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Home My WebLink About; 4016 Garfield Street; Preliminary Geotechnical Evaluation; 2003-08-06PRELIMINARY GEOTECHNICAL EVALUATION 4016 GARFIELD STREET CARLSBAD, SAN DIEGO COUNTY, CALIFORNIA FOR KARNAK ARCHITECTURE AND PLANNING 2802 STATE STREET, SUITE C CARLSBAD, CALIFORNIA 92008 W,0. 4001-A-SC AUGUST 6, 2003 Geotechnicai - Geologic • Environmental 5741 PalmerWay • Carisbad, California 92008 • (760)438-3155 • FAX (760) 931-0915 August 6, 2003 W.O. 4001-A-SC Karnak Architecture and Planning 2802 State Street, Suite C Carlsbad, California 92008 Attention: Mr. Robert Richardson Subject: Preliminary Geotechnical Evaluation, 4016 Garfield Street, Carlsbad, San Diego County California. Dear Mr. Richardson: In accordance with your request, GeoSoils, Inc. (GSI), has performed a preliminary geotechnical evaluation of the subject site. The purpose of the study was to evaluate the onsite soils and geologic conditions and their effects on the proposed site development from a geotechnical viewpoint. EXECUTIVE SUMMARY Based on our review ofthe available data (see Appendix A), field exploration, laboratory testing, geologic and engineering analysis, development of the property appears to be feasible from a geotechnical viewpoint, provided the recommendations presented in the text ofthis report are properly incorporated into the design and construction ofthe project. The most significant elements of this study are summarized below: • Based on the site plan provided by yourself, it appears that the proposed development consists ofthe demolition ofthe existing residential structure, and the construction of a new two-story, two-unit apartment building with underground parking and associated improvements. • All existing concrete slab/foundation, asphaltic concrete driveway, and vegetation debris should be removed from the site and properly disposed of, should settlement sensitive improvements be proposed within their influence. Removals of compressibletopsotl/colluvial soils, and weathered surficial Quaternary-age ten'ace deposits will be necessary prior to fill placement. Depths of removals are outlined in the Conclusions and Recommendations section of this report. In general, removals will be on the order of ±4 feet across a majority of the site. However, localized deeper removals cannot be precluded. To provide for a minimum 4-foot compacted fill blanket, overexcavation of the topsoil/colluvium and terrace deposits to a depth of 4 feet below finish pad grade elevation is recommended. If proposed footings or isolated pad footings are deeper than 24 inches below finish pad grade elevation, additional overexcavation will be necessary to provide a minimum 24 inches of compacted fill beneath the footing. The recommended overexcavation should be accomplished during removals. However, if removal depths are shallower than 4 feet below finish pad grade, overexcavation will be necessary. Based on site conditions and planned improvements, significant cut and/or fill slopes are not anticipated. • The expansion potential of tested onsite soils is very low (expansion index [E.L] less than 20). Conventional foundations may be utilized for these soil conditions. At the time of the publication of this report, the corrosion/sulfate testing data was of yet unavailable. An addendum report, indicating the corrosion/sulfate test results, will be issued when the data become available. • Groundwater was not observed during the field investigation and is not expected to be a major factor in development of the site. However, due to the nature of the site materials, seepage and/or perched groundwater conditions may develop throughout the site along boundaries of contrasting permeabilities (i.e., fill/terrace deposit contacts), and should be anticipated. Should perched groundwater conditions develop, this office could assess the affected area(s) and provide the appropriate recommendations to mitigate the observed groundwater conditions. • Owing to the relatively dense nature ofthe site sediments, our evaluation indicates that the site has a low potential for liquefaction under current hydrologic conditions. Therefore, provided our recommendations are implemented, no other measures for mitigation are deemed necessary. • The seismic acceleration values and design parameters provided herein should be considered during the design of the proposed development. Our evaluation indicates there are no known active faults crossing the site. • Adverse geologic features 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. Karnak Architecture and Pianning W.O. 4001-A-SC File:e:\wp9\4000\4001a.pge Rage Three GeoSoils, Inc. 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. GeoSoils, Inc. Rvan Bo Ryan Boehmer Statf Geologist Reviewed by: ohn P. Franklin Engineering Geologist. CEG 1340 Reviewed by: David W. Skelly Civil Engineer, RCE 47857 RB/RGC/JPF/DWS/jk Distribution: (4) Addressee Karnak Architecture and Planning File:e:\wp9\4000\4001 a.pge W.O. 4001-A-SC Page Three GeoSoils, Inc. TABLE OF CONTENTS SCOPE OF SERVICES 1 SITE CONDITIONS/PROPOSED DEVELOPMENT 1 SITE EXPLORATION 1 REGIONAL GEOLOGY 3 SITE GEOLOGIC UNITS 3 Topsoil/Colluvium (Not Mapped) 3 Quaternary-age Terrace Deposits (Map Symboi - Qt) 3 FAULTING AND REGIONAL SEISMICITY 4 Regional Faults 4 Seismicity 6 Seismic Shaking Parameters 6 Seismic Hazards 7 LIQUEFACTION 7 GROUNDWATER 8 SLOPE STABILITY 8 LABORATORY TESTING 8 General 8 Classification 9 Moisture-Density Relations 9 Laboratory Standard 9 Expansion Potential 9 Direct Shear Test 9 Corrosion/Suifate Testing 10 CONCLUSIONS 10 EARTHWORK CONSTRUCTION RECOMMENDATIONS 10 General 10 Site Preparation 11 Removals (Unsuitable Surficial Materials) 11 Fill Placement 11 Overexcavation 11 RECOMMENDATIONS - FOUNDATIONS 12 Preliminary Foundation Design 12 Bearing Value 12 Lateral Pressure 12 GeoSoils, Inc. Foundation Settlement 13 Footing Setbacks 13 Construction 13 Very Low to Low Expansion Potential (E.l. 0 to 50) 13 CORROSION 14 UTILITIES 14 WALLS/RETAINING WALLS 15 General 15 Restrained Walls 15 Cantilevered Walls 15 Wall Backfill and Drainage 16 Wall/Retaining Wall Footing Transitions 16 Topof Slope/Perimeter Walls 17 Footing Excavation Observation 17 Structural Loading 17 EXTERIOR FLATWORK 18 DEVELOPMENT CRITERIA 19 Slope Maintenance and Planting 19 Drainage 19 Erosion Control 20 Landscape Maintenance 20 Gutters and Downspouts 20 Subsurface and Surface Water 20 Site Improvements 21 Tile Flooring 21 Additional Grading 21 Footing Trench Excavation 21 Trenching 21 Utility Trench Backfill 22 SUMMARY OF RECOMMENDATIONS REGARDING GEOTECHNICAL OBSERVATION AND TESTING 22 OTHER DESIGN PROFESSIONALS/CONSULTANTS 23 PLAN REVIEW 23 LIMITATIONS 24 Karnak Architecture and Planning Table of Contents Fiie:e:\wp9\4000\4001 a.pge Page ii GeoSoils, Inc. FIGURES: Figure 1 - Site Location Map 2 Figure 2 -California Fault Map 5 ATTACHMENTS: Appendix A - References Rear of Text Appendix B - Boring Logs Rear of Text Appendix C - EQFAULT Rear of Text Appendix D - Laboratory Data Rear of Text Appendix E - General Earthwork and Grading Guidelines Rear of Text Plate 1 - Boring Location Map Rear of Text Karnak Architecture and Planning Tabte of Contents Rle:e:\wp9\400a\4001a.pge Page iii GeoSoils, Inc. PREUMINARY GEOTECHNICAL EVALUATION 4016 GARFIELD STREET CITY OF CARLSBAD, SAN DIEGO COUNTY, CALIFORNIA SCOPE OF SERVICES The scope of our services has included the following: 1. Review of the available geologic literature for the site (see Appendix A). 2. Geologic site reconnaissance, subsurface exploration (see Appendix B), sampling, and mapping. 3. General areal seismicity evaluation (see Appendix C). 4. Appropriate laboratory testing of representative soil samples (see Appendix D). 5. Engineering and geologic analysis of data collected. 6. Preparation of this report. SITE CONDITIONS/PROPOSED DEVELOPMENT The subject site consists of a gently (9:1 [horizontahvertical] orfiatter) eastward-sloping lot, located on the east side of Garfield Street in the City of Carlsbad. California. Site elevation is about ±56 to ±66 feet Mean Sea Level (MSL). Overall runoff across the site is approximately 10 feet. An existing residential structure is currently located on the eastern portion ofthe property. Drainage onsite appears to be by sheetflow runoff directed toward the east. Vegetation consists of typical residential landscaping. Based on a site plan provided by yourself, it appears that the proposed development consists of the construction of a two-story, two-unit apartment building with underground parking. Buiiding loads are assumed to be typical for this type of relatively light construction. It is anticipated that sewage disposal will be tied into the municipal system. The need for import soils is unknown at this time. SITE EXPLORATION Surface obsen/ations and subsurface explorations were performed on July 21,2003. by a representative ofthis office. Asurvey of line and gradefor the subject lot was not conducted by this firm at the time of our site reconnaissance. Near surface soil conditions were explored with three hand auger borings within the site to evaluate surficial soil and geologic conditions. The approximate location of each boring are shown on the attached Boring Location Map (see Piate 1). Boring logs are presented in Appendix B. GeoSoils, Inc. J4>TopD(^iidi Copyrighte 1999 Del^nneriniioiitli, ME 04096 Souree Dili: USGS Base Map: flg^ttett'^ly^^^^^ ' Series (Topographic), 0 Scale 2000 4000 Feet N C^^pitSf Inc. W.O. 4001-A-SC SITE LOCATION MAP Figure 1 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 underiain 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 ofthe basin. These rocks have been uplifted, eroded, and deeply incised. During early Pleistocene time, a broad coastai plain was developed from the deposition of marine terrace deposits. 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. SITE GEOLOGIC UNITS The site geologic units encountered during our subsurface investigation and site reconnaissance included colluviumAopsoil and Quaternary-age terrace deposits. The earth materials are generally described below ft-om the youngest to the oldest. The distribution of these materials is shown on Plate 1. Topsoil/Colluvium (Not Mapped) Topsoil/colluvium mantles the entire site at the surface and consists of gray brown, dry, loose/porous silty sands and sands with silt that are approximately ±V/2 to 2 feet thick. These materials are considered potentially compressible in their existing state and will require removal and recompaction if settlement sensitive structures are proposed within their influence. Quaternary-age Terrace Deposits (Map Symbol - Qt) Quaternary-age terrace deposits were observed to underlie the site and consist of loose becoming dense with depth, poorly graded sands with silt to silty sands. These deposits are generally yellow brown to red brown to light red brown and dry to moist. The upper ±2 to ±2y2 feet of these sediments are generally weathered and considered unsuitable for structural support in their present condition, and should be removed and recompacted. Bedding structure was not readily observed, but regionally is typically flat lying to sub-horizontal. These sediments are typically massive to weakly bedded. Karnak Architecture and Planning W.O. 4001-A-SC 4016 Garfield Street, Carlsbad August 4,2003 File:e:\wp9\4000\4001.a.pge Page 3 GeoSoils, Inc. FAULTING AND REGIONAL SEISMICITY Regional Faults Our review indicates that there are no known active faults crossing this site within the area proposed for development, and the site is not within an Earthquake Fault Zone (Hart and Bryant, 1997). However, the site is situated in an area of active as well as potentially active faulting. These 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. The location of these, and other major faults relative to the site, are indicated on Figure 2 (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 the following table (modified from Blake, 2000): ABBREVIATED FAULT NAME APPROXIMATE DISTANCE MILES (KM) Rose Canyon 4.7 (7.6) Newport - Inglewood (Offshore) 5.4 (8.7) Coronado Bank 20.6 (33.1) Elsinore-Temecula 24.7 (39.8) Elsinore-Julian 24.9(40.1) Elsinore-Glen Ivy 34.4 (55.3) Palos Verdes 35.8 (57.6) Earthquake Valley 44.1 (71.0) Newport-Inglewood (LA. Basin) 46.3 (74.5) San Jacinto-Anza 47.3 (76.1) San Jacinto-San Jacinto Valley 47.8 (77.0) Chino-Central Ave. (Elsinore) 48.3 (77.7) Karnak Architecture and Planning 4016 Garfield Street, Carlsbad File:e:\wp9\4000\4001 .a.pge W.O. 4001-A-SC August 4, 2003 Page 4 GeoSoils, Inc. 1100 CALIFORNIA FAULT MAP KARNAK 1000 -- 900 800 -- 700 -- 600 -- 500 400 -- 300 -- 200 100 -- 0 -- -100 I I I 1 I I I I I I I I I I ' I I ' I I I I ' I ' -400 -300 -200 -100 0 100 200 300 400 500 600 W.O. 4001-A-SC Figure 2 Seismicity The acceleration-attenuation relations of Bozorgnia, Campbell, and Niazi (1999) Horizontal Soft Rock Uncorrected PGA, Campbell and Bozorgnia (1997 Revised) Soft Rock, and Bozorgnia, Campbell, and Niazi (1999) Horizontal Soft Rock Corrected PGA Horizontal-Random have been incorporated into EQFAULT (Blake, 2000). Forthis study, peak horizontal ground accelerations anticipated at the site were determined based on the random mean plus 1 sigma attenuation cun/e developed by Joyner and Boore (1982a and 1982b), Sadigh et al. (1987), and Bozorgnia et al. (1999). EQFAULT is a computer program by Thomas F. Blake (2000), which performs deterministic seismic hazard analyses using up to 150 digitized California faults as earthquake sources. The program estimates the closest distance between each fautt 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 fauft. Site acceleration (g) is computed by any of at least 30 user-selected acceleration-attenuation relations that are contained in EQFAULT. Based on the EQFAULT program, peak horizontal ground accelerations from an upper bound event at the site may be on the order of 0.58g to 0.67g. The computer printouts of portions of the EQFAULT program are included within Appendix C. Seismic Shaking Parameters Based on the site conditions. Chapter 16 ofthe Uniform Bullding Code (UBC, international Conference of Building Officials [ICBO], 1997) seismic parameters are provided in the following table: 1997 UBC CHAPTER 16 TABLE NO. SEISMIC PARAMETERS Seismic Zone (per Figure 16-2*) 4 Seismic Zone Factor (per Table 16-1*) 0.40 Soil Profile Type (per Table 16-J*) SD Seismic Coefficient C^ (per Table 16-Q*) 0.44N. Seismic Coefficient C„ (per Table 16-R*) 0.64N^ Near Source Factor N^ (per Table 16-S*) 1.0 Near Source Factor N^ (per Table 16-T*) 1.1 Distance to Seismic Source 4.7 mi (7.6 km) Karnak Architecture and Planning 4016 Garfield Street, Carlsbad File:e:\\Ap9\4000\4001 .a.pge W.O. 4001-A-SC August 4, 2003 Page 6 GeoSoils, Inc. 1997 UBC CHAPTER 16 TABLE NO. SEISMIC PARAMETERS Seismic Source Type (per Table 16-U*) B Upper Bound Earthquake (Rose Canyon fault) M„6.9 * Figure and Table references from Chapter 16 of the UBC (ICBO, 1997) Seismic Hazards The following list includes other seismic related hazards that have been considered during our evaluation of the site. The hazards listed are considered negligible and/or completely mitigated as a result of site location, soil characteristics, and typical site development procedures: Tsunami Dynamic Settlement Surface Fault Rupture Ground Lurching or Shallow Ground Rupture Seiche It is important to keep in perspective that in the event of a maximum probable or credible earthquake occurring on any ofthe 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 ft*om those induced by the hazards considered above. This potential would be no greaterthan that for other existing structures, and improvements inthe immediate vicinity. There is no economic mitigation for tsunami potential that GSI is aware of, considering the site's location and surroundings. LIQUEFACTION Seismically-induced liquefaction is a phenomenon in which cyclic stresses, produced by earthquake-induced ground motion, create excess pore pressures in soils. The soils may thereby acquire a high degree of mobility and lead to lateral movement, sliding, sand boils, consolidation, and settlement of loose sediments and other damaging 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. Typically, liquefaction has a relatively low potential at depths greater than 45 feet and is virtually unknown below a depth of 60 feet. Karnak Architecture and Planning 4016 Garfield Street, Carlsbad File:e:\wp9\4000\4001 .a.pge W.O. 4001-A-SC August 4, 2003 Page 7 GeoSoils, Inc. Liquefaction susceptibility is related to numerous factors and the following conditions should be present for liquefaction to occur: 1) sediments must be relatively young in age and not have developed a large amount of cementation; 2) sediments generally consist of medium to fine grained relatively cohesionless sands; 3) the sediments must have low relative density; 4) ft-ee 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. Inasmuch as at least one to two ofthe necessary concurrent conditions listed above do not have the potential to affect the site, it is our opinion that liquefaction does not pose a significant constraint to development, provided our recommendations are implemented. GROUNDWATER Subsurface water was not encountered within the property during field work performed in preparation of this report. Subsurface water is not anticipated to adversely affect site development, provided that the recommendations contained in this report are incorporated into final design and construction. These observations reflect site conditions at the time of our investigation and do not preclude ftjture changes in local groundwater conditions from excessive irrigation, precipitation, or that were not obvious at the time of our investigation. Perched groundwater conditions along fillAerrace deposit contacts, and along zones of contrasting permeabilities, may not be precluded from occurring in the fijture 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 the appropriate recommendations to mitigate the observed groundwater conditions. SLOPE STABILITY Based on site conditions and planned improvements, significant cut and/or fill slopes are not anticipated. LABORATORY TESTING General Laboratory tests were performed on representative samples of the onsite earth materials in order to evaluate their physical characteristics. The test procedures used and results obtained are presented below. Karnak Architecture and Planning W.O. 4001-A-SC 4016 Garfield Street. Carlsbad August 4,2003 File:e:\wp9\4000\4001 .a.pge Page 8 GeoSoils, Inc. Classification Soils were classified visually according to the Unified Soils Classification System. The soil classifications are shown on the Boring Logs in Appendix B. Moisture-Density Relations The field moisture contents and dry unit weights were determined for selected undisturbed samples in the laboratory. The dry unit weight was determined in pounds per cubic foot (pcf), and the field moisture content was determined as a percentage ofthe dry weight. The results of these tests are shown on the Boring Logs in Appendix B. Laboratory Standard The maximum dry density and optimum moisture content was determined for the major soi! type encountered in the borings. The laboratory standard used was ASTM D-1557. The moisture-density relationship obtained for this soil is shown below: SOIL TYPE BORING (COMPOSITE) MAXIMUM DRY DENSITY (pcf) OPTIMUM MOISTURE CONTENT (%) 1 Silty SAND, Yellow Brown B-1 through B-3 (composite) 126.0 11.0 Expansion Potential Expansion testing was performed on a representative samples of site soil in accordance with UBC Standard 18-2. The results of expansion testing are presented In the following table. LOCATION EXPANSION INDEX EXPANSION POTENTIAL B-1 through B-3 (composite) <5 Very Low Direct Shear Test Shear testing was performed on a representative, "remolded" sample of site soil in general accordance with ASTM Test Method D-3080 in a Direct Shear Machine ofthe strain control type. The shear test results are presented as follows and are provided as Figure D-1 in Appendix D: Karnak Architecture and Planning 4016 Garfield Street, Carlsbad File:e:\wp9\4000\4001 .a.pge W.O. 4001-A-SC August 4,2003 Page 9 GeoSoils, Inc. SAMPLE LOCATION PRIMARY RESIDUAL SAMPLE LOCATION COHESION (PSF) FRICTION ANGLE (DEGREES) COHESION (PSF) FRICTION ANGLE (DEGREES) B-1 through B-3 (Remolded) 95 30 91 30 Corrosion/Suifate Testing At the time of the publication of this report, the corrosion/sulfate testing data was of yet unavailable. An addendum report, indicating the corrosion/sulfate test results will be issued when the data becomes available. CONCLUSIONS Based upon our site reconnaissance, subsurface exploration, and laboratory test results, it is our opinion that the subject site appears suitable for the proposed additional development, from a geotechnical viewpoint. The following recommendations should be incorporated into the construction details. EARTHWORK CONSTRUCTION RECOMMENDATIONS General All grading should conform to the guidelines presented in Appendix Chapter A33 of the UBC. the requirements of the City of Carlsbad, and the Grading Guidelines presented in AppendixE.exceptwherespecificallysuperceded in thetextofthis report. Priorto grading, a GSI representative should be present at the preconstruction meeting to provide additional grading guidelines, if needed, and review the earthwork scheduie. During earthwork construction, all site preparation and the general grading procedures of the contractor should be observed and the fill selectively tested by a representatlve(s) of GSI. If unusual or unexpected conditions are exposed in the field, they should be reviewed bythis office and, if warranted, modified and/or additional recommendations will be offered. All applicable requirements of local and national construction and generai industry safety orders, the Occupational Safety and Health Act (OSHA), and the Construction Safety Act should be met. Karnak Architecture and Planning 4016 Garfield Street, Carlsbad File:e:\wp9\4000\4001 .a.pge W.O. 4001-A-SC August 4,2003 Page 10 GeoSoils, Inc. Site Preparation Debris, vegetation, concrete, slab/foundation, asphaltic concrete driveway, and all deleterious material should be removed ft-om the building area prior to the start of construction. Removals (Unsuitable Surficial Materiais) Due to the relatively loose condition of the topsoil/colluvium, and weathered ten-ace deposits, these materials should be removed and recompacted in areas proposed for settlement sensitive structures or areas to receive compacted fill. At this time, removal depths on the order of ±4 feet (including topsoil/colluvium and weathered terrace deposits) below existing grade should be anticipated throughout a majority of the site; however, locally deeper removals cannot be precluded. Removals should be completed below a 1:1 projection down and away from the edge of any settlement sensitive structure and/or limit of proposed fill. Once removals are completed, the exposed bottom should be scarified in two perpendicular directions, moisture conditioned to at least optimum moisture content, and recompacted to 90 percent relative compaction. Fill Piacement Subsequent to ground preparation, onsite soils may be placed in thin (±6- to ±8-inch) lifts, cleaned of vegetation and debris, brought to at least optimum moisture content, and compacted to achieve a minimum relative compaction of 90 percent. If fill soil importation is planned, a sample ofthe soil import should be evaluated by this office prior to importing, in order to assure compatibility with the onsite soils and the recommendations presented in this report. At least three business days of lead time should be allowed by builders or contractors for proposed import submittals. This lead time wiil allow for particle size analysis, specific gravity, relative compaction, expansion testing, and blended import/native characteristics as deemed necessary. Import soils for a fill cap should be very low expansive (Expansion Index [E.L] less than 20). The use of subdrains at the bottom of the fill cap may be necessary, and subsequently recommended based on compatibility with onsite soils. Overexcavation To provide for a minimum 4-foot compacted fill blanket, overexcavation of the topsoil/colluvium and terrace deposits to a depth of 4 feet below finish pad grade elevation is recommended. If proposed, footings or isolated pad footings are deeper than 24 inches below finish pad grade eievation. additional overexcavation will be necessary to provide a minimum 24 inches of compacted fill beneath the footing. The recommended overexcavation should be accomplished during removals. However, if removal depths are shallower than 4 feet below finish pad grade, overexcavation will be necessary. Karnak Architecture and Pianning W.O. 4001-A-SC 4016 Garfield Street, Carlsbad August 4, 2003 File:e:\wp9\4000\4001 .a.pge Page 11 GeoSoils, Inc. RECOMMENDATIONS - FOUNDATIONS Preliminary Foundation Design in the event that the Information conceming the proposed development plans is not correct, or any changes in the design, location, or loading conditions ofthe proposed structures are made, the conclusions and recommendations contained in this report are forthe subject site only, and shall not be considered valid unless the changes are reviewed and conclusions of this report are modified or approved in writing by this office. The information and recommendations presented in this section are considered minimums and are not meant to supercede de5ign(s) by the project structural engineer or civil engineer specializing in structural design. Upon request. GSI could provide additional consultation regarding soil parameters, as related to foundation design. They are considered preliminary recommendations for proposed construction, in consideration of our fleld investigation, laboratory testing, and engineering analysis. Our review, field work, and recent laboratory testing indicates that onsite soils have a very low expansion potential (E.l. less than 20). Preliminary recommendations for foundation design and construction are presented below. Final foundation recommendations should be provided at the conclusion of grading, based on laboratory testing of fiil materials exposed at finish grade. Bearing Value 1. The foundation systems should be designed and constructed in accordance with guidelines presented in the latest edition ofthe UBC. 2. An allowable bearing value of 1.500 pounds per square foot (psf) may be used for design of continuous footings 12 inches wide and 12 inches deep, and for design of isolated pad footings 24 inches square and 18 inches deep, founded entirety into compacted fill or competent Quaternary-age terrace deposits and connected by grade beam or tie beam in at least one direction. This value may be increased by 20 percent for each additional 12 inches in depth to a maximum value of 2.500 psf. The above values may be increased by one-third when considering short duration seismic or wind loads. No increase in bearing for footing width is recommended. Lateral Pressure 1. For lateral sliding resistance, a 0.35 coefficient of ft-iction may be utilized for a concrete to soil contact when multiplied by the dead load. 2. Passive earth pressure may be computed as an equivalentfluld having a density of 250 pcf with a maximum earth pressure of 2,500 psf. Karnak Architecture and Planning W.O. 4001 -A-SC 4016 Garfield Street, Carlsbad August 4, 2003 File:e:\wp9\4000\4001.a.pge Page 12 GeoSoils, Inc. 3. When combining passive pressure and frictional resistance, the passive pressure component should be reduced by one-third. Foundation Settlement Foundation systems should be designed to accommodate a differential settlement of at least y4-inch in a 40-foot span. Footing Setbacks All footings should maintain a minimum 7-foot horizontal setback ft-om the base of the footing to any descending slope. This distance is measured from the footing face at the bearing elevation. Footings should maintain a minimum horizontal setback of H/3 (H = slope height) firom the base of the footing to the descending slope face and no less than 7 feet, nor need be greater than 40 feet. Footings adjacent to unlined drainage swales should be deepened to a minimum of 6 inches below the invert of the adjacent unlined swale. Footings for structures adjacent to retaining walls should be deepened so as to extend below a 1:1 projection from the heel fo 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. Construction The following foundation construction recommendations are presented as a minimum criteria ft-om a soils engineering standpoint. The onsite soil expansion potential is generally very low (E.l. 0 to 20). Recommendations for very low to low expansive soil conditions are presented herein. Recommendations by the project's design-structural engineer or architect, which may exceed the soils engineer's recommendations, should take precedence over the following minimum requirements. The design structural engineer should review and approve the minimal footing and slab design provided below. Final foundation design will be provided based on the expansion potential ofthe near surface soils encountered during grading. Very Low to Low Expansion Potential (E.l. 0 to 50) 1. Exterior and interiorfootings should be founded at a minimum depth of 12 inchesfor one-story floor loads, and 18 inches for two-story floor loads, into compacted fill. Isolated column and panel pads, or wall footings, should be founded at a minimum depth of 18 inches into compacted fill, excluding the landscape zone (6 inches) at the building footprint margin. Alt footings should be reinforced with two No. 4 reinforcing bars, once placed near the top and one placed near the bottom of the footing. Footing widths should be as indicated in UBC (ICBO, 1997). Karnak Architecture and Planning W.O. 4001-A-SC 4016 Garfield Street, Carlsbad August 4, 2003 File:e:\v\^9\4000\4001.a.pge Page 13 GeoSoils, Inc. 2. A grade beam, reinforced as above, and at least 12 inches square, should be provided across large (e.g., doorways) entrances. The base ofthe grade beam should be at the same elevation as the bottom of adjoining footings. Isolated, exterior square footings should be tied within the main foundation in at least one direction with a grade beam. 3. Concrete slabs, where moisture condensation is undesirable, including garage areas, should be underlain with a vapor barrier consisting of a minimum of 10 mil polyvinyl chloride, or equivalent membrane, with all laps sealed. This membrane should be covered with aminimum of 2 inches of sand to aid in uniform curing ofthe concrete, and to protect the membrane from puncture. 4. Concrete slabs should be a minimum of 5 inches thick and should be reinforced with No. 3 reinforcing bar at 18 inches on center in both directions. All siab reinforcement should be supported to ensure placement nearthe vertical midpoint ofthe concrete. "Hooking" of reinforcement is not considered an acceptable method of positioning the reinforcement. 5. Garage slabs should be reinforced as above and poured separately from the structural footings and quartered with expansion joints or saw cuts. A positive separation from the footings should be maintained with expansion joint material to permit relative movement. 6. Presaturation is not required for these soil conditions. The moisture content of the subgrade soils should be equal to, or greaterthan, optimum moisture content in the slab areas, prior to concrete placement. CORROSION Upon completion of grading, additional testing of soils (including import materials) for corrosion to concrete and metals should be performed priorto the construction of utilities and foundations. UTILITIES Utiiities should be enclosed within a closed utilidor (vault) or designed with flexible connections to accommodate differential settlement. Due to the potential for differential settlement, air conditioning (A/C) 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. A/C waste wateriines should be drained to a suitable outlet. Karnak Architecture and Planning W.O. 4001-A-SC 4016 Garfield Street, Carlsbad August 4,2003 File:e:\wp9\4000\4001.a.pge Page 14 GeoSoils, Inc. WALLS/RETAINING WALLS General Foundations may be designed using parameters provided in the Design section of Foundation Recommendations presented herein. Wall sections should adhere to the City of Carlsbad guidelines. All wall designs should be reviewed by a qualified structural engineer for structural capacity, overturning, and stability. The design parameters provided assume that onsite, or equivalent, very low expansive soils, or selected flli, are used to backfill retaining walls. If expansive soils are used to backfill the proposed walls within this wedge, increased active and at-rest earth pressures will need to be utilized for retaining wall design. Heavy compaction equipment should not be used above a 1:1 projection up and away from the bottom of any wall. The following recommendations are not meant to apply to specialty walls (cribwalls, loffel, earthstone, etc.). Recommendations for specialty walls will be more onerous than those provided herein, and can be provided upon request. Some movement ofthe constructed walls should be anticipated as soil strength parameters are mobilized. This movement could cause some cracking dependent upon the materials used to construct the wall. To reduce wall cracking due to settlement, walls should be internally grouted and/or reinforced with steel. Restrained Wails Any retaining walls that will be restrained priorto placing and compacting backfill material, or that have re-entrant or male corners, should be designed for an at-rest equivalent fluid pressures of65pcffornative soil backfill, plusany applicable surcharge loading. Forareas of male or re-entrant corners, the restrained wall design should extend a minimum distance of twice the height of the wall (2H) laterally ft-om the corner. Building walls below grade should be water-proofed, or damp-proofed, depending on the degree of moisture protection desired. Refer to the following section for preliminary recommendations fi-om surcharge loads. Cantilevered Waiis These recommendations are for cantilevered retaining walls up to 15 feet high. Active earth pressure may be used for retaining wal! design, provided the top ofthe wall is not restrained ft-om minor deflections. An empirical equivalent fluid pressure (EFP) approach may be used to compute the horizontal pressure against the wall. Appropriate fluid unit weights are provided for speciflc slope gradients ofthe retained material. These do not include other superimposed loading conditions such as traffic, structures, seismic events, or adverse geologic conditions. Karnak Architecture and Planning W.O. 4001 -A-SC 4016 Garfield Street, Carlsbad August 4. 2003 File:e:\wp9\4000\4001.a.pge Page 15 GeoSoils, Inc. SURFACE SLOPE EQUIVALENT SELECT OF RETAINED MATERIAL FLUID WEIGHT PCF MATERIAL PCF (Horizontal to Verticai) (Very Low Expansive Native Soil) (Gravel) Level 45 35 2 to 1 58 - The equivalent fluid density should be increased to 65 pcf for level backfill using the native soil at the angle point of the wall (corner or male re-entrant,) and extended a minimum lateral distance of 2H on either side of the corner. However, if the selected backfill with angle of ft-iction of 30 degrees is used, this value may be reduced to 62 pcf. Wall Backfill and Drainage All retaining walls should be provided with an adequate gravel and pipe backdrain and outiet system (a minimum two outlets per wall) to prevent buildup of hydrostatic pressures, and be designed in accordance with minimum standards presented herein. Pipe should consist of schedule 40 perforated PVC pipe. Gravel used in the backdrain systems should be a minimum of 3 cubic feet per lineal foot of %- to 1V2-inch clean crushed rock encapsulated in filter fabric (Mirafi 140 or equivalent). Perforations in pipe should face down. The surface of the backfill should be sealed by pavement or the top 18 inches compacted to 90 percent relative compaction with native soil. Proper surface drainage should also be provided. As an alternative to gravel backdrains, panel drains (Miradrain 6000, Tensar. etc.) may be used. Panel drains should be installed per manufacturer's guidelines. Regardless of the backdrain used, walls should be water proofed where they would impact living areas or where staining would be objectionable. Wall/Retaining Wali Footing Transitions Site walls are anticipated to be founded on footings designed in accordance with the recommendations in this report. Wall footings may transition from formational bedrock to select fill. If this condition is present the civil designer may specify either: a) If transitions from rock fill to select fill transect the wall footing alignment at an angle of less than 45 degrees (plan view), then the designer should perform a minimum 2-foot overexcavation for a distance of 2H and increase overexcavation until such transition is between 45 and 90 degrees to the wall alignment. b) Increase of the amount of reinforcing steel and wall detailing (i.e., expansion joints or crack control joints) such that an angular distortion of 1/360 for a distance of 2H Karnak Architecture and Planning W.O. 4001 -A-SC 4016 Garfield Street, Carlsbad August 4.2003 Ftle:e:\wp9\4000\4001 .a.pge Page 16 GeoSoils, Inc. on either side ofthe transition may be accommodated. Expansion joints should be sealed with a flexible, non-shrink grout. c) Embed the footings entirely into homogenous fill or terrace deposits. Top of Slope/Perimeter Walls The geotechnical parameters previously provided may be utilized for free standing sound walls or perimeter walls, which are founded in either competent bedrock or compacted fill materials. The strength of the concrete and grout should be evaluated by the structural engineer of record. The proper ASTM tests forthe concrete and mortar should be provided along with the slump quantities. The placing of joints (expansion and crack control) should be incorporated into the wall layout. These expansion joints shouid be placed no greater than 20 feet on-center and should be reviewed bythe civil engineer and structural engineer of record. GSI anticipates distortions on the order of Va to ± 1 inch in 50 feet forthese walls located at the tops of fill/cut slopes. To reduce this potential, the footings may be deepened and/or the use of piers may be considered. Footing Excavation Observation All footing excavations for walls and appurtenant structures should be observed by the geotechnical consultant to evaluate the anticipated near surface conditions prior to the placement of steel or concrete. Based on the conditions encountered during the observations of the footing excavation, supplemental recommendations may be offered, as appropriate. Structural Loading Surcharge loads delivered to lower footings from the adjacent, upper structural footings, should only be applied tothe portion ofthe lower footings that fall below the point where the 1:2 (h:v) downward projection from the footing edge meets the wall. Both vertical pressures and lateral pressures shouid be applied to the portion of the wall height falling below that point. The vertical pressure underthe adjacent footing may be assumed to spread out on a slope of 2:1 (h:v). Thus, a load Q acting concentrically on a footing with an area of (B x L) is assumed to be distributed over an area of (B + 2)(L +2) at a depth Z below the bottom ofthe footing. For cantileverwalls, the lateral surcharge on the wall, due to adjacent footing surcharge, should be equal to 33 percent of the vertical pressure at depth, while for restrained walls, it should be equal to 50 percent of the vertical surcharge. In order to mitigate surcharge loading, the upper foundations should be deepened below a 1:1 projection up and away fi-om the outer edge of the lower footing. The architect and/or structural engineer should provide supporting dates to GSI to confirm their design has included the above recommendations. Karnak Architecture and Planning W.O. 4001 -A-SC 4016 Garfield Street, Carlsbad August 4,2003 File:e:\wp9\4000\4001 .a.pge Page 17 GeoSoils, Inc. EXTERIOR FLATWORK Exterior driveways, walkways, sidewalks, or patios, using concrete slab on grade construction, should be designed and constmcted in accordance with the following criteria: 1. Concrete slabs should be a minimum 4 inches in thickness. A thickened edge (minimum of 12 inches) should be constructed for all fiatwork adjacentto landscape areas. 2. Slab subgrade (i.e., existing fill matenals) should be compacted to a minimum 90 percent relative compaction and moisture conditioned to the soils optimum moisture content to a minimum depth of 12 inches. This should be verified by this office at least 72 hours prior to pouring concrete. The use of Class 2, Class 3, or decomposed granite (i.e., DG) as a base for the concrete slab in non-vehicle traffic areas is not required. 3. The use of transverse and longitudinal control joints should be considered to help control slab cracking due to concrete shrinkage or expansion. Two ofthe best ways to control this movement are: 1) add a sufficient amount of reinforcing steel, increasing tensile strength ofthe slab; and/or, 2) provide an adequate amount of controi and/or expansion joints to accommodate anticipated concrete shrinkage and expansion. We would suggest that the maximum control joint spacing be placed on 5- to 8-foot centers, or the smallest dimension of the slab, whichever is least. 4. No traffic should be allowed upon the newly poured concrete slabs until they have been properly cured to within 75 percent of design strength. 5. 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. This may be accomplished using thickened PCC pavement edges and concrete cut off barriers or deepened curbs, in addition to eliminating granular base materials (i.e.. Class 2,3, DG etc.) underlying the slab. 6. In areas directly adjacent to a continuous source of moisture (i.e., irrigation, planters, etc.), all joints should be sealed with flexible mastic. 7. Concrete compression strength should be a minimum of 2,500 psi. Karnak Architecture and Planning W.O. 4001-A-SC 4016 Garfield Street, Carlsbad August 4,2003 File:e:\wp9\4000\4001.a.pge Page 18 GeoSoils, Inc. DEVELOPMENT CRITERIA Slope Maintenance and Planting Water has been shown to weaken the inherent strength of all earth materials. Slope stability is signiflcantly reduced by overly wet conditions. Positive surface drainage away ft-om slopes should be maintained and only the amount of irrigation necessary to sustain plant life should be provided for planted slopes. Over-watering should be avoided as it can adversely affect site improvements, and cause perched groundwater conditions. Graded slopes constructed utilizing onsite materials would be erosive. Eroded debris may be minimized and surficial slope stability enhanced by establishing and maintaining a suitable vegetation cover soon after constmction. Compaction to the face of fill slopes would tend to minimize short-term erosion until vegetation is established. Plants selected for landscaping should be light weight, deep rooted types that require little water and are capable of sun/iving the prevailing climate. Jute-type matting or other fibrous covers may aid in allowing the establishment of a sparse plant cover. Utilizing plants other than those recommended above will increase the potential for perched water to develop. A rodent control program to prevent burrowing should be implemented. Irrigation of natural (ungraded) slope areas is generally not recommended. These recommendations regarding plant type, irrigation practices, and rodent control should be provided to each homeowner. Over-steepening of slopes should be avoided during building construction activities and landscaping. Drainage Adequate lot 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 prevent ponding of water anywhere on a lot, and especially near structures and tops of slopes. Lot surface drainage should be careftjily taken into consideration during fine grading, landscaping, and building construction. Therefore, care should betaken that ftjture landscaping or construction activities do not create adverse drainage conditions. Positive site drainage within lots and common areas should be provided and maintained at all times. Drainage should not flow uncontrolled down any descending slope. Water should be directed away ft-om foundations and not allowed to pond and/or seep into the ground. In general, the area within 5 feet around a structure should slope away flrom the structure. We recommend that unpaved lawn and landscape areas have a minimum gradient of one percent sloping away from structures, and whenever possible, should be above adjacent paved areas. Consideration should be given to avoiding construction of planters adjacent to structures (buildings, pools, spas. etc.). Pad 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. Karnak Architecture and Planning ' " WO 4001-A-SC 4016 Garfield Street, Carlsbad August 4 2003 Fiie:e:\wp9\4000W001 .a.pge pggg ^ g GeoSoils, Inc. Groundwater conditions may change with the introduction of irrigation, rainfall, or other factors. Site improyements Recommendations for exterior concrete flatwork design and construction can be provided upon request. If in the future, any additional improvements (e.g., pools, spas, etc.) are planned for the site, recommendations concerning the geological or geotechnical aspects of design and construction of said improvements could be provided upon request. This office should be notified in advance of any flli placement, grading of the site, or trench backfllling after rough grading has been completed. This includes any grading, utility trench, and retaining wall backfllls. 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 signiflcant. Therefore, the designer should consider additional steel reinforcement for concrete slabs-on-grade where tile will be placed. The tile installer 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 grading in the street and parking areas 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 verify that the excavations are made into the recommended bearing material and to the minimum widths and depths recommended for construction, ft loose or compressible materials are exposed within the footing excavation, a deeper footing or removal and recompaction ofthe 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 90 percent, if not removed from the site. Trenching Considering the nature ofthe onsite soils, it should be anticipated that caving or sloughing could be afactor in subsurface excavations and trenching. Shoring or excavating the trench Karnak Architecture and Planning W.O. 4001-A-SC 4016 Garfield Street, Carlsbad August 4, 2003 File: e:\wp9\4000\4001 .a.pge Page 21 GeoSoils, Inc. walls at the angle of repose (typically 25 to 45 degrees) may be necessary and should be anticipated. All excavations should be observed by one of our representatives and minimally conform to CAL-OSHA and local safety codes. 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. Observation, probing and testing should be provided to verify 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 ali trenches beneath hardscape features and in slopes, should be compacted to at least 90 percent ofthe 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 verify the desired results. 3. All trench excavations shouid conform to CAL-OSHA 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 ofthe structural engineer. 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/recertification. • After excavation of building footings, retaining wall footings, and ft-ee standing wails 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 barriers (i.e., visqueen, etc.). • During retaining wall subdrain installation, priorto backflll placement. Karnak Architecture and Planning W.O. 4001-A-SC 4016 Garfield Street, Carisbad August 4, 2003 File:e:\wp9\4000\400l .a.pge Page 22 GeoSoils, Inc. During placement of backfill for area drain, Interior plumbing, utility line trenches, and retaining wall backfill. During slope construction/repair. When any unusual soil conditions are encountered during any construction operations, subsequent to the issuance of this report. When any developer or homeowner improvements, such as flatwork, spas, pools, walls, etc., are constructed. 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, post-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. PLAN REVIEW Final project plans should be reviewed by this office prior to construction, so that construction is in accordance with the conclusions and recommendations ofthis report. Based on our review, supplemental recommendations and/or further geotechnical studies maybe warranted. Karnak Architecture and Planning W.O. 4001 -A-SC 4016 Garfield Street, Carlsbad August 4,2003 File:e:\wp9\4000\4001.a.pge Page 23 GeoSoils, Inc. LIMITATIONS The materials encountered on the project site and utilized for our analysis are believed representative ofthe area; however, soil and bedrock materials vary in character between excavations and natural outcrops or conditions exposed 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 is expressed or implied. Standards of practice are subjectto change with time. GSI assumes no responsibility or liability for work ortesting performed by others, ortheir inaction, orwork performed when GSI is not requested to be onsite, to evaluate if our recommendations have been property implemented. Use ofthis report constitutes an agreement and consent by the user to ali the limitations outiined above, notwithstanding any other agreements that may be in place. In addition, this report may be subject to review by the controlling authorities. Karnak Architecture and Planning W.O. 4001-A-SC 4016 Garfield Street, Carlsbad August 4, 2003 File:e:\wp9\4000\4001.a.pge Page 24 GeoSoils, Inc. APPENDIXA REFERENCES APPENDIXA REFERENCES Blake, Thomas P., 2000, EQFAULT, A computer program for the estimation of peak horizontal acceleration ft-om 3-D fault sources; 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 SM1P99 seminar on utilization of strong-motion data, September 15, Oakland, pp. 23-49. Campbell. K.W. and Bozorgnia. Y., 1997, Attenuation relations for soft rock conditions; jn EQFAULT, A computer program for the estimation of peak horizontal acceleration ft-om 3-D fault sources; Windows 95/98 version, Blake, 2000. Campbell, K.W.. 1997, Empirical near-source attenuation relationships for horizontal and vertical components of peak ground acceleration, peak ground velocity, and pseudo-absolute acceleration response spectra, Seismological Research Letters, vol. 68. No. 1, pp. 154-179. Hart, E.W. and Bryant, W.A., 1997, Fault-rupture hazard zones in California, Alquist-Priolo earthquake fault zoning act with index to earthquake fault zones maps; California Division of Mines and Geology Special Publication 42, with Supplements 1 and 2,1999. International Conference of Building Officials, 1997, Uniform building code: Whittier, California, vol. 1,2, and 3. 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. Joyner. W.B, and Boore, D.M., 1982a, Estimation of response-spectral values as functions of magnitude, distance and site conditions, jn eds., Johnson, J.A., Campbell, K.W.. and Blake, T.F.: AEG Short Course. Seismic Hazard Analysis, June 18,1994. , 1982b, Prediction of earthquake response spectra, U.S. Geological Survey Open-File Report 82-977,16p. Karnak Planning and Design, undated, 2-unit apartment for Mr. and Mrs. Hart, 4016 Garfield Street (Site Plan), 10-scale, Sheet Cl .0, no project number. Sadigh, K., Egan, J., and Youngs, R., 1987, Predictive ground motion equations, jn Joyner. W.B. and Boore, D.M., 1988, Measurement, characterization, and prediction of strong ground motion, in Von Thun, J.L. ed.. Earthquake engineering and soil dynamics II, recent advances in ground motion evaluation, American Society of Civil Engineers Geotechnical Special Publication No. 20, pp. 43-102. GeoSoils, Inc. Sowers and Sowers. 1970, Unified soil classification system (After U. S. Waterways Experiment Station and ASTM 02487-667) m Introductory Soil Mechanics. New York. Tan, S.S., and Kennedy. Michael P., 1996. Geologic maps of the northwestern part of San Diego County, California, Plate 1: California Division of Mines and Geology, Open File Report 96-02. Karnak Architecture and Planning Appendix A Rle:e:\wp9\4000\4001 a.pge Page 2 GeoSoils, Inc. APPENDIX B BORING LOGS BORING LOG GeoSoils. Inc. PROJECT-. KARNAK 4016 Garfield Street W.O. 4001-A-SC BORING B-1 t Sample 32 Q. C — D S/*MPLE METHOD: HAND AUGER SHEET 1 OF_L 7-21-03 Standard Penetration Test Undisturbed, Ring Sample Sl ^ Groonchvater Description of Material SM TOPSOIUCOLLUVIUM: @ 0' SILTY SAND, gray brown, dry, loose; porous, rootlets. SP 110.8 1.6 8.8 WEATHERED TERRACE DEPOSITS: @ 2' SAND w/SILT, yellow brown, dry, loose to medium dense; porous. 3P/SW QUATERNARY-AGE TERRACE DEPOSITS: @ 4* SAND w/SILT to SILTY SAND, yellow brown to red brown, damp to moist, medium dense to dense. Total Depth = 5* No Groundwater/Caving Encountered Backfilled 7-21-2003 4016 Garfield Street GeoSoils, Inc. PLATE B-1 GeoSoils, Inc. PROJECT: KARNAK 4016 Garfield Street BORING LOG W.O. 4001-A-SC BORING B-2 Sample 11 Ui^ CO £ 5^ « a. c — D o D^TEEXCAWITED SAMPLE METHOD: HAND AUGER SHEET 1 OF 1 7-21-03 Standard Penetraton Tesf Undisturbed, Ring Sample XZ ¥- Groondivaier Description of Material SP TOPSOIL/COLLUVIUM: @ 0' SAND w/SILT, gray brown, dry, loose; porous, rootlets. SP 111.1 1.8 9.5 WEATHERED TERRACE DEPOSITS: @ 1!4' SAND w/SILT, yellow brown, dry, loose; porous. SP/SW QUATERNARY-AGE TERRACE DEPOSITS: @ 4' SAND w/SILT to SILTY SAND, yellow brown to red brown, damp to moist, medium dense to dense. Total Depth = 5' No Groundwater/Caving Encountered Backfilled 7-21-2003 4016 Garfield Street GeoSoils, Inc. PLATE B-2 GeoSoils. Inc. PROJECT: KARNAK 4016 Garfield Street BORING LOG W.O. 4001-A-SC BORING B-3 a. Sample CO 11 Oi^ tfi £ 5? o DATEEXCAVATED SAMPLE METHOD: HAND AUGER SHEET 1 OP 1 7-21-03 Standard Penetration Test Undisturbed, Ring Sample 2 ^ Groundwater Description of Material SP TOPSOIUCOLLUVIUM: @ 0' SAND w/SILT, gray brown, dry, loose; porous, rootlets. SP 115.9 1.9 11.6 WEATHERED TERRACE DEPOSITS: @ 2' SAND w/SILT, light red brown, dry, loose to medium dense; porous. 3P/SIV QUATERNARY-AGE TERRACE DEPOSITS: @ 4' SAND w/SILT to SILTY SAND, red brown, damp to moist, medium dense to dense. Total Depth = 5' No Groundwater/Caving Encountered Backfilled 7-21-2003 4016 Garfield Street GeoSoils, Inc. PLATE B-3 APPENDIX C EQFAULT C q cc 0) 0) o o < MAXIMUM EARTHQUAKES KARNAK 01 .001 .1 X X X X X X >^ XX x-" X-. X 1 10 Distance (mi) 100 W.O. 4001-A-SC Figure C-1 APPENDIX D LABORATORY DATA 3,000 2,500 2,000 z UJ I Q: r w 1,500 1,000 500 500 1,000 1,500 NORMAL PRESSURE, psf 2.000 2,500 3,000 Sample Depth/El. Primary/Residual Shear Sample Type Yd MC% c • B-1 0.0 Primary Shear Remolded 113.4 11.0 95 30 • B-1 0.0 Residual Shear Remolded 113.4 11.0 91 30 Note: Sample Innundated prior to testing GeoSoils, Inc. 5741 PalmerWay Carisbad, CA 92008 Telephone: (760)438-3155 Fax: (760)931-0915 DIRECT SHEAR TEST Project KARNAK Numben 4001-A-SC Date: July 2003 Figure D-1 APPENDIX E GENERAL EARTHWORK AND GRADING GUIDELINES GENERAL EARTHWORKAND GRADING GUiDELiNES General These guidelines present general procedures and requirements for earthwork and grading as shown on the approved grading plans, including preparation of areas to filled, placement of fill, installation of subdrains and excavations. The recommendations contained in the geotechnical report are part ofthe 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 recommendations which could supersede these guidelines orthe recommendations contained in the geotechnical report. The contractor is responsible for the satisfactory completion of all earthwork in accordance with provisions of the project plans and specifications. The project soil engineer and engineering geologist (geotechnical consultant) or their representatives should provide observation and testing services, and geotechnical consultation during the duration ofthe project. EARTHWORK OBSERVATIONS AND TESTING Geotechnical Consultant Priorto 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 conformance with the recommendations of the geotechnical report, the approved grading plans, and applicable grading codes and ordinances. The geotechnical consultant should provide testing and observation so that determination 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 schedule their personnel accordingly. All clean-outs, prepared ground to receive fill, key excavations, and subdrains should be observed and documented by the project engineering geologist and/or soil engineer prior to placing and fill. It is the contractors's responsibility to notify the engineering geologist and soil engineer when such areas are ready for observation. Laboratorv 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-1557-78. Random field compaction tests should be performed in accordance with test method ASTM designation D-1556-82, D-2937 or D-2922 and D-3017, at inten/als of approximately 2 feet of fill height or every 100 cubic yards of fill placed. These criteria would vary depending on the soil conditions and the size ofthe project. The location and frequency of testing would be at the discretion of the geotechnical consultant. GeoSoils, Inc. Contractor's Responsibility All clearing, site preparation. and earthwork performed on the project should be conducted bythe contractor, with observation by geotechnical consultants and staged approval bythe governing agencies, as applicable. It is the contractor's responsibility to prepare the ground surface to receive the fill, to the satisfaction of the soil engineer, and to place, spread, moisture condition, mix and compact the fill in accordance with the recommendations of the soil engineer. The contractor should also remove all major non-earth material considered unsatisfactory by the soil engineer. It is the sole responsibility ofthe contractorto provide adequate equipment and methods to accomplish the earthwork in accordance with applicable grading guidelines, codes or agency ordinances, and approved grading plans. Sufficient watering apparatus and compaction equipment should be provided bythe contractor with due consideration forthe fill material, rate of placement, and climatic conditions. If, in the opinion ofthe 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 Ali major vegetation, including brush, trees, thick grasses, organic debris, and other deleterious material shouid be removed and disposed of off-site. These removals must be concluded prior to placing fill. Existing fill, soil, alluvium, colluvium, or rock materials determined by the soil engineer or engineering geologist as being unsuitable in-place should be removed prior to 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 soil engineer. 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 bythe soil engineer. Soft, dry, spongy, highly fractured, or othenwise 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 soil engineer 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. Karnak Architecture and Planning Appendix E File:e:\wp9\4000\4001a.pge Page 2 GeoSoils, Inc. Existing ground which is determined to be satisfactory for support ofthe fills should be scarified to a minimum depth of 6 inches or as directed by the soil engineer. After the scarified ground is broughtto optimum moisture content or greater and mixed, the materials should be compacted as specified herein. If the scarified zone is grater that 6 inches in depth, it may be necessary to remove the excess and place the material in lifts restricted to about 6 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 soils engineer and/or engineering geologist. Scarification, disc harrowing, or other acceptable form 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, hollow, hummocks, or other uneven features which would inhibrt compaction as described previously. Where fills are to be placed on ground with slopes steeper than 5:1 (horizontal to vertical), 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 soil engineer and/or engineering geologist. 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 bythe Geotechnical Consultant. As a general rule, unless specifically recommended otherwise by the Soil Engineer, the minimum width of fill keys should be approximately equal to Vz 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 toe of fill benches should be observed and approved by the soil engineer and/or engineering geologist 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 determined to be suitable bythe soil engineer. These materials should be free of roots, tree branches, other organic matter or other deleterious materials. All unsuitable materials should be removed from the fill as directed by the soii engineer. 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 sen/e as a satisfactory fill material. Karnak Architecture and Planning Appendix E File:e:\wp9\4000\4001a.pge Page 3 GeoSoils, Inc. Fill materials derived fi-om benching operations should be dispersed throughoutthe fill area and blended with other bedrock derived 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 soil engineer. Oversized material should betaken off-site or placed in accordance with recommendations ofthe soil engineer in areas designated as suitable for rock disposal. Oversized material should not be placed within 10 feet vertically of finish grade (elevation) or within 20 feet horizontally of slope faces. To facilitate future trenching, rock should not be placed within the range of foundation excavations, fiJture utilities, or uaderground construction unless specifically approved by the soil engineer and/or the developers 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 soil engineer to determine its physical properties. If any material other than that previously tested is encountered during grading, an appropriate analysis ofthis material should be conducted by the soil engineer 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 6 inches in thickness. The soil engineer may approve thick lifts if testing 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 condition, 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 maximum density as determined by ASTM test designation, D-1557-78, or as otherwise recommended bythe soil engineer. 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 Karnak Architecture and Planning Appendix E File:e:\wp9\4000\4001a.pge Page 4 GeoSoils, Inc. tested and found to meet the density and moisture requirements, and is approved by the soil engineer. 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. Afinal determination of fill slope compacfion should be based on observation and/or testing of the finished slope face. Where compacted fill slopes are designed steeper than 2:1 (horizontal to vertical), specific material types, a higher minimum relative compaction, and special grading procedures, may 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 10 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 aiso be used to roll perpendicular to the slopes, and extend out over the slope to provide adequate compaction to the face of the slope. 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 ofthe slope at appropriate vertical inten/als, subsequent to compaction operafions. 4. After completion ofthe 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 verify compaction, the slopes should be grid-rolled to achieve compaction to the slope face. Final testing should be used to confirm compaction after grid rolling. 5. Where testing indicates less than adequate compaction, the contractor will be responsible to rip, water, mix and re-compact the slope material as necessary to achieve compaction. Additional testing should be performed to verify compaction. 6. Erosion control and drainage devices should be designed by the project civil engineer in compliance with ordinances ofthe controlling governmental agencies, and/or in accordance with the recommendation ofthe soil engineer or engineering geologist. Karnak Architecture and Planning Appendix E File:e:\wp9\4O00\40O1a.pge Page 5 GeoSoils, Inc. SUBDRAIN INSTALLATION Subdrains should be installed in approved ground in 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 soil engineer and/or engineering geologist may recommend and direct changes in subdrain line, grade and drain material in thefield, pending exposed conditions. The location of constructed subdrains should be recorded by the project civil engineer. EXCAVATIONS Excavations and cut slopes should be examined during grading by the engineering geologist. If directed by the engineering geologist, further excavations or overexcavation and re-filling 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 ofthe slope should be observed bythe engineering geologist priorto placement of materials for constmction of the fill portion of the slope. The engineering geologist should observe all cut slopes and should be notified by the contractor when cut slopes are started. If, during the course of grading, unforeseen adverse or potential adverse geologic conditions are encountered, the engineering geologist and soil engineer should investigate, evaluate and make recommendations to treat these problems. The need for cut slope buttressing or stabilizing should be based on in-grading evaluation bythe engineering geologist, whether anticipated or noL Unless otherwise specified in soil and geological reports, 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 contractors responsibility. Erosion control and drainage devices should be designed bythe project civil engineer and should be constructed in compliance with the ordinances ofthe controlling governmental agencies, and/or in accordance with the recommendations of the soli engineer or engineering geologist COMPLETION Observation, testing and consultation bythe geotechnical consultant should be conducted during the grading operations in order to state an opinion that all cut and filled areas are graded in accordance with the approved project specifications. After completion of grading and after the soil engineer and engineering geologist have finished their observations ofthe work, final reports should be submitted subject to review by the controlling governmental agencies. No further excavation or filling should be Karnak Architecture and Planning Appendix E File:e:\wp9\4000\4001a.pge Page 6 GeoSoils, Inc. undertaken without prior notification of the soil engineer and/or engineering geologist. All finished cut and fill slopes should be protected fi'om 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 GeoSoils, Inc. (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 are to be implemented for the safety of field personnel on grading and construction projects: Safety Meetings: GSI field personnel are directed to attend contractors regularly scheduled and documented safety meetings. Safety Vests: Safety vests are provided for and are to be worn by GSl personnel at all times when they are working in the field. Safety Flags: Two safety flags are provided to GSl 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 fiashing amber beacon, 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. Inthe eventthatthe contractor's representative observes any of our personnel notfollowing the above, we request that it be brought to the attention of our office. Karnak Architecture and Planning Appendix E File:e:\wp9\4000\4001a.pge Page 7 GeoSoils, Inc. Test Pits Location, Orientation and Clearance The technician is responsible for selecting test pit locations. A primary concern should be the technicians's safety. Efforts will be made to coordinate locations with the grading contractors authorized representative, and to select locations following or behind the established traffic pattern, preferably outside of current traffic. The contractors authorized representative (dump man, operator, supervisor, grade checker, etc.) should direct excavation ofthe pit and safety during the test period. Of paramount concern should be the soil technicians safety and obtaining enough tests to represent the fill. Test pits should be excavated so that the spoil pile is placed away form 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 established for 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 decreased 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 fiag should be placed at the top of the slope. The contractor's representative should effectively keep all equipment at a safe operation distance (e.g., 50 feet) away from the slope during this testing. The technician is directed to withdraw from the active portion ofthe fill as soon as possible following testing. The technician's vehicle should be parked at the perimeter ofthe fill in a highly visible location, well away fi'om 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 technicians safety is jeopardized or compromised as a resuft of the contractors failure to comply with any ofthe above, the technician is required, by company policy, to immediately withdraw and notify his/her supervisor. The grading contractors representative will eventually be contacted in an effort to effect a solution. However, in the interim, no further testing will be performed until the situation is rectified. Any fiil place can be considered unacceptable 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 brings this to his/her attention and notify this office. Effective communication and coordination between the contractors representative and the soils technician is strongly encouraged in order to implement the above safety plan. Karnak Architecture and Pianning Appendix E File:e:\wp9\4000\4001 a.pge Page 8 GeoSoils, Inc. 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. Ail 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. ff 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 contractors representative will eventually be contacted in an effort to effect a solution. All backfill not tested due to safety concerns or other reasons could be subject to reprocessing and/or removal. If GSl personnel become aware of anyone working beneath an unsafe trench wall or vertical excavation, we have a legal obligation to put the contractor and owner/developer on notice to immediately correctthe situation. If corrective steps are nottaken. GSI then has an obligation to notify CAL-OSHA and/or the proper authorities. Karnak Architecture and Planning Appendix E File:e:\wp9\4000\4001 a.pge Page 9 GeoSoils, Inc. PLATE EG-5 o o a: o < cc < u_ o _l LL LO PLATE EO-9 UJ CJ £ •£ =) Ul CO w a bl U) O a. X u a lU < m o UJ z z e Ul I- UJ o UJ ca 5 to tu LU £ a UJ cr a >- Ul a z < >-03 >• CC < in tn Ul u UJ z a Ul z z cs ut l- Ul a \k Q Ul z IC o UJ U) 0. 3 Ul o " o a Ul -J o g I z' S oe UJ ^ Ul a z Ul S z :3 K 3 CD U z °= w > Z Ul o o UL t) J- O g c w ^ S w ° S UJ z Q z < 5d Z o X I- o < X t/) lil o: Ul < ±: O < — o CD in UJ O a z o u Q: UJ > o a < a. CN UJ tn o to ut X PLATE EG-10 TRANSITION LOT DETAIL CUT LOT (MATERIAL TYPE TRANSITIONJ NATURAL GRADE COMPACTED RLL OVEREXCAVATE AMD RECOMPACT _ /^\V>^NV^ 3' MINIMUM* ^ UNWEATHERED BEDROCK OR APPROVED MATERIAL l7# TYPICAL BENCHING CUT-FILL LOT (DAYUGHT TRANSITION) 5* MINIMUM NATURAL GRADE -^-ViV^^-QVEREXCAVATE AND RECOMPACT ^0^ NJ'^^'^ >^m^P^^^W^^^^^^^^' MINIMUM* ^ UNWEATHERED BEDROCK OR APPROVED MATERIAL TYPICAL BENCHING NOTE: * DEEPER OVEREXCAVATION MAY BE RECOMMENDED BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST IN STEEP CUT-FILL TRANSITION AREAS. PLATE EG-11 TEST PIT SAFETY DIAGRAM SIDE VIEW ^^pTESTHTj^P^ { NOT TO SCALE 1 ^FLAG^ TOP VIEW too FEET 50 FEET SPOIL P!L£ iii u. a in 50 FEET APPRt3XIMATE CENTER OF TEST PIT VB«CL£ J L tii u. o tn FUG ( NOT TO SCALE 1 PLATE EG-16