 UTILITIES ............................................................. 47 PRELIMINARY ASPHALTIC CONCRETE PAVEMENT DESIGN ................... 48 Alternative Pavement Designs ....................................... 48 Pavement Grading Recommendations ................................ 48 General ................................................... 48 Subgrade .................................................. 49 Aggregate Base ............................................. 49 Paving .................................................... 49 Drainage ................................................... 50 DEVELOPMENT CRITERIA ............................................... 50 Drainage ........................................................ 50 Erosion Control ................................................... 51 Landscape Maintenance ........................................... 51 Gutters and Downspouts ........................................... 51 Subsurface and Surface Water ...................................... 51 Site Improvements ................................................ 52 Tile Flooring ..................................................... 52 Additional Grading ........................ : ....................... 52 Footing Trench Excavation ......................................... 52· Trenching/Temporary Construction Backcuts .......................... 53 Utility Trench Backfill .............................................. 53 SUMMARY OF RECOMMENDATIONS REGARDINq GEOTECHNICAL OBSERVATION AND TESTING ........................................................ 54 OTHER DESIGN PROFESSIONALS/CONSULTANTS .......................... 54 Chabad at La Costa File:e:\wp12\6300\6304a.gue GeoSoils, Ine. Table of Contents Page iii PLAN REVIEW ............................ .' ............................ 55 LIMITATIONS .......................................................... 56 FIGURES: Figure 1 -Lateral Earth Pressures for Temporary Shoring Systems ......... 25 Detail 1 -Typical Retaining Wall Backfill and Drainage Detail .............. 40 Detail 2 -Retaining Wall Backfill and Subdrain Detail Geotextile Drain ....... 41 Detail 3 -Retaining Wall and Subdrain Detail Clean Sand Backfill ........... 42 ATTACHMENTS: Appendix A -References ................................... Rear of Text Appendix B -Exploration Logs .............................. Rear of Text Appendix C -EQFAULT, EQSEARCH, and PHGA ............... Rear of Text Appendix D -Laboratory Test Results ......................... Rear of Text Appendix E -Slope Stability Analysis ......................... Rear of Text Appendix F -General Earthwork and Grading Guidelines ......... Rear of Text Plate 1 -Geotechnical Map ................................. Rear of Text Plate 2-Geologic Cross Sections .................... Rear of Text in Folder Chabad at La Costa File:e:\wp12\6300\6304a,gue GeoSoils, lne. Table of Contents Page iv GEOTECHNICAL UPDATE EVALUATION PROPOSED JEWISH COMMUNITY COMPLEX 1980 LA COSTA AVENUE CARLSBAD, SAN DIEGO COUNTY, CALIFORNIA SCOPE OF SERVICES The scope of our services has included the following: 1. Review of available soils and geologic data for the site, including previous onsite and near-site geotechnical investigation reports (see Appendix A). 2. Site reconnaissance and supplemental subsurface exploration with two (2) exploratory test pit excavations and two (2) borings (see Appendix 8). 3. Updated general areal seismicity evaluation (see Appendix C). 4. Laboratory testing of soil samples collected during the subsurface exploration program (Appendix D). 5. Engineering and .geologic analysis of data collected, including slope stability. 6. Preparation of this report and accompaniments. SITE DESCRIPTION AND PROPOSED DEVELOPMENT The subject site is generally in the same condition as reported in HEI (1999) with the exception of recent modifications to the slope that descends from the property to the west and north as a result of grading on those properties. Currently, portions of this slope are being retained by retaining walls Based on a review of KP&D (2011) and C&A (2011), proposed site development includes removing the existing building, sheds, and parking lot, and preparing the site for the construction of a new two-story Jewish Community Complex with associated asphaltic concrete (AC) parking lot and driveway, Portland Cement Concrete (PCC) walkv.,:ays and staircases, and retaining walls. The proposed building will incorporate one below-grade floor level with a main floor level above. C&A (2011) indicates that the design grades will primarily be achieved by excavations on the order of 7 to 11 feet. Minor fills on the order of 3 feet or less will also be necessary. Onsite storm water will be collected into underground drainage pipes that discharge into a bio-retention planter prior to its introduction into the municipal system. Permanent graded slopes up to approximately 1 foot in overall height are planned to accommodate grade differentials. Other grade differentials will be provided by the construction of retaining walls with overall heights ranging between approximately 4 and 1 o feet. GeoSoils, Ine. SUPPLEMENTAL FIELD STUDIES GSI performed supplemental field studies on September19, 2011 and November 4, 2011. Field studies consisted of geologic mapping and excavating two exploratory test pits within the site to observe the near-surface geologic conditions and record the orientation of geologic structure (i.e., bedding, fractures, etc.) within the bedrock materials. In addition, two exploratory hollow-stem borings were advanced within the site to further evaluate the geologic profile, and to collect representative bulk and undisturbed samples of the onsite soils for laboratory testing. The test pits and borings were logged by a geologist from this firm. The logs of the borings are presented in Appendix 8. The approximate locations of the test pits and borings are shown on Plate 1, which uses C&A (2011) as a base. PROJECT BACKGROUND Beginning in 1999, HEI conducted a geotechnical investigation at the site for a then-proposed two-story Synagogue and associated parking lot (HEI, 1999). For that study, HEI advanced three hollow-stem auger borings to depths ranging between approximately 7 and 21 feet below the existing grade. HEI also performed laboratory testing on samples of soil collected during the subsurface exploration. HEl's evaluation regarding the stability of the slope descending from the site was based on data provided in Agra (1994b). Based on their subsurface exploration, laboratory testing, and engineering reviews and analyses, HEI concluded that the project was feasible from a geotechnical standpoint provided thatthe grading and foundation plans accounted for the appropriate geotechnical features of the site. The HEI (1999) boring locations are indicated on Plate 1. In 201 o, HEI performed a geotechnical update evaluation and a percolation study for a then.,.proposed modular sanctuary/office structure, covered patio and atrium, modular restroom structure, and driveway/parking area at the site. For the update evaluation (HEI, 201 0a), HEI advanced and down-hole logged one large diameter boring, and performed updated seismicity and slope stability evaluations. Based on their subsurface data and engineering evaluations, HEI concluded that: 1) the descending slope on the north and west sides of the property is grossly stable due to favorable geologic structure but may be subject to surficial slumping; and 2} the analyzed development concept was feasible from a geotechnical standpoint, provided that the grading and foundation plans accounted for the appropriate geotechnical features of the site. The location of the HEI (201 0a) boring is also indicated on Plate 1. The HEI percolation study (HEI, 2010b) was performed to provide the project civil consultant the percolation rates of sandstone bedrock materials, which underlie the site at a shallow depth, for the design of storm water best management practices. For their percolation study, HEI excavated and logged four test pits. HEI then used these test pits to evaluate percolation rates in accordance with County of San Diego Department of Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, lne. - W.O. 6304-A-SC December 15, 2011 Page2 Environmental Health standards. Based on their testing, HEI concluded that the percolation rate of the sandstone materials varied between 53 and 480 minutes per inch. The locations of the HEI (201 Ob) test pits are shown on Plate 1. In late September 2011, GSI provided observation and compaction testing during the backfill of a trench created for the repair of a failed sewer lateral servicing the existing building (GSI, 2011). The services GSI provided during trench backfill included observations during the placement of 3-sack sand-cement slurry to the approximate bottom of footing elevation for the proposed Synagogue and compaction testing on native backfill materials where the trench crossed the adjoining, westerly property. NEAR-SITE GEOTECHNICAL STUDIES DY&A (2005) In 2005 DY&A performed a geotechnical investigation for a then-proposed 4,000 square foot commercial building and associated retaining walls (DY&A, 2005) on the adjoining property to the west of the subject property. For their investigation, DY&A advanced three borings and excavated two test.pits. The borings ranged in depth between approximately 21 and 26 feet. The test pits were excavated to depths on the order of 5 to 7 feet. Within subsurface explorations, DY&A encountered existing fills up to 11 feet thick and alluvium on the order of 4 to 6 feet thick. DY&A reported that the Torrey Sandstone Formation was observed in their Test Pit TP-1. However, given the location of this test pit and regional mapping by Kennedy and Tan (2005), it is GSl's opinion that DY&A mistook the sandstone facies of the Delmar Formation for the Torrey Sandstone. DY&Aalso encountered siltstone and claystone belonging to the Santiago Formation in their borings. Again, based on our review of Tan and Kennedy (2005), it is GSl's opinion that DY&A incorrectly mapped the Delmar Formation as the Santiago Formation. DY&A did not encounter groundwater in their subsurface explorations to the depths explored As part of their investigation DY&A evaluated the gross stability of the west-facing slope that ascends from the site toward 1980 La Costa Avenue. Based on their analysis, the slope had gross factors of safety greater than 1.5 (static) and 1.1 (seismic). However, their analysis only evaluated the presence of rotational failure planes and did not consider the geologic structure within the underlying sedimentary rocks. Based on their analysis, DY&A concluded that the commercial site was suitable for the proposed development. DY&A regarded undocumented fills as the primary geotechnical concern with respect to site development. Chabad at La Costa 1980 La 'Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, Inc. W.O. 6304-A-SC December 15, 2011 Page3 GSI (1997) In 1997, GSI performed a preliminary geotechnical investigation for then-proposed commercial development located north and east of the subject site on a partially developed commercial property. For this investigation, GSI performed geologic reconnaissance mapping and advanced 14 hollow-stem borings. During the field investigation, GSI encountered undocumented fill on the order of 7 to 25 feet thick, existing fill placed during previous grading of a pre-existing shopping center, alluvial sediments with thicknesses estimated up to 150 feet, and interbedded sandstone, siltstone, and claystone belon_ging to the Delmar Formation. Groundwater was logged in the GSI borings at depths ranging between 11 and 26 feet below pre-existing grades. GSI evaluated the potential for the site to be adversely affected by geologic hazards including mass wasting, surface fault rupture, and subsidence. In addition, owing to soft soil conditions at the site, GSI evaluated secondary seismic hazards such as liquefaction/lateral spread susceptibility, ground surface amplification, and dynamic settlement. GSI also evaluated the potential for other secondary seismic hazards, including ground surface amplification, tsunami and seiche to affect the site. Based on our subsurface studies, laboratory testing, and geotechnical engineering analysis, GSI concluded that the then-proposed commercial development was feasible from a geotechnical engineering and geologic viewpoint, provided our recommendations were properly incorporated into the design and construction phases of site development. Agra (1994a and 1994b) Beginning in early 1994, Agra performed a geotechnical investigation within the neighboring Leucadia Wastewater District property (previously referred to as the Gafner Water Reclamation Plant). The purpose of that investigation (Agra, 1994b) was to evaluate the general soil and rock conditions at the site for the design of a then-proposed building foundation, andto develop design alternatives for remedial earthwork or other construction to ensure gross and surficial stability of the slope that ascends toward 1980 La Costa Avenue (Chabad at La Costa site). As part of their investigation, Agra down-hole logged two 30-inch diameter borings advanced to depths of 16 feet below pre-existing grades (Agra Boring B-1) and 36 feet below existing grades (Agra Boring 8-2). Agra also performed laboratory testing of relatively undisturbed and bulk soil samples collected during the subsurface exploration. Based on their geotechnical engineering and geologic analyses of the subsurface data and laboratory testing, Agra concluded that the slope was stable with respect to gross stability, owing to the absence of adversely oriented bedding or other planes of weakness in their Boring B-2. However, Agra surmised that the slope was susceptible to surficial instability as a result of the slope's steepness and the erosive nature of residual soils that mantle the slope. Agra also concluded that the then-proposed building could be supported on shallow foundations bearing on approved formational materials. Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, lne. W.O. 6304-A-SC December 15, 2011 Page4 In order to mitigate surficial slope instability, Agra recommended either stripping vegetation, loose soils, and weathered rock from the slope and covering the slope with reinforced gunite and other mitigation scenarios, including the construction of one to two retaining walls combined with laying-back the slope to a 2:1 (h:v) gradient. Agra also recommended covering a portion of the slope with Loffelstein blocks in one of their recommended wall and slope reconstruction plans. r In September 1994, Agra performed geotechnical observations and compaction testing services during the construction of an approximately 11-foot high geogrid-reinforced Keystone retaining wall and slope reconstruction used to remediate the surficiallyunstable slope at the site (Agra, 1994a). Based on the field observations and soil compaction testing, Agra concluded that the wall and slope construction was performed in general accordance with their recommendations. REGIONAL GEOLOGY The subject property is located within a prominent natural geomorphic province in southwestern California known as the Peninsular Ranges. It is characterized by steep, elongated mountain ranges and valleys that trend northwesterly. The mountain ranges are underlain by basement rocks consisting of pre-Cretaceous metasedimentary rocks, Jurassic metavolcanic rocks, and Cretaceous plutonic rocks of the southern California batholith. In the San Diego County region, deposition occurred during the Cretaceous Period and Cenozoic Era in the continental margin of a forearc basin. Sediments, derived from Cretaceous-age plutonic rocks and Jurassic-age volcanic rocks, were deposited into the narrow, steep, coastal plain and continental margin of the basin. These rocks have been uplifted, eroded, and deeply incised. During early Pleistocene time, a broad coastal plain was developed. During mid-to late-Pleistocene time, this plain was uplifted, eroded, and incised. Alluvial deposits have since filled the lower valleys, and young marine sediments are currently being deposited/eroded within coastal and beach areas. Regional mapping by Tan and Kennedy (2005) indicate that the site is underlain by Tertiary-age sedimentary rock belonging to the Delmar Formation. SITE GEOLOGIC UNITS The geologic units encountered during this and the HEI investigations consisted of undocumented artificial fill, Quaternary colluvium (topsoil), and Tertiary-age sedimentary rocks belonging to the Delmar Formation. These units are further described below. The distribution of these units across the site are the shown on Plate 1. Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, Ine. W.O. 6304-A-SC December 15, 2011 Pages Artificial Fill -Undocumented (Map Symbol-Afu) Artificial fill was locally encountered at the surface near the top of the west-facing slope, near La Costa Avenue, and within the existing parking lot. The fill generally consisted of medium brown, olive gray, and gray clayey sand with local silt; olive gray, yellowish brown, dark brown, and light brown silty sand; yellowish brown and gray clayey sand, and olive gray clayey silt. The fill was generally dry to moist and loose/soft to dense. The thickness of the fill varied between½ foot to 4½ feet thick, with the thicker section of fill occurring near the western margin of the property. Quaternary Colluvium (Not Mapped) GSI observed colluvium underlying the fill soils in our Test Pit TP-1 and our Boring B-2. The colluvium consisted of dark gray silty sand and gray clayey sand that was dry to moist, and loose. Where observed, the thickness of the colluvium was approximately ¼ foot to 1 ½ feet thick. Tertiary Delmar Formation (Map Symbol -Td) The Tertiary Delmar Formation was observed underlying the fill and/or colluvium in the HEI and GSI subsurface explorations. In the upper 15½ to 24 feet of the borings and test pits, the Delmar Formation primarily consisted of fining upward sequences of light tan, olive gray, olive brown, light gray, light brown, white, buff, and gray silty to clayey fine-to coarse-grained sandstone. The sandstone was observed to interfinger with siltstone and claystone in HEI (2010) Boring B-4 at a depth of 8½ feet. In addition, the sandstone contained reddish yellow and yellowish orange iron-oxide stained topset, forset, and bottom set beds that were approximately ¼-inch or less in thickness. Below depths ranging from approximately 15.½ to 24 feet, the Delmar Formation abruptly transitions into a light gray, olive gray, gray, and reddish yellow sandy siltstone/sandy claystone and a greenish gray, gray brown, and gray claystone. These finer-grained rocks were generally damp to moist and hard. Concretions (well cemented zones), also occur in the Delmar Formation. Where explored, the Delmar Formation was generally moist, well consolidated, and moderately cemented. However, as exposed in the GSI test pits and borings, the upper ± 1 foot to ± 1 ¼ feet of the Delmar Formation was slightly to moderately weathered, and generally not as consolidated as the underlying, unweathered materials. GEOLOGIC STRUCTURE Regional geologic mapping by Tan and Kennedy (1996) indicate Delmar Formation bedding dips to the northwest at 5 degrees. However, as exposed in GSI Test Pit TP-1 bedding within the sandstone portion of the Delmar Formation is gently to moderately inclined from 1 0 to 25 degrees in a westerly direction. Delmar Formatidn sandstone Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304ague GeoSoils, Inc. W.O. 6304-A-SC December 15, 2011 Page6 bedding exposed in GSI Test Pit TP-2 generally dips 13 to 15 degrees in a southerly direction. Agra (1994b} indicated that Delmar Formation sandstone bedding exposed in their Boring B-2 is gently to moderately inclined from 11 to 17 degrees in a southerly direction. The variation in sandstone bedding orientation between subsurface explorations is likely attributed to cross bedding or broad small amplitude folding. HEI (201 Oa) indicated Delmar Formation claystone bedding dips 29 degrees in a southerly direction in their Boring 8-4. HEI (201 Oa} indicated that the contact between the sandstone and interbedded members of the Delmar Formation (see Plate 2} is gently inclined to the north at 8 degrees. Whereas, Agra (l994b) indicated that this contact dips to the southwest at 1 O degrees. The variation in dip is likely the result of channel scour within paleo-tidal channels or broad small amplitude folding. Kennedy and Tan (2005) indicate a zone of relatively short faults southeast of the subject site. These old faults generally trend northeast,.southwest and dip 60 degrees in a northwesterly direction. GROUNDWATER Groundwater was not encountered in the GSI and HEI subsurface explorations to the depths explored. As indicated in GSI (1997), the elevation of the regional groundwater table is generally coincident with Mean Sea Level (MSL) or approximately 46 feet below the lowest site elevation. In general, our review indicates that regional groundwater should not significantly affect site development, based on the available data. However, it is possible that perched water may occur at shallower depths in the future, ~specially along boundaries of contrasting permeabilities (i.e., clayey and sandy fill lifts, fill/Delmar Formation contacts, sandstone/claystone contacts, joints/fractures [discontinuities], etc.), and should be anticipated. Due to the scoured and undulatory nature of the contact between the more permeable sandstone and less permeable claystone members of the Delmar Formation, it is possible that perched water may migrate where the contact is more deeply incised. The potential for the occurrence of perched water should be disclosed to all interested/affected parties. Should shallower perched water conditions manifest in the future, this office could provide recommendations for mitigation. Typical geotechnical mitigation may include the installation of subdrains and moisture cut-off barriers. Because of the presence of low permeable formational materials, there is a potential for perched water conditions to develop at the site, more onerous slab design is necessary for new slab-on-grade floors (State of California, 2011). Recommendations for reducing the amount of water and/or water vapor through slab-on-grade floors are provided in the "Soil Moisture Considerations" sections of this report. Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, Ine. W.O. 6304-A-SC December 15, 2011 Page? MASS WASTING/LANDSLIDE SUSCEPTIBILITY Mass wasting refers to the various processes by which earth materials are moved down slope in response to the force of gravity. Examples of these processes include slope creep, surficial failures, rockfalls, and deep-seated landslides. Creep is the slowest form of mass wasting and generally involves the outer 5 to 1 o feet of the slope surface. During heavy rains, such as those experienced in 1969, 1978, and 1980, 1983, 1993, 1998, 2004/2005, 2007/2008, and 2010, creep-affected materials may become saturated, resulting in a more rapid form of down slope movement (i.e., landslides and/or surficial slope failures). According to regional landslide susceptibility mapping by Tan and Giffen (1995), the site is located within landslide susceptibility Subarea 4-1 which is characterized as being 11most susceptible11 to landsliding. This designation was likely assigned to this area because the hillside upon which the site is located is relatively steep and is generally comprised of relatively weak sedimentary rocks. In addition, this hillside has experienced numerous slope failures in the past. Recently, a large-scale hillside stabilization project was performed in conjunction with grading for a proposed condominium development located approximately½ mile east of the subject site. Further, Agra (1994b) reported numerous surficial slope failure occurring along the slope that descends from the site toward 1960 La Costa Avenue (Leucadia Wastewater District) prior to mitigation construction along the portion of the slope they investigated. Owing to the site location and as required by code, GSI performed slope stability analyses of the descending westerly slope, and the existing and planned graded configurations. The results of our analyses are summarized herein. UPDATED FAULTING AND REGIONAL SEISMICITY Regional .Faults Our review indicates that there are no known active faults crossing this site, and the site is not within an Alquist-Priolo Earthquake Fault Zone (Bryant and Hart, 2007). However, the site is situated in a region of active faulting. These faults include, but are not limited to: the San Andreas fault; the San Jacinto fault; the Elsinore fault; the Coronado Bank fault zone; and the Newport-Inglewood -Rose Canyon fault zone (NIRCFZ). Portions of the nearby NIRCFZ are located in an Alquist-Priolo Earthquake Fault Zone (Bryant and Hart, 2007). The location of these, and other major faults relative to the site, are indicated in Appendix C (California Fault Map). The possibility of ground acceleration, or shaking at the site, may be considered as approximately similar to the southern California region as a whole. Major active fault zones that may have a significant affect on the site, should they experience activity, are listed in Appendix C (modified from Blake, 2000a). According to Blake {2000a), the closest known active fault to the site is the Rose Canyon fault which is approximately 5.7 miles (9.2 kilometers) away. Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, lne. W.O. 6304-A-SC December 15, 2011 Pages Local Faulting No local faulting was observed to transect the site during the HEI and our field investigations. Additionally, a review of available regional geologic maps does not indicate the presence of local faults crossing the site. As previously indicated, Kennedy and Tan (2005) have mapped a zone of relatively short, northeast-:s6uthwest trending faults to the southeast of the site. This zone is likely associated with a system of relatively short northerly/northeasterly trending faults that locally occur within the region. These faults are characteristic of extensional faulting between right-stepping, right-lateral faults. GSI is unaware of any documentation indicating that these faults offset Holocene (last + 11,000 years) sediments. Therefore, these faults are likely not active (i.e., movement in Holocene time) based on State of California criteria. Seismicity Deterministic Maximum Credible Site Acceleration The acceleration-attenuation relation of Bozorgnia, Campbell, and Niazi (1999)has been incorporated into EQFAULT (Blake, 2000a). EQFAULT is a computer program developed by Thomas F. Blake (2000a), which performs deterministic seismic hazard analyses using digitized California faults as earthquake sources. The program estimates the closest distance between each fault and a given site. If a fault is found to be within a user-selected radius, the program estimates peak horizontal ground acceleration that may occur at the site from an upper bound ("maximum credible") earthquake on that fault. Site acceleration (g) was computed by one user-selected acceleration-attenuation relation that is contained in EQFAULT. Based on the EQFAUL T program, a peak horizontal ground acceleration from an upper bound event at the site may be oh the order of 0.58 g. The computer printouts of . pertinent portions of the EQFAUL T program are included within Appendix C. Historical Site Acceleration Historical site seismicity was evaluated with the acceleration-attenuation relation of Bozorgnia, Campbell, and Niazi {1999), and the computer program EQSEARCH (Blake, 2000b, updated to December 2010). This program performs a search of the historical earthquake records for magnitude 5.0 to 9.0 seismic events within a 1 DO-kilometer radius, between the years 1800 through December 2010. Based on the selected acceleration-attenuation relationship, a peak horizontal ground acceleration is estimated, which may have effected the site during the specific event listed. Based on the available data and the attenuation relationship used, the estimated maximum (peak) site acceleration during the period 1800 through December 2010 was 0.40 g. A historic earthquake epicenter map and a seismic recurrence curve are also estimated/generated Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, Inc. W.O. 6304-A-SC December 15, 2011 Page9 from the historical data. Computer printouts of the EQSEARCH program are presented in AppendixC. Probabilistic Site Acceleration A probabilistic seismic hazards analysis was performed using 2008 Interactive Deaggregations {20l0 Beta) Seismic Hazard Analysis tool available at the USGS website (https://geohazards.usgs.gov/deaggnit/2008/) which evaluates the site specific probabilities of exceedance for selected spectral periods. Based on a review of these data, and considering the relative seismic activity of the southern California region as a whole, a probabilistic seismic hazard assessment is presented herein. Printouts from this analysis are included in Appendix C. Seismic Shaking Parameters Based on the site conditions, the following table summarizes the site-specific design criteria obtained from the 2010 CBC (CBSC, 2010), Chapter 16 Structural Design, Section 1613, Earthquake Loads. The computer program Seismic Hazard Curves and Uniform Hazard Response Spectra, provided by the United States Geologic Survey ([U.S.G.S.], 2011) was utilized for design. The short spectral response utilizes a period of 0.2 seconds. Site Class C Table 1613.5.2 Spectral Response -(0.2 sec), S5 1.193g Figure 1613.5(3) Spectral Response -(1 sec), S, 0.449g Figure 1613.5(4) Site Coefficient, Fa 1.0 Table 1613.5.3(1) Site Coefficient, Fv 1.351 Table 1613.5.3(2) Maximum Considered Earthquake Spectral 1.193g Section 1613.5.3 Response Acceleration (0.2 sec), SMs (Eqn 16-37) Maximum Considered Earthquake Spectral 0.606g Section 1613.5.3 Response Acceleration (1 sec), SM, (Eqn 16-38) 5% Damped Design Spectral Response 0.796g Section 1613.5.4 Acceleration (0.2 sec), S05 (Eqn 16-39) 5% Damped Design Spectral Response 0_4049 Section 1613.5.4 Acceleration (1 sec), S01 (Eqn 16-40) Distance to Seismic Source (Rose Canyon fault) from Blake {2000a) Upper Bound Earthquake (Rose Canyon fault) Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, Inc. 5.7 mi. (9.2 km) W.O. 6304-A-SC December 15, 2011 Page 10 I;.>. :-,. ,-;,;.;_: :,,:·:·: .. :<:,,: __ , ·-<·-'-:GENERALsetsMiC-DESIGN i>ARAMEtERS' ·:: -: ··:· -:i, '---. · -~-:·~:I---~<..·~-:·-,',',{,,, ... -:•,:,·-' ,..,t',<_,:..,_~,-.. ..... ,.,,--·:"' , '. ,,, ' ,,~ < ,' ~-·'.-· •• ,' ~· -··· ,".,.• •• " I Probabilistic Horizontal Site Acceleration 0.44g ([PHSA] 2% probability of exceedance in 50 years) Probabilistic Horizontal Site Acceleration _, 0.23g ([PHSA] 10% probability of exceedance in 50 years) (1) -International Conference of Building Officials (ICBO, 1998) <2> -Cao, et al. (2003) Conformance to the criteria above for seismic design does not constitute any kind of guarantee or assurance that significant structural damage or ground failure will not occur in the event of a large earthquake. The primary goal of seismic design is to protect life, not to eliminate all damage, since such design may be economically prohibitive. Cumulative effects of seismic events are not addressed in the 2010 CBC (CBSC, 2010) and regular maintenance and repair following locally significant seismic events (i.e., Mw5.0) will likely be necessary. Liquefaction and Seismic Densification Liquefaction Liquefaction describes a phenomenon in which cyclic stresses, produced by earthquake-induced ground motion, create excess pore pressures in relatively cohesionless soils. These soils may thereby acquire a high degree of mobility, which can lead to vertical deformation, lateral movement, lurching, sliding, and as a result of seismic loading, volumetric strain and manifestation in surface settlement of loose sediments, sand boils and other damaging lateral deformations. This phenomenon occurs only below the water table, but after liquefaction has developed, it can propagate upward into overlying non-saturated soil as excess pore water dissipates. One of the primary factors controlling the potential for liquefaction is depth to groundwater. Typically, liquefaction has a relatively low potential at depths greater than 50 feet and is unlikely and/or will produce vertical strains well below 1 percent for depths below 60 feet when relative densities are 40 to 60 percent and effective overburden pressures are two or more atmospheres (i.e., 4,232 psf [Seed, 2005]). The condition of liquefaction has two principal effects. One is the consolidation of loose sediments with resultant settlement of the ground surface. The other effect is lateral sliding. Significant permanent lateral movement generally occurs only when there is significant differential loading, such as fill or natural ground slopes within susceptible materials. No such loading conditions exist at the site. Liquefaction susceptibility is related to numerous factors and the following five conditions should be concurrently present for liquefaction to occur: 1) sediments must be relatively Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, Inc. W.O. 6304-A-SC December 15, 2011 Page 11 young in age and not have developed a large amount of cementation; 2) sediments must generally consist of medium-to fine-grained, relatively cohesionless sands; 3) the sediments must have low relative density; 4) free groundwater must be present in the sediment; and 5) the site must experience a seismic event of a sufficient duration and magnitude, to induce straining of soil particles. Our evaluation indicates that only one of these conditions has the potential to affect the site. Seismic Densification Seismic densification is a phenomenon that typically occurs in low relative density granular soils (i.e., Unified Soil Classifications [Sowers and Sowers, 1979] SW, SP, SM, and SC) that are above the groundwater table. These unsaturated granular soils are susceptible if left in the original density (unmitigated), and are generally dry of the optimum water content (as defined by the ASTM D 1557). During seismic induced ground shaking, these natural or artificial soils deform under loading and volumetrically strain, potentially resulting in ground surface settlements. Some densification of the adjoining un-mitigated properties may influence improvements at the perimeter of the site. Special setbacks and/or foundations may be utilized if significant structures/improvements are placed close to the perimeter of the site. Our evaluation assumed that the current conditions will not be significantly modified by future grading at the time of the design earthquake, which is a reasonably conservative assumption. Some seismic densification of the backfill for the building basement walls will likely occur if low expansive select backfill is used. The settlement will be of low magnitude due to the lateral confinement and the thickness of the planned backfill (i.e., less than 12 feet) Summary It is the opinion of GSI that the susceptibility of the site to experience damaging deformations from seismically-induced liquefaction and densification is relatively low owing to the dense nature of the Delmar Formation that underlies the site in the near-surface, and the depth to regional groundwater. In addition, the recommended removal and re-compaction of low-density surficial soils (i.e., undocumented fill, colluvium, and weathered Delmar Formation) would further reduce any significant liquefaction/densification potential. Some seismic densification of the adjoining un- mitigated site(s) may adversely influence planned improvements at the perimeter of the site. However, given the remedial earthwork and foundation recommendations provided herein, the potential for the planned building to be affected by offsite seismic densification may b-e considered low. The backfill settlement may be reduced by compacting the basement wall backfill in relatively thin lifts to a compaction standard greater than 90 percent of the laboratory standard (ASTM D 1557). Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, Inc. W.O. 6304-A-SC December 15, 2011 Page 12 Other Geologic/Seismic Hazards The following list includes. other geologic/seismic related hazards that have been considered during our evaluation of the site. The hazards listed are considered negligible and/or mitigated as a result of site location, soil characteristics, and typical site development procedures: • Surface Fault Rupture • Ground Lurching or Shallow Ground Rupture • Subsidence Due to Tectonism or Groundwater Withdrawal • Tsunami • Seiche • Densification/Settlement of Basement Wall Backfill It is important to keep in perspective that in the event of an upper bound (maximum credible) earthquake occurring on any of the nearby major faults, strong ground shaking would occur in the subject site's general area. Potential damage to any structure(s) would likely be greatest from the vibrations and impelling force caused by the inertia of a structure's mass than from those induced by the hazards considered above. Following implementation of remedial earthwork and design of foundations described herein, this potential would be no greater than that for other existing structures and improvements in the immediate vicinity that comply with current and adopted building standards. LABORATORY TESTING General Laboratory tests were performed on representative bulk and relatively undisturbed soil samples collected from the subsurface explorations. The laboratory test procedures and results are summarized in the following sections. Classification Soils were classified visually according to the Unified Soils Classification System (Sowers and Sowers, 1979). The soil classifications are shown on the Boring and Test Pit Logs in AppendixB. Moisture-Density Relations The field moisture contents and dry unit weights were evaluated for selected relatively undisturbed samples in the laboratory. Testing was performed in general accordance with ASTM D 2937. The dry unit weight was determined in pounds per cubic foot (pcf), and the field moisture content was determined as a percer)tage of the dry weight. The results of these tests are shown on the Boring and Test Pit Logs in Appendix B. Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, lne. W.O. 6304-A-SC December 15, 2011 Page 13 Laboratory Standard The maximum density and optimum moisture content was evaluated for a composite bulk soil sample in general accordance with ASTM D 1557. The moisture-density relationships obtained for this soil is shown on the following table: ·;sA:MPLE:toc'AtJoN\. \,.,-:::;,~_:i~:::;: · ... ,_·!;i'.'-:: .. ,,.·t:,::?f-i,}::/-:}. ::-::;;\::MAXiMtiM\{;:{;: t · J.,optiMUNl:'MOlSTURE·:-> ,'."· .. v •. :N·"'·o··" 'o· 'e''p·.,.,r···H· • 1·~-~ ,:c,_,,., '.·-·:,'.,' .,.._ ·,.SOIL:TYRE·,::,,:-' t,:-:·,.: .. , :. ·,: ·o':'·e· ,·.N°'s-1~r' ;p-·"',:.:,..;l.\:: .::. ·,, · -i'/ · ·,-:c· o·.N ... ,T ... e' N ... T. ·-ioA--~· _;; · ,;.: :·> · .#'\ ~: · . ~ -:tr. ,fJ :.~-. :·;;::: 1>·u <·----:. : ':J_::_,·-:·'-:;/• ?:: :_~-; ,-.;--'..';'..:.;.'_ --~ ~· \. ,"'·: 1:1· 1 ~-., 1 ... ,.;,,17.1,,;f__,. -:,.· -; :Y,',~~.\: , ·· ]1101; : .. ~ ~ ,...,.--:.·· .. TP-1 @0-15' CLAYEY SAND, Liqht Yellowish Grav Expansion Index (E.I.) Testing 121.5 12.0 Expansion Index (E.I.) testing was performed on a representative bulk soil samples in general accordance with ASTM D 4829, and were classified according to Table 18-I-B, as outlined in Section 1803 of the 2001 California Building Code ([2001 CBC], International Conference of Building Officials [ICBO], 2001). Please note the current 201 o CBC (CBSC, 201 O) does not classify an expansion potential index and as such, we have utilized these previous standards only to characterize the expansion potential of this material. The laboratory test results are presented in the following table. ;\'.~E:tl~~i~i1~ti~~tlt~~)_;: ~::;f?ft~,K~~~~~Jitt~ )JR~itiiij~~~i~~~ t}'.J~t~Sll~~\;_:_·:. TP-2 @ 10-1 O½' CLAYEY SAND 21 Low B-2 c@ 16-18' SANDY CLAY 51 Medium * -Per Table 18-1-B of the 2001 CBC (International Conference of Buildina Officials, 2001) Atterberg Limits Tests were performed on a representative fine-grained, soil sample to evaluate the liquid limit, plastic limit, and plasticity index (P.I.) in general accordance with ASTM D 4318. Test results are presented in the following table. TP-2@ 10-10½' I B-2@ 16-18' Chabad at La Costa · 1980 La Costa Avenue, Carlsbad File:e:\wp 12\6300\6304a.gue 34 47 GeoSoils, lne. 17 17 17 30 W.O. 6304-A-SC December 15, 2011 Page 14 Swell Pressure Swell pressure testing was performed on a relatively undisturbed soil sample of sandy claystone (B-2 @ 20 feet) in general accordance with ASlM D 4545 (Method A). Testing indicates the swell pressure of the tested sample is 4,000 psf. Particle-Size Analysis An evaluation was performed on a representative, bulk soil sample in general accordance with ASTM D 422-63. The grain-size distribution curve is presented in Appendix D. The testing was utilized to evaluate the soil classification in accordance with the Unified Soil Classification System (USCS). The results of the particle-size analysis indicate that the tested soil is a clayey sand (SC). Shear Testing Shear testing was performed on representative, undisturbed samples of site soil in general accordance with ASTM D 3080 in a direct shear machine of the strain control type. Test results are presented in Appendix D. Unconsolidated. Undrained Triaxial Test (UU, Q) Unconsolidated, undrained triaxial testing was performed on a relatively undisturbed soil sample in general accordance with ASTM D 2850 to evaluate the ultimate undrained shear strength. The results of this test are included in Appendix D. Saturated Resistivity, pH, and Soluble Sulfates, and Chlorides GSI conducted sampling of onsite earth materials for general soil corrosivity and soluble sulfates, and chlorides testing. The testing included evaluation of soil pH, soluble sulfates, chlorides, and saturated resistivity. Test results are presented in Appendix D and the following table: Chabad at La Co~ta 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, Ine. W.O. 6304-A-SC December 15, 2011 Page 15 :· ,:s1i~DfU,-fitid~-i'..:-~ ~r~·:\':'~. \r:~AtVa4r,~ttr~.{: (f }··\~9tv:~1~,t~? i: f'_: ):\~i?i,t1J:i~§<t:;.:".': ;,:·,;, ANffDEPlii-icrn -,_' --, ·i pH,;~ 0', ,; \:'RESISTIVIT:Yi r--_,,, ,',"':;Y,'.:.;&UlF.ATES{i/ , . ' ~.,,.,,·CHLORIDES/,:,,';' :\.):,_,.~::---'.,.:-0=-,:::_,r::,, r~, __ ~.t/::/_· ?!: i-·• /}:~/:,(Qhm°~Smt//~), \:·1_;,}%?ffy~'.~ilgttit?:.f--·-:,:;i;+:::;.-cfu~/R~>t) _ >) TP-2 @ 10 -1,0½' 6.0 660 0.160 ND* B-1 @25-27' 7.12 235 Q.580 123 Corrosion Summary Laboratory testing indicates that the site soils are medium acid to neutral with respect to soil acidity/alkalinity, are severely corrosive to exposed, butied metals when saturated, present moderate to severe sulfate exposure to concrete, and are below the action level for chloride exposure (per State of California Department of Transportation [2003]). Metal building components in contact with the onsite soils should be protected from the corrosive effects of the onsite soils. Typical mitigation would include code-compliant concrete coverforsteel reinforcement, wrapping buried metal piping in corrosion resistant tape or membranes, sleeving buried metal piping in plastic conduit, or the use of cathodic protection. In order to reduce sulfate exposure to concrete, GSI recommends that reinforced concrete mix design conform to "Exposure Class S2" in Table 4.3.1 of ACI 318-08. This implies the use of Type V concrete with a maximum water to cement ratio of 0.45 and a minimum compressive strength of 4,500 pounds per square inch (psi). It should be noted that GSI does not consult in the field of corrosion engineering. Therefore, additional comments and recommendations may be obtained from a qualified corrosion engineer based on the level of corrosion protection required for the project, as determined by the project architect and/or structural engineer. SLOPE STABILITY ANALYSIS Gross Stability GSI performed gross slope stability analyses of the slope that descends from the property. The analysiswas performed along Geologic Cross Section 8-8'. This section was selected because it represents the most critical slope owing to its steepness and the removal of toe materials for offsite retaining wall construction. For the analyses, GSI utilized the two-dimensional slope stability computer program "GSTA8L7 v.2.11 The program was used to calculate the factor-of-safety (FOS) for specified surfaces or searches for the block, or irregular slip surface Section 8-8' having the minimum FOS using the Simplified Janbu (non-circular block) Method. Additional information regrading the methodology utilized in this program is included in Appendix E. Soil shear strengths used in our analyses are also provided in Appendix E. As considered prudent, GSI used the residual shear strengths rather than the peak values. In addition, the measured residual values were reduced to maintain a reasonably conservative effect. To account for the variability of dipping beds within the Delmar Formation, observed in GSI, HEI (201 0a) and Agra (1994b) subsurface Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, lne. W.O. 6304-A-SC December 15, 2011 Page 16 explorations, our analysis incorporated anisotropic soil strength properties for the sandstone, interbedded, and claystone members within the slope and pad areas (see Appendix E). Our analysis assumes that the offsite retaining wall at the toe of the slope has been properly designed and constructed. Based on our analyses, the slope, in its existing and planned graded configurations, possesses a gross FOS greater than 1.5 and 1 .1 for static and seismic conditions, respectively. Computer printouts of the slope stability calculations are presented in Appendix E. GSI also evaluated the general stability of the slope shown on Geologic Cross Section A-A'. This evaluation primarily focused on the potential for slope failures occurring along the hillside south of La Costa Avenue to impact the subject site. The evaluation included an interpretation of the mapped geologic conditions exposed on the north-facing slope (south of La Costa Avenue), subsurface data from the GSI, HEI (2010a), and Agra (1994b) field explorations, as well as the regional geology (Kennedy and Tan, 2005). Based on our evaluation, it is our opinion that the potential for deep-seated slope failure to affect the site is low. Rather, the mode of failure would likely occur as shallow, rotational slumps within highly weathered and/or highly erosive formational materials or along dip slope fractures. Given the likely mode of failure and width of La Costa Avenue (i.e., 84 feet), the potential for shallow rotational failures occurring along this slope to affect the subject site is considered low. That is to say that failed debris would likely accumulate along the slope or within La Costa Avenue. GSI observations made during our field investigation indicated that the slope south of La Costa Avenue is virtually devoid of colluvium with a depth of weathering of approximately 2 or less feet. To that end, it appears that previous grading has been performed along this slope to possibly improve slope stability or as a part of widening La Costa Avenue in the past. However, GSI is currently not aware of any documents indicating to such grading work. Surficial Stability Based on our review of Agra (1994b), the slope that descends from the site has experienced surficial slope failures in the past. Although no indications of surficial slope failures were noted during our field exploration, there is potential for surficial slope failures to occur in the future as a result of poor surface drainage, leaking irrigation lines, and/or long duration, high intensity rainfall. Such failures would likely originate near the toe or mid-portions of the slope, and if left unabated, would progressively migrate in an up-slope direction. Because this slope is located beyond the boundaries of the site, little can be done to reduce this potential; however, it should be the responsibility of the offsite property owner(s) to maintain that slope. GSI performed a two-dimensional surficial slope stability analysis for upper portion of the slope descending from building pad area where the slope is mantled by undocumented Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, Ine. W.O. 6304-A-SC December 15, 2011 Page 17 fill. A surficial FOS of less than 1 .5 was exhibited on the existing fill in our analysis. The results of the surficial stability analysis are presented in Appendix E. Based on our understanding of the possible mode of failure and the proposed development, it is our opinion that the potential for the proposed building foundation to be adversely affected by surficial slope failures, along the descending slope, is considered low. However, improvements (walls, flatwork, etc.) located within 5 feet from the top of this slope are considered susceptible to the effects. of such failures. Therefore, GSI recommends that these improvements be supported by cast-in-drilled-hole (CIDH) piles. In addition, surface runoff should be directed away from the top of this slope. ROCK HARDNESS · During our field investigation with a rubber-tire backhoe, discontinuous, highly cemented concretionary zones within the sandstone member of the Delmar Formation resulted in practical refusal at approximately 12½ feet below the existing grade (see TP-2, Appendix B). In addition, GSI encountered practical refusal within the interbedded member of the Delmar Formation at approximately 15½feet belowthe existing grade (see TP-1, Appendix B). As such, it is the opinion of GSI that excavations into the Delmar Formation may range from easy to very difficult to the grades proposed, and the use of rock breaker attachments and/or rock buckets cannot be precluded. These cemented zones may generate oversize materials that may require special handling during grading. This should be considered during project planning and construction. Excavation equipment should be appropriately sized. UPDATE PRELIMINARY CONCLUSIONS AND RECOMMENDATIONS Based on our field exploration, laboratory testing, and geotechnical engineering analyses, it is our opinion that the site appears suitable for the proposed development from a geotechnical engineering and geologic viewpoint, provided that the recommendations presented in the following sections are properly incorporated into the design and construction phases of site development. The primary geotechnical concerns with respect to the currently proposed development are: • Earth materials characteristics and depth to competent bearing material. • Slope stability including temporary slopes. • Potential to encounter cemented zones during excavation, possibly generating oversize materials requiring special handling. • Non-structural zone on un-mitigated perimeter conditions (improvements subject to distress). • On-going expansion and corrosion potential of site soils. • Potential for perched groundwater to occur during and after development. • Regional seismic activity. Chabad at La Costa 1980 La CostaAvenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, Inc. W.O. 6304-A-SC December 15, 2011 Page 18 The recommendations presented herein consider these as well as other aspects of the site. The engineering analyses, performed, concerning site preparation and the recommendations presented herein have been completed using the information provided and obtained during our field work. In the eveht that any significant changes are made to proposed site development, the conclusions and recommendations contained in this report shall not be considered valid unless the changes are reviewed and the recommendations of this report are evaluated or modified in writing by this office. Foundation design parameters are considered preliminary until the foundation design, layout, and structural loads are provided to this office for review. 1. Geotechnical engineering, observation, and testing services should be provided during earthwork to aid the contractor in removing unsuitable soils and in his effort to compact the fill, should grading be necessary. 2. Geologic observations should be performed during any grading to verify and/or further evaluate geologic conditions. Although unlikely, if adverse geologic structures.are encountered, supplemental recommendations and earthwork may be warranted. 3. In general, remedial grading excavations to remove and re-compact potentially compressible soils are anticipated to be on the order of ¼-foot to 6 feet across a majority of the site. However, local deeper remedial grading excavations cannot be precluded and should be anticipated. Potentially compressible soils should be removed and re-compacted below a 1 :1 (h:v) projection down from the bottom, outermost edge of proposed settlement-sensitive improvements and/or planned fills. Based on the available subsurface data and planned the excavation for the Synagogue building, GSI anticipates that unsuitable soils, within the building footprint, will generally be removed by default during the planned excavation. 4. It should be noted that the 2010 CBC (CBSC, 2010) indicates that removals of unsuitable soils be performed across all areas under the purview of the grading permit, not just within the influence of the proposed building. Relatively deep · removals may also necessitate a special zone of consideration on perimeter/confining areas. This zone would be approximately equal to the depth of removals, if removals cannot be performed onsite or offsite. Thus, any settlement-sensitive improvements (walls, flatwork, etc.), constructed within this zone may require deepened foundations, reinforcement, etc., or will retain some potential for settlement and associated distress. The presence of existing, offsite improvements may limit remedial earthwork along property boundaries. Should unmitigated soils remain within the property boundaries at the conclusion of grading, the potential for settlement-sensitive improvements, constructed within the influence of these soils, to experience settlement-associated distress should be anticipated and be properly disclosed to all interested/affected parties. It is possible that perimeter/confining conditions would affect planned improvements located up to 6 feet from the property lines, based on the available data. Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, Ine. W.O. 6304-A-SC December 15, 2011 Page 19 5. Expansion index and Atterberg Limits testing indicates that the onsite soils have an expansion index greater than 21 and a plasticity index greater than 15. Thus, site soils meet the criteria outlined in Section 1803.5.2 of the 201 o CBC (CBSC, 201 0) for expansive soils. In addition, swell pressure testing by GSI indicates that relatively undisturbed sample of claystone, located within approximately 12 feet of pad grade, exerts a swell pressure of 4,000 pounds per square foot (psf). Foundations within the influence of expansive soils should be designed and constr'ucted in accordance with the minimum guidelines presented herein, and as presented in Sections 1808.6.1 or 1808.6.2 of the 201 0 CBC. Recommendations for the design of foundations within the influence of expansive soils are provided herein. 6. Corrosion testing indicates that the site soils are medium acid to neutral with respect to soil acidity/alkalinity, are severely corrosive_to exposed, buried metals when saturated, present moderate to severe sulfate exposure to concrete, and are below the action level for chloride exposure (per State of California Department of Transportation [2003]). Metal building components in contact with the onsite soils should be protected from the corrosive effects of the onsite soils. Typical mitigation would include code-compliant concrete cover for steel reinforcement, wrapping buried metal piping in corrosion resistanttape or membranes, sleeving buried metal piping in plastic conduit, or the use of cathodic protection. In order to reduce sulfate exposure to concrete, GSI recommends that reinforced concrete mix design conform to "Exposure Class S2" in Table 4.3.1 of ACI 318-08. This implies the use of Type V concrete with a maximum water to cement ratio of 0.45 and a minimum compressive strength of 4,500 psi. As previously indicated, this will primarily influence the footings, masonry (if native backfill is used), soldier piles, grade beams, and concrete slabs in contact with the onsite soils. It should be noted that GSI does not consult in the field of corrosion engineering. Therefore, additional comments and recommendations may be obtained from a qualified corrosion engineer based on the level of corrosion protection required for the project, as determined by the project architect and/or structural engineer. 7. In general and based upon the available data to date, regional groundwater should not significantly affect site development, based on the available data. However, it -is possible that perched water may occur at shallower depths in the future, especially along boundaries of contrasting permeabilities (i.e., clayey and sandy fill lifts, fill/Delmar Formation contacts, sandstone/claystone contacts, joints/fractures [discontinuities], etc.), and should be anticipated. This potential should be disclosed to all interested/affected parties. Should perched water conditions manifest in the future, this office could provide recommendations for mitigation. Typical geotechnical mitigation may include the installation of subdrains and moisture cut-off barriers. Because of the potential for perched water conditions to develop at the site, more onerous slab design is necessary for new slab-on-grade floors (State of California, 2011). Recommendations for reducing the amount of Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, Ine. W.O. 6304-A-SC December 15, 2011 Page·20 water and/or water vapor through slab-on-grade floors are provided in the "Soil Moisture Considerations" sections of this report. 8. Our slope stability analysis indicates that.the slope descending from the subject site, in its existing and planned configurations, possesses a gross factor-of-safety of at least 1.5 and 1.1 for static and seismic conditions, respectively. However, surficial slope failures may occur along this slope. It does not appear that such failures would affect the proposed Synagogue foundation but they could impact planned improvements (walls, flatwork, etc.) within about 5 feet of the top of slope. Therefore, these improvements should be supported by CIDH piles. Surficial slope failures occurring along the ascending slope, south of La Costa Avenue, would likely come to rest on the slope or within La Costa Avenue prior to reaching the site. 9. The seismicity-acceleration values provided herein should be considered during the design and construction of the proposed development. 1 o. General Earthwork and Grading Guidelines are provided at the end of this report as Appendix E. Specific recommendations are provided below. EARTHWORK CONSTRUCTION RECOMMENDATIONS General Remedial grading should be performed in all areas to receive the planned settlement- sensitive improvements (building, walls, underground utilities, hardscape, etc.) and/or planned fill. Grading (both remedial and planned) should conform to the guidelines presented in Appendix J of the 201 o CBC (CBSC, 201 O), the requirements of the City of Carlsbad, and the Grading Guidelines presented in Appendix E, except where specifically superceded in the text of this report. In case of conflict, the more onerous code or recommendations should govern. Prior to grading, a GSI representative should be present at the pre- construction meeting to provide additional grading guidelines, if needed, and review the earthwork schedule. During earthwork construction, all site preparation and the general grading procedures of the contractor should be observed and the fill selectively tested by a representative(s) of GSI. If unusual or unexpected conditions are exposed in the field, they should be reviewed by this office and, if warranted, modified and/or additional recommendations will be offered. All applicable requirements of local and national construction and general industry safety orders, the Occupational Safety and Health Act (OSHA), and the Construction Safety Act should be met. It is the onsite general contractor and individual subcontractors responsibility to provide a safe working environment for our field staff who are onsite. GSI does not consult in the area of safety engineering. Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, lne. W.O. 6304-A-SC December 15, 2011 Page 21 Demolition/Grubbing 1. Vegetation, and any miscellaneous deleterious debris generated from the demolition of existing site improvements should be removed from the areas of proposed grading/earthwork. 2. Cavities or loose soils remaining after demolition and site clearance should be cleaned out and observed by the geotechnical consultant. The cavities should be replaced with fill materials that have been moisture conditioned to at least optimum moisture content and compacted to at least 90 percent of the laboratory standard (ASTM D 1557). Remedial Removals (Removal of Potentially Compressible Surficial Materials) Where planned fills or settlement-sensitive improvements are proposed, potentially compressible undocumented fill, Quaternary colluvium/topsoil, and weathered Delmar Formation should be removed to expose dense unweathered Delmar Formation. Removed soils may be reused as properly engineered fill provided that major concentrations of organic material have been removed prior to placement. In general, the remedial grading excavations to remove potentially compressible earth materials are anticipated to be on the order of ¼-foot to 6 feet across a majority of the site. However, local deeper removal excavations cannot be precluded and should be anticipated. The removal and re-compaction of potentially compressible soils should be performed below a 1 :1 (h:v) projection down from the bottom, outermost edge of proposed settlement- sensitive improvements and/or areas of planned fill. Based on the available data, GSI anticipates that unsuitable soils within the influence of planned Synagogue building will be removed by default during the planned excavation for such. Once the unsuitable soils have been removed, the exposed Delmar Formation should be scarified approximately 6 to 8 inches, moisture conditioned as necessary to achieve the soil's optimum moisture content and then be re-compacted to at least 90 percent of the laboratory standard prior to fill placement. Reprocessing the bottoms of remedial grading excavations should be performed in all areas of the -site except the slab subgrade area of the building. The bottoms of remedial grading excavations should be observed by the geotechnical consultant prior to scarification. Temporary Slopes Temporary slopes for excavations should conform to CAL-OSHA and/or OSHA requirements for Type "B" soils. Temporary slopes, up to a maximum height of ±20 feet, may be excavated at a 1 :1 (horizontal to vertical [h:v]) gradient, or flatter, provided groundwater and/or running sands are not encountered . Construction materials or soil stockpiles should not be placed within 'H' of any temporary slope, where 'H' equals the height of the temporary slope. All temporary slopes should be observed by a licensed engineering geologist and/or geotechnical engineer prior to worker entry into the excavation. Based on the conditions exposed during construction, inclining temporary Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp 12\6300\6304a.gue GeoSoils, lne. W.O. 63O4-A-SC December 15, 2011 Page 22 slopes to flatter gradients or the use of shoring may be necessary if adverse conditions are observed. Shoring will be necessary where property lines and existing improvements (to remain) limit the recommended temporary slope inclination. Engineered Fill Placement Engineered fill should be placed in thin lifts, moisture conditioned, and mixed to at least the soil's optimum moisture content, and then be compacted to at least 90 percent of the laboratory standard (ASTM D 1557). Engineered fill placement should be observed and selectively tested fo_r moisture content and compaction by the geotechnical consultant. Import Fill Materials Should import fill material be necessary for this project, it should have an expansion index of 20 or less and a plasticity index less than 15. Prior to delivery at the site, a sample of the proposed import should be collected from the source area by GSI personnel and then tested in the laboratory for compatibility with the onsite soils. Prior to delivery, the Client should also obtain an environmental report indicating that the proposed import material should not pose any risk to human health. At least three days of lead time is recommended prior to import delivery so the appropriate laboratory testing can be performed and environmental reports reviewed. Excavation Observation {All Excavations) When excavations are made adjacent to an existing structure (i.e., underground utility, road or building) there is a risk of some damage to that structure or improvements. We therefore recommend that a systematic program of observations be made before, during, and after construction to determine the effects (if any) of construction on the existing structures. We believe that this is necessary for two reasons: first, if excessive movements (i.e., more than ½ inch) are detected early enough, remedial measures can be taken which could possibly prevent serious damage to the existing structure; and, second, the responsibility for damage to the existing structure can be determined more equitably if the cause and extent of the damage can be determined more precisely. Monitoring should include the measurement of any horizontal and vertical movements of the existing structures. Locations and type of the monitoring devices should be selected as prior to the start of construction. The program of monitoring should be agreed upon between the projectteam, the site surveyor and the Geotechnical Engineer of Record, prior to excavation. Reference points on existing building and walls should be placed as low as possible on the exterior of the building/wall adjacent to the excavation. Exact locations may be Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, lne. W.O. 6304-A-SC December 15, 2011 Page 23 dictated by critical points within the structure, such as bearing walls or columns for buildings; and surface points on roadways and sidewalks near the top of the excavation. For a survey monitoring system, an accuracy of a least 0.01 foot should be required. Reference points should be installed and read initially prior to excavation. The readings should continue until all construction below ground has been completed and the backfill has been brought up to final grade. The frequency of readings will depend upon the results of previous readings and the rate of construction. Weekly readings could be assumed throughout the duration of construction with daily readings during rapid excavation near the bottom and at critical times. The reading should be plotted by the Surveyor and then reviewed by the Geotechnical Engineer. In addition to the monitoring system, it would be prudent for the Contractor to make a complete inspection of the nearby existing structures both before and after construction. The inspection should be directed toward detecting any signs of damage, particularly those caused by settlement. Notes should be made and photographs should be taken where necessary. SHORING DESIGN AND CONSTRUCTION Shoring of Excavations A review of C&A (2011), indicates that planned excavations to achieve the finish grade elevation for the proposed building may be up to approximately ± 11 feet below the existing grade. Owing to the depth of planned excavations and space restrictions, temporary shoring, utilizing a system of cast-in-place soldier beams and wood lagging, may be necessary to retain some excavation walls. The use of tiebacks or soil nails is not anticipated to be feasible on this site. If necessary, the use of internal braces, rakes, and/or temporary slopes may be used to achieve the maximum shoring height needed to perform grading and foundation installation. Shoring of excavations of this size is typically performed by specialty contractors with knowledge of the City of Carlsbad ordinances, and current building codes, as well as the local area soil conditions. Lateral earth pressures for shoring design are presented as Figure 1 . Since the design of retaining systems is sensitive to surcharge pressures behind the excavation, we recommend that this office be consulted if unusual load conditions are uncovered in the placement/installation. To that end, GSI should perform field reviews during shoring construction. Care should be exercised when excavating into the on-site soils since caving or sloughing of the earth materials above the bedrock is possible. Observation of soldier pile excavations and special inspections/testing should be performed during shoring construction. Chabad at La Costa 1980 La Costa Avenue, Carlsbad Fife:e:\wp12\6300\6304a.gue GeoSoils, Ine. W.O. 6304-A-SC December 15, 2011 Page 24 Cantilever Shoring System r - -Surcharge Pressure p (pSf) i-----\ --i---- -Line Load a L (pounds) xH t R- H (feet) D (feet) 45 H (psf) H 0.35 P (psf) I · 300 D (psf) --- X 0.1 Y (feet) 0.3 0.5 0.7 X R .{0.4 0.55 OL >o.4 (0.64 a~ x2t 1 } Tie-Back Shoring· System _ -Surcharge Pressure P (psf) r \ . ---- -Line Load a L (pounds) 0.2 H (ft.) _L . R---- H (feet) --Minimum 7' depth f~r supporting H piers . . I I® o.35 p (psf) 400 D (psf) © · · 27 H (psf) y 0.6H 0.6H 0.56H 0.48H Y (feet) NOTES (D Include groundwater effects below .groundwater level. ® Include water effects below groundwater level. Grouted length greater than 7 feet; field test anchor· strength. RIVERSIDE CO. ORANGE CO. SAN DIEGO CO. LATERAL EARTH PRESSURES FOR TEMPORARY SHORING ® © Neglect passive pressure below base of excavation to a depth of 1-------s....--r;_s_Ti_E_M_s__,---'Fa.;.IG:a.;;U;.;.;R,;;;.E -:1---1 one pier diameter. W.O. 6304-A-SC DATE 12/11 SCALE None - Shoring of the excavation is the responsibility of the shoring contractor. Extreme caution should be used to reduce damage to any adjacent improvements caused by settlement or reduction of lateral support. Accordingly, we recommend a system of surveying and monitoring until the permanent building walls are backfilled to the design grade in order to evaluate the effects of shoring on existing onsite and offsite improvements. Pre-construction photo-documentation is also advisable. Unless incorporated into the shoring design, construction equipment storage or traffic, and/or stockpiles should not be stored or operated within 'H' feet of the top of any shored excavations (where 'H' equals the height of the retained earth). Temporary/permanent provisions should be made to direct any potential runoff away from the top of shored excavations. All applicable surcharges from vehicular traffic and existing structures within 'H' of a shored excavation should be evaluated. Drainage -Shoring If the shoring is to be turned to permanent by reinforcement and shotcreting, then adequate drainage should be provided behind the shored profile. The drainage should be in the form of miradrain 6000 drainage panels, or an equivalent product, in order to intercept any water behind the shoring and direct it to an appropriate drainage outlet. Alternatively, the space behind lagging may be provided with a Caltrans Class II drain rock in the soil-lagging gap to allow for drainage. Lateral Pressure -Shoring 1. The active pressure to be utilized for the design of temporary shoring retaining level backfill conditions may be computed by the triangular pressure distribution shown in Figure 1. For temporary shoring retaining a descending 2:1 (h:v) slope (i.e .• negative sloping conditions), the shoring design may incorporate an active pressure of 35H (psf) 2. Passive pressure may be computed as an equivalent fluid having a given density shown in Figure 1. 3. The above criteria assumes that hydrostatic pressure is not allowed to build up behind excavation walls. 4. Traffic; Surcharge: These recommendations are for exposed excavation walls up to 12 feet high. An empirical equivalent fluid pressure approach may be used to compute the horizontal pressure against the wall. Appropriate fluid unit weights are provided for specific slope gradients of the retained material; these do not include other superimposed loading conditions such as traffic, structures, seismic events, expansive soils or adverse geologic conditions. Traffic surcharges (if applicable) for shoring walls should be minimally applied as 200 psf per lineal foot in the upper 5 feet of the shoring wall(s) if traffic is within 'H' of the back of the wall. Alternatively, Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, Inc. W.O. 6304-A-SC December 15, 2011 Page 26 for temporary shoring, this may be completed using a surface surcharge of 100 psf within 'H' of the top of the wall. It is not recommended to allow sloping surcharge (other than level backfill) within H behind the shored walls from either stockpiled soils or temporary/permanent graded slopes. Steeper slope gradients (more than level) will increase the EFP for shoring design significantly and import the cost. Regrading is recommended prior to shoring installation, as needed. 5. Deflection: The shoring system should be designed such that the maximum lateral deformation at the top of the soldier pile not exceed 1 inch. The maximum lateral deformation for the drilled pier concrete shafts at the lowest grade level should not exceed½ inch. The point of fixity, given a CIDH diameter of 18 to 24 inches and the allowable deflection, should be on the order of 1 pile diameter from the depth of excavation (dredge line) into formation. Lateral deflection may result in settlement of approximately ½ percent the total shoring height behind the wall. 6. Should a braced temporary shoring system be necessary, a maximum allowable bearing of 3,000 psf may be used for a temporary concrete raker footing (deadman) or by permanent lateral footings that are at least 12 inches wide by 12 inches below the lowest adjacent grade (deep) into unweathered bedrock. These footings should be poured with the bearing surface normal to rakers inclined at 45 degrees. Alternatively, if a pile-supported raker is used, a passive pressure of 400 pcf may be used in the design of an 18-inch diameter cast-in-drilled hole (CIDH) pile embedded into unweathered bedrock. This value may be increased by 20 percent for each additional foot of depth to a maximum of lateral bearing 4,000 psf. The coefficient of friction between concrete and formational earth materials should be 0.35 when combined with the dead load forces. Please note that tieback or soil nail type walls are· deemed geometrically infeasible on this site due to property line restrictions and descending sloping backfill on the north, northwestern sides of the proposed shored areas. Shoring Vertical Bearing Based upon personal communication with the project architect and structural engineer, it is our understanding that some of the shoring soldier piles will provide vertical bearing support for planned staircase and landing walls near the northern property line. As such, GSI is providing the following geotechnical parameters for vertical bearing elements of the temporary shoring wall. GSI has assumed that shoring soldier piles will be a CIDH pile with a minimum diameter of 18 inches that is embedded a minimum of 5 feet into bedrock. Vertical bearing of the shoring H-piles encased in concrete will be gained by friction within the bedrock (formation) support and end bearing of the pile. Minor down-drag due to settlement of unsuitable bearing soils overlying the formation will not impose a significant load to the pier Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue W.O. 6304-A-SC December 15, 2011 Page 27 supported temporary shoring, as this settlement is anticipated to be less than 1 inch. Vertical pier support for the portion of the piers (H-piles) embedded in the bedrock will be gained by adhesion of the bedrock to the pier surface, as well as end bearing on the piers. If the bottom of the pier holes are relatively clean of loose soil prior to the placement of steel and concrete into the shaft excavation, the designer may utilize a 4,000 psf bearing on the end surface of the pier hole in bedrock. If the hole is left in a loose condition or the temporary shoring design does not need end bearing for vertical support, this end bearing should be neglected in the design. Another component ofthe vertical bearing of the drilled pier support for the temporary shoring will come from the adhesion of the bedrock against the concrete. This will provide up to 300 psf of adhesion for well cemented, dense, relatively unweathered bedrock. This should be applied over the surface area of the pier embedded into the bedrock, excluding the end or return wall. Due to the primarily lateral loads on the pier, this will likely provide sufficient support from a vertical load standpoint, which should be confirmed by the shoring designer. For shoring piers adjacent or within 5 feet of new footings, the pier should be designed for 15 percent of bearing load below the point of fixity for the CIDH. Continuous wood or metal lagging will be required between the soldier piles. The soldier piles should be designed for the full anticipated lateral pressure. However, the pressure on the lagging will be less due to arching in the soils. When con.sidering nearby improvements located above a 1 :1 (h:v) projection up from the toe of the shored excavation, GSI recommends that a Boussinesq approach be used in the design. This approach may model the surcharge as a line load on the back of the shoring. Wood lagging should be installed as the cut progresses to its ultimate configuration. Maximum pressure on shoring lagging should be limited to 300 psf/ft or 0.5 x unit weight of soil backfill where wood lagging is used. We recommend that the lagging be designed for the recommended earth pressures provided above, but limited to a maximum value of 1,000 psf. Shoring Construction Recommendations 1. The excavation and installation of the soldier piles should be observed and documented by the project geotechnical engineer to further evaluate the geologic conditions within the influence of the temporary shoring wall and to ensure the soldier pile construction conforms to the requirements of the shoring plan 2. Drilled excavations for soldier piles should be straight and plumb. If boulders and cobbles are encountered during drilling, the contractor should periodically recheck the drilled shaft for plumbness. 3. Although not anticipated, casing should be provided in drilled shafts if perched water and/or caving conditions be encountered during drilling operations. The bottom of the casing should be at least 4 feet below the top of the concrete as the concrete is poured and the casing is withdrawn. Although not anticipated, dewatering may be required for concrete placement if significant seepage or Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, lne. W.O. 6304-A-SC December 15, 2011 Page 28 groundwater is encountered during construction. This should be considered during project planning. 4. The exact tip elevation of the soldier piles should be clearly indicated on the shoring plans. 5. Owing to the severe sulfate exposure from the onsite soils, the concrete mix design for permanent shoring components should minimally conform to the guidelines in Table 4.3.1 of ACI 318-08 for "Exposure Class S2." All concrete should delivered through a tremie pipe immediately subsequent to approved excavation and steel placement. Care should be taken to prevent striking the walls of the excavations with the tremie pipe during concrete placement. Concrete should not be allowed to free fall more than 5 feet. "Tailgating" concrete will not be permitted. 6. Proper spacing (minimum of 3 inches) between H beams and the side walls, and bottoms of the drilled shafts should be provided 7. Concrete used in the shoring construction should be tested by a qualified materials testing consultant for strength and mix design. 8. Excavation for lagging should not commence until the soldier pile concrete reaches its 28-day compressive strength. 9. A complete and accurate record of all soldier pile locations, depths, concrete, strengths, quantity of concrete per pile should be maintained by the special inspector and geotechnical consultant. The shoring design engineer should be notified of any unusual conditions encountered during installation. Monitoring of Shoring 1 . The shoring designer or his designee should make periodic inspections of the job site for the purpose of observing the installation of the shoring system and monitoring of survey. 2. Monitoring points should be established at the top of selected soldier piles and at intermediate intervals as considered appropriate by the Geotechnical Engineer. 3. Control points should be established outside the area of influence of the shoring system to ensure the accuracy of the monitoring readings. 4. Initial monitoring and photo-documentation should be performed prior to any excavation. Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, lne. W.O. 6304-A-SC December 15, 2011 Page 29 5. Once the excavation .has commenced, periodic readings should be taken weekly until the permanent retaining wall is backfilled to the design grade. If the performance of the shoring system is within established guidelines, the shoring engineer may permit the periodic readings to be bi-weekly. Permission to conduct bi-weekly readings should be provided by the shoring design engineer in writing, and be distributed to the Geotechnical Engineer-of-Record, Structural Engineer-of-Record, Civil Engineer-of-Record, and shoring contractor. Once initiated, bi-weekly readings should continue until the permanent retaining wall is backfilled to the design grade. Thereafter, readings can be made monthly. Additional readings should be taken when requested by the special inspector, Shoring Design, Engineer, Structural Engineer-of-Record, Geotechnical Engineer- of-Record, or the Building Official. 6. Monitoring reading should be submitted to the Shoring Design Engineer, Engineer in Responsible Charge, and the Building Official (if applicable) within three business days after they are conducted. Monitoring readings should be accurate to within 0.01 feet. Results are to be submitted in tabular form showing at least the initial date of monitoring and reading, current monitoring date and reading and difference between the two readings. 7. If the total cumulative horizontal or vertical movement (from start of shoring construction) of the existing building reaches½ inch or soldier piles reaches 1 inch, all excavation activities should be suspended until the Geotechnical Engineer and Shoring Design Engineer determine the cause of movement and provide corrective measures, as necessary. Excavation should not re-commence until written permission is provided by the Geotechnical Engineer and Shoring Design Engineer. 8. If the total cumulative horizontal or vertical movement (from start of shoring construction) of any nearby existing improvement reaches ½ inch or soldier piles reaches 1 inch, all excavation activities should be suspended until the Geotechnical Engineer and Shoring Design Engineer determine the cause of movement. Supplemental shoring should be devised to eliminate further movement. Supplemental shoring design will require review and approval by the Building Official. Excavation should not re-commence until written permission is provided by the Building Official. Monitoring of Structures 1 . The contractor should complete a written and photographic log of the existing building or other structures located within 100 feet or three times the depth of shoring (whichever is greater) prior to shoring construction. A licensed surveyor should document all existing substantial cracks (i.e., greater than 1/a inch horizontal or vertical separation) in the structures/improvements. Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, lne. W.O. 6304-A-SC December 15, 2011 Page 30 2. The contractor should document the condition of the existing improvements adjacent to the shoring wall prior to the start of shoring construction. 3. The contractor should monitor existing improvements for movement or cracking that may result from the adjacent shoring. 4. If excessive movement or visible cracking occurs, the shoring contractor should stop work and shore/reinforce the excavation, and contact the Shoring Design Engineer and the Building Official. 5. Monitoring of the existing improvements should be made at reasonable intervals as required by the registered design professional, subject to approval by the Building Official. Monitoring should be performed by a licensed surveyor. 6. Prior to commencing shoring construction, a pre-construction meeting should take place between the contractor, Shoring Design Engineer, Surveyor, Geotechnical Engineer, and the Building Official to identify monitoring locations on existing improvements. 7. If in the opinion of the Building Official or Shoring Design Engineer, monitoring data indicate excessive movement or other distress, all excavation should cease until the Geotechnical Engineer and Shoring Design Engineer investigates the situation and makes recommendations for remedial actions or continuation. 8. All readings and measurements should be submitted to the Building Official (if applicable) and Shoring Design Engineer. PRELIMINARY FOUNDATION DESIGN RECOMMENDATIONS General This report presents minimum design criteria for the design of foundations and other elements possibly applicable to the project. These criteria should not be considered as substitutes for actual designs by the structural engineer. The proposed foundation systems should be designed and constructed in accordance with the guidelines contained in the 201 o CBC (CBSC, 201 O). In the event that the information concerning the proposed development plan is not correct, or any changes in the design, location or loading conditions of the proposed structure are made, the conclusions and recommendations contained in this report shall not be considered valid unless the changes are reviewed and conclusions of this report are modified or approved in writing by this office. Chabad at La Costa 1980 La Costa.Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, Inc. W.O. 6304-A-SC December 15, 2011 Page 31 These preliminary foundation design and construction recommendations are based on laboratory testing and engineering evaluations of onsite earth materials by GSI. Final foundation design and construction recommendations will be based on the as-graded conditions exposed in the building pad area. Based on communication with Sun Structural Engineering, Inc. (Project Structural Consultant), GSI understands that planned wall and column loads are on the order of 3 kips per lineal foot and 60 kips, respectively. The pattern and magnitude of the building loads on the foundation should be reviewed as soon as they become available. The following preliminary foundation construction recommendations are presented as a minimum criteria from a soils engineering viewpoint. As currently evaluated, the onsite soils expansion indices range between 21 and 51 . Swell pressure testing indicates that the claystone occurring approximately 6 to 13 feet below proposed pad grade can exert an in-place (natural) swell pressure of 4,000 psf. To that end, foundations will need to be designed to resist expansive soil effects in accordance with Sections 1808.6.1 and 1808.6.2 of the 2010 CBC (CBSC, 2010). The information and recommendations presented in this section are not meant to supersede design by the project structural engineer or civil engineer specializing in structural design. Upon request, GSI could provide additional input/consultation regarding soil parameters, as related to foundation design. General Foundation Design 1. Foundation systems should be designed and constructed in accordance with guidelines presented in the latest adopted edition of the 2010 CBC (CBSC, 2010). All new foundations should be embedded into suitable bedrock or engineered fill, but not simultaneously on both. 2. An allowable bearing value of 1 ,500 psf may be used for design of footings that maintain a minimum width of 12 inches and a minimum depth of 12 inches, and founded into engineered fill or bedrock. This value may be increased by 20 percent for each additional 12 inches in depth to a maximum value of 2,500 psf. The maximum bearing values may be increased by 500 psf for bedrock such that a maximum allowable bearing of 2,000 psf for 12 inches of embedment and a maximum bearing value of 3,000 psf is reached on approved bedrock surfaces. In addition, this value may be increased by one-third when considering short duration seismic or wind loads. Isolated pad footings should have a minimum dimension of at least 24 inches square and a minimum embedment of 24 inches into suitable bedrock or engineered fill, excluding any landscaped zone or topsoil. The depth of embedment excludes slab thickness, underlayment, landscape zone, etc. Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, Ine. W.O. 6304-A-SC December 15, 2011 Page32 3. Passive earth pressure may be computed. as an equivalent fluid having a density of 250 pcf, with a maximum earth pressure of 2,500 psf for fill and 350 pcf and 3,000 psf for approved bedrock. 4. An allowable coefficient of friction between soil and concrete of 0.35 may be used when combined with the dead load forces on fill or bedrock. 5. When combining passive pressure and frictional resistance, the passive pressure component should be reduced by one-third. 6. The expansion index of the onsite soils evaluated appear to be low to medium expansive. However, should high (E.I. = 91 to 130) expansive soils be encountered, foundation design may need to be amended. Foundations shall be designed in accordance with Section 1808 of the 2010 CBC (CBSC, 2010). This implies that the Code may require the use of more onerous foundations (i.e., post-tension, mat, etc.). 7. Foundation systems should be designed to accommodate a differential static and seismic settlement indicated in the settlement section of this report. Foundations within the influence of expansive soils should also be designed for swell pressure and seasonal shrinking and swelling. 8. Footings for structures adjacent to retaining walls should be deepened so as to extend below a 1 :1 projection from the heel of the wall. Alternatively, walls may be designed to accommodate structural loads from buildings or appurtenances as described in the "Retaining Wall" section of this report. DESIGN OF FOUNDATIONS WITHIN THE INFLUENCE OF EXPANSIVE SOILS USING THE WIRE REINFORCEMENT INSTITUTE (WRI) METHODOLOGY As previously, indicated soils within the influence of the proposed Synagogue building foundation and basement slab-on-grade floor are considered expansive. Based on communication with the project design team, designing the foundation and slab-on-grade floor for the proposed Synagogue building using the Wire Reinforcement Institute (WRI) methodology (WRI, 1996) appears to be the most practical and cost-effective approach to resist expansive soil effects. Recommended design parameters used in the design of WRI foundations and slabs-on-grade are provided in the following table. Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, Ine. W.O. 6304-A-SC December 15, 2011 Page 33 1::>:::~;{r?\:/ti:<:: i':'.::·{'.;:··/>.:-<_<~·:-__ :-WRfbtsi~kPA~NIEJJ;0S:':'_: __ ·:: '/ _: -·~··:--. "<~:, __ ·.:. ----_--:::_ .. .I Effective Plasticity Index 25 Unconfined Compressive Strength 1,000 psf (0.5 tsf) for Delmar Sandstone 1,300 psf (0.65 tsf) for lnterbedded Delmar Formation Modulus of Subgrade Reaction 100 pound per cubic inch (pci) Resistance Value (R-value) 30 Swell Pressure 900 psf Minimum Slab Thickness Binches Minimum Steel Reinforcement Double Mat of Steel Reinforcement Bars per per Structural Engineer Structural Consultant For this method, either a uniform thickness foundation (UTF) or mat may be used. Alternatively, the slab (in plan view) may be divided up into at least quarters and grade beams should be used to enhance the strength of the slab to resist the expansive soil forces. GSI estimates that the expansive soil forces acting on the foundations and slab may be on the order of 900 psf of swell pressure when considering the overburden pressure of the Delmar sandstone located between the bottom of the foundation and the top of the interbedded Delmar Formation. The foundation bearing capacity and other geotechnical parameters previously provided in this report are still applicable. Soil Moisture Specific pre-moistening and moisture testing of the slab subgrade is recommended for expansive soil conditions (E.I. > 20 and P.I. of 15 or greater). The moisture content of the subgrade soils shbuld be equal to or greater than the soil's optimum moisture content to a depth of 18 inches for medium expansive soils. Pre-moistening and/or pre-soaking should be evaluated by the soils engineer 72 hours prior to vapor retarder placement. Perimeter Cut-Off Walls Perimeter cut-off walls may be incorporated into the UTF design and should be 18 inches deep for medium expansive soil conditions, respectively. The cut-off walls may be integrated into the slab design or independent of the slab. The cut-off walls should be a minimum of 6 inches thick. The bottom of the perimeter cut-off wall should be designed to resist tension, using reinforcement per the structural engineer. Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, Inc. W.O. 6304-A-SC December 15, 2011 Page34 Foundation Settlement Given the reported wall and column loads and the primary bearing surface (i.e., sandstone member of the Delmar Formation), the compression of the prepared/approved (cut) surface of the formation will likely respond to new foundation loads with less than ½-inch compression and with ¼-inch of differential compression between the heaviest and lightest foundation elements. Foundations and other improvements in the basement wall backfill (on the order of 12 feet thick or less) may exhibit settlements on the order of 1 inch due to the difficulty of compacting soils adjacent to the ba,sement walls related to the potential for damaging the water proofing and the panel drain with compaction equipment. As such, pavements and foundations for ancillary site improvements that span the basement wall backfill zone and extend into the cut area of the building pad should either be structurally supported by the basement walls or be able to accommodate a differential settlement of ¾-inch over this backfill zone lateral distance approximately 10 to 15 feet (maximum ½ to 1 percent [Clough and Tsui, 19741). POST-TENSIONED FOUNDATIONS Post-tension (PT) foundations may also be used to mitigate the damaging effects of expansive soils on the planned building's foundation and slab-on-grade floor if there is space available to tension· the PT cables. If additional space is needed for cable tensioning, a gap slab on the order of 3 feet in width on the tensioning edge of the slab may be incorporated into the PT design. Post-tension (PT) design may be either ribbed or mat-type. The latter is also referred to as uniform thickness foundation (UTF). The use of a UTF is an alternative to the traditional ribbed-type. The UTF offers a reduction in grade beams (i.e., the UTF method typically uses a single perimeter grade beam and possible "shovel" footings), but has a thicker slab than the ribbed-type. The project designer, civil engineer, and structural engineer should evaluate the feasibility of PT foundations for this project based on space availability for PT cable tensioning. Should PT foundations be considered a favorable alternative to foundations and slabs-on-grade using the WRI methodology, this office could provide PT design criteria upon request. However, based on recent communication with the project design team, GSI understands that PT installation will likely present constraints during construction that are not desired by the owner or design team. SOIL MOISTURE TRANSMISSION CONSIDERATIONS GSI has evaluated the potential for vapor or water transmission through the concrete floor slab, in light of typical floor coverings and improvements. Please note that slab moisture emission rates range from about 2 to 27 lbs/ 24 hours/1,000 square feet from a typical slab (Kanare, 2005), while floor covering manufacturers generally recommend about 3 lbs/24 hours as an upper limit. The recommendations in this section are not intended Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, Ine. W.O. 6304-A-SC December 15, 2011 Page 35 to preclude the transmission of water or vapor through the foundation or slabs. Foundation systems and slabs shall not allow water or water vapor to enter into the structure so as to cause damage to another building component or to limit the installation of the type of flooring materials typically used for the particular application (State of California, 2011 ). These recommendations may be exceeded or supplemented by a water "proofing" specialist, project architect, or structural consultant. Thus, the client will need to evaluate the following in light of a cost vs. benefit analysis (owner expectations and repairs/replacement), along with disclosure to all interested/affected parties. It should also be noted that vapor transmission will occur in new slab-on-grade floors as a result of chemical reactions taking place within the curing concrete. Vapor transmission through concrete floor slabs as a result of concrete curing has the potential to adversely affect sensitive floor coverings depending on the thickness of the concrete floor slab and the duration oftime between the placement of concrete, and the floor covering. It is possible that a slab moisture sealant may be needed prior to the placement of sensitive floor coverings if a thick slab-on-grade floor is used and the time frame between concrete and floor covering placement is relatively short. Considering the E.I. test results presented herein, and known soil conditions in the region, the anticipated typical water vapor transmission rates, floor coverings, and improvements {to be chosen by the Client and/or project architect) that can tolerate vapor transmission rates without significant distress, the following alternatives are provided: • Concrete slabs should be a minimum of 5 inches thick. • Concrete slab underlayment should consist of.a 15-mil vapor retarder, or equivalent, with all laps sealed per the 201 0 CBC and the manufacturer's recommendation. The vapor retarder should comply with the ASTM E 17 45 -Class A criteria, and be installed in accordance with ACI 302.1 R-04 and ASTM E 1643. • The 15-mil vapor retarder (ASTM E 17 45 -.Class A criteria) shall be installed per the recommendations of the manufacturer, including all penetrations {i.e., pipe, ducting, rebar, etc.). • Concrete slabs, including any garage area, shall be underlain by 2 inches of clean, washed sand (SE> 30) above a 15 mil vapor retarder {ASTM E-1745 -Class A criteria, per Engineering Bulletin 119 [Kanare, 2005]) installed per the recommendations of the manufacturer, including all penetrations {i.e., pipe, ducting, rebar, etc} The manufacturer shall provide instructions for lap sealing, including minimum width of lap, method of sealing, and either supply or specify suitable products for lap sealing {ASTM E 1745), and per code. ACI 302.1 R-04 (2004) states "If a cushion or sand layer is desired between the vapor retarder and the slab, care must be taken to protect the sand layer from taking on additional water from a source such as rain, curing, cutting, or cleaning. Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, Ine. W.O. 6304-A-SC December 15, 2011 Page36 Wet cushion or sand layer has been directly linked in the past to significant lengthening of time required for a slab to reach an acceptable level of dryness for floor covering applications." Therefore, additional observation and/or testing will be necessary for the cushion or sand layer for moisture content, and relatively uniform thicknesses, prior to the placement of concrete. • The vapor retarder shall be underlain by 2 inches of sand (SE > 30) placed directly on the prepared, moisture conditioned, subgrade and should be sealed to provide a continuous retarder under the entire slab, as discussed above. As discussed previously, GSI indicated this layer of import sand may be eliminated below the vapor retarder, if laboratory testing indicates that the slab subgrade soil has a sand equivalent (SE) of 30 or greater. If the slab subgrade has an E.I. >91, then the vapor retarder underlayment should increase to 4 inches. • Concrete should have a maximum water/cement ratio of 0.45. This does not supercede Table 4.3.1 of Chapter 4 of the ACI (2008) for corrosion or other corrosive requirements. Additional concrete mix design recommendations should be provided by the structural consultant and/or waterproofing specialist. Concrete finishing and workablity should be addressed by the structural consultant and a waterproofing specialist. • Where slab water/cement ratios are as indicated herein, and/or admixtures used, the structural consultant should also make changes to the concrete in the grade beams and footings in kind, so that the concrete used in the foundation and slabs are designed and/or treated for more uniform moisture protection. • The owner(s) should be specifically advised which areas are suitable for tile flooring, vinyl flooring, or other types of water/vapor-sensitive flooring and which are not suitable. In all planned floor areas, flooring shall be installed per the manufactures recommendations. • Additional recommendations regarding water or vapor transmission should be provided by the architect/structural engineer/slab or foundation designer and should be consistent with the specified floor coverings indicated by the architect. Regardless of the mitigation, some limited moisture/moisture vapor transmission through the· slab should be anticipated. Construction crews may require special training for installation of certain product(s), as well as concrete finishing techniques. The use of specialized product(s) should be approved by the slab designer and water-proofing consultant. A technical representative of the flooring contractor should review the slab and moisture retarder plans and provide comment prior to the construction of the foundations or improvements. The vapor retarder contractor should have representatives onsite during the initial installation. Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, Inc. W.O. 6304-A-SC December 15, 2011 Page 37 WALL DESIGN PARAMETERS CONSIDERING EXPANSIVE SOILS Conventional Retaining Walls The design parameters provided below assume that either very low expansive soils (typically Class 2 permeable filter material or Class 3 aggregate base) or native onsite materials with an expansion index (El) of 50 or less are used for backfill within a minimum of 5 feet behind any retaining wall. The type of backfill (i.e., select or native), should be specified by the wall designer, and clearly shown on the plans. Based on laboratory testing, the onsite soils are not considered select backfill. However, a mixture of import (decomposed granite [DG] or manufactured sand) with the Delmar Sandstone may yield the select backfill criteria reported herein . • Building walls, below grade, should be water-proofed. A waterproofing specialist should be retained to provide recommendations for waterproofing the basement walls .The foundation system for the proposed retaining walls should be designed in accordance with the recommendations presented in this and preceding sections of this report, as appropriate. Footings should be embedded a minimum of 24 inches below adjacent grade (excluding landscape (ayer, 6 inches) and should be 24 inches in width. There should be no increase in bearing for footing width. Recommendations for specialty walls (i.e., crib, earthstone, geogrid, etc.) can be provided upon request, and would be based on site specific conditions. Restrained Walls Any retaining walls that will be restrained prior to placing and compacting backfill material or that have re-entrant or male corners, should be designed for an at-rest equivalent fluid pressure (EFP) of 55 pounds per cubic foot (pcf} for select backfill and 65 pcf for native backfill, plus any applicable surcharge loading. For areas of male or re-entrant corners, the restrained wall design should extend a minimum distance of twice the height of the wall (2H} laterally from the corner. Cantilevered Walls The recommendations presented below are for cantilevered retaining walls up to 12 feet high. Design· parameters for walls less than 3 feet in height may be superceded by City and/or County standard design. Active earth pressure may be used for retaining wall design, provided the top of the wall is not restrained from minor deflections. An equivalent fluid pressure approach may be used to compute the horizontal pressure against the wall. Appropriate fluid unit weights are given below for specific slope gradients of the retained material. These do not include other superimposed loading conditions due to traffic, structures, seismic events or adverse geologic conditions. When wall configurations are finalized, the appropriate loading conditions for superimposed loads can be provided upon request. For planning purposes, there does not appear to be traffic loads within the Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, lne. W.O. 6304-A-SC December 15, 2011 Page 38 influence of basement walls. Furthermore, surcharges from footings within the backfill of the basement will add surcharge of 0.35 multiplied by the contact pressure in the upper one-half of the wall and 0.2 multiplied by the contact pressure in the lower one-half of the wall. :_tf :rr~iiilr~t\t::-::,:--;: ·:,·FLlJfu1~t¼1iJ:t/\-·: f~:-}IG~tg!lNJ.d~/:-\: i/ao1::(1zotJrA(;VERTIGAL \:· .. ,;' ,-SELEc'.t'ijAc'iw1Ei.if _:, :~·:lNAftvE:aA~.KFILL *~* ·:' : I ;-:;· I ~~ I : I * Level backfill behind a retaining wall is defined as compacted earth materials, properly drained, without a slope for a distance of 2H behind the wall. ** As evaluated by testing, P.I. <15, E.I. <21, S.E. >30, and <10% passing No. 200 sieve. *** As evaluated by testin , E.I. <50, S.E. >25 and <15% passing No. 200 sieve. Earthquake Loads {Seismic Surcharge) Given the nature of the site soils and the anticipated level of potential earthquake shaking given herein, GSI recommends that for walls retaining more than, or equal to, 6 feet of soil and are 6 feet or less from the building or may inhibit ingress/egress for the site and/or building, incorporated into the building (stepped foundations), or critical access pathways (i.e., collector streets, fire access roads, etc.), a seismic surcharge (increment) of 15H should be used where H is the height of the wall and the surcharge is applied as a uniform pressure for restrained walls. For cantilever walls, this distribution may be taken as an inverted triangular distribution. This complies with a 0.23g Probabilistic Horizontal Site Acceleration (PHSA) 1 o percent probability of exceedance in 50 years. The resulting wall design should be safe from seismic induced overturning with a minimum factor-of-safety (F.O.S.) of 1.3. When considering a total lateral resistance of passive pressure on footings, friction, and support for the basement slab, the lateral pressures and friction may be increased by 1 .2 such that the earthquake load FOS against sliding when combined with the soil pressures, will yield a FOS of 1 .1 against sliding for the wall (assuming no shear key in footing). Basement walls, or utility or below grade storage areas, if proposed, will need to be evaluated as retaining walls, as well as part of the wall design from a seismic standpoint per the 2010 CBC (CBSC, 2010) and Section 15.6.1 of ASCE 7-05 (ASCE, 2006). Retaining Wall Backfill and Drainage Positive drainage must be provided behind all retaining walls not designed for hydrostatic loading in the form of gravel wrapped in geofabric and outlets. A backdrain system is considered necessary for retaining walls that are 2 feet or greater in height. Details 1, 2, and 3, present the back drainage options discussed below. Backdrains should consist of Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, lne. W.O. 6304-A-SC December 15, 2011 Page 39 (1) Waterproofing membrane ---, CMU or reinforced-concrete wall Structural footing or settlement-sensitive improvement Provide surface drainage via an engineered V-ditch (see civil plans for details) 2=1 (h=v) slope ~ ~ ... 4 . Proposed grade t - sloped to drain per precise civil drawings (5) Weep hole Footing and wall design by others--- (1) Waterproofing membrane. (2) Gravel= Clean, crushed, ¾ to 1½ inch. (3) Filter fabric= Mirafi 140N' or approved equivalent. Native backfill 1=1 (h=v) or flatter backcut to be properly benched (6) Footing (4) Pipe= 4-inch-diameter perforated PVC, Schedule 40, ot approved alternative with minimum of 1 percent gradient sloped to suitable, approved outlet point (perforations down). (5) Weep hole= Minimum 2-inch diameter placed at 2o~toot centers along the wall and placed 3 inches above finished surface. Design civil engineer to provide drainage at toe of wall. No weep holes for below-grade walls. (6) Fqoting= If bench is created behind the footing greater than the footing width, use level fill or cut natural earth materials. An additional "heel" drain will likely be required by geotechnical const.Jltant. RETAINING WALL DETAIL -ALTERNATIVE A Detail 1 .,, ~ . . (1) Waterproofing membrane (opt_ional)---, CMU or reinforced-concrete j\ 6inches -t (5) Weep hole Proposed grade sloped to drain per precise civil drawings //~~\\~~~\y~S\~(\\ Footing and wall design by others-..G-'-91o--1 Structural footing or settlement-sensitive improvement Provide surface drainage via engineered V-ditch (see civil plan details) 2=1 (h:v) slope : . . .. . ~ . . ... . ·... . · ... Native backfill 1:1 (h:v) or flatter backcut to be properly benched ------(6) 1 cubic foot of ¾-inch crushed rock (7) Footing (1) Waterproofing membrane (optional): Liquid boot or approved mastic equivalent. (2) Drain: Miradrain 6000 or J-drain 200 or equivalent for non-waterproofed walls; Miradrain 6200 or J-drain 200 or equivalent for waterproofed walls (all perforations down). (3) Filter fabric= Mirafi 140N or approved equivalent; place fabric flap_ behind core. (4) Pipe= 4-inch-diameter perforated PVC, ·Schedule 40, or approved alternative with minimum of 1 percent gradient to proper outlet point (perforations down). (5) Weep hole: Minimum 2-inch diameter placed at 20-foot centers along the wall and placed 3 inches above finished surf ace. Design civil engineer to provide drainage at toe of wall. No weep holes for below-grade walls. (6) Gravel: Clean, crushed,¾ to 1½ inch. (7) Footing: If bench is created behind the footing greater than the footing width, use level fill or cut natural earth materials. An additional "heel" drain will likely be required by geotechnical consultant. RETAINING WALL DETAIL -ALTERNATIVE B Detail 2 (1) Waterproofing membrane -~- CMU or reinforced-concrete wall Structural footing or settlement-sensitive improvement ,---Provide surf ace drainage 2=1 (h=v) slope .·. .. -· :-:-.. . · . ·... · .... : . . .. ~ ·:. : " ~ ..• -I) ----·-. . ~ ...... •.· .. " . . . ±12 inches .. . .. . . '. · j-.. ··:·. : ..... ~ .· ... . .-~-. ,. . ·.; ... ~ . . :_ . . ...... -.. . / ...................... l . . . . . . . . . . . . . . . . . . . . . . -·· . (5) Weep hole H [Proposed grade sloped to drain per precise civil drawings -<~~\\);(\\~\/'.: Footing and wall design by others . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ·-.. (3) Filter fabric (2) Gravel _(4) Pipe (7) Footing (1) Waterproofing membrane: Liquid boot or approved masticequivalent. (2) Gravel= Clean, crushed,¾ to 1½ inch. (3) Filter fabric= Mirafi 140N or approved equivalent. (8) Native backfill (6) Clean sand backfill 1=1 (h:v) or flatter backcut to be properly benched (4) Pipe: 4-inch-diameter perforated PVC, Schedule 40, or approved alternative with minimum of 1 percent gradient to proper outlet point (perforations down). (5) Weep hole: Minimum 2-inch diameter placed at 20-foot centers along the wall and placed 3 inches above finished surf ace. Design civil engineer to provide drainage at toe of wall. No weep holes. for below-grade walls. (6) Clean sand backfill: Must have sand equivalent value (S.E.) of 35 or greater; can be densified by wa:ter jetting upon approval by geotechnical engineer. (7) Footing: If bench is created behind the f coting greater than the footing width, use level fill or cut natural earth materials. An additional "heel" drain will likely be required by geotechnical consultant. (8) Native backfill: If E.I. (21 and S.E. 2,35 then all sand requirements also may not be required and will be reviewed by the geotechnical consultant. RETAINING WALL DETAIL -ALTERNATIVE C Detai.l 3 a 4-inch diameter perforated PVC or ABS pipe encased in either Class 2 permeable filter material or ¾-inch to 1 ½-inch gravel wrapped in approved filter fabric (Mirafi 140 or equivalent). The subdrain should flow via gravity at a minimum 1 percent slope to an approved outlet. A sump pump appears necessary to help drain the permanent below- grade walls. The project architect should design the sump pump such that saturation of the surrounding soils is avoided. For low expansive backfill, the filter material should extend a minimum of 1 horizontal foot behind the base of the walls and upward at least 1 foot. For native backfill that has an E.I. up to 50, continuous Class 2 permeable drain materials should be used behind the wall. This material should be continuous (i.e., full height) behind the wall, and it should be constructed in accordance with the enclosed Detail 1 (Typical Retaining Wall Backfill and Drainage Detail). For limited access and confined areas, (panel) drainage behihd the wall may be constructed in accordance with Detail 2 (Retaining Wall Backfill and Subdrain Detail Geotextile Drain). Materials with an E.I. potential of greater th~n 50 should not be used as backfill for retaining walls. For more onerous expansive situations, backfill and drainage behind the retaining wall should conform with Detail 3 (Retaining Wall And Subdrain Detail Clean Sand Backfill). Outlets should consist of a 4-inch diameter solid PVC or ABS pipe spaced no greater than ± 100 feet apart, with a minimum of two outlets, one on each end. The use of weep holes, only, in walls higher than 2 feet, is not recommended. The surface of the backfill should be sealed by pavement or the top 18 inches compacted with native soil (E.I. <50). Proper surface drainage should also be provided. For additional mitigation, consideration should be given to applying a water-proof membrane to the back of all retaining structures. The use of a waterstop should be considered for all concrete and masonry joints. Wall/Retaining Wall Footing Transitions Site walls are anticipated to be founded on footings designed in accordance with the recommendations in this report. Should wall footings transition from cut to fill, the civil designer may specify either: a) A minimum of a 2-foot overexcavation and recompaction of cut materials for a distance of 2H, from the point of transition. b) Increase of the amount of reinforcing steel and wall detailing (i.e., expansion joints or crack control joints) such that a angular distortion of 1 /360 for a distance of 2H on either side of the transition may be accommodated. Expansion joints should be placed no greater than 20 feet on-center, in accordance with the structural engineer's/wall designer's recommendations, regardless of whether or nottransition conditions exist. Expansion joints should be sealed with a flexible, non-shrink grout. c) Embed the footings entirely into native formational material (i.e., deepened footings). Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, Inc. W.O. 6304-A-SC December 15, 2011 Page 43 If transitions from cut to fill transect the wall footing alignment at an angle of less than 45 degrees (plan view), then the designer should follow recommendation 11a11 (above) and until such transition is between 45 and 90 degrees to the wall alignment. TOP-OF-SLOPE WALLS/FENCES/IMPROVEMENTS AND EXPANSIVE SOILS Expansive Soils and Slope Creep Soils atthe site are likely to be expansive and therefore, become desiccated when allowed to dry. Such soils are susceptible to surficial slope creep, especially with seasonal changes in moisture content. Typically in southern California, during the hot and dry summer period, these soils become desiccated and shrink, thereby developing surface cracks. Th_e extent and depth of these shrinkage cracks depend on many factors such as the nature and expansivity of the soils, temperature and humidity, and extraction of moisture from surface soils by plants and roots. When seasonal rains occur, water percolates into the cracks and fissures, causing slope surfaces to expand, with a corresponding loss in soil density and shear strength near the slope surface. With the passage of time and several moisture cycles, the outer 3 to 5 feet of slope materials experience a very slow, but progressive, outward and downward movement, known as slope creep. For slope heights greater than 1 O feet, this creep related soil movement will typically impact all rear yard flatwork and other secondary improvements that are located within about 15 feet from the top of slopes, such as concrete flatwork, etc., and in particular top of slope fences/walls. This influence is normally in the form of detrimental settlement, and tilting of the proposed improvements. The dessication/swelling and creep discussed above continues over the life of the improvements, and generally becomes progressively worse. Accordingly, the developer should provide this information to all interested/affected parties. In addition, surficial slope failures occutring along the slope descending from the subject site have the potential to affect improvements (walls, flatwork, etc.) constructed within about 5 feet from the top of this slope. To that end, improvements located within this zone should be supported by CIDH piles (caissons). Top of Slope Walls/Fences Due to the potential for slope creep for slopes higher than about 1 o feet, some settlement and tilting of the walls/fence with corresponding distress, should be expected. To mitigate the tilting of top of slope walls/fences, we recommend that the walls/fences be constructed on a combination of grade beam and caisson foundations. The grade beam should be at a minimum of 12 inches by 12 inches in cross section, supported by drilled caissons, 12 inches minimum in diameter, placed at a maximum spacing of 6 feet on center, and with a minimum embedment length of 7 feet below the bottom of the grade beam. The strength of the concrete and grout should be evaluated by the structural engineer of record. The Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, lne. W.O. 6304-A-SC December 15, 2011 Page 44 proper ASTM tests for the concrete and mortar should be provided along with the slump quantities. The concrete used should be appropriate to mitigate severe sulfate exposure. The design of the grade beam and caissons should be in accordance with the recommendations of the project structural engineer, and include the utilization of the following geotechnical parameters: Creep Zone: Creep Load: Point of Fixity: Passive .Resistance: 5-foot vertical zone below the slope face and projected upward parallel to the slope face. The creep load projected on the area of the grade beam should be taken as an equivalent fluid approach, having a density of 60 pcf. For the caisson, it should be taken as a uniform 900 pounds per linear foot of caisson's depth, located above the creep zone. Located a distance of 1.5 times the caisson's diameter, below the creep zone. Passive earth pressure of 300 psf per foot of depth per foot of caisson diameter, to a maximum value of 4,000 psf may be used to determine caisson depth and spacing, provided that _ they meet or exceed the minimum requirements stated above. To determine the total lateral resistance, the contribution of the creep prone zone above the point of fixity, to passive resistance, should be disregarded. Allowable Axial Capacity: · Shaft capacity : Tip capacity: 350 psf applied below the point of fixity (in bedrock) over the surface area of the shaft. 4,000 psf. EXPANSIVE SOILS, DRIVEWAY. FLATWORK. AND OTHER IMPROVEMENTS The soil materials on site are likely to be expansive. The effects of expansive soils are cumulative, and typically occur over the lifetime of any improvements. On relatively level areas, when the soils are allowed to dry, the dessication and swelling process tends to cause heaving and distress to flatwork and other improvements. The resulting potential for distress to improvements may be reduced, but not totally eliminated. To that end, it is recommended that the developer should notify all interested/affected parties of this long-term potential for distress. To reduce the likelihood of distress, the following recommendations are presented for all exterior flatwork: Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, Jne. W.O. 6304-A-SC December 15, 2011 Page45 potential for basement wall backfill settlement and any walkvyays that span the area may exhibit settlement relative to basement top-of-wall as ½ to ¾ inch. 8. Planters and walls should not be tied to the building. Landscape vegetation within the basement wall backfill zone should be located in below grade, enclosed planters so as to not introduce water into the underlying soils and not surcharge the basement walls. This may be achieved by providing an impermeable liner along the sides and bottoms of planter areas. The project civil engineer and structural engineer should provide the design of enclosed planters. 9. Overhang structures should be supported on the slabs, or structurally designed with continuous footings tied in at least two directions. Surcharges of overhang structures in the influence of the basement wall backfill should be evaluated as previously discussed. 1 O. Any masonry landscape walls that are to be constructed throughout the property should be grouted and articulated in segments no more than 20 feet long. These segments should be keyed or doweled together. 11. Positive site drainage should be maintained at all times. Finish grade on the lots should provide a minimum of 1 to 2 percent fall to the street, as indicated herein. It should be kept in mind that drainage reversals could occur, including post-construction settlement, if relatively flat yard drainage gradients are not periodically maintained by the owner or tenant. 12. Shrinkage cracks could become excessive if proper finishing and curing practices are not followed. Finishing and curing practices should be performed per the Portland Cement Association Guidelines. Mix design should incorporate rate of curing for climate and time of year, sulfate content of soils, corrosion potential of soils, and fertilizers used on site. UTILITIES Utilities should be enclosed within a closed utilidor {vault) or designed with flexible connections to accommodate differential settlement and expansive soil conditions. Due to the potential for differential settlement, air conditioning (NC) units should be supported by slabs that are incorporated into the building foundation or constructed on a rigid slab with flexible couplings for plumbing and electrical lines. NC waste waterlines should be drained to a suitable non-erosive outlet. Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, lne. W.O. 6304-A-SC December 15, 2011 Page 47 PRELIMINARY ASPHALTIC CONCRETE PAVEMENT DESIGN Asphaltic concrete pavement sections were analyzed using an assumed R-value and an assumed traffic index (T.1.) value. For preliminary planning purposes, the following AC pavement structural sections are provided in the following table. Final pavement structural sections should be based on R-value testing of soils exposed near the subgrade elevation following grading and underground utility construction. >/:\/./'(i .. '.:: .::~: : --<--·_'..,_ .. -~'</t :;~~Y(~~~.fJ~~j.1!;-9;211.~~~~ts;e~vgMs~t\.::-.'.-. :>·::::::/:\ >-_:,-.,. ... ~t:~~./.i: ~, it~!iJtI~-i{"1{1;'~;}¾t\·_;.: :t,i~~l :: ~~t~::tI~: t;t,r~i!!;!~ Drive Lanes 5.5 30 4.0 6.0 Parking Stalls 4.5 30 4.0 4.0 <1>TI values have been assumed for planning purposes herein and should be confirmed by the design team during future plan development. <2>Denotes standard Caltrans Class 2 aoaregate base R > 78, SE >22). The recommended pavement sections provided above are meant as minimums. If thinner or highly variable pavement sections are constructed, increased maintenance and repair could be expected. If the ADT (average daily traffic) beyond that intended, as reflected by the traffic index used for design, increased maintenance and repair could be required for the pavement section. Best management construction practices should be in effect at all times. Alternative Pavement Designs Alternative designs may be provided for drive lanes can be completed with either Portland Cement Concrete (PCC) or paver stones (pavers). Additional geotechnical recommendations to support design alternatives can be provided upon request. Pavement Grading Recommendations General Subgrade preparation and aggregate base preparation should be performed in accordance with the recommendations presented below, and the minimum subgrade (upper 12 inches) and Class 2 aggregate base compaction should generally be 95 percent of the maximum dry density (ASTM D 1557). If adverse conditions (i.e., saturated ground, etc.) are encountered during preparation of subgrade, special construction methods may need to be employed. Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, Ine. W.O. 6304-A-SC December 15, 2011 Page 48 These recommendations should be considered preliminary. Actual R-value testing and pavement design analyses should be performed upon completion of grading and underground utility trench backfill. All section changes should be properly transitioned. If adverse conditions are encountered during the preparation of subgrade materials, special construction methods may need to be employed. Subgrade Within streetareas, all surficial deposits of loose soil material generated underground utility construction should be removed or re-compacted as recommended. After the loose soils are removed, the exposed ground should be scarified to a depth of 12 inches, moisture conditioned as necessary and compacted to 95 percent of maximum laboratory density, as determined by ASTM Test Method D 1557. Deleterious material, excessively wet or dry pockets, concentrated zones of oversized rock fragments, and any other unsuitable materials encountered during roadway grading should be removed. The compacted fill material should then be brought to the elevation of the proposed subgrade for the pavement. The subgrade should be proof-rolled in order to ensure a uniformly firm and unyielding surface. All grading and fill placement should be observed by the project soil engineer and/or his representative. Aggregate Base Compaction tests are required for the recommended aggregate base section. The minimum relative compaction required will be 95 percent of the maximum laboratory density as determined by ASTM Test Method D 1557. Base aggregate should be in accordance to the "Standard Specifications for Public Works Construction" (green book) current edition. Paving Prime coat may be omitted if all of the following conditions are met 1. The asphalt pavement layer is placed within two weeks of completion of base and/or sub base course. 2. Traffic is not routed over completed base before paving. 3. Construction is completed during the dry season of May through October. Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, Ine. W.O. 6304-A-SC December 15, 2011 Page49 4. The base is free of dirt and debris. If construction is performed during the wet season of November through April, prime coat may be omitted if no rain occurs between completion of base course and paving and the time between completion of base and paving is reduced to three days, provided the base is free of dirt and debris. Where prime coat has been omitted and rain occurs, traffic is routed over base course, or paving is delayed, measures shaU be taken to restore base course, subbase course, and subgrade to conditions that will meet specifications as directed by the soil engineer. Drainage Positive drainage should be provided for all surface water to drain towards an approved drainage facility. Positive site drainage should be maintained at all times. Water should not be allowed to pond or seep into the ground. If planters or landscaping are adjacent to paved areas, measures should be taken to minimize the potential for water to enter the pavement section. These measures may include but not limited to subdrainage devices, thickened curbs, or concrete cut-off walls. DEVELOPMENT CRITERIA Drainage Adequate surface drainage is a very important factor in reducing the likelihood of adverse performance of foundations, hardscape, and slopes. Surface drainage should be sufficient to mitigate ponding of water anywhere on the property, and especially near foundations and pavements. Surface drainage should be carefully taken into consideration during fine grading, landscaping, and building construction. Therefore, care should be taken that future landscaping or construction activities do not create adverse drainage conditions. Positive site drainage should be provided and maintained at all times. Water should be directed away from tops of slopes and foundations, and not allowed to pond and/or seep into the ground. Site drainage should be designed in accordance with Section 1804.3 of the 201 o CBC. It should be kept in mind that drainage reversals could occur, including post-construction settlement, if relatively flat yard drainage gradients are not periodically maintained. Consideration should be given to avoiding construction of planters adjacent to the building and vehicular pavements. Site drainage should be directed toward the street or other approved area(s). Although not a geotechnical requirement, roof gutters, down spouts, or other appropriate means may be utilized to control roof drainage. Down spouts, or drainage devices should outlet a minimum of 5 feet from structures or into a subsurface drainage system. Areas of seepage may develop due to irrigation or heavy rainfall, and should be anticipated. Minimizing irrigation will lessen this potential. If areas of seepage develop, recommendations for minimizing this effect could be provided upon request. Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp 12\6300\6304a.gue GeoSoils, Ine. W.O. 6304-A-SC December 15, 2011 Page 50 Erosion Control Onsite earth materials have a moderate to high erosion potential. Consideration should be given to providing hay bales and silt fences for the temporary control of surface water, from a geotechnical viewpoint. Landscape Maintenance Only the amount of irrigation necessary to sustain plant life should be provided. Over-watering the landscape areas will adversely affect proposed site improvements. We would recommend that any proposed open-bottom planters adjacent to proposed structures be eliminated for a minimum distance of 1 O feet. As an alternative, closed-bottom type planters could be utilized. An outlet placed in the bottom of the planter, could be installed to direct drainage away from structures or any exterior concrete flatwork. If planters are constructed adjacent to structures, the sides and bottom of the planter should be provided with a moisture retarder to mitigate penetration of irrigation water into the subgrade. Provisions should be made to drain the excess irrigation water from the planters without saturating the subgrade below or adjacent to the planters. Graded slope areas should be planted with drought resistant vegetation. Consideration should be given to the type of vegetation chosen and their potential effect upon surface improvements (i.e., some trees will have an effect on concrete flatwork with their extensive root systems). From a geotechnical standpoint leaching is not recommended for establishing landscaping. If the surface soils are processed for the purpose of adding amendments, they should be recompacted to 90 percent minimum relative compaction. Gutters and Downspouts As previously discussed in the drainage section, the installation of gutters and downspouts should be considered to collect roof water that may otherwise infiltrate the soils adjacent to the structures. If utilized, the downspouts should be drained into PVC collector pipes or other non-erosive devices (e.g., paved swales or ditches; below grade, solid tight-lined PVC pipes; etc.), that will carry the water away from the structure, to an appropriate outlet, in accordance with the recommendations of the design civil engineer. Downspouts and gutters are not a requirement; however, from a geotechnical viewpoint, provided that positive drainage is incorporated into project design (as discussed previously). Subsurface and Surface Water Subsurface and surface water are not anticipated to affect site development, provided that the recommendations contained in this report are incorporated into final design and construction and that prudent surface and subsurface drainage practices are incorporated into the construction plans. Perched groundwater conditions along zones of contrasting permeabilities may not be precluded from occurring in the future due to site irrigation, poor drainage conditions, or damaged utilities, and should be anticipated. Should perched groundwater conditions develop, this office could assess the affected area(s) and provide Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, Ine. W.O. 6304-A-SC December 15, 2011 Page 51 the appropriate recommendations to mitigate the observed groundwater conditions. Groundwater conditions may change with the introduction of irrigation, rainfall, or other factors. Site Improvements If in the future, any additional settlement-sensitive improvements are planned for the site, recommendations concerning the geological or geotechnical aspects of design and construction of said improvements could be provided upon request. Fountains, spas, or pools should not be constructed without specific design and construction recommendations from GSI, and this construction recommendation should be provided to all interested parties. This office should be notified in advance of any fill placement, grading of the site, or trench backfilling after rough grading has been completed. This includes any grading, utility trench and retaining wall backfills, flatwork, etc. Tile Flooring Tile flooring can crack, reflecting cracks in the concrete slab below the tile, although small cracks in a conventional slab may not be significant. Therefore, the designer should consider additional steel reinforcement for concrete slabs-on-grade where tile will be placed. The tile in$taller should consider installation methods that reduce possible cracking of the tile such as slipsheets. Slipsheets or a vinyl crack isolation membrane (approved by the Tile Council of America/Ceramic Tile Institute) are recommended between tile and concrete slabs on grade. Additional Grading This office should be notified in advance of any fill placement, supplemental regrading of the site, or trench backfilling after rough grading has been completed. This includes completion of driveway approaches and utility trench, and retaining wall backfills. Footing Trench Excavation All footing excavations should be observed by a representative of this firm subsequent to trenching and prior to concrete form and reinforcement placement. The purpose of the observations is to evaluate that the excavations have been made into the recommended bearing material and to the minimum widths and depths recommended for construction. If loose or compressible materials are exposed within the footing excavation, a deeper footing or removal and recompaction of the subgrade materials would be recommended at that time. Footing trench spoil and any excess soils generated from utility trench excavations should be compacted to a minimum relative compaction of 92 percent, if not removed from the site. Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a:gue GeoSoils, Ine. W.O. 6304-A-SC December 15, 2011 Page 52 Trenching/Temporary Construction Backcuts Considering the nature of the onsite earth materials, it should be anticipated that caving or sloughing could be a factor in subsurface excavations and trenching. Shoring or excavating the trench walls/backcuts at the angle of repose {typically 25 to 45 degrees [except as specifically superceded within the text of this report]), should be anticipated. All excavations should be observed by an engineering geologist or soil engineer from GSI, prior to workers entering the excavation or trench, and minimally conform to Cal-OSHA, state, and local safety codes. Should adverse conditions exist, appropriate recommendations would be offered at that time. The above recommendations should be provided to any contractors and/or subcontractors, or property owners, etc., that may perform such work. Utility Trench Backfill 1. All interior utility trench backfill should be brought to at least 2 percent above optimum moisture content and then compacted . to obtain a minimum relative compaction of 90 percent of the laboratory standard. As an alternative for shallow (12-inch to 18-inch) under-slab trenches, sand having a sand equivalent value of 30 or greater may be utilized and jetted or flooded into place if approved by the controlling authorities. Observation, probing and testing should be provided to evaluate the desired results. 2. Exterior trenches adjacent to, and within areas extending below a 1 :1 plane projected from the outside bottom edge of the footing, and all trenches beneath hardscape features and in slopes, should be compacted to at least 92 percent of the laboratory standard. Sand backfill, unless excavated from the trench, should not be used in these backfill areas. Compaction testing and observations, along with probing, should be accomplished to evaluate the desired results. 3. All trench excavations should conform to Cal-OSHA, state, and local safety codes. 4. Utilities crossing grade beams, perimeter beams, or footings should either pass below the footing or grade beam utilizing a hardened collar or foam spacer, or pass through the footing or grade beam in accordance with the recommendations of the structural engineer. Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, Ine. _ W.O. 6304-A-SC December 15, 2011 Page 53 SUMMARY OF RECOMMENDATIONS REGARDING GEOTECHNICAL OBSERVATION AND TESTING We recommend that observation and/or testing be performed by GSI at each of the following construction stages: • During grading. • During excavation. • During placement of subdrains, toe drains, or other subdrainage devices, prior to placing fill and/or backfill. • After excavation of building footings, retaining wall footings, and free standing walls footings, prior to the placement of reinforcing steel or concrete. • Prior to pouring any slabs or flatwork, after presoaking/presaturation of building pads and other flatwork subgrade, before the placement of concrete, reinforcing steel, capillary break {i.e., sand, pea-gravel, etc.), or vapor retarders (i.e., visqueen, etc.). • During fountain construction. • During retaining wall subdrain installation, prior to backfill placement. • During placement of backfill for area drain, interior plumbing, utility line trenches, and retaining wall backfill. • When any unusual soil conditions are encountered during any construction operations, subsequent to the issuance of this report. • When any owner improvements, such as flatwork, fountains, walls, etc., are constructed, prior to construction. • A report of geotechnical observation and testing should be provided at the conclusion of each of the above stages, in order to provide concise and clear documentation of site work, and/or to comply with code requirements. OTHER DESIGN PROFESSIONALS/CONSULTANTS The design civil engineer, structural engineer, po~t-tension designer, architect, landscape architect, wall designer, etc., should review the recommendations provided herein, incorporate those recommendations into all their respective plans, and by explicit reference, make this report part of their project plans. This report presents minimum Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, lne. W.O. 6304-A-SC December 15, 2011 Page 54 design criteria for the design of slabs, foundations and other elements possibly applicable to the project. These criteria should not be considered as substitutes for actual designs by the structural engineer/designer. Please note that the recommendations contained herein are not intended to entirely preclude the transmission of water or vapor-through the slab or foundation. The structural engineer/foundation and/or slab designer should provide recommendations to not allow water or vapor to enter into the structure so as to cause damage to another building component, or so as to limit the installation of the type of flooring materials typically used for the particular application. The structural engineer/designer should analyze actual soil-structure interaction and consider, as needed, bearing, expansive soil influence, and strength, stiffness and deflections in the various slab, foundation, and other elements in order to develop appropriate, design-specific details. As conditions dictate, it is possible that other influences will also have to be considered. The structural engineer/designer should consider all applicable codes and authoritative sources where needed. If analyses by the structural engineer/designer result in less critical details than are provided herein as minimums, the minimums presented herein should be adopted. It is considered likely that some, more restrictive details will be required. If the structural engineer/designer has any questions or requires further assistance, they should not hesitate to call or otherwise transmit their requests to GSI. In order to mitigate potential distress, the foundation. and/or improvement's designer should confirm to GSI and the governing agency, in writing, thatthe proposed foundations and/or improvements can tolerate the amount of differential settlement and/or expansion characteristics and other design criteria specified herein. PLAN REVIEW Final project plans (grading, precise grading, foundation, retaining wall, landscaping, etc.), should be reviewed by this office prior to construction and bidding, so that construction is in accordance with the conclusions and recommendations of this report. Based on our review, supplemental recommendations and/or further geotechnical studies may be warranted. Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, lne. W.O. 6304-A-SC December 15, 2011 Page 55 LIMITATIONS The materials encountered on the project site and utilized for our analysis are believed representative of the area; however, soil and bedrock materials vary in character between excavations and natural outcrops or conditions exposec:f during mass grading. Site conditions may vary due to seasonal changes or other factors. Inasmuch as our study is based upon our review and engineering analyses and laboratory data, the conclusions and recommendations are professional opinions. These opinions have been derived in accordance with current standards of practice, and no warranty, either express or implied, is given. Standards of practice are subject to _change with time. GSI assumes no responsibility or liability for work or testing performed by others, or their inaction; or work performed when G_SI is not requested to be onsite, to evaluate if our recommendations have been properly implemented. Use of this report constitutes an agreement and consent by the user to all the limitations outlined above, notwithstanding any other agreements that may be in place. In addition, this report may be subject to review by the controlling authorities. Thus, this report brings to completion our scope of services for this portion of the project. All samples will be disposed of after 30 days, unless specifically requested by the client, in writing. Chabad at La Costa 1980 La Costa Avenue, Carlsbad File:e:\wp12\6300\6304a.gue GeoSoils, Inc. W.O. 6304-A-SC December 15, 2011 Page56 ' ' '' ,/' ( I' I· --{ APP,ENDIX. A ', \ •\ APPENDIX A REFERENCES ACI Committee 302, 2004, Guide for concrete floor and slab construction, ACI 302.1 R-04, dated June. Agra Earth and Environmental, Inc., 1.994, Report of geotechnical services, retaining wall and slope southeast of tank, Gafner Water Reclamation Plant, Carlsbad, California, Job No. 694-206, dated October 6. American Society for Testing and Materials, 1998, Standard practice for installation of water vapor retarder used in contact with earth or granular fill under concrete slabs, Designation: E 1643-98 (Reapproved 2005). __ , 1997, Standard specification for plastic water vapor retarders used in contact with soil or granular fill under concrete slabs, Designation: E 1745-97 (Reapproved 2004). American Society of Civil Engineers, 2006, Minimum design loads for buildings and other structures, ASCE Standard ASCE/SEI 7-05. BOS Engineering, Inc., 2003, Grading and erosion control plans for: Leucadia Wastewater District, sheet 9 of 9, DWG No. 452-4A, Project No. PDP 05-01, 30-scale, dated October 19. Blake, Thomas F., 2000a, EQFAULT, A computer program for the estimation of peak horizontal acceleration from 3-D fault sources; Windows 95/98 version. __ , 2000b, EQSEARCH, A computer program for the estimation of peak horizontal acceleration from California historical earthquake catalogs; Updated to December 201 o, Windows 95/98 version. Bozorgnia, Y., Campbell K.W., and Niazi, M., 1999, Vertical ground motion: Characteristics, relationship with horizontal component, and building-code implications; Proceedings of the SMIP99 seminar on utilization of strong-motion data, September 15, Oakland, pp. 23-49. Bryant, W.A., and Hart, E.W., 2007, Fault-rupture hazard zones in California, Alquist- Presley earthquake fault zoning act with index to earthquake fault zones maps; California Geological Survey, Special Publication 42, interim revision. California Building Standards Commission, 201 O, California Building Code, California Code of Regulations, Title 24, Part 2, Volume 2 of 2, Based on the 2009 International Building Code, 201 O California Historical Building Code, Title 24, Part 8; 201 o California Existing Building Code, Title 24, Part 1 O. GeoSoils, Ine. California Department of Conservation, California Geological Survey (CGS), 2003, The revised 2002 California probabilistic seismic hazard maps, June. California Department of Transportation, Division of Engineering Services, Materials Engineering, and Testing Services, Corrosion Technology Branch, 2003, Corrosion Guidelines, Version 1.0, dated September. California, State of, 2011, Civil Code, Sections 895 et seq. __ , 2001, Senate Bill 800, Burton. Liability: construction defects, February 23; approved by Governor September 20, 2002; filed with Secretary September 20, 2002; effective January 1, 2003. · Cao, T., Bryant, W.A., Rowshandel, 8., Branum, D., and Wills, C.J., 2003, The revised 2002 California probabilistic seismic hazard maps, dated June, http://www.conservation.ca.gov/cgs/rghm/psha/fault_parameters/pdf/Documents /2002 _CA_ Hazard_ Maps.pdf City of Carlsbad, 1991, Orthotopo mapping, sheet 189 of 225, DWG No. 296-5, 100-scale. Clough, G. W., and Tsui, Y., 1974, Performance of tied back walls in clay, Journal of Geotechnica/ Engineering Division, ASCE 100(GT12), 1259-1274 Leighton and Associates, Inc., 1992, City of Carlsbad, geotechnical hazards analysis and mapping study, Carlsbad,. California, Conway and Associates, Inc., 2011, Grading plans for: Chabad at La Costa, Submittal #1, 5 sheets, 10-scale, dated August 17. Diaz Yourman and Associates, 2005, Geotechnical investigation, La Costa Plaza -phase II building, Carlsbad, California, Proje_ct No. 2005-020, dated July 7. GeoSoils, Inc., 2011, Report of soil compaction testing during sewer lateral repair trench backfill, 1980 La Costa Avenue, Carlsbad, San Diego County, California, W.O. 6304-C-SC, dated October 1 o. __ , 1997, Preliminary geotechnical investigation, proposed Proposed Lucky/Savon Drug/Grocery Store #121-283, La Costa Area, Carlsbad, California, W.O. 2176-A-SC, dated February 6. Gregory, G.H., 2003, GSTABL7 with STEDwin, slope stability analysis system; Version 2.004. Chabad at La Costa File:e:\wp12\6300\6304a.gue GeoSoils, lne. Appendix A Page2 Heatherington Engineering, Inc., 201 0a, Geotechnical update, proposed sanctuary structure, 1980 La Costa Avenue, Carlsbad, California, Project No. 3462.2, Log No. 14706, dated August 13. __ , 201 Ob, Results of percolation testing, Chabad at La Costa, 1980 La Costa Avenue, Carlsbad, California, Project No. 3462.2, Log No. 14727, dated August 13. __ , 1999, Geotechnical .investigation, proposed Synagogue, 1980 La Costa Avenue, Carlsbad, California, Project No. 3462.1, Log No. 5062, dated October 26. International Conference of Building Officials, 2001, California building code. Jennings, C.W., 1994, Fault activity map of California and adjacent areas: California Division of Mines and Geology, Map Sheet No. 6, scale 1 :750,000. Kanare, H.M., 2005, Concrete floors and moisture, Engineering Bulletin 119, Portland Cement Association. Karnak Planning and Design, 2011, Preliminary architectural plans for: new Jewish community complex, Sheets A-001, A-101, A-102, A-201, A-202, A-203, A-301, A- 302, A-303, A-903, and A-904, Scales: 1 inch = 1 0 feet,-¼-inch = 1 foot, and ½- inch = 1 foot, Project No. 20110103, dated August 2. Kennedy, M.P, and Tan, S.S, 2005, Geologic map of the Oceanside 30' x 60' quadrangle, California, United States Geological Survey. Krinitzsky, E.L., Gould, J.P., and Edinger, P.H., 1993, Fundamentals of earthquake resistant construction: John H. Wiley & Sons, Inc., 299 p. M&T Agra, Inc., 1994,. Report of geotechnical investigation, building and slope southeast of tank, Gafner Water Reclamation Plant, Carlsbad, California, Job No. 694-107, dated July 15. Moss, R.E.S., Seed, R.B., Kayen, R.E., Steward, J.P., Tokimatsu, K., 2005, Probabilistic liquefaction triggering based on the cone penetration test, American Society of Civil Engineers. Romanoff, M., 1957, Underground corrosion, originally issued April 1. Seed, R.B., 2005, Evaluation and mitigation of soil liquefaction hazard "evaluation of field data and procedures for evaluating the risk of triggering (or inception) of liquefaction", in Geotechnical earthquake engineering; short course, San Diego, California,. April 8-9. Chabad at La Costa File:e:\wp12\6300\6304a.gue GeoSoils, Inc. Appendix A Page3 Sowers and Sowers, 1979, Unified soil classification system (After U. S. Waterways Experiment Station and ASTM 02487-667) in Introductory Soil Mechanics, New York. Tan, S.S., and Giffen, D.G., 1995, Landslide hazards in the northern part of the San Diego Metropolitan area, San Diego County, California, Landslide hazard identification map no. 35, plate 35D, Department of Conservation, Division of Mines and Geology, DMG Open File Report 95-04. Taniguchi, E., and Sasaki, Y., 1986, Back analysis of landslide due to Naganoken Seibu Earthquake of September 14, 1984; Proceedings, XI ISSMFE Conference, Session 78, San Francisco, California. Rolla, MO: University of Missouri. United States Geological Survey, 2011, Seismic hazard curves and uniform hazard response spectra -v5.1.0, dated October 21. Wire Reinforcement Institute, 1996, Design of slab-on-ground foundations, an update: a design, construction, and inspection aid for consulting engineers, TF 700-R-07 Update, dated March. __ , 1981, Design of slab-on-ground foundations: a design, construction, and inspection aid for consulting engineers, TF 700-R-07, dated August. Chabad at La Costa File:e:\wp12\6300\6304a.gue GeoSoils, Ine. Appendix A Page4 .~ , :· ) · ·, APPENDIX.B· -EXP.LO-R-ATIOJ~.t' · LOGS -' . ' -' ' ' . , . -~ -- •' '- 1 /' I' -1 ·· \. UNIFIED SOIL CLASSIFICATION SYSTEM CONSISTENCY OR RELATIVE DENSITY Major Divisions Group Typical Names CRITERIA Symbols GW Well-graded gravels and gravels sand mixtures, little or no fines Standard Penetration Test II) C: ~ 6i al II) ..,_ c·cn ~ ~ Poorly graded gravels and Penetration II) 0 0"¢ (.) .... > Cl) ~ :g . 0 GP gravel-sand mixtures, little or no Resistance N Relative II) "iii - 0 al 0 fines (blows/ft) Density 6 g?E.i:Z 0 e om 5 C\I 0 ::R .... -0 Silty gravels gravel-sand-silt 0-4 Very loose en • O al II) o5 .c GM =O 0 0 c: mixtures oz LOO I fa.:!: en c: -0 0 & 3: 4-10 Loose II) -0 Clayey gravels, gravel-sand-clay £ II) GC ~ .f: mixtures 10-30 Medium 0 al O> ID Well-graded sands and gravelly rn .... 30-50 Dense a3 ~ C en SW sands, little or no fines oO -II) (.) LO 0 C: 6i ca -o a, C > 50 Very dense C: ';fi._Q-;;; -ca al 0 (/) Poorly graded sands and -:5 o-enLOg~ SP ~ ~ffi-1:=0 gravelly-sands, little or no fines 0 al.c 11)2 ~ Cl)~~cn SM Silty sands, sand-silt mixtures II) al II) 1--.: 0 UJ {l -:5 ill o O rn E [ C: ·-C: Clayey-sands, sand-clay ~ == u:: SC mixtures Inorganic silts, very fine sands, Standard Penetration Test ML rock flour, silty or clayey fine sands en II) ~-'!::: ~ Unconfined 6i 5 _§ .!!! Inorganic clays of low to P~netration Compressive "iii ~ 32 0 CL medium plasticity, gravelly clays, Resistance N Strength 0 :;: .§-~ sandy clays, silty clays, lean ~~ (blows/ft) Consistency (tons/ft2) ~ _J lO clays ·5 . (/) (/) ~ Organic silts a:nd orgcl!lic silty <2 Very Soft <0.25 ai. ill OL clays of low plasticity -~ m Soft .... al 2-4 0.25-.050 0 Cl. Inorganic silts, micaceous or Q) ~ 4-8 Medium 0.50-1.00 .!: 0 MH diatomaceous fine sands or silts, u... E rn *->, 0 elastic silts 0 as .:::: u, 6 ,§ @ 8-15 Stiff 1.00-2.00 *-Inorganic clays of high plasticity, 0 -g32-5 CH LO ca ::J .... fat clays 15-30 Very Stiff 2.00-4.00 ~g~ ·-Q) (/) .... Organic cl11ys of medium to high >30 Hard >4.00 Cl OH plasticity Highly Organic Soils PT Peat, mucic, and other highly organic soils 3" 3/4" #4 #10' #40 #200 U.S. Standard Sieve Unified Soil Gravel Sand Silt or Clay Classification Cobbles I I I coarse fine coarse medium fine MOISTURE CONDITIONS MATERIAL QUANTITY OTHER SYMBOLS Dry Absence of moisture: dusty, dry to the touch trace 0-5% C Core Sample Slightly Moist Below optimum moisture content for compaction few 5-10% s SPTSample Moist Near optimum moisture content little 10-25 % B Bulk Sample Very Moist Above optimum moisture content some 25-45% ~ Groundwater .Wet Visible free water; below water table Qp Pocket Penetrometer BASIC LOG FORMAT: Group name, Group symbol, (grain size), color, moisture, consistency or relative density. Additional comments: odor, presence-of roots, mica, gypsum, coarse grained particles, etc. EXAMPLE: Sand (SP), fine to medium grained, brown, moist, loose, trace silt, little fine gravel, few cobbles up to 4" in size, some hair roots and rootlets. File:Mgr: c;\SoilClassif.wpd PLATE B-1 2 3 GeoSoils, Inc. PROJECT: CHABAD AT LA COSTA 1980 La Costa Ave., Carlsbad Sample 0 .c E (n en (.) en :::> SC SC BORING LOG w.o. ___ 63_0_4_-A_-_s_c_-1 BORING _____ B-_1 __ SHEET_ OF _3_ DATE EXCAVATED __ 11_-4_-_11 __ LOGGED BY:-'--R""B""B'---_ SAMPLE METHOD: Modifieg Cal Sampler, 140 lbs @ 30" Drop Standard Penetration Test Undisturbed, Ring Sample Approx. Elevation: 51' MSL '5l.. Groundwater Description of Material ARTIFICIAL FILL -UNDOCUMENTED: @0' CLAYEY SAND, yellowish brown and gray, moist, medium dense. HIGHLY WEATHERED TERTIARY DELMAR FORMATION: @ 2' CLAYEY SAND, gray, moist, medium dense. 5-1---+...,.,.,Jl-2-6-+--S-M---+------I--+---+"-_ ,.,,.. ..... _..,. .· -T,-,,E=R=-=TIA~R-Y-=-, =-DE""L-::MA:-::-:-:R-=Fo-=--R=-M-::-::-,ATl:=-::-0-::-:N-: --------------1 -~-· 6 ·,-,:-·. @5' SILTY SANDSTONE; reddish yellow, buff, and gray, moist 7 8 9 · ..:,..· · medium dense. .er.· ..;.:-.·. . "-r .. -~- "'-'17'" • 10-l---\,=,.J---:-l--::--::--+----+---+--½;,4--=-:-=--=---:--:-:=-::-=--::-:--:-:=-==-:-=--:-;;-:----c::-----:---::::---:------:--:------1 25/ SC @ 10' CLAYEY SANDSTONE, reddish yellow, buff, and gray, moist, . '-{"". 11 50-5" very dense. 12 13 14 21 22 5.1 24/ 50-2" SM SC .'-:".· .v-.· -~·-·...;,:.· . . er.· -~-- ·...;,,--·. ,;..r-.· -~-·.....:.-:-·. ,"-("".· .~.: -~-. :0:-.er. @ 15' SILTY SANDSTONE, reddish yellow, buff, and gray, moist, dense; fine te> coarse grained. @20' As per 15'. @22' CLAYEY SANDSTONE, reddish yellow, wet, dense. 23 24-l--i---J-~--+-,--ii----+--+---ffi7.;+---::::--::,-,-:--:::-:--:-=-.-:---=--:---::-::-:=c::c-:-:-=----:--:----:--:-----:--:----------l CL @24' SANDY CLAYSTONE, greenish gray, wet, hard; trace gypsum. 25 66 111.7 17.2 91.5 @25'Asper24'. 27 28 29 1980 La Costa Ave., Carlsbad GeoSoils, Inc. Plate B-2 GeoSoils, Inc. PROJECT: CHABAD AT LA COSTA 1980 La Costa Ave., Carlsbad ~ !E. t -"' Ql '3 0 Ill 31 32- 33- 34- 35- 36- 37- 38- 39- . 40- 41- 42- 43- 44c 45- 46~ 47- 48- 49- 50- 51- 52- 53- 54- 55- 56- 57- 58- 59- Sample "C Ql -e .a U), :a c:: ::, ~ 'c5 ..c [ en en 0 en ::, 50-6" CUML 1980 La Costa Ave., Carlsbad 'ts .e, ~ ~ ~ ~ ~ ::, .a U) c:-·o 0 ::E 113.0 14.8 ~ ~ 0 ~ c:: 0 :;:; E .a ca en 82.2 BORING LOG W.O. ___ 63_0_4_-A_-S_C __ -s BORING _____ B_-1 __ SHEET _3_ OF _3_ DATE EXCAVATED __ 1_1-4~_ -_1_1 __ LOGGED BY:.-'-R=B=B'--_ SAMPLE METHOD: Modified Cal Sampler, 140 lbs@ 30" Drop Standard Penetration Test Undisturbed, Ring Sample Approx. Elevation: 51' MSL '5;l.. Groundwater Description of Material @30' SANDY CLAYSTONE/SANDY SILTSTONE, gray, wet, hard. Total Depth= 31' No Groundwater/Caving Encountered Backfilled 11-4-2011 GeoSoils, Inc. Plate 8-3 BORING LOG GeoSoils, Inc. W. 0. 6304-A-SC PROJECT: CHABAD AT LA COSTA 1980-La Costa Ave., Carlsbad BORING ~----8-_2 __ SHEET_1 _ OF_1_ Sample 'O s· CD -e ~ ~ t rn . .><! 'O s: CD 'S C 0 Cl Ill ::> ii:i 1- 2- 0 .c E >, (I) (I) u (I) ::> SC '2 ::> ~ Cl DATE EXCAVATED __ 11_-4_-_11 __ LOGGED BY:..,_R=B:.:cB'--_ SAMPLE METHOD: Modified Cal Sampler, 140 lbs@30" Drop Standard Penetration Test Undisturbed, Ring Sample Approx. Elevation: 47' MSL ¥ Groundwater Description of Material ARTIFICIAL FILL -UNDOCUMENTED: @O' CLAYEY SAND, yellowish brown and gray, moist, medium dense. -~ ~ 3-r:7;; l----+----1--+-~--l-----1----+------fr/(..+-//,4--__ ~--~-..... --=---------------------l 4-· SC ¾ QUATERNARY COLLUVIUM: 1// @3½' CLAYEY SAND, gray, moist, loose. 5--1--~--+-@~e--3-8-+--S-M-+-'--~e-----1---+-: ::=e;,..:q. __ T_E_R_T_IA_R...,Y---D-EL_MA_R--:-._-,FO~R-M-AT_I_O_N_: -------------1 6-~ -;.,,;.-· @ 5' SIL TY SANDSTONE, buff and gray, moist, dense. 7- 8- 9- 10- 11- 12- 13- 14 ~ 38 ·...;.-:.·. .er.· .;...,:-.: ·....:r.-·. -~--~-- ·...;.-:-·. _'-'("',· .:._...:..,· ":---":"". ·..:,...·. ~---~-~ ,·..;.-:..· . . --r-.. .~.- ·...;.-:-·. . "-;'. -~-- @ 10' SILTY SANDSTONE, reddish yellow, buff, and gray, moist, dense; fine to medium grained. 15-~ 63 :0:: @ 15' SILTY SANDSTONE, grayish brown, moist, dense; fine grained, W, ·er.· micaceous. 16-+-----f-'-=<i----+--C-L--+-----+---+---+rr-'---'-='-"~~~c:-:-=-=-=-==-c=------=----,---------_/r · @ 16' SANDY CLA YSTONE, gray, wet, hard. 17- 18- 19- 20-1---1~..1--~--+-----l-----l---l----W'.U!--------,,-,-----,--,-------------------I 21 - W 301 CUML 1 ~ @20' SANDY CLAYSTONE/SANDY SILTSTONE, gray and reddish ~ 50-5" yellow, wet, hard. 22- 24- 23-I 25~-1--------1----~~----,----------l ~ 28/ CL ~ @ 25' SANDY CLAYSTONE, greenish gray, wet, hard. 26-l-----ifLLL4-la~>lhi-~,::...'",,1---+-----'-'--l---+----f<..£.u4---=-:-=--:----:-:-:--~-------------------l Total Depth = 26' 27- 28- 29- 1980 La Costa Ave., Carlsbad No Groundwater/Caving Encountered Backfilled 11-4-2011 GeoSoils, Inc. Plate B-4 I r . . . • LOG OF EXPLORATORY TEST PITS W.O. 6304-A-SC CHABAD AT LA COSTA 1980 La Costa Ave., Carlsbad, CA Logged By: RB September 19, 2011 f ;~~~~: ~It :~r:?i~~r1;~~1: ~~§~t~~ ~t~~;'.f !! !!~ii!~~ ~if ~i;~{f ~?~;~:~~;~;'.~~~?:~,~r~:;:~;~:;~;:~~,;,ff, TP-1 46 0-4½ 4½-4¾ 4¾-6 6-8 8-9½ 9½-15 15-15½ SC SM SP SW SM/ML SP/SM /ML Ml/CL UND@5 UND@10 UND@15 UND = Undisturbed 10.2 100.9 9.7 118.1 14.4 109.9 ARTIFICIAL FILL: CLAYEY SAND, mediµm brown, moist, dense; abundant organics. QUATERNARY COLLUVIUM: SILTY SAND, dark gray, dry, loose. HIGHLY WEATHERED TERTIARY DELMAR FORMATION: SIL TY SANDSTONE, light gray, damp, dense; highly fractured, @ 5' fractures: N60°E/68°NW, N2:9°W/73°SW. TERTIARY DELMAR FORMATION: SIL TY SANDSTONE, buff to reddish yeilow, moist, qense; fine to coarse grained, iron-oxide staining. @ 6½' Bedding: N3°E/10°NW (along iron-oxide stained bed). . SILTY SANDSTONE/SANDY SILTSTONE, light brownish gray, moist, dense. $IL TY SANDSTONE, light gray to reddish yellow, moist, very dense; trace discontinuous beds of silty fine grained sandstone/sandy siltstone. Bedding@ 12' N-S/25°W Bedding @ 15' N-S/22°W . SANDY SILTSTONE/SANDY CLAYSTONE; gray, moist, hard. Practical Refusal @ 15½' No Groundwater/Caving Encountered Backfilled 9-22-2011 PLATE B-5 "l·,t~)'· [ s} 'v' ',• ,", . :?t;;.:.:{', -'~.' ,, ~ LOG OF EXPLORATORY TEST PITS W.O. 6304-A-SC CHABAD AT LA COSTA 1980 La Costa Ave., Carlsbad, CA Logged By: RB September 19, 2011 ~ :?~;;~.~~ ... rJ,.;, { r-;-'_,.'>'1 ,"J, .. ·: -:.'}·.:";;;; ~~ ~;;~ .. :....-.~'-:(,·--~{.-. ···:-:' 7-·,;:\ , ~-"J "Ti-i:~:!,,-f_..2 ,:i: :1~:-,z: .. ::""1< .-: .:,., ••• ,-",., • , -~. '<:;,•. , ~ ..... .., ~.,. •• ,.__ , ,., ,, •••• -./ .,-; ~. ., .,,. ........ -.-,----, ---- 1 :-':,iJ'.'fEST ":,,·: ', ,f:[;EV ,,,, .. ,'.'i:>EP;J:W.;-, .''·GROlJP;,5:; ,i}~:,-,,§Al'y!P.l;.c,':}''~l"' l~~M6IST.t:J'Rif1 ~·f>FIElrO:DRiW::t ;:i;'.;,"';(,..;N?,-7;-r<i;,,.:./.J;' · .. ::<:, -'~·_;;,,:;,~-,.:,;·--.. _::: ·.· _',.'.i-\;::: ,,,_y_,.,:,:,, :?~ -:::•;:,,;r.,:·:'.· ,._ ;,;· , ··· '._ , ,t t;:i1~>3i~;r\f (\!~(:t: ,·~1~~;; ,it'f-tit~~~;?i~t~",~J°!,f~~;:l0~~tltlr:~~Jtt~'~~~~1~~~i.'.,\~:r,;::t\,L:::;, TP-2 48½ 0-1½ SC/SM 1½-2½ SM 2½-5¼ SM 5¼-6½ SM 6½-7½ SM 7½-9 SM 9-10 SM/ML - 10-12 SM .12-12½ SM UND@6 UND@12 Bulk @ 10-1 0½ UND = Undisturbed 10.5 115.3 ARTIFICIAL FILL (UNDOCUMENTED): CLAYEY SAND, gray, moist, medium dense to SILTY SAND, yellowish brown, moist, medium dense;· abundant organics. SLIGHTLY WEATHERED TERTIARY DELMAR FORMATION: SILTY SAND, light brownish gray, moist, dense. TERTIARY DELMAR FORMATION: SIL TY SANDSTONE, buff to light gray, moist, very dense; fine to medium grained with trace coarse grains. SIL TY SANDSTONE, light gray to reddish yellow, moist, very dense; cross· bedded. SILTY SANDSTONE, light gray to reddish yellow, moist, very dense; fine to coarse grained. SIL TY SANDSTONE, light gray to reddish yellow, moist, very dense. SIL TY fine grained SANDSTONE/SANDY SILTSTONE, light brownish gray, moist, very dense; locally scoured. SIL TY SANDSTONE, light gray and reddish yellow, wet, dense; fine to, medium grained with trace coarse grains . . SILTY $ANDSTONE, gray, moist, v~ry dense;@ 12' undulatory bedding dips N60°W/13°SWto N50°E/15°SE. Practical Refusal @ 12½ due to concretion No Groundwater/Caving Encountered Backfilled 9-22-2011 PLATE 8-6 \' ,I APP:ENDIXC '; :EQFAULT, EQSEARC'H;-J\1\,10 PHGA •T• ,. , • > Ir . • _I ./. / (. , 6304.0UT * * * E Q F A u L T * * * * version 3.00 * * * DETERMINISTIC ESTif"1ATION OF PEAK ACCELERATION FROM DIGITIZED FAULTS JOB NUMBER: 6304-A-SC DATE: 09-21-2011 JOB NAME: CHABAD AT LA COSTA CALCULATION NAME: 6304 FAULT-DATA-FILE NAME: c:\Program Files\EQFAULTl\CGSFLTE.DAT SITE COORDINATES: SITE LATITUDE: 33.0859 SITE LONGITUDE: 117.2662 SEARCH RADIUS: 62.14 mi ATTENUATION RELATION: 12) Bozorgnia Campbell Niazi (1999) Hor.-soft Rock-Cor. UNCERTAINTY (M=Median, S=5igma): s Number of sigmas: 1.0 DISTANCE MEASURE: cdist SCOND: 1 Basement Depth: .00 km Campbell SSR: 1 Campbell SHR: o COMPUTE PEAK HORIZONTAL ACCELERATION FAULT-DATA FILE USED: c:\Program Files\EQFAULTl\CGSFLTE.DAT MINIMUM DEPTH VALUE (km): 3.0 Page 1 W.O. 6304-A-SC Plate C-1 GeoSoils, Ine. 6304.0UT EQFAULT SUMMARY DETERMINISTIC SITE PARAMETERS Page 1 I !ESTIMATED MAX. EARTHQUAKE EVENT I APPROXIMATE 1------------------------------- ABBREVIATED I DISTANCE I MAXIMUM I PEAK !EST. SITE FAULT NAME I mi (km) !EARTHQUAKE! SITE !INTENSITY I I MAG.(Mw) I ACCEL. g IMOD.MERC. ==============l======l=====l====I==== ROSE CANYON I 5.7( 9.2)1 7.2 I 0.585 I X NEWPORT-INGLEWOOD (offshore) I 10.7( 17.3)1 7.1 I 0.361 I IX CORONADO BANK I 20.6( 33.2)1 7.6 I 0.275 I IX ELSINORE (JULIAN) I 25.0( 40.2)1 7.1 I 0.163 I VIII ELSINORE (TEMECULA) I 25.0( 40.2)1 6.8 I 0.133 I VIII ELSINORE (GLEN IVY) I 38. 8 c 62. ·s) 1 6. 8 1 o. 084 1 VII EARTHQUAKE VALLEY I 40.2( 64.7)1 6.5 I 0.066 I VI PALOS VERDES I 41.3( 66.5)1 7.3 I 0.112 I VII SAN JOAQUIN HILLS I 41.8( 67.2)1 6.6 I 0.097 I VII SAN JA~INTO-ANZA . I 47.8( 76.9)1 7.2 I 0.089 I VII SAN JACINTO-SAN JACINTO VALLEY I 49.5( 79.7)1 6.9 I 0.070 I VI SAN JACINTO-COYOTE CREEK I 50.9( 81.9)1 6.6 I 0.055 I VI NEWPORT-INGLEWOOD (L.A.Basin) I 52.4( 84.4)1 7.1 I 0.076 I VII ELSINORE (COYOTE MOUNTAIN) I 53.1( 85.4)1 6.8 I 0.061 I VI CHINO-CENTRAL AVE. (Elsinore) I 53.7( 86.5)1 6.7 I 0.079 I VII WHITTIER I 57.7( 92.8)1 6.8 I 0.056 I VI ·····~~······~~~~~~~~~····~···~·~······~~~··~·~·~~~·~···~······~~~~~··~·~··~·~~ -END OF SEARCH-16 FAULTS FOUND WITHIN THE SPECIFIED SEARCH RADIUS. THE ROSE CANYON FAULT rs CLOSEST TO THE SITE. IT IS ABOUT 5.7 MILES (9.2 km) AWAY. LARGEST MAXIMUM-EARTHQUAKE SITE ACCELERATION: 0.5846 g ·, Page 2 W.O. 6304-A-SC Plate C-2 GeoSoils, Inc. CALIFORNIA FAULT MAP CHABAD AT LA COSTA 1100 -,--------------------------------, 1000 900 800 700 600 500 ,, 400 I 300 ' I ' ll I 200 I I ., ' 100 0 -400 -300 -200 -100 0 100 200 300 400 500 600 W.O. 6304-A-SC Plate C-3 GeoSoils, Ine. 1 -s .1 C 0 .:: m :i.. (1) cii (,) (,) <( .1 W.O. 6304-A-SC MAXIMUM EARTHQUAKES CHABAD AT LA COSTA 1 l"I ~ ·• • • 10 Distance (mi) GeoSoils, lne. ~ 41 ., 1 '"~ 100 Plate C-4 6304.0lJT * * * E Q s E A R C H * * * * version 3.00 * * * ESTIMATION OF PEAK ACCELERATION FROM CALIFORNIA EARTHQUAKE CATALOGS JOB NUMBER: 6304-A-SC JOB NAME: CHABAD AT LA COSTA EARTHQUAKE-CATALOG-FILE NAME: ALLQUAKE.DAT SITE COORDINATES: SITE LATITUDE: 33.0859 SITE LONGITUDE: 117.2662 SEARCH DATES: START DATE: 1800 END DATE: 2010 SEARCH RADIUS: 62 .1 mi 100.0 km DATE: 09-21-2011 ATTENUATION RELATION: 12) Bozorgnia Campbell Niazi (1999) Hor.-soft Rock-cor. UNCERTAINTY (M=Median, S=Sigma): s Number of sigmas: 1.0 ASSUMED SOURCE TYPE: 55 [SS=Strike-slip, DS=Reverse-slip, BT=Blind-thrust] SCOND: 1 Depth Source: A Basement Depth: .00 km Campbell SSR: 1 Campbell SHR: 0 COMPUTE PEAK HORIZONTAL ACCELERATION MINIMUM DEPTH VALUE (km): 3.0 Page 1 W.O. 6304-A-SC Plate C-5 GeoSoils, Ine. 6304.0UT -------------------------EARTHQUAKE SEARCH RESULTS ------------------------- Page 1 -------------------------------------------------------------------------------I I I I TIME I I I SITE !SITE! APPROX. FILE! LAT. I LONG. I DATE I (UTC) IDEPTHIQUAKEI ACC. I MM I DISTANCE CODE! NORTH I WEST I I HM Seel (km)I MAG. I g !INT. I mi [km] ----+-------+--------+---------+--------+-----+-----+-------+----+------------ DMG l33.0000l117.3000 11/22/180012130 0.01 0.0 6.50I 0.396 I X I 6.2( 10.0) MGI l33.0000l117.0000 09/21/18561 730 0.01 0.0 5.00 0.065 I VI I 16.5( 26.6) MGI !32.8000 117.1000 05/25/18031 0 0 0.01 0.0 5.00 0.049 I VI I 22.0( 35.3) DMG 32.7000 117.2000 05/27/1862 20 0 0.01 0.0 5.90 0.069 I VI I 26.9( 43.3) T-A 32.6700 117.1700 12/00/1856 0 0 0.01 0.01 5.00 0.037 I V I 29.2( 47.1) T-A 32.6700 117.1700 10/21/1862 0 0 0.01 0.0 5.001 0.037 I VI 29.2( 47.1) T-A 32.6700 117.1700 05/24/1865 0 0 0.01 0.0 5.001 0.037 I V I 29.2( 47.1) • DMG 132.8000 116.8000 10/23/1894123 3 0.0 0.0 5.701 0.048 I VI I 33.5( 53.8) DMG l33.2000lll6.7000l01/0l/1920I 235 0.0 0.0 ~.00j 0.032 I V l 33.7( 54.2) PAS 132.9710 117.8700107/13/1986 1347 8.2 6.0 5.30! 0.035 I v I 35.8( 57.7) MGI 133.2000 116.6000!10/12/1920 1748 0.0 0.0 5.301 0.032 I VI 39.3( 63.3) DMG l33.7000 117.4000105/15/1910 1547 0.0 0.01 6.001 0.045 I VI I 43.1( 69.3) DMG 133.7000 117.4000105/13/1910 620 0.01 0.01 5.001 0.024 I V I 43.1( 69.3) DMG 133.7000 117.4000104/11/19101 757 0.01 0.01 5.001 0.024 V I 43.1( 69.3) DMG 33.6990 117.5110105/31/19381 83455.41 10.01 5.501 0.032 v I 44.6( 71.8) DMG 33.7100 116.9250109/23/1963 144152.6 16.51 5.00l 0.022 IV I 47.4( 76.2) DMG 33.7500 117.0000106/06/1918 2232 0.0 0.01 5.001 0.022 IV I 48.3( 77.8) DMG 33.7500l117.0000I04/21/1918 22322?.0 0.01 6.801 0.067 VI I 48.3( 77.8) DMG l33.0000l116.4330l06/04/1940 1035 8.3 0.01 5.101 0.023 I IV I 48.6( 78.2) GSP 133.5290 116.5720106/12/2005 154146.5 14.0I 5.201 0.023 I IV I 50.4( 81.1) PDG 133.4200 116.4890107/07/2010 235333.5 14.0I 5.501 0.028 I V I 50.5( 81.2) DMG 133.8000 117.0000112/25/1899 1225 0.01 0.01 6.40 0.048 I VI I 51.6( 83.1) PAS 133.5010 116.5130102/25/1980 104738.5 13.61 >.50 0.027 I v I 52.1( 83.8) GSP 133.5080 116.5140110/31/2001 075616.6 15.0I 5.10-0.021 I IV I 52.3( 84.1) DMG 133.5000 116.5000109/30/19161 211 0.0 0.01 5.00 0.020 I IV I 52.7( 84.7) MGI 133.8000 117.6000104/22/191812115 0.0 0.01 5.00 0.020 I IV I 52.9( 85.2) DMG l33.5750lll7.9830I03/ll/1933I 518 4.01 0.01 5.201 0.022 I IV I 53.4( 85.9) DMG l33.6170ll17.9670l03/ll/1933I 154 7.81 0.01 6.301 0.042 l VI I 54.6( 87.8) DMG 33.3430 116.3460104/28/19691232042.91 20.01 5.801 0.030 VI 56.0( 90.2) DMG 33.9000 117.2000112/19/18801 0 0 0.01 0.01 6.001 0.034 v I 56.3( 90.7) DMG 33.6170 118.0170103/14/1933119 150.0I 0.01 5.101 0.019 IV I 56.7( 91.3) T-A 32.25.00 117 .5000I01/13/1877j;W O 0.01 0.01 5.001 0.018 IV I 59.3( 95.4) DMG 33.4000l116.3000l02/09/1890l12 6 0.01 0.01 6.301 0.038 VI 59.9( 96.3) DMG l33.6830lll8.0500I03/ll/1933I 658 3.01 0.01 5.501 0.023 IV I 61.2( 98.4) DMG l32.7000l116.3000I02/24/1892I 720 0.01 0.01 6.701 0.048 VI I 62.0( 99.8) DMG l33.2000l116.2000I05/28/1892llll5 0.01 0.01 6.301 0.037 v I 62.1(100.0) -END OF SEARCH-36 EARTHQUAKES FOUND WITHIN THE SPECIFIED SEARCH AREA. TIME PERIOD OF SEARCH: 1800 TO 2010 LENGTH OF SEARCH TIME: 211 years THE EARTHQUAKE CLOSEST TO THE SITE IS ABOUT 6.2 MILES (10.0 km) AWAY. LARGEST EARTHQUAKE MAGNITUDE FOUND IN THE SEARCH RADIUS: 6.8 Page 2 W.O. 6304-A-SC GeoSoils, lne. Plate C-6 6304.0UT LARGEST EARTHQUAKE SITE ACCELERATION FROM THIS SEARCH: 0.396 g COEFFICIENTS FOR GUTENBERG & RICHTER RECURRENCE RELATION: a-value= 0.597 b-value= 0.311 beta-value= 0.717 TABLE OF fvtAGNITUDES AND EXCEEDANCES: Earthquake I Number of Times I cumulative Magnitude I Exceeded I No./ Year -----------+-----------------+------------ 4.0 I 36 I o.17143 4.5 I 36 I 0.17143 5.o I 36 I o.17143 5.5 I 16 I 0.07619 6.o I g I o.04286 6.5 I 3 I 0.01429 Page 3 W.O. 6304-A-SC GeoSoils, Ine. Plate C-7 s.. ca ~ --z -u, -C Cl) > w -0 s.. Cl) .a E :::J z Cl) > i -:::J E E :::J 0 EARTHQUAKE RECURRENCE CURVE CHABAD AT LA COSTA 100 10 1 .1 .01 .001 ;'i;l •!! t~ ill i I fl ~ ft~ ffl wi l'il I ;g, t. .................... i. 0 .......... ~· I ~1 ~ .. fq -~ ~ I j I ~ ---I ....... .......__ ill' 0 ' ' ' ffl iii! I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I " ...,. .~ -%+,<,,;»!$,~tf£3'1 {~'f;,{"£~·vef·rs .~~ ~ 'f.!'~-)':,_1",,,~ '" ,~:o'..l>""~{f <"' ~ ·l-:;~w1~~u f!'i'~"-w" .. 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 Magnitude (M) W.O. 6304-A-SC Plate C-8 GeoSoils, Inc. EARTHQUAKE EPICENTER MAP CHABAD AT LA COSTA 1100------------------------~ 1000 900 800 700 600 500 400 300 LEGEND· 1- 200 "' ··,( M =4 c· M =5 100 .J D M=6 L M=7 c::. 0 '. .. .-M = 8 -400 -300 -200 -100 0 100 200 300 400 500 600 W.O. 6304-A-SC Plate C-9 GeoSoils, Ine. ~ "'D!=> s~ mt' c;>~ ..., en oO 34• ,., ~ ' ' --~--_,...,,.. CHABAD Geographic Deagg. Seismic Hazard for 0.00-s Spectral Accel, 0.4352 g PGA Exceedance Return Time: 2475 year Max. significant source distance 106. km. View angle is 35 degrees above horizon Gridded-source hazard accum. in 45° intervals Soil site. Vs30(m/s).; 500.0 ~ -.... -..,,...,.._,. . . ....... . _,. . . \ \ 8.4 8.1 7.8 7.5 7.2 M 6.9 6.6 6.3 6.0 5.7 ·-----........ . \ l a , . • ~ . ~--------. ------, I t -,~~-. · . . --------·----..:...__ ' . '-, -... . ·._201oed-____ ~--· ....... '---..... -~.............. ... . . --<""'", ·,.. ~ -~--,,_ / .,_~ .,,........__ . "-... ..... B ~ i'. ., ' '~..?<~~~ .. ',._ . Iv·•''· '.e ·.,X··~-.... I ·.~i,".,,,,_' :,~,,·:,:;j/f ~~, -. ...___ ,,,·J, ... '~/·:· ... ·~ "· · .. :: /; \~ r ""''"c:.-•.... , ' ::\'tt~'-·• : . ·~-· . n\\, '-' ·"¾~:: 1t,.~•;/. > • :: >. ,· '.\\. : tf ~'.t~~\. ~{I~~--··\~ ,, ·= -. ->--;.~ ~~ ,;3,{:'f --,.':':-. •. ,..,.~:,;,'§ > •• 33• 7: •. ~-· · · · \. :sl,~ -~ :~; r·-~:;,·u:i_:,": ~ \ ii~~~ :~ #.~~J~ • ""~t ~ -.1:~-" • ' • ,,..< • .,~ ,,) :· ,··"fl.,,, .,,. ', w .. ,,gc< 1 .Clil, .$:'oi{ ··· :::,,.. . · ,..,..x'\1;-,._; ,\, ·:: t· . I .!!!! Iii 0 11111 "'-~ . ~ . ., ..• ~,,,., .:·A·!!,.',,-.,;, .. i·•l\x··••,: ···· ~. a, ,, '.'\<< 4 /-;~; '\ :~. -·· ,,. =>··... /' 1 ·,., . , .... ,.,,,..,,,.,, . .,.,,,. . -·so, · «:::: . 7 ). ~~ ... :1 .4, ';: -~ . " .. ---. . .- c ·• ~· ~' ·.~· ~} ,,.,,\ ·--,~· / ;r •... c~~~t~-;J ,~~, ....... ;.·· "' cli .· 2:,.,,:;, ~' ,:;\!#:;; -~:;,.;_.l,•''.c,~.-, J~~:, ~ 34• 33· #Mi• 2011 Nov 22 22:26:38 j Site Coords:•117.266 33.0859 (yellow disk) Vs30= 500.0. Max annual ExcdRate .1235E·03 (column height prop. to ExRate). Red diamonds: historical earthquakes, M>6 ~ ,,9 r en ~~ mt 0~ .!.. (/) .... 0 34• 33• 32" "' ~ CHABAD Geographic Deagg. Seismic Hazard for 0.00-s Spectral Accel, 0.2308 g PGA Exceedance Return Time: 475 year Max. significant source distance 1.39. km. View angle is 35 degrees above horizon Gridded-source hazard accum. in 45° intervals Soil site. Vs30(m/s) ~ 500.0 ~ ... ~,-~~' .... · 8.3 8.0 7.7 7.4 7.1 M 6.8 6.5 6.2 5.9 5~6 ~ ~!t.1.- -... ___ .,.,,,, ..,:.-'""'.:-..... 1010ed""--.. -.. , __ -_ __... , · •' . . ,,. .. ---~~~-=~-':f·;:;:;.<.. __ =~·=::;:~·-··--" \ ,. -. . -~. ··•-·, ··--~ "' ~ c::,.._. ____ _ ~ -----r----o-·----\\ • ..___--~ ......... ........__~- ,..,.,,.,,, ... , "° ~-- ~; ,,·,....,_ -~· --·--....... C: A" .. ·--~, '. ~ . '\.,,, ' '·· .. ,,._ ~ ......... -... ' ~-.. ~ ,,.., -~ . :/., .. .., ~ 34• 33• 32• Site Coords:-117,266 33.0859 (yellow disk) Vs30= 500.0. Max annual ExcdRate .3427E-03 (column height prop. to ExRate). Red diamonds: historical earthquakes, M>S / '· I, \' ,' ,· APPENDIX ·Q. .. ' LASORATO.RV .DATA· '' . / • I ./ 60 / V / ~v / CL CH / / / / 50 / 1,/ / / / / >< / / w 40 / V 0 v z / / >-/ / I-/ g 30 / --/ Cl) / <( / _J / a. / / 20 / / , V / D / / / / / / 10 / / / CL-t,'1L ML MH I 0 I 0 20 40 60 80 100 LIQUID LIMIT Sample Depth/El. LL PL Pl Fines uses CLASSIFICATION e B-2 16.0 47 17 30 D TP-2 10.0 34 17 17 20 CLAYEY SAND(SC) cli :,;: " I-C C) o:i 5 en ::, -, 0. C) <t 0 "' CD en A TTERBERG LIMITS' RESULTS I-~ GeoSoils, Inc. :::; C) {§ 'ii:. 57 41 Palmer Way Project: CHABAD AT LA COST A 0: UJ Carlsbad, CA 92008 "' ti 0: <~;\ Telephone: (760) 438-3155 Number: 6304-A-SC UJ , ' I-!;i" en Fax: (760) 931-0915 Date: December 2011 Plate: D -1 ::, - -U.S. SIEVE OPENING IN INCHES I U.S. SIEVE NUMBERS I HYDROMETER 6 4 3 2 1.5 1 3/4 1/23/8 3 4 6 s10 1416 20 30 40 50 60 100140200 100 I II I I I :r{ I I I I I I 95 : I". : '\ 90 : \ : : : 85 : : : \ : : 80 75 : : 70 : •' : --I-65 :r: : C) : : I ui60 : : I s : : fu55 -~ 0::: W50 z : ;\ ~45 : \ : z ~40 0::: ~ ~35 : \ : : \ 30 ' : : 25 .- : : \~ 20 : : : : 15 : : 10 : : 5 : 0 : 100 10 1 0.1 0.01 GRAIN SIZE IN-M!LL!METERS I COBBLES GRAVEL SAND ] · coarse I SILT OR CLAY coarse fine medium fine _ Sample Depth Range Visual Classification/USCS CLASSIFICATION LL PL Pl Cc • TP-2 10.0 10-10.5 CLAYEY SAND(SC) 34 17 17 Sample Depth D100 D60 D30 D10 %Gravel %Sand %Silt I iii. TP-2 10.0 4.75 0.549 0.162 0.0 79.6 20.4 ~· ~ I-0 (!) iri <( ..J (/) :::, .., ll.. (!) ..; 0 "' co w N w- z <( 0:: (!) (/) :::, tti~~~( ' 'ils~Im:. l ~\;;[~ ~~' t,; GeoSoils, Inc. GRAIN SIZE DISTRIBUTION 57 41 Palmer Way Project: CHABAD AT LA COSTA Carlsbad, CA 92008 Telephone: (760) 438-3155 Number: 6304-A-SC Fax: (760) 931-0915 Date: December 2011 Plate: D-2 0.001 I Cu %Clay b (!) ; Cl) :::, --, a. (!) ... 0 ra a: iii :c Cl) f-u w a: 0 Cl) :::, • D - 4,000 3,500 3,000 / vi ~ 2,500 it / / / -Cl) a. / V I°" I-C) z UJ 2,000 / c:: v[ V I-en, c:: <( / UJ / :r: en 1,500 / / / V 4 1,000 ,.,-1 n / 1/ 500v / ,- 0 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 NORMALPRESSURE, psf Sam!)le Depth/El. Range Classification. Primary/Residual Sami:>le Type % MC% C ~ TP-2 10.0 10-10.5 CLAYEY SAND(SC) Primary Shear Undisturbed 109:9 14.5 917 29 TP-2 10.0 Residual Shear Undisturbed 109.9 14.5 446 32 Note: Sample lnnundated Prior To Test GeoSoils, Inc. DIRECT SHEAR TEST fl t.1~~~Jp 57 41 Palmer Way Proj~ct: CHABAb AT LA COSTA ils~Im:. Carlsbad, CA 92008 ,:;,:;:;}-~ ,Fi Telephone: (760) 438-3155 Number: 6304-A-SC '"·<i..''.f,.,;>!.,"11'.,,.,. .. ,.,.·t,,::; Fax: E760) 931-0915 Date: -December 2011 Plate: D -3 I-D (!) ID 5 en :::, -, a. (!) ..,. g (0 a:: <t lU :c en 1-(.) lU a:: i5 en :::, • D 1/ 3,000 / V V / 2,500 / / / V / • / 2,000 --I/ V U) 0.. / Ji !-Cl z / w 0::: !-en 1,500 0::: I/ / c:( w / :r: en 1,000 V 500 V 0 0 500 1,000 1,500 2,000 2,500 3,000 NORMAL PRESSURE, psf Sample Depth/El. Range Classifi~tion Primary/Residual Sample Type Y4 MC% C <p B-1 30.0 Clayw/ Sand Primary Shear Undisturbed 113.0 14.8 1373 36 B-1 30.0 Residual Shear Undisturbed 113.0 14.8 62 42 Note: Sample lnnundated Prior To Test GeoSoils, Inc. DIRECT SHEAR TEST &~:m;~ 5741 Palmer Way . Project: CHABAD AT LA COSTA ·-··:.Ink Carlsbad, CA 92008 ''.I\"":,"_&'\ • Telephone: (760) 438-3155 Number: 6304-A-SC ¾.t;:9 {.; Fax: (760) 931-0915 Date: December 2011 Plate: D-4 AP Engineering & Tesf.ing, Inc. UNCONSOUDATED UNDRAINED TRIAX!Al TESl (UU,Q) ASTM D2850 Client Name: GeoSoils, Inc. Project N9me: Chabad at La Costa Project No.: 6304-A-SC Boring No.: B-1 Sample No.: Depth (feet}: 25 Soil Description Dark Greenish Gray Clay Sample Diameter (inch): Sample Hieght (inch): Sample Weight (gms}: Wt. Wet Soil+Container(gms) Wt. Dry Soil+'Container(gms) Wt. Container (gms} Cell Pressure (ksf): Back Pressure·(ksf): Eff. Confining Pressure (ksf): Shear Rate(%/min): Maximum Deviator Stress (ksf): Ultimate Deviator Stress (ksf), 2.350 5.978 891.88 1038.99 908.16 147.76 Ultimate Undrained Shear Strength (ksf): Axial Strain@ Maximum Stress(%) i.::-! 1.75 0.0 J.75 0.3 13.20 9.76 4.88 4.18 TEST DATA /g 8.0 +---t----t-------t-----+------1 E -en ... .S 6.0 -1-+-----f-------+---~-------r (IS ·;;: Q) Cl 0 5 10 15 20 Axial Strain (%). Tested By: ST Date: 11/14/11 11/18/11 ---Checked by: AP Date: --- Sample Type: Mod Cal Wet Unit Weight (pcf): 131.0 Dry Unit Weight (pcf): 111.7 Moisture Content(%}: 17.2 Void Ratio for Gs=2.7: % Saturation: 0.51 91.5 Load {lbs) 0 32 48 80 94 110 192 280 325 375 406 415 414 368 358 331 313 315 314 308 315 324 331 338 344 348 353 evIator Def. (inch) Area Stress AxIa Strain (sq.in) (ksf) (%) 0.000 4.34 0.00 0.00 0.005 4.34 1.06 0.08 0.010 4.34 1.59 0.17 0.020 4.35 2.65 0.33 0.025 4.36 3.11 0.42 0.030 4.36 3.63 0.50 0,060 4.38 6.31 1.00 0.090 4.40 9.16 1.51 0.120 4.43 10,57 2.01 0. i50 · '4.45 12.14 · 2.5i 0.200 4.49 13.03 3.35 0.250 4.53 13.20 4.18 0.300 4.57 13.05 5.02 0.350 4.61 11.50 5.85 0.400 4.65 11.09 6.69 0.450 4.69 10.16 7.53 0.500 4.73 9.52 8.36 0.550 4.78 9.50 9.20 0.600 4.82 9.38 10.04 0.650 4.87 9.11 10,87 0.700 4.91 9.23 11.71 0.750 4.96 9.41 12.51? 0.800 5.01 9.52 13.38 0.850 5.06 9.63 14.22 0.900 5.11 9.70 15.06 0.950 5.16 9.72 15.89 1.000 5.21 9.76 16.73 Prime Testing1 Inc. 41658 Ivy Street Ste 114 Murrieta, CA 92562 ph (951) 894-2682 • fl:: (951) 894-2683 Work Order No.: 11J2200 Client: GeoSoils, lr:ic. Project No.: 6304-A-OC Project Name: Chabad Report Date: October 27, 2011 Laboratory Test(s) Results Summary The subject soil s~mple was processed in accordance with California Test Method CTM 643 and tested for pH/ Minimum Resistivity (CTM 643), Sulfate Content (CTM 417) and Chloride Content (CTM 422). The test results follow: Minimum Sulfate Sulfate Chloride Sample Identification pH Resistivity Content Content Content (ohm-cm) (mg/kg_) (% bywgt) (ppm) TP-2@ 10' 6.0 660 1,600 0.160 ND *ND=No Detection We appreciate the-opportunity to serve you. Please do not hesitate to contact us with any questions or clarifications regarding these results or procedures . .. Jlfilk: I ' ___ ,_;JR f' f,'liTlrnNATta-rlAL ' C!Cllt'llZATIONAL f~EMBER www.primetesting.com . Ahmet K. Kaya, Laboratory Manager Form No. CP-1R w.o. 6304-l~gll!10 Plate D-6 Cal Land Engineering, !nc. dba Quartech Consultant Geotechnical, Environmental, and Givil Engineering SUMMARY OF LABORATORY TEST DATA GeoSoils, Inc. 57 41 Palmer Way, Suite D Carlsbad, CA 9201 0 Client: Chabad Geo Soils W.O. 6304-A-SC Sample JD B-1 @ 25'-27' QCI Project No.: 11-029-11e Date: November 11, 2011 Summarized by: ABK Corrosivity Test Results pH Chloride Sulfate _ Resis~vity . CT-417 CT-532 CT-.422 %By CT-532 {643) (643) (ppm) W~iQht (ohm-cni)_ 7.12 123 0.580 235 576 East Lambert Road, Brea: California 92821; Tel: 714-671-1050; Fax: '714~671-1090 W.O. 6304-A-SC Plate D-7 ,· /' r, / SLOPE STABILITY.ANALYS]S ·-', ' • r ; ., ,, / I - APPENDIX E SLOPE STABILITY ANALYSIS INTRODUCTION OF GSTABL7 v.2 COMPUTER PROGRAM Introduction GSTABL v.2 is a fully integrated slope stability analysis program. It permits the engineer to develop the slope geometry interactively and perform slope analysis from within a single program. The slope analysis portion of GSTABL v .2 uses a modified version of the popular STABL program, originally developed at Purdue University. GSTABL v.2 performs a two dimensional limit equilibrium analysis to compute the factor of safety for a layered slope using the modified Bishop or Janbu methods. This program can be used to search for the most critical surface or the factor of safety may be determined for specific surfaces. GSTABL v.2 is programmed to handle: 1. Heterogenous soil systems 2. Anisotropic soil strength properties 3. Reinforced slopes 4. Nonlinear Mohr-Coulomb strength envelope 5. Pore water pressures for effective stress analysis using: a. Phreatic and piezometric surfaces b. Pore pressure grid c. R factor d. Constant pore water pressure 6. Pseudo-static earthquake loading 7. Surcharge boundary loads 8. Automatic generation and analysis of an unlimited number of circular, noncircular and block-shaped failure surfaces 9. Analysis of right-facing slopes 1 o. Both SI and Imperial units. General Information If the reviewer wishes to obtain more information concerning slope stability analysis, the following publications may be consulted initially: 1. 2. The Stability of Slopes, by E.N. Bromhead, Surrey University Press, Chapman and Hall, 374 pages, ISBN 412 01061 5, 1985. Rock Slope Engineering. by E. Hoek and J.W. Bray, Inst. of Mining and Metallurgy, London, England, Third Edition, 358 pages, ISNB 0 900488 573, 1981. GeoSoils, Inc. 3. Landslides: Analysis and Control. by R.L. Schuster and R.J. Krizek (editors), Special Report 176, Transportation Research Board, National Academy of Sciences, 234 pages, ISBN 0 309 02804 3, 1978. GSTABL v.2 Features The present version of GSTABL v.2 contains the following features: 1 . Allows user to calculate factors of safety for static stability and dynamic stability situations. 2. Allows user to analyze stability situations with different failure modes. 3. Allows user to edit input for slope gebmetry and calculate corresponding factor of safety. 4. Allows user to readily review on-screen the input slope geometry. 5. Allows user to automatically generate and analyze unlimited number of circular,non- circular and block-shaped failure surfaces (i.e., bedding plane, slide plane, etc.). Input Data Input data includes the following items: 1. Unit weight, residual cohesion, residual friction angle, peak cohesion, and peak friction angle of fill material, bedding plane, and bedrock, respectively. Residual cohesion and friction angle is used for static stability analysis, whereas peak cohesion and friction angle is for seismic stability analysis. 2. Slope geometry and surcharge boundary loads. 3. Apparent dip of bedding planes can be specified in angular range (i.e., from 0 to 90 degrees. The Table E-1 presents the apparent dip and orientation (with respect to the slope face) of bedding used in our analysis: Chabad at La Costa File:e:\wp12\6300\6304a.gue GeoSoils, Ine. Appendix E Page2 TABLE E-1 APPARENT DIP OF BEDDING PLANES Tertiary Delmar Forrnatior;i 25 out of slope Slope (Sandstone Member [Tdss]) 15 into slope Tertiary Delmar Formation 15 out of slope Building Pad (Sandstone Member [Tdss] 15 into slope Tertiary Del Mar Formation 25 out of slope (lnterbedded Member [Td-ib]) Slope 15 into slope Tertiary Del Mar Formation 30 out of slope (lnterbedded Member [Td-ib]) Building Pad 30 into slope Tertiary Delmar Formation (Claystone Member Slope N/A NIA [Td-clstn]) Tertiary Delmar Formation 25 Out of Slope (Claystone Member Building Pad [Td-clstnl) 20 Into Slope 4. The horizontal seismic coefficient utilized for pseudo-static earthquake loading was reasonably and conservatively estimated at 0.15 and the vertical seismic coefficient was considered at 0.08. Seismic Discussion Seismic stability analyses were approximated using a pseudo-static approach. The major difficulty in the pseudo-static approach:arisesfrom the appropriate selection of the seismic coefficient used in the analysis. The use of a static inertia force equal to this acceleration during an earthquake (rigid-body response) Yiould be extremely conservative for several reasons including: 1) only low height, stiff/dense embankments or embankments in confined areas may respond essentially as rigid structures; 2) an earthquake's inertia force is enacted on a mass for a short time period. Therefore, replacing a transient force by a pseudo-static (seismic) force representing the maximum acceleration is considered unrealistic; 3) assuming that total pseudo-static loading is applied evenly throughout the embankment for an extended period of time is an incorrect assumption, as the length of the failure surface analyzed is usually much greater than the wave length of seismic waves generated by earthquakes; and 4) the seismic waves would place portions of the mass in compression and some in tension, resulting in only a limited portion of the failure surface analyzed moving in a downslope direction, at any one instant of time. Chabad at La Costa File:e:\wp12\6300\6304a.gue GeoSoils, lne. Appendix E Page3 The coefficients usually suggested by regulating agencies, counties and municipalities are in the range of 0.05 to 0.25. For example, past regulatory guidelines within the City and County indicated that the slope stability pseudostatic coefficient should be 0.15. The method developed by Krinitzsky, Gould, and Edinger (1993) which was in turn based on Taniguchi and Sasaki (T&S, 1986), was referenced. This method is based on empirical data and the performance of existing earth embankments during seismic loading. Our review of "Guidelines for Evaluating and Mitigating Seismic Hazards in California (California Dept. of Conservation, 1997) indicates the State of California recommends using a horizontal pseudo-static coefficient of 0.15 and a vertical pseudo-static coefficient of 0.80 for design earthquakes of M 8.25 or greater and using 0.1 for earthquake parameter M 6.5. In this analysis, reasonably conservative horizontal and vertical seismic coefficients of 0.15 and 0.08 were respectively used in our analysis. GSI has not used an increase in the static soil strength to model the transient loads during the design seismic event due to the non- liquefiable soil conditions and the anticipated design seismic horizontal ground acceleration. Output Information Output information includes: 1. All input data. 2. Factors of safety for the ten most critical surfaces for static and pseudo-static stability situation. 3. High quality plots can be generated. The plots include the slope geometry, the critical surfaces and the factor of safety. Results of Slope Stability Calculation Table E-2 shows parameters used in slope stability calculations. Detailed output information is presented in Plates E-1 to E-7. Chabad at La Costa Appendix E File:e:\wp12\6300\6304a.gue Page 4 GeoSoils, Inc. ;'t. :.iv j! t !'; ,;_t, h '1/ (, ,, ~ J (~, ;-,.~ r tr .,,. f f, TABLE E-2 SOIL PARAMETERS USED Tertiary Delmar Formation Slope 120 (Sandstone Member [Tdss]) 130 100 100 Tetiary Delmar Formation Building Pad 120 (Sandstone Member [Tdss]) 126 400 100 Tertiaty·Delmar Formation (lnterbedded Member Slope 120 125 400 100 [Td-ib]) Tertiary Delmar Formation (lnterbedded Member Building Pad 120 135 400 200 [Td-ib]) Tertiary Delmar Formation (Claystone Member Slope 120 125 1,370 580 [T d-clstn]) Artificial Fill N/A 115 125 300 Undocumented Artificial N/A 110 Fill (Afu) 130 200 TABLE E-3 SUMMARY OF SLOPE STABILITY ANALYSIS Section 8-8' Existing Configuration Without Gross Foundation Load Section 8-8' Existing Configuration With Gross Foundation Load Section 8-8! Proposed Configuration with Gross Foundation Load Surficial 2:1 (H:V) Slope Descending from Building Pad Chabad at La Costa File:e:\wp12\6300\6304a.gue 2.14 1.51 2.15 1.38 GeoSoils, Inc. 1.42 1.18 1.49 N/A 42 27 42 27 28 22 28 24 38 27 27 22 Plates E-1 and E-2 Plates E-3 and E-4 Plates E-5 and E-6 Plate E-7 Appendix E Pages =E 0 . en Ci,) 'tJo -.i::-~. Cl) l> I m cn .!...o ... 'f ~ ~ t.r-... ~"'I~"' . .,...,_~ . - Chabad WO 6304 Sec B-B' Static Natural /Existing Pad W/o Key 250 x:\shared\word perfect data\carlsbad\6300\6304 chabacfat la costa\slope stability\gsi1 static bb .pl2 Run By: ATG,GSI 12/5/2011 ·04:38PM i # FS SQil Soil Total Saturated Cohesion Friction 'Pore Pressure Piez. 1 a 2.1-4·1 Desc. Type Unit Wt. Unit Wt. Intercept Angle. Pressure Constant Surface ' l;J 2.345 No. (pcf} (pcf} (psf) (deg) Param. (psf) N9, c 2.364 Af-sctr 1 115.0 125.0 300.0 27.0 0.00 0.0 · W1 d 2.364 Tdss-'slp 2 120.0· 130.0 Aniso Anisa 0.00 0.0 W1 ~ 2.457 Af1.1 3 110.0 130.o· 200.0 22.0 0.00 0.0 W1 f 2'493 Tdss-pad 4 12d.O 1'26.0 Aniso Anisa Q:00 0.0 W1 200 g 2.507 Tq-clstn 5 120.0 126.0 Aniso Aniso 0.00 0,0 W1 h 2.511 Td-ibslp 6 120.0 126.0 Anisa Aniso 0.00 0.0 W1 i 2.557 Td-ibpad 7 120.0 126.0 Aniso Anisa O.QO 0:0 . . W1 1.50. 100 20 €) 21 ~ C : 4 39 4 !r3 l 4 43 sol I I :!J 5 1 . t~ :u, 5 9' ,/5 ~-· 5 ~ 7 46 5 ,fl o~----~-----~----~-----~----~-----~----~ 0 50 100 150 200 250 300 350 GSTABL7 v.2 FSmin=2.141 Safety Factors Are Calculated By The Simplified Janbu Method for the case of c & phi both > 0 GSTABL~ ?E p 0) "tJ w -0 a ti (I) )> m' I (/) I\) 0 Ch~bad WO 6304 Sec B-B' Seismic Natural JE~isting Pad W/o Key 250 x:\shared\word perfect c!a~\carlsb13d\9300\6304 chabad at la costa\slope stability\gsi1 seismic bb no pad loads .pl2 Run By; ATG,GSI 12/5/2011 04:50Pilll # FS Soil a 1.421 Desc. b i.517 C U17 Af-sctr d 1.561 Tdss-slp e 1.595 Afu f 1,610 Tdss-pad g 1.6.1.0 200 H h 1.e2s Td0clstn Td-ibslp i 1.625 Td-ibpad 150 100 50,. ' Soil Total Saturated Cohesion Frlction Pore Pressure Piez. Type· Unit Wt. Unit wt. Intercept Angle Pressure Constant Surface No. 23 5 1 2 3 4 5 6 7 (pcf) 115.0 120.ci 110.0 120.0 120.0 120.Q 120.0 1 (pcf) (psf) 125.0 300.0 130.0 Anise 130.0 200.0 126.0 Artiso 126.0 Aniso 126.0 Anise 126.0 Anisa ;~ (deg) 27.0 Aniso 22.0 Aniso Aniso Aniso Aniso ]./. 5 ] 1 Param. 0.00 0.00 0.00 o:oo 0.00 0.00 9,00 25 i~ 5w (psf) No. 0.0 W1 0.0 W1 0,0 W1 0.0 W1 0.0 W1 0:0 W1 0.0 Wi Load Peak(A£ kh Coe. kvCoef. Value 0.440(9) 0.150(g)< 0,0BQ(g)/\ ~7 '~ 4~3 4~ · 4 20 ~---11. ~-11,dLe 7./6; 5 .© v"tJ 0'----------'-------'-------l------'----------'------'-------' 0 50 100 150 200 250 300 350 GSTABL7 v.2 FSmin=1.421 Safety Factors Are Calculated By The Simplified Janbu Method for the case of c & phi both > 0 GSTABL,~ ~FECWL ;.a.v•" ~· 9 a, "'CJ w -0 D) +:a, ,-i, I (l) l> m' I C/l w (') ·Chabad WO 6304 Sec B-B' Static Natul'.'al /Existing Pad W/Q Key x:\shared\word perfect data\carlsbad\6300\6304 chabad at la costa\slope stability\gsi1 static bb .pl2 Run By: ATG,GSI 12/5/2011 04:41 PM 250 , , 200 150 100 50,i, # FS Soil Soil Total Saturated Cohesion Friction Pore Pressure Piez. r1· 1.51'1' D.esc. Type lJnitWt. UnitWt. Intercept Angle Pr!\!ssure Constant Surface b 1.566 No. (pcf) (pcf) (psf) (deg) Param. (psf) No. c 1.5,66 Af-sctr 1 115.0 125.0 300:0 27.0 0.00 0.0 W1 d 1.s:12 Tdss-slp 2 120.0 130.0 Aniso Aniso ·0.00 o.p Wt e 1.618 Afu 3 110.0 130.0 200;0 22.0 o.oo o.o W1 f U}47 Tdss-pad 4 12.M 1.46.0: Aniso Aniso O.OQ O.Q W1' g 1.704 Td-clstn 5 120.0 126.0 Aniso Aniso 0.00 0.0 W1 h 1.704 Td-ibslp 6 120.0 126.0 Aniso Anisa Q.00 0.0 W1 I 1.710 Td-igpad 7 120.0 146.0 Anisa Aljisp Q.00 0.0 W1 13 5 1 ~- J.j 5 Load Ll 12 L:l Value :iq90 psr J000psf 3d0d,psf a JL- ,, ~-o---~ 4 ?/!ft® . ~ 4 ;:-$ 4 . ./3 74(, . 5 .~ o~----~-----~-~--~-----~----~-----~----~ 0 50 100 150 200 250 300 350 GSTABL7 v.2 FSmin=1.511 Safety Factors Are Calculated By The Simplified Janbu Method for the case of c & phi both > O GSTABL7l =e 9 0) "ti (,,) -0 m .I::,, ; :r> m' I CJ) .1::i,O 250 200 1'~0 100 50:t Chabad WO 6304 Sec i3-B' Seismic Natural /Existing Pad W/o Key .x:\shar'ed\word perfe~dat~\carll[lbad\6300\6304 chabad at'la costa\slope stability\gsi1 seismic bb .pl2 Run By: ATG,GSI 12/5/2011 04:47PM # FS Soil Soil Total Saturated Cohesion Friction Pore Pressure Pie~. a 1.180 Desc. Typ~ Unit"Wt. Unit Wt.' Intercept Angle Pressure Constant Surface b 1.207 No. (pcf) (pcf) (psf) (d_eg) P!lram. (psf) No. c 1.207 Af-sctr 1 115.0 125.0 300.0 21:0 o.oo: o.o W1 d 1.?34 Tdss-slp 2 1'20;0 130:0 AnisQ A_n,iso 0.00 0.0 VV1 e 1.287 Afu 3 110.0 130:0 200.0 22.0 o.oo o.o W1 f 1.321 '.Tdss-pad 4 120.0 126.0 Aniso · Anisa 0.00 0.0 W1 g 1.336 Td-clstn 5 120.0 126.0 Aniso Anise p.oo 0.0 W1 h 'l.336 Td-ibslp 6 120.0 126.0 Aniso Ariiso o·.oo o.o W1 i 1.347 Td-ibpad 7 120.0 126.0 AnisQ Aniso 0.00 0.0 W1 Load Ll L2 L3 Peak(A) kh Coef. kvCoef. Value 3000psf 1000 psf ,3009 psf 0.440(9). 0.1?0{g)< JJ.0B0{g)/\ ~ -,, _ __)l ,, )J!~51--~.; 4 3: ·-~-~ ~. .. o'4 23 5 1 ?~ 2 14 5 1 /Ji:/ ~~ 4 ./3 746 5 ·s 0'-------'------'-------'---------''-------'------'--------' 0 50 100 150 200 250 300 350 GSTABL7 v.2 FSmin=1.180 Safety Factors Are Calculated By The Simplified Janbu Method for the case of c & phi both > 0 GSTABL7fJ SURFICIAL SLOPE STABILITY ANALYSIS Seepage parallel to slope Tract/Project: Chabad at L.a Costa/6304-A-SC 1-------------------------1 Material Type: 1-----U_n_d_o_cu_m_e.._. n_-te_d.;..; ___ Fi_ll _,_(A_f_u)._.__ ____ -1 2:1 (Horizor-ital:Vertical) Slope Depth of Saturation (z) 4 feet Slope Anole (i) (for 2:1 slopes) 26.6 deorees Unit Weight of Water (rw) 62.4 lb/ft3 Saturated Unit Weight of Soil (Ysat) 130 lb/ft3 Aooarent AnQle of Internal Friction ( d>) 22 degrees Apparent Cohesion (C) 200 lb/ft:2 Fs = Static Safety Factor= z {Ysat-YwJ Cos2(i) Tan (<I>)+ C z (Ysat) Sin (i) Cos (i) DE:PTH OF SATURATION SLOPE FACTOR OF SAFETY 4 Feet 1.5:1 1.38 ecfl if. W.0. 6304-A-SC SURFICIAL SLOPE STABILITY 2: 1 SLOPE Plate E-7 ,,, . . \. .. I ... ~ • • ' I APPENDIX:F' GE.NERAL EARTHWORK AND GRADING GUl'D:ELINES . ', , .· . / . i • .-• GENERAL EARTHWORK, GRADING GUIDELINES, AND PRELIMINARY CRITERIA General These guidelines present general procedures and requirements for earthwork and grading as shown on the approved grading plans, including preparation of areas to be filled, placement of fill, installation of subdrains, excavations, and appurtenant structures or flatwork. The recommendations contained in the geotechnical report are part of these earthwork and grading guidelines and would supercede the provisions contained hereafter in the case of conflict. Evaluations performed by the consultant during the course of grading may result in new or revised recommendations which could supercede these guidelines or the recommendations contained in the geotechnical report. Generalized details follow this text. The contractor is respor,sible for the satisfactory completion of all earthwork in accordance with provisions of the project plans and specifications and latest adopted code. In the case of conflict, the most onerous provisions shall prevail. The project geotechnical engineer and engineering geologist (geotechnical consultant), and/or their representatives, should provide observation and testing services, and geotechnical consultation during the duration of the project. EARTHWORK OBSERVATIONS AND TESTING Geotechnical Consultant Prior to the commencement of grading, a qualified geotechnical consultant (soil engineer and engineering geologist) should be employed for the purpose of observing earthwork procedures and testing the fills for general conformance with the recommendations of the geotechnical report(s}, the approved grading plans, and applicable grading codes and ordinances. The geotechnical consultant should provide testing and observation so that an evaluation may be made that the work is being accomplished as specified. It is the responsibility of the contractor to assist the consultants and keep them apprised of anticipated work schedules and changes, so that they may sc~edule their personnel accordingly. All remedial removals, clean-outs, prepared ground to receive fill, key excavations, and subdrain installation should be observed and documented by the geotechnical consultant prior to placing any fill. It is the contractor's responsibility to notify the geotechnical consultant when such areas are ready for observation. Laboratory and Field Tests Maximum dry density tests to determine the degree of compaction should be performed in accordance with American Standard Testing Materials test method ASTM designation D 1557. Random or representative field compaction tests should be performed in accordahce with test methods ASTM designation D 1556, D 2937 or D 2922, and D 3017, GeoSoils, Inc. at intervals of approximately ±2 feet of fill height or approximately every 1 ,000 cubic yards placed. These criteria would vary depending on the soil conditions and the size of the project. The location and frequency of testing would be at the discretion of the geotechnical consultant. Contractor's Responsibility All clearing, site preparation, and earthwork performed on the project should be conducted by the contractor, with observation by a geotechnical consultant, and staged approval by the governing agencies, as applicable. It is the contractor1s responsibility to prepare the ground surface to receive the fill, to the satisfaction of the geotechnical consultant, and to place, spread, moisture condition, mix, and compact the fill in accordance with the recommendations of the geotechnical consultant. The contractor should also remove all non-earth material considered unsatisfactory by the geotechnical consultant. Notwithstanding the services provided by the geotechnical consultant, it is the sole responsibility ofthe contractor to provide adequate equipment and methods to accomplish the earthwork in strict accordance with applicable grading guidelines, latest adopted codes or agency ordinances, geotechnical report(s), and approved grading plans. Sufficient watering apparatus and compaction equipment should be provided by the contractor with due consideration for the fill material, rate of placement, and climatic conditions. If, in the opinion of the geotechnical consultant, unsatisfactory conditions such as questionable weather, excessive oversized rock or deleterious material, insufficient support equipment, etc., are resulting in a quality of work that is not acceptable, the consultant will inform the contractor, and the contractor is expected to rectify the conditions, and if necessary, stop work until conditions are satisfactory. During construction, the contractor shall properly grade all surfaces to maintain good drainage and prevent ponding of water. The contractor shall take remedial measures to control surface water and to prevent erosion of graded areas until such time as permanent drainage and erosion control measures have been installed. SITE PREPARATION All major vegetation, including brush, trees, thick grasses, organic debris, and other deleterious material, should be removed and disposed of off-site. These removals must be concluded prior to placing fill. In-place existing fill, soil, alluvium, colluvium, or rock materials, as evaluated by the geotechnical consultant as being unsuitable, should be removed prior to any fill placement. Depending upon the soil conditions, these materials may be reused as compacted fills. Any materials incorporated as part of the compacted fills should be approved by the geotechnical consultant. Any underground structures such as cesspools, cisterns, mining shafts, tunnels, septic tanks, wells, pipelines, or other structures not located prior to grading, are to be removed or treated in a manner recommended by the geotechnical consultant. Soft, dry, spongy, Chabad at La Costa File:e:\wp12\6300\6304a.gue GeoSoils, lne. Appendix F Page2 highly fractured, or otherwise unsuitable ground, extending to such a depth that surface processing cannot adequately improve the condition, should be overexcavated down to firm ground and approved by the geotechnical consultant before compaction and filling operations continue. Overexcavated and processed soils, which have been properly mixed and moisture conditioned, should be re-compacted to the minimum relative compaction as specified in these guidelines. Existing ground, which is determined to be satisfactory for support of the fills, should be scarified (ripped) to a minimum depth of 6 to 8 inches, or as directed by the geotechnical consultant. After the scarified ground is brought to optimum moisture content, or greater and mixed, the materials should be compacted as specified herein. If the scarified zone is greater than 6 to 8 inches in depth, it may be necessary to remove the excess and place the material in lifts restricted to about 6 to 8 inches in compacted thickness. Existing ground which is not satisfactory to support compacted fill should be overexcavated as required in the geotechnical report, or by the on-site geotechnical consultant. Scarification, disc harrowing, or other acceptable forms of mixing should continue until the soils are broken down and free of large lumps or clods, until the working surface is reasonably uniform and free from ruts, hollows, hummocks, mounds, or other uneven features, which would inhibit compaction as described previously. Where fills are to be placed on ground with slopes steeper than 5:1 (horizontal to vertical [h:v]), the ground should be stepped or benched. The lowest bench, which will act as a key, should be a minimum of 15 feet wide and should be at least 2 feet deep into firm material, and approved by the geotechnical consultant. In fill-over-cut slope conditions, the recommended minimum width of the lowest bench or key is also 15 feet, with the key founded on firm material, as designated by the geotechnical consultant. As a general rule, unless specifically recommended otherwise by the geotechnical consultant, the minimum width of fill keys should be equal to ½ the height of the slope. Standard benching is generally 4 feet (minimum) vertically, exposing firm, acceptable material. Benching may be used to remove unsuitable materials, although it is understood that the vertical height of the bench may exceed 4 feet. Pre-stripping may be considered for unsuitable materials in excess of 4 feet in thickness. All areas to receive fill, including processed areas, removal areas, and the toes of fill benches, should be observed and approved by the geotechnical consultant prior to placement of fill. Fills may then be properly placed and compacted until design grades (elevations) are attained. COMPACTED FILLS Any earth materials imported or excavated on the property may be utilized in the fill provided that each material has been evaluated to be suitable by the geotechnical consultant. These materials should be free of roots, tree branches, other organic matter, Chabad at La Costa File:e:\wp12\6300\6304a.gue GeoSoils, Ine. Appendix F Page3 or other deleterious materials. All unsuitable materials should be removed from the fill as directed by the geotechnical consultant. Soils of poor gradation, undesirable expansion potential, or substandard strength characteristics may be designated by the consultant as unsuitable and may require blending with other soils to serve as a satisfactory fill material. Fill materials derived from benching operations should be dispersed throughout the fill area and blended with other approved material. Benching operations should not result in the benched material being placed only within a single equipment width away from the fill/bedrock contact. Oversized materials defined as rock, or other irreducible materials, with a maximum dimension greater than 12 inches, should not be buried or placed in fills unless the location of materials and disposal methods are specifically approved by the geotechnical consultant. Oversized material should be taken offsite, or placed in accordance with recommendations of the geotechnical consultant in areas designated as suitable for rock disposal. GSI anticipates that soils to be utilized as fill material for the subject project may contain some rock. Appropriately, the need for rock disposal may be necessary during grading operations on the site. From a geotechnical standpoint, the depth of any rocks, rock fills, or rock blankets, should be a sufficient distance from finish grade. This depth is generally the same as any overexcavation due to cut-fill transitions in hard rock areas, and generally facilitates the excavation of structural footings and substructures. Should deeper excavations be proposed (i.e., deepened footings, utility trenching, swimming pools, spas, etc.), the developer may consider increasing the hold-down depth of any rocky fills to be placed, as appropriate. In addition, some agencies/jurisdictions mandate a specific hold-down depth for oversize materials placed in fills. The hold-down depth, and potential to encounter oversize rock, both within fills, and occurring in cut or natural areas, would need to be disclosed to all interested/affected parties. Once approved by the governing agency, the hold-down depth for oversized rock (i.e., greater than 12 inches) in fills on this project is provided as 10 feet, unless specified differently in the text of this report. The governing agency may reqaire that these materials need to be deeper, crushed, or reduced to less than 12 inches in maximum dimension, at their discretion. To facilitate future trenching, rock (or oversized material), should not be placed within the hold-down depth feetfrom finish grade, the range of foundation excavations, future utilities, or underground construction unless specifically approved by the governing agency, the geotechnical consultant, and/or the developer's representative. If import material is required for grading, representative samples of the materials to be utilized as compacted fill should be analyzed in the laboratory by the geotechnical consultant to evaluate it's physical properties and suitability for use onsite. Such testing should be performed three (3) days prior to importation. If any material other than that previously tested is encountered during grading, an appropriate analysis of this material should be conducted by the geotechnical consultant as soon as possible. Approved fill material should be placed in areas prepared to receive fill in near horizontal layers, that when compacted, should not exceed about 6 to 8 inches in thickness. The Chabad at La Costa File:e:\wp12\6300\6304a.gue _GeoSoils, Ine. Appendix F Page4 geotechnical consultant may approve thick lifts iftesting indicates the grading procedures are such that adequate compaction is being achieved with lifts of greater thickness. Each layer should be spread evenly and blended to attain uniformity of material and moisture suitable for compaction. Fill layers at a moisture content less than optimum should be watered and mixed, and wet fill layers should be aerated by scarification, or should be blended with drier material. Moisture conditioning, blending, and mixing of the fill layer should continue until the fill materials have a uniform moisture content at, or above, optimum moisture. After each layer has been evenly spread, moisture conditioned, and mixed, it should be uniformly compacted to a minimum of 90 percent of the maximum density as evaluated by ASTM test designation D 1557, or as otherwise recommended by the geotechnical consultant. Compaction equipment should be adequately sized and should be specifically designed for soil compaction, or of proven reliability to efficiently achieve the specified degree of compaction. Where tests indicate that the density of any layer of fill, or portion thereof, is below the required relative compaction, or improper moisture is in evidence, the particular layer or portion shall be re-worked until the required density and/or moisture content has been attained. No additional fill shall be placed in an area until the last placed lift of fill has been tested and found to meet the density and moisture requirements, and is approved by the geotechnical consultant. In general, per the 1997 UBC and/or latest adopted version of the California Building Code (CBC), fill slopes should be designed and constructed at a gradient of 2:1 (h:v), or flatter. Compaction of slopes should be accomplished by over-building a minimum of 3 feet horizontally, and subsequently trimming back to the design slope configuration. Testing shall be performed as the fill is elevated to evaluate compaction as the fill core is being developed. Special efforts may be necessary to attain the specified compaction in the fill slope zone. Final slope shaping should be performed by trimming and removing loose materials with appropriate equipment. A final evaluation of fill slope compaction should be based on observation and/or testing of the finished slope face. Where compacted fill slopes are designed steeper than 2:1 (h:v), prior approval from the governing agency, specific material types, a higher minimum relative compaction, special reinforcement, and special grading procedures will be recommended. If an alternative to over-building and cutting back the compacted fill slopes is selected, then special effort should be made to achieve the required compaction in the outer 1 O feet of each lift of fill by undertaking the following: 1. An extra piece of equipment consisting of a heavy, short-shanked sheepsfoot should be used to roll (horizontal) parallel to the slopes continuously as fill is placed. The sheepsfoot roller should also be used to roll perpendicular to the slopes, and extend out over the slope to provide adequate compaction to the face of the slope. Chabad at La Costa File:e:\wp12\6300\6304a.gue GeoSoils, Ine. Appendix F Page5 2. Loose fill should not be spilled out over the face of the slope as each lift is compacted. Any loose fill spilled over a previously completed slope face should be trimmed off or be subject to re-rolling. 3. Field compaction tests will be made in the outer (horizontal) ±2 to ±8 feet of the slope at appropriate vertical intervals, subsequent to compaction operations. 4. After completion of the slope, the slope face should be shaped with a small tractor and then re-rolled with a sheepsfoot to achieve compaction to near the slope face. Subsequent to testing to evaluate compaction, the slopes should be grid-rolled to achieve compaction to the slope face. Final testing should be used to evaluate compaction after grid rolling. 5. Where testing indicates less than adequate compaction, the contractor will be responsible to rip, water, mix, and recompact the slope material as necessary to achieve compaction. Additional testing should be performed to evaluate compaction. SUBDRAIN INSTALLATION Subdrains should be installed in approved ground ih accordance with the approximate alignment and details indicated by the geotechnical consultant. Subdrain locations or materials should not be changed or modified without approval of the geotechnical consultant. The geotechnical consultant may recommend and direct changes in subdrain line, grade, and drain material in the field, pending exposed conditions. The location of constructed subdrains, especially the outlets, should be recorded/surveyed by the project civil engineer. Drainage at the subdrain outlets should be provided by the project civil engineer. EXCAVATIONS Excavations and cut slopes should be examined during grading by the geotechnical consultant. If directed by the geotechnical consultant, further excavations or overexcavation and refilling of cut areas should be performed, and/or remedial grading of cut slopes should be performed. When fill-over-cut slopes are to be graded, unless otherwise approved, the cut portion of the slope should be observed by the geotechnical consultant prior to placement of materials for construction of the fill portion of the slope. The geotechnical consultant should observe all cut slopes, and should be notified by the contractor when excavation of cut slopes commence. If, during the course of grading, unforeseen adverse or potentially adverse geologic conditions are encountered, the geotechnical consultant should investigate, evaluate, and make appropriate recommendations for mitigation of these conditions. The need for cut Chabad at La Costa File:e:\wp12\6300\6304a.gue GeoSoils, lne. Appendix F Page6 slope buttressing or stabilizing should be based on in-grading evaluation by the geotechnical consultant, whether anticipated or not. Unless otherwise specified in geotechnical and geological report(s), no cut slopes should be excavated higher or steeper than that allowed by the ordinances of controlling governmental agencies. Additionally, short-term stability of temporary cut slopes is the contractor's responsibility. Erosion control and drainage devices should be designed by the project civil engineer and should be constructed in compliance with the ordinances of the controlling governmental agencies, and/or in accordance with the-recommendations of the geotechnical consultant. COMPLETION Observation, testing, and consultation by the geotechnical consultant should be conducted during the grading operations in order to state an opinion that all cut and fill areas are graded in accordance with the approved project specifications. After completion of grading, and after the geotechnical consultant has finished observations of the work, final reports should be submitted, and may be subject to review by the controlling governmental agencies. No further excavation or filling should be undertaken without prior notification of the geotechnical consultant or approved plans. All finished cut and fill slopes should be protected from erosion and/or be planted in accordance with the project specifications and/or as recommended by a landscape architect. Such protection and/or planning should be undertaken as soon as practical after completion of grading. JOB SAFETY, General At GSI, getting the job done safely is of primary concern. The following is the company's safety considerations for use by all employees on multi-employer construction sites. On-ground personnel are at highest risk of injury, and possible fatality, on grading and construction projects. GSI recognizes that construction activities will vary on each site, and that site safety is the prime responsibility of the contractor; however, everyone must be safety conscious and responsible at all times. To achieve our goal of avoiding accidents, cooperation between the client, the contractor, and GSI personnel must be maintained. In an effort to minimize risks associated with geotechnical testing and observation, the following precautions a(e to be implemented for the safety of field personnel on grading and construction projects: Chabad at La Costa File:e:\wp12\6300\6304a.gue GeoSoils, lne. Appendix F Page? Safety Meetings: GSI field personnel are directed to attend contractor's regularly scheduled and documented safety meetings. Safety Vests: Safety vests are provided for, and are to be worn by GSI personnel, at all times, when they are working in the field. Safety Flags: Two safety flags are provided to GSI field technicians; one is to be affixed to the vehicle when on site, the other is to be placed atop the spoil. pile on all test pits. Flashing Lights: All vehicles stationary in the grading area shall use rotating or flashing amber beacons, or strobe lights, on the vehicle during all field testing. While operating a vehicle in the grading area, the emergency flasher on the vehicle shall be activated. In the event that the contractots representative observes any of our personnel not following the above, we request that it be brought to the attention of our office. Test Pits Location, Orientation, and Clearance The technician is responsible for selecting test pit locations. A primary concern should be the technician's safety. Efforts will be made to coordinate locations with the grading contractor's authorized representative, and to select locations following or behind the established traffic pattern, preferably outside of current traffic. The contractor's authorized representative (supervisor, grade checker, dump man, operator, etc.) should direct excavation of the pit and safety during the test period. Of paramount concern should be the soil technician's safety, and obtaining enough tests to represent the fill. Test pits should be excavated so that the spoil pile is placed away from oncoming traffic, whenever possible. The technician's vehicle is to be placed next to the test pit, opposite the spoil pile. This necessitates the fill be maintained in a driveable condition. Alternatively, the contractor may wish to park a piece of equipment in front of the test holes, particularly in small fill areas or those with limited access. A zone of non-encroachment should be establishedfor all test pits. No grading equipment should enter this zone during the testing procedure. The zone should extend approximately 50 feet outward from the center of the test pit. This zone is established for safety and to avoid excessive ground vibration, which typically decreases test results. When taking slope tests, the technician should park the vehicle directly above or below the test location. If this is not possible, a prominent flag should be placed at the top of the slope. The contractor's representative should effectively keep all equipment at a safe operational distance (e.g., 50 feet) away from the slope during this testing. The technician is directed to withdraw from the active portion of the fill as soon as possible following testing. The technician's vehicle should be parked at the perimeter of the fill in Chabad at La Costa File:e:\wp12\6300\6304a.gue GeoSoils, Ine. Appendix F Pages a highly visible location, well away from the equipment traffic pattern. The contractor should inform our personnel of all changes to haul roads, cut and fill areas or other factors that may affect site access and site safety. In the event that the technician's safety is jeopardized or compromised as a result of the contractor's failure to comply with any of the above, the technician is required, by company policy, to immediately withdraw and notify his/her supervisor. The grading contractor's representative will be contacted in an effort to affect a solution. However, in the interim, no further testing will be performed until the situation is rectified. Any fill placed can be considered unacceptabie and subject to reprocessing, recompaction, or removal. In the event that the soil technician does not comply with the above or other established safety guidelines, we request that the contractor bring this to the technician's attention and notify this office. Effective communication and coordination between the contractor's representative and the soil technician is strongly encouraged in order to implement the above safety plan. Trench and Vertical Excavation It is the contractor's responsibility to provide safe access into trenches where compaction testing is needed. Our personnel are directed not to enter any excavation or vertical cut which: 1) is 5 feet or deeper unless shored or laid back; 2) displays any evidence of instability, has any loose rock or other debris which could fall into the trench; or 3) displays any other evidence of any unsafe conditions regardless of depth. All trench excavations or vertical cuts in excess of 5 feet deep, which any person enters, should be shored or laid back. Trench access should be provided in accordance with Cal/OSHA and/or state and local standards. Our personnel are directed not to enter any trench by being lowered or "riding down" on the equipment. If the contractor fails to provide safe access to trenches for compaction testing, our company policy requires that the soil technician withdraw and notify his/her supervisor. The contractor's representative will be contacted in an effort to affect a solution. All backfill not tested due to safety concerns or other reasons could be subject to reprocessing and/or removal. If GSI personnel become aware of anyone working beneath an unsafe trench wall or vertical excavation, we have a legal obligation to putthe contractor and owner/developer on notice to immediately correct the situation. If corrective steps are not taken, GSI then has an obligation to notify Cal/OSHA and/or the proper controlling authorities. Chabad at La Costa File:e:\wp12\6300\6304a.gue GeoSoils, lne. Appendix F Page9 TYPE A TYPE B Selection of alternate subdrain details, location, and extent of subdrains should be evaluated by the geotechnical consultant during grading. 1Le .. flr. CANYON SUBDRAIN OETAIL Plate F-1 12-inch minimum --6-inch minimum A--1 8-1 Filter material: Minimum volume of 9 cubic feet per lineal foot of pipe. FIL TEA MATERIAL Perforated pjpe: 6-inch-diameter ABS or PVC pipe or approved substitute with minimum 8 perfQrations {¼-inch diameter) per lineal foot in bottom half of pipe (ASTM D-2751, SDR-35, or ASTM D-1527, Schd. 40). For continuous run in excess.of 500 feet, use a-inch-diameter pipe (ASTM D-3034, SDR-35, or· ASTM D-1785, Schd. 40). Sieve Size 1 inch ¾ inch ¾ inch No.4 N<;>.8 No.30 No.SO No.200 Percent Passing 100 90-100 40-100 25-40 18-33 5-15 0-7 0-3 AL TERNA 1E 1= PERFORATED PIPE AND RL TEA MATERIAL \ _....-\ _t __ _ Riter fabric \~ 6-inch minimum I I \ ~I I / /~~-!nch I 1 6-inch minimum ~--'-minimum A-2 Gravel Material: 9 cubic feet per lineal foot. Perforated Pipe: See Alternate 1 Gravel= Clean ¾-inch rock or approved substitute. Filter Fabric: Mindi 140 or approved substitute. I· I ALTERNATE 2= PERFORAlED PIPE, GRAVEL, AND FILTER FABRIC CANYON SUBDRAIN ALTERNATE DETAILS Plate F-2 Original ground surf ace to be restored with compacted fill I Back-cut varies; For deep removals,_ backcut should be made no steeper than 1=1 (H:V), or flatter as necessary for safety considerations. 2D / Toe of slope as shown on grading plan ~··-;--:-.. -.-.-.-·:--- < ,.~< . .<: <.i,:~··~_ .. :;.~:_ .. :: .. ·.:.,·. :,_ .... ··<··. .~·.\. = .. : ··· .. : .. compa.C?t$d.Fill-: ::· ·. :-· .. <-: .. :\._.:":: .. ;: ·,··.;. '·.::_ .. .-·.> ... ::··'.'..:::-<.:··:: :·:. ·: , ........ :.·.:. of~/ I \__Original· ground surface ~ ~' / D • Anticipated removal of· unsuitable material -~/ (depth per g~otechnical engineer) ~~-- '-I"-/ Provide a 1:1 (H:V) minimum projection from toe of slope as shown on grading plan to the recommended removal depth. Slope height, site conditions, and/ or local conditions could dictate flatter projections. i ' 4 c. FILL SLOPE TOEING OUT ON FLAT ALLUVIATED CANYON DETAIL Plate F-3 Proposed grade~ ---- -- ~-Previously placed, temporary compacted fill for drainage only · --~ Proposed additional compacted fill Existing co ~;::::::::::::::;::?::: ::Jc:~~~~~.<.-·· . mpacted f'1II 0 ~· ;__:::::: · :::::: · :.-.-.:-:-?. · ··: · · · Un· su1·t·· p · ,. · · · .. '· ·· ··'' ·· ·.' "'"-".. .. .. · · · .. · /.'' a le .. ·· -. 'l> .... ,,,,.,, ... ,,,,y ..... · . . . . .. mater'i!ll c·· . . . . . "' :;:::: / > : < '.. ' ?:; ;~;t · 1 !!>JEi re.moved) 0-\~~\\ '?(i:1/> \$'.(\{;:s'0?·~;;,.\\\((?'>W'< .v'\\0,Y~ y\ \Y:c:-' To Qe remo Be~rock or a .additional c:ed before placing -~-native materiJproved mpacted fill REMOVAL ADJACENT TO EXISTING FILL ADJOINING CANYON FILL DETAIL Plate F-4 Drainage per design civil engineer ~ Blanket fill (if recommenqed by the geotechnical consultant) Design finish slope -~ / / 1 1-0-foot minimum / 25-foot maximum/ · ---__,,,,,,._ -::::::::::======= Buttress or stabilization fill L1~_toot __ l I m1n1mum I I ::::::::::::::::::~_:::::::-::~~ 4.,..inch-diameter non-perforated 2-Percent Gradient. Typical benching (4-foot minimum) outlet pipe and backdrain (see detail Plate F-6). Outlets to be spaced at 100-foot maximum intervals and shall extend 2 feet beyond the face of slope at time approved native material Subdrain as recommended by geotechnical consultant of rough grading completion. At the completion of rough grading. the design civil engineer should provide recommendations to convey any outlet's discharge to a· suitable conveyance, utilizing a non-erosive device. 1ft. /B'et. TYPICAL STABILIZATION / BUTTRESS FILL DETAIL Plate F-5 I. ~-!oot ... ; I minimum I I --~-----...... t ........ J ........ . . . . . . . . . . . . 4-inch minimu :::: .... : .. :::. 3 foot [ pipe ..... _. ........ _._. .. _._ 2-inch minim1,1m .·:.·.· ... ·.·.·.·.·.·.·. [ minimum j ----.. .,_,__,.;-..···,/ ··1 l:;""" I 2-foot I .. . . .. I m1n1mum I =l~ Lf~ 4-inch ! J mini mu~ 2-inch pipe minimum Filter Material: Minimum of 5 cubic feet per lineal foot of pipe or 4 cubic feet per lineal feet of pipe when placed in square cut trench. Alternative in Lieu of Filter Material= Gravel may be encased in appr~ved filter fabric. Filter fabric shall be Mirafi 140 or equivalent. Filter fabric shall be lapped a minimum of 12 inches in all joints. Minimum 4-lnch-Diameter Pipe: ABS-ASTM 0-2751, SOR 35; or ASTM 0-1527 Schedule 40, PVC-ASTM 0-3034, SOR 35; or ASTM D-1785 Schedule 40 with a crushing strength of 1,000 pounds minimum, and a minimum of 8 uniformly-spaced perforations per foot of pipe. Must be installed with perforations down at bottom of pipe. Provide cap at upstream end of pipe. Slope at 2 percent to outlet pipe. Outlet pipe to be connected to subdrain pipe with tee or elbow. Notes: 1. Trench for outlet pipes to be backfilled and compacted with onsite soil. 2. Backdrains and lateral drains shall be located at elevation of every bench drain. First drain located at elevation just above lower lot grade. Additional drains may be required at the discretion of the geotechnical consultant. Filter Material shall be of the following specification or an approved equivalent. Sieve Size 1 inch ¾inch ¾ inch No.4 No.8 No.30 No.SO No.200 Percent Passing 100 90-100 40-100 25-40 18-33 5-15 0-7 0-3 Gravel shall be of the following specification or an approved equivalent. Sieve Size 1½ inch No.4 No.200 Percent Passing 100 50 8 TYPICAL BUTTRESS SUBDRAIN DETAIL Plate F-6 Toe of slope as shown on grading plan Natural slope to be restored with compacted fill Proposed grade \ / / / ,,,,,-- / Compacted fill / / / / ~.· ...... ,.: , •.. ::'.:',,;"}::/'.:\>:.;:::.; / ,-,,::; . .,. ... .:· . .-.. . . ·. . : ' . . . ., "".; wa.\el'\ec. . . ·. . , -:_..;.. ... ...--. . .. . . .. . . . . . r-u{\S'l\'w ... , .. , ....... ,. . . ... ...,,.-- · .. _-:-··--.. :·:. ,, ' ·.:.'· :·~· ~c;,~\uii-·O ......... .-... ·· :· ~ . L , . ,,i,, /'--· ·· _.: . :··;,, ~~6·\.0~~·. ·' · .. · ·' .. ..: ... , • :' ,. .. ~ · '___..--f\' )\ A< / - 2-foot · · ~ ": .i ...... , " :• .. .,e,·--·. · ., . . ' · ·. ,_j...-. . . ..--c:::____ / ., \ Y°;V . minimum . i· : .. " . ·if(, '· · ·. .. · .··" ·· .. · · .. ·..,_;c. • · ~ ;,,:: v\, ; 44001 m" r ,anpbedrock or ... : ·. , .. ::,. . , .... : .. : •. ·.";,_~ . ./. · ._., : . ,_:, C· ·, ~ .. , •. : . : .,.: . ._;.,.---· r,, ;..('\, < /)\ y\ \'--:.,,(,\,-!\__ _ _ 1rnmlrn """""' .. .. . . ·.. . . ~,, ·.. ... · · ..-.. ~~v~~-__E ,\, ' · - earth t . ·, ·. . .. _,.,..,1/. .•... :.,....;:, . . -;Y\.\ A\<.,.,,,.-:.v\' :,.-( I r =-_ ~aeria:._··~: ., .. _:·:· .. :·:···:·t~''.:_:·· ·:.~ (?vr,::::'"~~...,,....__t'-; • ' ',<v;-\ \\ I r ---_·_:,,__.~.: .... ''"'~----\\;(\'(<,,.;;-)A\' _ . i__""nchwtctt• I ,.-'·\ \,'' :(,J\ 2 Percent Gr-nf - - -*--[ 3 foot minimum I may vary --1 '] ., \ \ :..<, /, Y]\ -\ ----(4-foot minimum) I Bedrock I , A\\:1/--.;'/ _ _ or Backc:;ut varies 15-foot minimum / ~ . - - -approved tt, 2"here H • I I native material I _ .. _ -H/ or I · e slope height ~ I Subdrain as recommended by geotechnical consultant NOTES: 1. Where the natural slope approaches or exceeds the design slope ratio, special recommendations would be provided by the geotechnical consultant. 2. The need for and disposition of drains should be evaluated by the geotechnical consultant, based upon exposed conditions. FILL OVER NATURAL (SIDEHILL FILL) DETAIL Plate F-7 H ~ height of slope Cut/fill contact as shown on grading plan Cut/fill contact as shown on as-built plan -----, Original ( existing) grade Proposed grade . / / / Compacted fill Subdrain as recommended by geotechnical consultant NOTE= The cut portion of the slope should be excavated and evaluated by the geotechnical consultant prior to construction of the fill portion. ,jjac. FILL OVER CUT DETAIL Plate F-8 :•. '• :···· .. · .. ,:,. Natural slope Proposed finish grade ,~-··, '· .': ·.·· ... ::·:.,.· .. ··_.\1en{Jv~\~~~it~~e ·_,. :_._. ~ . . . .. .--~--.>:·-·-<·>: ~:·: ~ :.:..· · >r·. \:. :- ~:-_:··i·._···1 .... ;_·:::::.·· ~-.. -· .. :_· __ .····_····.· .... ···· '. ': .. : <. :: .. '._. <: _·::· ·.·: ~-·:': ... · .. _-·.· _ _::: .;: ·:.: .. ·:. -~·. :~ ... __ :_ .. ~-. ;· ::.·· :._·_ .. :_ --~-: ... :. ·:·. _ _.. :.::: .... : ... ··: :., -~-. ·: ·=:· ·: i / / ~.J~:to_q~, · . , .;_ · · · · · · '. . 1 ·· .. •,. l·_:.:.:.i--- ............. _ .-•• . • • . • • -~ ·r----r-~ Typical benching (4-foot minimum) Compacted stablization fill ------Bedrock or other approved native material / ~--~---If recommended by the geotechnical consultant, the remaining cut portion of the slope may r~quire removal and replacement with compacted fill. Subdra.in as recommended by geotechnical consultant NOTES: 1. Subdrains may be required as specified by the geotechnical consultant. ,_, l. IT.' ,. .. ,,:::i, '~, 2 W shall be equipment width (15 feet) for slope heights less than 25 feet. For slopes greater than 25 feet, W shall be evaluated by the geotechnical consultant. At no time, shall W be less than H/2, where H is the height of the slope. ~ """o'.-,. '\' c. STABLIZATION FILL FOR UNSTABLE MATERIAL EXPOSED IN CUT SLOPE DETAIL Plate F-9 Proposed finish grade_-~ Natural grade c, -------------------. ----' ---_,A ::, H • height of slope I --....... ..... . ;.:: ... ,.·...... ._.-~:= ; .. ·· . . . '• . key depth minimum \\Y<~~Y\ ~y l\?~0~ I • ~\\ {\\~ ~~ ~\~ ~\\½\~ Bedrock or ~/ I( , ,. «, ,...;~ approved \\~ native material Typical benching (4-foot minimum) Subdrain as recommended by geotechnical consultant NOTES: 1. 15-f oat minimum to be maintained from proposed finish slope face to back cut. 2. The need and disposition: of drains will be evaluated by the geotechnical consultant based on field conditions. 3. Pad overexcavation and recompaction should be performed if evaluated to be necessary by the geotechnical consultant. ~~c. Jr~· SKIN FILL OF NATURAL GROUND DETAIL Plate F-10 Reconstruct compacted fill slope at .2=1 or flatter (may increase or decrease pad area) Overexcavate and recompact · replacement fill Back-cut varies ----'--'-1 Avoid .and/ or clean up spillage of materials on the natural slope Natural gr1;1de Subdrain as recommended by geotechnical consultant .... NOTES= 1. Subdrain and key width requirements will be evaluated based on exposed subsurface conditions and thickness of overburden. 2. Pad overexcavation and recompaction should be performed if evaluated necessary by the geotechnical consultant. .• Sf , . .. , e. <i', DAYLIGHT CUT LOT DETAIL Plate F"-11 Natural grade -__L CUT LOT OR MATERIAL -TYPE TRANSITION Typical benching ( 4..,.foot minimum) Bedrock or approved native materiaf Natural grade . "· . ..... ::·: ... ':~ ··.-.~ ___ J_ * Deeper overexcavation may be recommended by the geotechnical consultant in steep cut-fill transition areas, such that the underlying topography is no steeper than 3:1 (H:V) CUT-FILL LOT (DAYLIGHT TRANSITION) TRANSITION LOT DETAILS Plate F-12 j_ VIEW NORMAL TO SLOPE FACE Proposed finish grade ~ (E)~ ~ 7 ---~ , (E) Hold-down depth / ,.,cco -z:co 6J / ~\ / c:co 6J I (A) I I ~15-foot~c:co f_ 6J ~I '-0 m1rnmum c:co (D) CCC) c:co -=-i (B) 6J jg> C:CO(F) ~0.~~~~~~0~\%~0-~\%<-~ Bedrock or approved minimum native material VIEW PARALLEL TO SLOPE FACE Proposed finish grade ~ . . (E) Hold-down depth --~ t 15-foot minimum~ ,-.-~ -,-------- ---- .. 100~foot--- 1 • I maximum (D) ~--~ ~ Cs 3-foot minimum minimum NOTES: A. One equipment width or a minimum of 15 feet between rows (or windrows). Bedrock or approved native material 8. Height and width may vary depending on rock size and typ~ of equipment. Length of windrow shall be no greater than 100 feet. C. If approved by the geotechnical consultant, windrows may be placed direclty on competent material or bedrock, provided adequate space is available for compaction. D. Orientation of windrows may vary but should be as recommended by the geotechnical engineer and/ or engineering geologist. Staggering of windrows is not necessary unless recommended. E. Clear area for utility trenches, foundations, and swimming pools; Hold-down depth as specified in text of report, subject to governing agency approval. F. All fill over and around rock windrow shall be compacted to at least 90 percent relative compaction or as recommended. G. After fill between windrows is placed and compacted, with the lift of fill covering windrow, windrow should be proof rolled with a D-9 dozer or equivalent. VIEWS ARE DIAGRAMMATIC ONLY AND MAY BE SUPERSEDED BY REPORT RECOMMENDATIONS OR CODE ROCK SHOULD NOT TOUCH ANb VOIDS SHOULD BE COMPLETELY FILLED . ' . OVERSIZE ROCK DISPOSAL DETAIL Plate F-13 ROCK DISPOSAL PITS Fill lifts compacted 01/er . rock after embedment r-··------ . I . . ...... Granular material L . · · :::::::::. Large Rock ---......... -~-·.·.·.· . I I I I Compacted Fill I . ------7 ~ Size of excavation to : be commensurate I with rock size I ROCK DISPOSAL LA YEAS Granular soil to fill voids, densified by flooding . . _. __ -!-~ompacte~f~ _ . . .. Layer one rock high --ft.c JCDcr _t_L._ Proposedf1n1shgrade ~~~~~ .. '_:_Hold-down depth ~ " PAO-;:LE ALONG LA veA- 1 = "---.....____ (. Hold-down depth . ~ t_ Compacted. fill 3-foot tmSlope 1 · . l •• Clear zone TOP VIEW Layer one rock high • Hold-down depth or below lowest utility as specified in text of report, subject to governing agency approval. •• Clear zone for utility trenches, foundations, and swimming pools, as specified in text of report. VIEWS ARE DIAGRAMMATIC ONLY AND MAY BE SUPERSEDED BY REPORT flECOMMENDA TIONS OR CODE ROCK SHOULD NOT TOUCH AND VOIDS SHOULD BE COMPLETELY FILLED IN ROCK DISPOSAL DETAIL Plate F-14 Existing grade 5-foot-high impact/debris wall METHOD 1 1 Pad grade _L __ -- · Existing grade 5-foot-high impact/debris wa,11 METHOD 2 ""' ~ Pad grade __ Existing grade 5-foot-wide catchment area f 5-foot-high METHOD 3 impact/ debris wall ?>.o~-__ ~Padgrad_e __ Existing grade ~\' 2:1(h:v) slope cence -\\),~. \ _ · 2=1 (h=v) slope METHOD 4 0'\ \r-_r---Pad grade '\\\\.__ . .........___ _(_ ·-- ~ ,; NOTTO SCALE Ii ' c. DEBRIS DEVICE · CONTROL METHODS DETAIL Plate F-15 Rock-filled gabion basket Existing grade Proposed grade Filter fabric Compacted fill Gabion impact or diversion wall should be constructed at the base of the ascending slope subject to rock fall. Walls need to be constructed with high segments that sustain impact and mitigate potentie.l for overtopping, and low segment that provides channelization of sediments and debris to desired depositional area for subsequent clean-out. Additional subdrain may be recommended by geotechnical consultant. From GSA, 1987 ROCK FALL MITIGATION DETAIL Plate F-16 / 2-f oot x 2-foot x ¼-inch steel plate Standard ¾-inch pipe nipple welded to top of plate ~------t--¾-inch x 5-foot galvanized pipe, standard pipe threads top and bottom; extensions threaded on both ends and added in 5-foot increments 3-inch schedule 40 PVC pipe sleeve, add in 5-foot increments with glue joints Proposed finish grade ~ AV ~---t_ I 5feet 5feet -I 1 I l . I I J 5 feet / L 2feet // t \·.. ·· · -· ...... , ·. ,.-. ·.· .. -.·. ·-.:·/-----Bottom of cleanout ---ttoot ·:/:::/:\\:::::::::::::t~·_./:\\:::::":::::::::\4-Provide a minimum 1-foot -t-bedding of compacted sand tiG>TES: · 1. Locations of settlement plates should be clearly marked. and readily visible (red flagged) to equipment operators. 2. Contractor should maintain clearance of. a 5-foot radius of plate base and withiin 5 feet (vertical) for heavy equipm~nt. Fill within clearance area should .be hand compacted to project specifications or compacted by alternative approved method by the geotechnical consultant (in writing, prior to construction). 3. After 5 feet (vertical) of fill is in place, contractor st1outd maintain a 5-foot radius equipment clearance from riser. 4; Place and mechanically hand compact initial 2 feet of fill prior to establishing the initial reading. 5. In the event of damage to the settlement plate or extension resulting from equipment operating within the specified clearance area, contractor should immediately notify the geotechnical consultant and should be responsible for restoring the settlement plates to working order. 6. An alternate design and method of installation may be provided at the discretion of the geotechnical consultant. iv-o. J8· SETTLEMENT PLATE AND RISER DETAIL Plate F-18 Finish grade ~~ Jc. LI <J <J "<J·LI LI' <J 3 to 6 feet LI . ,d . <J . LI <J . <J LI LI . <J. ¾-inch-diameter X 6-inch-long carriage bolt or equivalent , .... 6-inch diameter X 3½-inch-long hole .....___ Concrete backfill -· ------------- TYPICAL SURFACE SETTLEMENT MONUMENT Plate F-19 SIDE VIEW Spoil pile Test pit TOP VIEW Flag Flag Spoil pile Light ... -·.-. Vehicle -------50 feet-------1--------50 feet------ --~---~--------'----'----'100fee,T---'----~---~------- TEST PIT SAFETY DIAGRAM Plate F-20 I A~ - TP-2 @12' 1~ @12' fos· 1 B-4 @81/2' f14• @151/2' .!i._ @24' f29• @31' /40• .,.,~ .,.,. .,;• .,,. ..... ~-- .,.._,,.,. _.,r-, ~-.,.-~~,,,,--:;----~~/ " .,.,. .,.,. ~ V) \~::,-..;..----'.)( _,.,/ -:i, .... -i . _,..,,,.-- EXISTIN_G 'TEMPLE;' II'' ,-1 ll 1 Td @5' 6~ @5' 73, @61/2' 10~ @12' 2s·:J @15' 22~ EXIST . / SlREETU<itlT . ;/ ST= / / / // .,.,. ., tor B / . . // / x~ / .· /. / ~It~ i.rXIIT/' [XS~, -~:27 / "'~~;// .. / ~ £, / y, ~x . . / ·--:::V . ' / ~ '/ // /A.~ y/ /// ///-i // / "' / / /1/ //// o/.,. // //· / / / ?,/ / . ~ ~,W""' / / / / Cy\, 7 "7"'"'''> / 0/ // / e,/ / / / / / / / / / / / / / ..-,/" ,. ,, / _,,,. ; / / / / ,., / ./ I' I' ! N '4 GRAPHIC SCALE GS/ .LEGEND Afu -ARTIFICIAL FILL (uNDocuMENTEDJ T d -TERTIARY DEUIAR FORUA 110N, CIRCLED VIIERE BURIED • _. -APPROX/MA TE LOCATION OF GEOLOGIC CONTACT f 29° -BEDDING A7711UDE WITH DIP IN DEGREES ~3~ -FRAC1URE A T111UDE WITH DIP IN DEGREES S-2· s TD=31' V TD=32' TP-2 -APPROX/MA TE LOCATION AND TOTAL DEPTH OF EXPLORATORY BORING (THIS S1UDY) -APPROXIMATE LOCATION AND TOTAL DEPTH OF EXPLORATORY BORING (HE/, 2O1Ob) > I -APPROXIIIA 1E LOCA 110N OF EXPLORATORY TEST PIT (1HIS STUDY) ~TP-4 -APPROXIIIA1E LOCA110N OF EXPLORATORY 1EST PIT · (HB, 2010a) . B B' -LOCATION OF GEOLOGIC CROSS SECTION I I Pll01'EltTY LtlE DATA WAS llERIYED FROM REOORD SClURCES. OWNER IS 1D UllUZE A UCENSED. LAND: . E~~~fi~~TR~.:~ SET SE£ Dttn RECORDEtl 3/1.f.ft,ooa AS INSl!IIJloW::kr ilo: 20C)e,..Q1Jll&04' ~; SAN OIEC(MXIUMlY. CA O· fi\SEMEPIT OATft 1) E"9:MDIT f.Oft THE: BDIEFlT Of I.A alSTA · Hlml. AND SPA· F.OR l~SS, DlRl,$lf AW fi;llElilliW! ANQ '1'9-WCIJ[M MCESS TO lA C(ISTA. A'eJUE .. AlfD INCEENTAL Pl/Rl"QSl;S,, RECOltPEll NOl,Bll!Elt' :w; 111117 AS ltJSlR\luelT NO. 1987~10&2 D.R.: EASEIENT FOR THE BENEFIT CF I.ElJCftDIA lll'A.lER DISTAICT FOR ·ACCESS ftHl PN!IC!Nli Mil IHCIJEHTAL l'UR?<JSEs;; RECOllllE!hWIUAR'r 14, 111111 AS INS.lRUM~ N!). 11199-22481. O.R, . . 2, EAsa1ENr F'OR mE BENEFIT 0r tot a. MAP 1~38 fQft J>RIVA'IE $S\lilER l..,\lERI\L P~E$ PER llOC0"1ENT AECOROEJ)• M~ .14, 2008 AS INSlRUll:Nr NO. 2006-:-0!3&605 o]t 11-£ laASEt.lalT ANl £Xls'lm SE¥11:'.R LA1ERAI.. LOC/\llONS ARE-INOETEFIMIHATE AND THE E~ 'M>lll IS NOT SPEdFEI) S'r' '!HE DOCIJ11£11t. ALL LOCATIONS ARE APPROXIMATE This document or efi/e is not a part of the Construction Documents and should not be relied upon as being an accurate depiction of design. ,\·~"'-~ / / / ,. / 20 0 10 20 40 GEOTECHNICAL MAP / 111 = 201 Plate 1 w.o. 6304-A-SC DATE: 12111 I SCALE: 1" = 20' .,.•., _·. ,· A 140 120 100 40 20 0 200 180 160 140 80 ~ ---· .- JP-1 PRQ.£CTE:D INTO SE:CDON (OYA. 2005) If. ,__-----PROPOSE:D S7RUCTURE: -----t I 1P-Z PROJE:CTE:D INTO srcnoN (GS/, This Study) B-4 PROJE:ClE:D INTO SE:CTION (H£1, 2010a) If. I Propos&d A~u Shoring II _...J~-----~~-t--------------:-:-==:::-r Qco1 · .~---. · .. -:::;;;.;;;;ff""----17;;;;;-;;;;;'·~:r_ _ ___ -· Proposed Shoring ? ...,..~·· ~· TdrssJ ·· ··········· ... 6::15• ·:::::::::: ::t::·.;~· . TdrssJ ·· -·-.--·-·-· -----·----·------. ------.-.::-·-? ?. Tdrsii1 .·. : ? , ? ? ------? ?. ..... .-·· ....... · .......... , ................ . . . .......... ,· .''... .. . . . . -. .. · .. · ................... T d ,ss•, .. I' , . 9" ........... _. .•.•• ......... : ..... ; ..... ,.. ....... , . . . . -. ', ___ ;;;;,__ -------?---------?-·----:-·-._-:-·-·-·-·-· I ---~,:-"·---------. ...:::::-·-~ -·-·-·-·-·-·-·-·-6' Td(SSISLST) ~.· -·-~l --~---. ---·---:::.: :::.: :::.: :::.: -. _: .-::: ::-· -· -------?----"T,--?----?::.: ?-... ? .? I Td (SHALE) ? ::.-::_---------.--?--------,---~· Td(SS) ' 'J.-'_oi::.:-.-.-.. · -.---ri""'a-r------?-------__,~· 7·----?·---·---1 +---r---------?-----. -.-.-_ ---?---·------?----------?·----------?--_-. -.· -.. ------?·------t-----?---- ._ ..... ;;;:;;:::·~·~~· .; •. !"';. :· :.:~~ •. :·-;;;;;;a-,;-:_~Ai~-~'~~.if~-;;· ;.;-;. -~~~~~~c;;.::. :_? ............ : ..... · ·_. -..,'~---_--1_,N_rE~s_E_oo_Eo_s_S1s:::Ls~r1t.-_-·--~--_-~ ... -~~ ~~;.-i ....... ---__ ·-----1---_--...... ----?-_.. ____ ..:_.·_·_.'_.2 __________ ?~-----_---.?---------_,!-_----~..,·-'_·..,· ... ·-..,··-r~(IN:E.R~ED~E°_-SSl~T)-l--? __ ,..._--- s --.:: --.~100 ---- ~ I I I . I --- ---., ....... ·. ·. TdrssJ · · ............ ···········• ........... . . . ........... . ................. , .................................. : .......... '. ........... :, ....... : ... 9' .. Td(C;;TN) - · ... ............................. . ..... , ... :··:; .. ,;.:-··· ........ · ...... . .......... . ........... . ..... - A' RESIDENDAL BLDG. PAD ........ 200 180 160 140 120 h' i:J ~ ······· .. :::::::::::.;:::::.; .. ,. . .. . 1 · ------?-;.._..,,,_. ·~-~--?----------.;--?--------···-==---?-·,;.·· -----=-t 2 ·§ ·-·-·-·-·-·-·-·-·-·- -6' -·--- -. _I :::.: ~. ·~-; ::.-::: .-::: ::-t ·--- T drsstsLsrJ ·---·-----·--------- ----------·-·-----. .....:::.:-:-·-·---------·-·- ·-·-·-------60 "' 100 ~ 80 -----,----.I --~ Td(CLSTN) . -- ;:::- ~ ~ is "" § uJ c;j ------------- N34°W B B' 100 80 60 40 20 lP-1 PRO,,£CTE:V INTO SEC110N (GS/, THIS STUDY) APPROXIMA 1E: LDCA TION OF---. EXISTING OFF'Sllf RE."TAJNING WALL lP-1 PROJEC1E:D INTO SEC110/I B-1 PROJE:ClE:D INTO SECTION DY&A, 2oo5) 1------PROPOSED S7RUCTURE: -----i PROPOSE:D TE:MPORARY SHORING B-4 PRO.£CTE:V INTO SE."C110N (H£1, 2010a) .. Afu ·· ·. . ·· . · .. ·. · · · ··· .· ·. · ·. / Afu .. :.~.?.::::::::::::: .. ·: ·... . . _· .. -T d-_. . .:-.. _. . ·-. -.. _ -i...J ·. B-14 PROJE:CTE:D INTO SE:CTION .......•. ..... . · (SS) . . . . . . (GS/, 1997) (GS/' 1997., 10·· . , 25' · :·······: 14' . . . . . · . . : . · · . j Afu LA COSTA AVE" .. ? . ·. TdrssJ I 5 .... )2'-0•-. -. . . . . . . . . L--~,_..,--,,::-,:-::7---~-:::--:::::~~--~;;----''---'--Lil"/-• -·-· .. •?. . . ·--·--------- •? 100 80. 60 40 ' -.. ----;--,,-"'-~ . .. . --==!.1'. · .. ·~-~ . -_:_ _ _:_ __ _:_-Td (l~TE.~BEDDEDSS!SLST} . ~ : •.. ; ·.-·.Af~ : ~>;.:., .. ?ie.1..-:_-?.-_-----T --,,..,-... ?--------=--2s·-------?---~-· -.id·=----·---?-------~----+ 20 ·, -:' .. ··. :: -fV .. ~. -?-----IU(CLSTN} ---c:.6,----_. (CLSTN} ----~---.--' ----~-'"-',-. ..,_, ·9 --. -0 --N89°W ;:::- i:l ~ is "" § ~ \.--?------?-t-------7--=-:::.:::.--.:•·: ... ··.:.?:===-====:-:::.:=~?--. -:T,:,:-d-;-(S-SJ-,.:-·· :?:::::-:::.:== 60 __________ L--t· Td(SHALEj . ....... -.-;------1· t-?----------?---·------?--------- :ar 60 40 I ·• TdrssJ . ? I. -~ ? 20 - ---------?-·----------?~--------T d (INTERBEDDED SSISLST} --?~----------?------~--?-------....... -~-: ----I --I --. --0 - N34°W ? 40 ? ? 20 - -- 0 Afu Qcol Td(SS) T d (SS/SLST} Td1sHALEJ LEGEND ARTIFICIAL FILL -UNDOCUMENTED QUA TERNARY COLLUWUM TERTIARY DELMAR FORMATION (SANDSTONE MEMBER) TERTIARY DELMAR FORMATION (SANDSTONE/SILTSTONE MEMBER) . TERTIARY DELMAR FORMATION (SHALE MEMBER) Td · -TERTIARY DELMAR FORMATION (INTERBEDD£D SANDSTONE/SILTSTONE MDJBER) {INTERBEDDED SS/SLST} . Td(CLSTNJ TERTIARY DELMAR FORMATION (CLAYSTONE MEMBER) ___ ?__, APPROXIMATE LOCATION OF GEOLOGIC CONTACT (QUERIED WHERE UNCERTAIN) NOTE: Cross Section Extensions are based on mapping performed by the City of Carlsbad (1991) and BDS Engineering, Inc. (2003) ALL LOCATIONS ARE APPROX/MA TE This document or efile is not a part cf tho Construction Documents and should not be relied upon as being an accurate depiction of design. 140 . 120 100 80 40 20 0 .;--... .... :··-.·::--,..., .....:·::.::·2e0 APPARENT DIP (IN DEGREES) OF BEDDING GRAPHIC SCALE GEOLOGIC CROSS SECTIONS APPARENT DIP (IN DEGREES) OF FRACTURE I 52' /" = 20' Plate2 w.o. 6304-A-SC DATE: 12/11 SCALE: 1" = 20'.