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HomeMy WebLinkAboutCDP 04-58; Kokopelli Residence; Preliminary Geotechnical Evaluation; 2005-01-21PRELIMINARY GEOTECHNICAL EVALUATION KOKOPELLI RESIDENCE, APN 210-111-08 NORTHEAST CORNER OF CEREZO DRIVE AND CARLSBAD BOULEVARD CARLSBAD, SAN DIEGO COUNTY, CALIFORNIA FOR KOKOPELLI BUILDERS, INC. 2107 NORTH DECATUR ROAD, SUITE 424 DECATUR, GEORGIA 30033 W.O. 4646-A-SC JANUARY 21, 2005 Geotechnical • Geologic • Environmental 5741 Palmer Way • Carlsbad, California 92008 • (760)438-3155 • FAX (760) 931-0915 January 21,2005 W.O. 4646-A-SC Kokopelli Builders, Inc. 2107 North Decatur Road, Suite 424 Decatur, Georgia 30033 Attention: Mr. Hugh Pitts Subject: Preliminary Geotechnical Evaluation, Kokopelli Residence, APN 210-111 -08, Northeast Corner of Carlsbad Boulevard and Cerezo Drive, Carlsbad, San Diego County, California Dear Mr. Pitts: In accordance with your request, GeoSoils, Inc. (GSI) has performed a preliminary geotechnical evaluation ofthe subject site. The purpose ofthe 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 of the available data (see Appendix A), field exploration, laboratory testing, geologic and engineering analysis, 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: All deleterious debris and vegetation should be removed from the site and properly disposed, should settlement-sensitive improvements be proposed within their influence. Removals of all compressible topsoil/colluvium, and near-surface weathered Quaternary terrace deposits will be necessary prior to fill placement. In general, removals will be on the order of ±272 to ±3 feet below the existing grade. However, localized deeper removals cannot be precluded and should be anticipated. To provide for the uniform support ofthe residential structure(s), footings should not simultaneously bear on compacted fill and terrace deposits. During grading, the cut portion of a cut/fill transition pad or a building pad with planned fills that are less than 3 feet thick should be overexcavated a minimum of 3 feet below pad grade, or to a depth which provides for a minimum of 24 inches of compacted fill beneath the footing, whichever is greater. The overexcavation should be completed per the Uniform Building Code ([UBC], International Conference of Building Officials [ICBO], 1997), or to a minimum lateral distance of 5 feet outside the building footprint, whichever is greater. Lower floor levels, exposing terrace deposits at finish grade, will require the minimum overexcavation ifthe upper floors are to be supported by compacted fill. Additionally, if paleoliquefaction features are encountered during site earthwork, overexcavation of the building pad, to a depth of at least 3 feet below slab subgrade, or 24 inches below the bottom ofthe footing (whichever is deeper), will be necessary in order to mitigate the potential differential settlements. The overexcavation should be completed per the UBC (ICBO, 1997), or to a minimum of 5 feet outside the building footprint, whichever is greater. The maximum to minimum fill thickness, below settlement-sensitive improvements, should not exceed a ratio of 3:1 (maximum:minimum). The expansion potential of tested onsite soils is generally very low (Expansion Index [E.I.] 0 to 20). Conventional foundations may generally be utilized for these very low expansive soil conditions. However, post-tension foundations will be specifically recommended to mitigate the potential for differential settlement if the presence of regionally pervasive paleoliquefaction features are encountered during site grading. Post-tension foundation design and construction recommendations are provided herein. If desired, mat foundation recommendations could be provided upon request. Site soils are considered to be moderately corrosive to ferrous metals when saturated and present negligible sulfate exposure to concrete. Consultation with a qualified corrosion engineer is recommended, regarding foundations, piping, etc. Regional 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. Thus, more onerous slab design for mitigation is warranted. Regional groundwater is anticipated to exist at, or near. Mean Sea Level (MSL). On a preliminary basis, temporary slopes should be designed and constructed in accordance with criteria established by CAL-OSHA for "Type C" soil conditions. However, temporary slopes should be reevaluated during grading. Kokopelli Builders, Inc. W.O. 4646-A-SC File:e:\wp9\4600\4646a.pge Page Two GeoSoils, Inc. • Our evaluation indicates that the site currently has a very low potential for liquefaction. Therefore, no recommendations 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. 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. l^iyan Boehmer .Geologist ohn P. Franklin ngineering Geologis RB/JPF/DWS/jk David W. Skelly Civil Engineer, RCE 47857 Distribution: (4) Addressee (1) JL Design Architecture and Planning, Attention: Mr. Jennifer Bolyn Kokopelli Builders, Inc. Flle:e:\wp9\4G0O\4646a.pge GeoSoils, Inc. W.O. 4646-A-SC Page Three TABLE OF CONTENTS SCOPE OF SERVICES 1 SITE CONDITIONS/PROPOSED DEVELOPMENT 1 SITE EXPLORATION 3 REGIONAL GEOLOGY 3 Paleoliquefaction Features 3 SITE GEOLOGIC UNITS 4 Topsoil/Colluvium (Not Mapped) 4 Quaternary Terrace Deposits (Map Symbol - Qt) 4 FAULTING AND REGIONAL SEISMICITY 4 Regional Faults 4 Local Faulting 6 Seismicity 6 Seismic Shaking Parameters 7 Seismic Hazards 8 GROUNDWATER 8 LIQUEFACTION POTENTIAL 8 SETTLEMENT 9 SLOPE STABILITY 10 LABORATORYTESTING 10 General 10 Classification 10 Moisture-Density Relations 10 Laboratory Standard 10 Expansion Potential 11 Direct Shear Test 11 Saturated Resistivity, pH, and Soluble Sulfates 11 PRELIMINARY CONCLUSIONS AND RECOMMENDATIONS 12 General 12 EARTHWORK CONSTRUCTION RECOMMENDATIONS 14 General 14 Site Preparation 14 Removals (Unsuitable Surficial Materials) 14 GeoSoils, Inc. Fill Placement 15 Transitions/Overexcavation 15 Temporary Slopes 15 Monitoring Existing, Offsite Improvements 16 RECOMMENDATIONS - FOUNDATIONS 16 Preliminary Foundation Design 16 Bearing Value 16 Lateral Pressure 17 Foundation Settlement 17 Footing Setbacks 17 Construction 17 Very Low Expansion Potential (E.I. 0 to 20) 18 POST-TENSION SLAB FOUNDATIONS 19 General 19 Construction 19 CORROSION 21 WALL DESIGN PARAMETERS 21 Conventional Retaining Walls 21 Restrained Walls 21 Cantilevered Walls 22 Retaining Wall Backfill and Drainage 22 Wall/Retaining Wall Footing Transitions 26 DRIVEWAY, FLATWORK, AND OTHER IMPROVEMENTS 26 DEVELOPMENT CRITERIA 28 Drainage 28 Erosion Control 29 Landscape Maintenance 29 Gutters and Downspouts 29 Subsurface and Surface Water 30 Site Improvements 30 Tile Flooring 30 Additional Grading 30 Footing Trench Excavation 31 Trenching/Temporary Construction Backcuts 31 Utility Trench Backfill 31 SUMMARYOF RECOMMENDATIONS REGARDING GEOTECH NICAL OBSERVATION AND TESTING 32 Kokopelli Builders, Inc. Table of Contents File:e:\wp9\4600\4646a.pge Page ii GeoSoils, Inc. OTHER DESIGN PROFESSIONALS/CONSULTANTS 33 PLAN REVIEW 33 LIMITATIONS 34 FIGURES: Figure 1 - Site Location Map 2 Figure 2 - California Fault Map 5 Detail 1 - Typical Retaining Wall Backfill and Drainage Detail 23 Detail 2 - Retaining Wall Backfill and Subdrain Detail Geotextile Drain 24 Detail 3 - Retaining Wall and Subdrain Detail Clean Sand Backfill 25 ATTACHMENTS: Appendix A - References Rear of Text Appendix B - Boring Logs Rear of Text Appendix C - EQFAULT, EQSEARCH, and FRISKSP Rear of Text Appendix D - Laboratory Data Rear of Text Appendix E - General Earthwork and Grading Guidelines Rear of Text Plate 1 - Test Pit Location Map Rear of Text in Folder Kokopelli Builders, Inc. Table of Contents Flle:e:\wp9\4600\4646a.pge Page iii GeoSoils, Inc. PREUMINARY GEOTECHNICAL EVALUATION KOKOPELLI RESIDENCE, APN 210-111-08 NORTHEAST CORNER OF CARLSBAD BOULEVARD AND CEREZO DRIVE 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 with four exploratory test pit excavations (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 site consists of a relatively flat-lying property located of the northeast corner of the intersection of Carlsbad Boulevard and Cerezo Drive, in Carlsbad, San Diego County, California (Figure 1, Site Location Map). The site is bounded by existing development to the east and north, Cerezo Drive to the south, and Carlsbad Boulevard to the west. Site drainage appears to be directed toward the streets. The site's elevation is approximately ±55 feet Mean Sea Level (MSL). Vegetation consists of abundant ice plant and weeds. It is our understanding that the proposed development will consist of preparing the site for the construction of a 6,241 square-foot, two-story residence (including a media room), with 1,301 square feet of underground garage/parking, and associated underground utilities. We further understand that the proposed residence would include retaining walls for the basement level, and would utilize continuous spread footings with a slab-on-grade and/or post-tension/mat foundation, and wood-frame and/or masonry block construction, with wood siding and/or a stucco exterior. Building loads are assumed to be typical for this type of relatively light construction. It is anticipated that cut and fill grading techniques will be utilized to bring the site to the design grade. Maximum proposed fill and cut slopes are on the order of 3 and 6Vz feet, respectively. Excavation would be required for the garage. GeoSoils, Inc. 1000 ri:£T Base Map: TOPO!® ©2003 National Geographic, USGS San Luis Rey Quadrangle, California-San Diego Co., 7.5-Minute, dated 1997, current 1999. .ocim 1000 FEET Base Map: The Thomas Guide, San Diego Co. Street Guide and Directory, 2005 Edition, by Thomas Bros. Maps, page 1126. LOCATION AND SCALES APPROXIMATE Reproduced with permission granted by Ttiomas Bros. Maps. This map is copyrighted by Thomas Bros. Maps. It is unlawful to copy or reproduce all or any part thereof, whether for personal or resale, without permission. All rigtits Reserved w.o. GisoSoils, Ilie. 4646-A-SC SITE LOCATION MAP Rgure 1 SITE EXPLORATION Surface observations and subsurface explorations were performed on January 6,2004, by a representative of this office. A survey of line and grade for the subject site was not conducted by this firm at the time of our site reconnaissance. Near surface soil and geologic conditions were explored with four exploratory test pit excavations within the site. The approximate locations of each exploratory test pit are shown on the attached Test Pit Location Map (see Plate 1). Test Pit Logs are presented in Appendix B. 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 ofthe basin. These rocks have been uplifted, eroded, and deeply incised. During early Pleistocene time, a broad coastal 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. Paleoliquefaction Features Franklin and Kuhn (2000) conducted a geologic investigation on a site, located approximately 2 miles south of the subject site, underlain by similar deposits, such as those that exist onsite. Their investigation indicated "several epochs of liquefied sediments (sand dikes, lateral spreads, and a sand laccolith)." These regional liquefied sediments range from late Holocene (no more than 2,000 to 3,000 years old) to perhaps Pleistocene in age, and reflect at least two, and perhaps multiple, paleoliquefaction events, based on soil and stratigraphic relationships. However, features potentially associated with paleoliquefaction were not directly observed at the subject site during our field investigation. Kokopelli Builders, Inc. W.O. 4646-A-SC Kokopelli Residence, Carlsbad January 21, 2005 Flle:e:\wp9\4600\4646a.pge Page 3 GeoSoils, Inc. SITE GEOLOGIC UNITS The site geologic units encountered or observed during our subsurface investigation and site reconnaissance included topsoil/colluvium and Quaternary terrace deposits (weathered and unweathered). The earth materials are generally described below, from the youngest to the oldest. The distribution of these materials is shown on Plate 1. Topsoil/Colluvium (Not Mapped) Topsoil/colluvium was observed to mantle the entire site and primarily consists of brown to dark red brown, moist, loose, sands with silt that are on the order of ±% foot thick. The loose nature of these soils renders them unsuitable to support settlement-sensitive improvements in their existing state. Mitigation in form of removal and recompaction will be necessary. Quaternarv Terrace Deposits (Map Symbol - Qt) Quaternary terrace deposits were observed to directly underlie the colluvial soils, and consist of dark red brown, moist, medium dense sands with silt (where weathered) to orange brown, damp to moist, dense to very dense silty sands (unweathered). These sediments are also exposed in the nearby coastal bluff, and are as much as ±45 to ±50 feet thick. The near-surface, weathered portion ofthe terrace deposits is on the order of ± 13/4 to ±2V4 feet thick. All weathered terrace deposits are slightly porous and therefore are considered unsuitable for support of settlement-sensitive improvements in their present condition, and should be removed and recompacted. The terrace deposits generally exhibited massive structure. Although not observed during our site exploration, paleoliquefaction features (as discussed above) could be encountered within the terrace deposits during future site earthwork. 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; Jennings, 1994). 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, 2000a): Kokopelli Builders, Inc. ~~ W.O. 4646-A-SC Kokopelli Residence, Carlsbad January 21, 2005 Flle:e:\wp9\4600\4646a.pge GCOSoilS, InC. ^^^^ CALIFORNIA FAULT MAP KOKOPELLI BUILDERS, INC. 1100 1000 -100 900 -- 800 -- 700 -- 600 -- 500 -- 400 -- 300 -- 200 -- 100 -- -400 -300 -200 -100 100 200 300 400 500 600 W.O. 4646-A-SC Figure 2 GeoSoils, Inc. ABBREVIATED FAULT NAME APPROXIMATE DISTANCE MILES (KM) Rose Canyon 3.9 (6.3) Newport - Inglewood (Offshore) 5.9 (9.5) Coronado Bank 20.0 (32.2) Elsinore (Temecula) 25.2 (40.5) Elsinore (Julian) 25.2 (40.6) Elsinore (Glen Ivy) 35.5 (57.2) San Joaquin Hills 36.7 (59.0) Palos Verdes 36.7(59.1) Earthquake Valley 43.6 (70.2) Newport - Inglewood (LA. Basin) 47.5 (76.5) San Jacinto - Anza 47.9(771) San Jacinto - San Jacinto Valley 48.6 (78.2) Chino - Central Ave. (Elsinore) 48.8 (78.6) Local Faulting No local faulting was observed to transect the site during the field investigation. Additionally, a review of regional geologic maps does not indicate the presence of local faults crossing the site. Seismicitv The acceleration-attenuation relations of Boore et al. (1997), Bozorgnia, Campbell, and Niazi (1999), and Campbell and Bozorgnia (1997 Revised) have 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) is computed by one or more 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 0.66g to 0.77g. The computer printouts of portions of the EQFAULT program are included within Appendix C. Kokopelli Builders, Inc. Kokopelli Residence, Carlsbad Fi!e:e:\wp9\4600\4646a.pge GeoSoils, Inc. W.O. 4646-A-SC January 21, 2005 Page 6 Historical site seismicity was evaluated with the acceleration-attenuation relations of Boore et al. (1997) and the computer program EQSEARCH (Blake, 2000b). This program performs a search of the historical earthquake records for magnitude 5.0 to 9.0 seismic events within a 100-mile radius, between the years 1800 to December 31,2004. 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 to December 31, 2004 was 0.33g. A historic earthquake epicenter map and a seismic recurrence curve are also estimated/generated from the historical data. Computer printouts ofthe EQSEARCH program are presented in Appendix C. A probabilistic seismic hazards analyses was performed using FRISKSP (Blake, 2000c), which models earthquake sources as 3-D planes and evaluates the site specific probabilities of exceedance for given peak acceleration levels or pseudo-relative velocity levels. Based on a review of this data, and considering the relative seismic activity of the southern California region, a peak horizontal ground acceleration of 0.30g was calculated. This value was chosen as it corresponds to a 10 percent probability of exceedance in 50 years (or a 475-year return period). Computer printouts of the FRISKSP program are included in Appendix C. Seismic Shaking Parameters Based on the site conditions. Chapter 16 of the Uniform Building 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*) O.44N3 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*) 1.15 Distance to Seismic Source 3.9 mi (6.3 km) Seismic Source Type (per Table 16-U*) B Upper Bound Earthquake (Rose Canyon) M„ 6.9 * Figure and Table references from Chapter 16 of the UBC (ICBO, 1997) Kokopelli Builders, Inc. Kokopelli Residence, Carlsbad File:e:\wp9\4600\4646a.pge GeoSoils, Inc. W.O. 4646-A-SC January 21, 2005 Page 7 Seismic Hazards The following list includes other seismic related hazards that have been considered during our evaluation ofthe site. The hazards listed are considered negligible and/or completely mitigated as a result of site location, soil characteristics, and typical site development procedures: Dynamic Settlement • Surface Fault Rupture Ground Lurching or Shallow Ground Rupture • Tsunami • Seiche It is important to keep in perspective that in the event of a maximum probable or 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. This potential would be no greater than that for other existing structures and improvements in the immediate vicinity. 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 thatthe 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 future changes in local groundwater conditions from excessive irrigation, precipitation, or that were not obvious at the time of our investigation. The regional groundwater table is anticipated to be near MSL, or approximately ±55 feet below the site. Perched groundwater conditions along fill/terrace deposit contacts, and 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. Thus, more onerous slab design for mitigation is warranted. Should perched groundwater conditions develop, this office could assess the affected area(s) and provide the appropriate recommendations to mitigate the observed groundwater conditions. LIQUEFACTION POTENTIAL 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 Kokopelli Builders, Inc. W.O. 4646-A-SC Kokopelli Residence, Carlsbad January 21, 2005 Flle:e:Vwp9\4600\4646a.pge GCOSoilS, InC. ^^^^ ^ 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 belowthe watertable; 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. Liquefaction susceptibility is related to numerous factors and the following conditions should be concurrently 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) 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. 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 on the site. In the site area, we found there is a potential for seismic activity. However the regional water table is located approximately ±55 feet belowthe site, and the terrace deposits were observed to become dense with depth. Since at least three or four of these five required concurrent conditions discussed above do not have the potential to affect the site, our evaluation indicates that the potential for liquefaction and associated adverse effects within the site is very low, even with a future rise in groundwater levels, based on the available data. The site conditions will also be improved by removal and recompaction of low density near-surface soils. Therefore, it is our opinion that the liquefaction potential does not constitute a significant risk to site development, provided our recommendations are implemented. SETTLEMENT Although not directly observed during the field investigation, paleoliquefaction features may create a non-uniform bearing condition within the underlying native soils that has the potential to provide for relatively large differential settlement. This potential differential settlement could be on the order of 1 to 1 inches in a 40-foot span, or respective angular distortions of 1/480 to 1/320. A differential settlement on the order of 1 inch in a 40-foot span (1/480), is considered to be the tolerance limit for typical concrete slabs-on-grade and conventional foundation systems. As such, the presence of paleoliquefaction features, during grading, would preclude the use of conventional foundations, and a post-tension design would then be more appropriate and recommended. On a preliminary basis, Kokopelli Builders, Inc. " W.O. 4646-A-SC Kokopelli Residence, Carlsbad January 21, 2005 File:e:\wp9\4600\4646a.pge Page 9 GeoSoils, Inc. differential settlement is anticipated to be on the order of % inch in a 40-foot span, provided that paleoliquefaction features are not encountered during grading. SLOPE STABILITY Based on site conditions and planned improvements, significant cut and/or fill slopes are not anticipated. Therefore, no recommendations are deemed necessary at this time. 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. Classification Soils were classified visually according to the Unified Soils Classification System (Sowers and Sowers, 1979). The soil classifications are shown on the Test Pit Logs in Appendix B. Moisture-Densitv 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 of the dry weight. The results of these tests are shown on the Test Pit Logs in Appendix B. Laboratorv Standard The maximum dry density and optimum moisture content was determined for a representative bulk soil sample. The laboratory standard used was ASTM D-1557. The moisture-density relationship obtained for this soil is shown below: SOILTYPE SAMPLE LOCATION AND DEPTH (FT) MAXIMUM DRY DENSITY (PCF) OPTIMUM MOISTURE CONTENT (%) Silty SAND, Dark Gray TP-2 @ 1 - 2V2 123.5 9.5 Kokopelli Builders, Inc. Kokopelli Residence, Carlsbad Flle:e:\wp9\4600\4646a.pge GeoSoils, Inc. W.O. 4646-A-SC January 21,2005 Page 10 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. SAMPLE LOCATION AND DEPTH (ft) EXPANSION INDEX EXPANSION POTENTIAL TP-2 @ 1 - 2Vz <5 Very Low Direct Shear Test Shear testing was performed on a representative, "undisturbed" 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 in Appendix D: SAMPLE LOCATION AND DEPTH (ft) PRIMARY RESIDUAL SAMPLE LOCATION AND DEPTH (ft) COHESION (PSF) FRICTION ANGLE (DEGREES) COHESION (PSF) FRICTION ANGLE (DEGREES) TP-1 @ 5 120 35 92 33 Saturated Resistivity. pH. and Soluble Sulfates A typical sample of the site material was analyzed for corrosion/acidity potential. The testing included determination of soluble sulfates, pH, and saturated resistivity. Results indicate that site soils are strongly acidic (pH = 5.2) with respect to acidity, and are moderately corrosive to ferrous metals when saturated (saturated resistivity = 5,900 ohm-cm). Moderately corrosive soils are considered to range between 2,000 and 10,000 ohms-cm. Based upon the soluble sulfate results of 0.0065 percent by weight in soil, the site soils have a negligible corrosion potential to concrete (UBC range for negligible sulfate exposure is 0.00 to 0.10 percentage by weight soluble [SOJ in soil). Alternative testing methods and additional comments may be obtained from a qualified corrosion engineer regarding foundations, piping, etc. Test results are presented on the attached Appendix B. Kokopelli Builders, Inc. Kokopelli Residence, Carlsbad Flle:e:\wp9\4600\4646a.pge GeoSoils, Inc. W.O. 4646-A-SC January 21,2005 Page 11 PRELIMINARY CONCLUSIONS AND RECOMMENDATIONS General Based on our field exploration, laboratory testing, and geotechnical engineering analysis, 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 incorporated into the design and construction phases of site development. The primary geotechnical concerns with respect to the proposed development are: Depth to competent bearing material. Overexcavation ofthe building pad(s). Potential for perched groundwater during and after development Ongoing expansion and corrosion potential of site soils. Regional seismic activity and related hazards. The recommendations presented herein considerthese as well as other aspects ofthe 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 event 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 verified 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. Soil engineering, observation, and testing services should be provided during grading to aid the contractor in removing unsuitable soils and in his effort to compact the fill. 2. Geologic observations should be performed during 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. All compressible topsoil/colluvium on the order of ±y4-foot thick, and the upper ±1% to ±2y4 feet ofthe weathered terrace deposits are considered unsuitable for the support of settlement-sensitive improvements in their present condition, based on current industry standards. These materials are potentially compressible in their present condition, and may be subject to differential settlement. Mitigation in the form of removal and recompaction will be necessary. At this time removal depths on the order of ±272 to ±3 feet below the existing grade (including weathered terrace deposits) should be anticipated. However, locally deeper removals cannot be precluded and should be anticipated. Kokopelli Builders, Inc. W.O. 4646-A-SC Kokopelli Residence, Carlsbad January 21, 2005 File:e:Nwp9\4600\4646a.pge GCOSoilS, InC. ^^^^ 4. The cut portion of a cut/fill transition pad or a building pad with planned fills that are less than 3 feet thick should be overexcavated to a depth that provides for a 3-foot thick compacted fill blanket, or 24 inches of compacted fill beneath the footings, whichever is greater. The overexcavation should be completed per the UBC (ICBO, 1997), or to a minimum of 5 feet outside the building footprint, whichever is greater. Lower floor levels exposing terrace deposits at finish grade will require the minimum overexcavation if the upper floors are to be supported by compacted fill. The maximum to minimum fill thickness, below settlement-sensitive improvements, should not exceed a ratio of 3:1 (maximum:minimum) Additionally, if paleoliquefaction features are encountered during site earthwork, overexcavation of the building pad, to a depth of at least 3 feet below slab subgrade, or 24 inches below the bottom ofthe footing (whichever is greater), will be necessary in order to mitigate the potential differential settlements. The overexcavation should be completed per the UBC (ICBO, 1997), or to a minimum of 5 feet outside the building footprint, whichever is greater. 5. In general and based upon the available data to date, regional groundwater is not expected to be a major factor in development of the site. However, perched groundwater conditions along fill/terrace deposit contacts, and 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. Thus, more onerous slab design for mitigation is warranted. Should perched groundwater conditions develop, this office could assess the affected area(s) and provide the appropriate recommendations to mitigate the observed groundwater conditions. In addition, subdrainage systems for the control of localized groundwater seepage should be anticipated. The proposed locations of such drains can be delineated at the grading plan review stage of planning. 6. Our laboratory test results and experience on nearby sites related to expansion potential indicate that soils with very low expansion indices generally underlie the site. This should be considered during project design and construction. Preliminary foundation design and construction recommendations are provided herein for a very low expansion potential classification. 7. On a preliminary basis, conventional foundations may be utilized for the soil conditions encountered during this investigation. However, if paleoliquefaction features are encountered during grading, post-tension foundations will be specifically recommended to support the residence in orderto mitigate the potential for differential settlement. Preliminary conventional and post-tension foundation design and construction recommendations are provided herein for a very low expansion potential classification. If desired, mat foundation recommendations could be provided upon request. Final foundation design and construction recommendations will be provided at the conclusion of site grading. Kokopelli Builders, Inc. ~~ W.O. 4646-A-SC Kokopelli Residence, Carlsbad January 21, 2005 File:e:\wp9\4600\4646a.pge Page 13 GeoSoils, Inc. 8. The seismicity-acceleration values provided herein should be considered during the design and construction of the proposed development. 9. 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 All grading should conform to the guidelines presented in Appendix Chapter A33 of the UBC, the requirements ofthe City, and the Grading Guidelines presented in Appendix E, except where specifically superceded in the text of this report. Prior to grading, a GSI representative should be present at the preconstruction 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. Site Preparation All vegetation and deleterious debris should be removed from the site prior to the start of construction. Removals (Unsuitable Surficial Materials) Due to the relatively loose condition ofthe topsoil/colluvium, and weathered, near-surface terrace deposits, these materials should be removed and recompacted in areas proposed for settlement-sensitive improvements or areas to receive compacted fill. At this time, removal depths on the order of ±272 to ±3 feet (including weathered terrace deposits) below the existing grade should be anticipated throughout a majority ofthe site; however, locally deeper removals cannot be precluded and should be anticipated. Removals should be minimally completed below a 1:1 projection down and away from the edge of any settlement-sensitive improvements and/or limits 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. Kokopelli Builders, Inc. W.O. 4646-A-SC Kokopelli Residence, Carlsbad January 21, 2005 File:e:\wp9\4600\4646a.pge Page 14 GeoSoils, Inc. Fili Placement 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 will 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 to low expansive (Expansion Index [E.I.] less than 50). The use of subdrains at the bottom of the fill cap may be necessary, and subsequently recommended based on compatibility with onsite soils. Transitions/Overexcavation In order to provide for the uniform support of the proposed settlement-sensitive improvements, a minimum 3-foot thick compacted fill blanket is recommended for lots containing earth material transitions (i.e., fill juxtaposed to terrace deposits). Any cut portion of a transition lot or lots with planned fills less than 3 feet should be overexcavated a minimum 3 feet below finish pad grade in order to provide for a minimum 3-foot compacted fill blanket, or 24 inches of compacted fill beneath the footings (whichever is greater). Lower floor levels exposing terrace deposits at finish grade will require the minimum overexcavation if the upper floors are to be supported by compacted fill. The maximum to minimum fill thickness, below settlement-sensitive improvements, should not exceed a ratio of 3:1 (maximum:minimum). The overexcavation should be completed per the UBC (ICBO, 1997), or to a minimum of 5 feet outside the building footprint, whichever is greater. Additionally, if paleoliquefaction features are encountered during site earthwork, overexcavation of the building pad, to a depth of at least 3 feet below slab subgrade, or 24 inches belowthe bottom ofthe footing (whichever is deeper), will be necessary in order to mitigate the potential differential settlements. The overexcavation should be completed per the UBC (ICBO, 1997), or to a minimum of 5 feet outside the building footprint, whichever is greater. Temporary Slopes On a preliminary basis, temporary slopes should be designed and constructed in accordance with criteria established by CAL-OSHA for "Type C" soil conditions due to the relatively cohesionless nature of site soils. Heavy equipment and/or stockpile should not be stored within 5 feet of any temporary slope. Additionally, heavy equipment should not be operated within 5 feet from the top of any temporary cut slope. Temporary slopes Kokopelli Builders, Inc. W.O. 4646-A-SC Kokopelli Residence, Carlsbad January 21, 2005 File:e:\wp9\4600\4646a.pge Page 15 GeoSoils, Inc. should be further evaluated during site grading. The possibility of inclining temporary slopes to a flatter gradient may be recommended if adverse soil conditions are observed. If the required gradient of any temporary slope conflicts with property boundaries, shoring may be necessary Monitoring Existing. Offsite Improvements It is recommended that the condition of existing, offsite improvements (buildings, walls, fences, pavement, etc.) be reviewed and documented prior to the start of earthwork and be monitored during, and at the conclusion of, construction to evaluate if construction at the site has influenced the condition of these improvements. RECOMMENDATIONS - FOUNDATIONS Preliminarv Foundation Design 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 structures are made, the conclusions and recommendations contained in this report are for the 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 design(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 field 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.I. = 0 to 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 soils 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, founded entirely into compacted fill or Kokopelli Builders, Inc. W.O. 4646-A-SC Kokopelli Residence, Carlsbad January 21, 2005 File:e:\wp9\4600\4646a.pge Page 16 GeoSoils, Inc. competent terrace deposits and connected by grade beam or tie beam in at least one direction to prevent lateral drift (exterior isolated pad footings only). 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. Footings should not simultaneously bear on compacted fili and terrace deposits. Lateral Pressure 1. For lateral sliding resistance, a 0.35 coefficient of friction may be utilized for a concrete to soil contact when multiplied by the dead load. 2. 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. 3. When combining passive pressure and frictional resistance, the passive pressure component should be reduced by one-third. Foundation Settlement Conventional foundation systems should be designed to accommodate a differential settlement of at least % inch in a 40-foot span, provided that paleoliquefaction features are not observed during site grading. Footing Setbacks All footings should maintain a minimum 7-foot horizontal setback from 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) from 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 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. Construction The following foundation construction recommendations are presented as minimum criteria from a soils engineering standpoint. The onsite soil expansion potential is generally very low (E.I. 0 to 20). Preliminary foundation construction recommendations for very low expansive soil conditions are presented herein. If paleoliquefaction features are observed Kokopelli Builders, Inc. W.O. 4646-A-SC Kokopelli Residence, Carlsbad January 21, 2005 Flle:e:\wp9\4600\4646a.pge GCOSollS InC Page 17 during site grading, post-tension foundations will be specifically recommended for the support ofthe residential structure(s). 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. Final foundation design will be provided based on the expansion potential ofthe near surface soils encountered during grading. Very Low Expansion Potential (E.I. 0 to 20) 1. Exterior and interior footings should be founded at a minimum depth of 12 inches for one-story floor loads, and 18 inches for two-story floor loads, entirely into compacted fill or competent terrace deposits. Column and panel pads should be founded at a minimum depth of 24 inches entirely into compacted fill or competent terrace deposits. All footings should be reinforced with two No. 4 reinforcing bars, one placed near the top and one placed near the bottom of the footing. Footing widths should be as indicated in UBC (ICBO, 1997). 2. A grade beam, reinforced as above, and at least 12 inches square, should be provided across large (e.g., doorways) entrances. The base of the grade beam should be at the same elevation as the bottom of adjoining footings. Isolated, exterior pad footings should be tied into the main foundation in at least one direction with a grade beam to prevent lateral drift. 3. Concrete slabs should be a minimum of 5 inches thick and should be minimally reinforced with No. 3 reinforcing bars at 18 inches on center in both directions. All slab reinforcement should be supported to ensure placement near the vertical midpoint of the concrete. "Hooking" of reinforcement is not considered an acceptable method of positioning the reinforcement. The design engineer should determine the actual thickness of the slab based on loadings and use. 4. 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. 5. Concrete utilized for slabs-on-grade (including garages), shall utilize a maximum water-cement ratio of 0.50 and a minimum strength of 4,000 psi to mitigate the effects from post-development perched water and to impede water vapor transmission. Slab underlayment for the residences and garages should consist of 2 inches of washed sand placed above a vapor barrier consisting of 15-mil polyvinyl chloride, or equivalent, will all laps sealed per the UBC. The vapor barrier shall be underlain by 4 inches of pea gravel placed directly on the slab subgrade, and should be sealed to provide a continuous water-proof barrier under the entire slab, Kokopelli Builders, Inc. W.O. 4646-A-SC Kokopelli Residence, Carlsbad January 21, 2005 File:e:\wp9\4600\4646a.pge Page 18 GeoSoils, Inc. as discussed above. All slabs shall be additionally sealed with a suitable slab sealant. Presaturation is not required for these soil conditions. The moisture content ofthe subgrade soils should be equal to (or greater than), the soil's optimum moisture content to a minimum depth of 18 inches in the slab areas, prior to concrete placement. POST-TENSION SLAB FOUNDATIONS General As stated earlier, post-tension foundations are exclusively recommended to support the proposed residential structure jf paleoliquefaction features are observed during site grading. The recommendations presented below should be followed in addition to those contained in the previous sections, including differential settlement, as appropriate. The information and recommendations presented below in this section are not meant to supercede design by a registered structural engineer or civil engineer familiar with post-tensioned slab design. Upon request, GSI can provide additional data/consultation regarding soil parameters as related to post-tensioned slab design. The presence of paleoliquefaction features creates a non-uniform condition within the underlying native soils that has the potential to provide for relatively large differential settlement. This potential differential settlement could be on the order of 172 inches in a 40-foot span, or an angular distortion of 1/320. Furthermore, from a soil expansion/shrinkage standpoint, a common contributing factor to distress of structures using post-tensioned slabs is fluctuation of moisture in soils underlying the perimeter of the slab, compared to the center, causing a "dishing" or "arching" of the slabs. To mitigate this possibility, a combination of soil presaturation and construction of a perimeter cut-off wall should be employed. Construction Perimeter cut-off walls should be a minimum of 12 inches deep for very low expansive soils, below the lowest adjacent grade. The walls should be a minimum of 12 inches in thickness. The cut-off walls may be integrated into the slab, and should be a minimum of 6 inches thick (wide). Concrete utilized for slabs-on-grade, shall utilize a maximum water-cement ratio of 0.50 and a minimum strength of 4,000 psi to mitigate the effects from post-development perched water and to impede water vapor transmission. Slab underlayment for the residences and garages should consist of 2 inches of washed sand placed above a vapor barrier consisting of 15-mil polyvinyl chloride, or equivalent, will all laps sealed per the UBC. The vapor barrier shall be underlain by 4 inches of pea gravel Kokopelli Builders, Inc. W.O. 4646-A-SC Kokopelli Residence, Carlsbad January 21, 2005 File:e:\wp9\4600\4646a.pge Page 19 GeoSoils, Inc. placed directly on the slab subgrade, and should be sealed to provide a continuous water-proof barrier under the entire slab, as discussed above. All slabs shall be additionally sealed with a suitable slab sealant Specific soil presaturation is not required for very low expansive soils. However, the slab subgrade moisture content should be at or slightly above the soil's optimum moisture content to a depth of 12 inches. Post-tensioned slabs should be designed using sound engineering practice and be in accordance with local and/or national code requirements. Soil related parameters for post-tensioned slab design are presented below: Allowable surface bearing value 1,000 psf Modulus of subgrade reaction 75 psi per inch Coefficient of friction 0.35 Passive pressure 250 pcf Post-Tensioning Institute Method: Post-tensioned slabs should have sufficient stiffness to resist excessive bending due to non-uniform swell and shrinkage of subgrade soils. The differential movement can occur at the corner, edge, or center of slab. The potential for differential uplift can be evaluated using the 1997 UBC Section 1816, based on design specifications of the Post-Tensioning Institute. The following table presents suggested minimum coefficients to be used in the Post-Tensioning Institute design method. Thornthwaite Moisture Index -20 inches/year Correction Factor for Irrigation 20 inches/year Depth to Constant Soil Suction 7 feet Constant soil Suction (pf) 3.6 Modulus of Subgrade Reaction (pci) 75 Moisture Velocity 0.7 inch/month The coefficients are considered minimums and may not be adequate to represent worst case conditions such as adverse drainage and/or improper landscaping and maintenance. The above parameters are applicable provided structures have positive drainage that is maintained away from structures. Therefore, it is important that information regarding drainage, site maintenance, settlements, and effects of expansive soils be passed on to future owners. Based on the above parameters, the following values were obtained from figures or tables ofthe 1997 UBC Section 1816. The values may not be appropriate to account for possible differential settlement of the slab due to other factors. If a stiffer slab is desired, higher values of ym may be warranted. Kokopelli Builders, Inc. Kokopelli Residence, Carlsbad File:e:\wp9\4600\4646a.pge GeoSoils, Inc. W.O. 4646-A-SC January 21, 2005 Page 20 EXPANSION INDEX OF SOIL SUBGRADE VERY LOW EXPANSION (E.L = 0-20) e^, cjenter lift 5.0 feet e^ edge lift 2.5 feet y^ center lift 1.0 inch y,, edge lift 0.3 inch CORROSION Upon completion of grading, additional testing of soils (including import materials) for corrosion to concrete and metals should be performed prior to the construction of utilities and foundations. WALL DESIGN PARAMETERS Conventional Retaining Walls The design parameters provided below assume that either non expansive soils (typically Class 2 permeable filter material or Class 3 aggregate base) or native onsite materials (up to and including an E.I. of 65) are used to backfill any retaining walls. The type of backfill (i.e., select or native), should be specified by the wall designer, and clearly shown on the plans. Building walls, below grade, should be water-proofed or damp-proofed, depending on the degree of moisture protection desired. 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 18 inches below adjacent grade (excluding landscape layer, 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 Walis 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 pressure (EFP) of 65 pcf, 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. Kokopelli Builders, Inc. Kokopelli Residence, Carlsbad Flle:e:\wp9\4600\4646a.pge GeoSoils, Inc. W.O. 4646-A-SC January 21,2005 Page 21 Cantilevered Walls The recommendations presented below are for cantilevered retaining walls up to 10 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 ofthe 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. SURFACE SLOPE OF RETAINED MATERIAL (HORIZONTALrVERTICAL) EQUIVALENT FLUID WEIGHT P.C.F. (SELECT BACKFILL) EQUIVALENT FLUID WEIGHT P.C.F. (NATIVE BACKFILL) Level* 2 tol 35 50 45 60 * Level backfill behind a retaining wall is defined as compacted earth materials, properly drained, without a slope for a distance of 2H befiind the wall. Retaining Wail Backfill and Drainage Positive drainage must be provided behind all retaining walls 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 a 4-inch diameter perforated PVC or ABS pipe encased in either Class 2 permeable filter material or y2-inch to y4-inch gravel wrapped in approved filter fabric (Mirafi 140 or equivalent). 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 up to medium expansion potential, 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 behind 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 than 65 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. Kokopelli Builders, Inc. Kokopelli Residence, Carlsbad File:e:\wp9\4600\4646a.pge GeoSoils, Inc. W.O. 4646-A-SC January 21, 2005 Page 22 DETAILS N.T.S. Provide Surface Drainage ©Waterproofing Membrane (optional) ® Weep Hole Finished Surface 1 or Flatter (D WATERPROOFING MEMBRANE (optional): Liquid boot or approved equivalent. (D ROCK: 3/4 to 1-1/2" (inches) rock. ® FILTER FABRIC: Mirafi 140N or approved equivalent; place fabric flap behind core. ® PIPE: 4" (inches) diameter perforated PVC. schedule 40 or approved alternative w/ith minimum of 1% gradient to proper outlet point. ® WEEP HOLE: Minimum 2" (inches) diameter placed at 20' (feet) on centers along the wall, and 3" (inches) above finished surface. (No weep holes for basement walls.) TYPICAL RETAINING WALL BACKFILL AND DRAINAGE DETAIL DETAIL 1 Geotechnical • Geologic • Environmental DETAILS Provide Surface Drainage (Dwaterproofing MerTtbrane (optional) Weep Hole Finished Surface (D WATERPROOFING MEMBRANE (optional): Liquid boot or approved equivalent. (D DRAIN: Miradrain 6000 or J-drain 200 or equivalent for non-waterproofed walls. Miradrain 6200 or ]-drain 200 or equivalent for waterproofed walls. (D FILTER FABRIC: Mirafi 140N or approved equivalent; place fabric flap behind care. ® PIPE: 4" (inches) diameter perforated PVC. schedule 40 or approved alternative with minimum of 1% gradient to proper outlet point. ® WEEP HOLE: Minimum 2" (inches) diameter placed at 20" (feet) on centers along the wall, and 3" (inches) above finished surface. (No weep holes for basement walls.) RETAINING WALL BACKFILL AND SUBDRAIN DETAIL GEOTEXTILE DRAIN DETAIL 2 Geotechnical • Geologic • Environmental DETAILS N.T.S. Provide Surface Drainage Clean Sand Backfill (D WATERPROOFING MEMBRANE (optionai): Liquid boot or approved equivalent. ® CLEAN SAND BACKFILL: Must have sand equivalent value of 30 or greater; can be densified by water jetting. ® FILTER FABRIC: Mirafi 140N or approved equivalent. ® ROCK: 1 cubic foot per linear feet of pipe or 3/4 to 1-1/2" (inches) rock. ® PIPE: 4" (inches) diameter perforated PVC. schedule 40 or approved alternative with minimum of 1% gradient to proper outlet point. © WEEP HOLE: Minimum 2" (inches) diameter placed at 20' (feet) on centers along the wall, and 3" (inches) above finished surface. (No weep holes for basement walls.) RETAINING WALL AND SUBDRAIN DETAIL CLEAN SAND BACKFILL DETAIL 3 Geotechnical • Geologic • Environmental 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. <.90). 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 ofthe 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). 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 "a" (above) and until such transition is between 45 and 90 degrees to the wall alignment. DRIVEWAY. FLATWORK. AND OTHER IMPROVEMENTS The soil materials on site may 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 any homeowners or homeowners association of this long-term potential for distress. To reduce the likelihood of distress, the following recommendations are presented for all exterior flatwork: 1. The subgrade area for concrete slabs should be compacted to achieve a minimum 90 percent relative compaction, and then be presoaked to 2 to 3 percentage points above (or 125 percent of) the soils' optimum moisture content, to a depth of Kokopelli Builders, Inc. ~~ W.O. 4646-A-SC Kokopelli Residence, Carlsbad January 21, 2005 File:e:\wp9\4600\4646a.pge Page 26 GeoSoils, Inc. 18 inches below subgrade elevation. If very low expansive soils are present, only optimum moisture content, or greater, is required and specific presoaking is not warranted. The moisture content of the subgrade should be proof tested within 72 hours prior to pouring concrete. 2. Concrete slabs should be cast over a non-yielding surface, consisting of a 4-inch layer of crushed rock, gravel, or clean sand, that should be compacted and level prior to pouring concrete. If very low expansive soils are present, the rock or gravel or sand may be deleted. The layer or subgrade should be wet-down completely prior to pouring concrete, to minimize loss of concrete moisture to the surrounding earth materials. 3. Exterior slabs should be a minimum of 4 inches thick. Driveway slabs and approaches should additionally have a thickened edge (12 inches) adjacent to all landscape areas, to help impede infiltration of landscape water under the slab. 4. The use of transverse and longitudinal control joints are recommended to help control slab cracking due to concrete shrinkage or expansion. Two ways to mitigate such cracking are: a) add a sufficient amount of reinforcing steel, increasing tensile strength of the slab; and, b) provide an adequate amount of control and/or expansion joints to accommodate anticipated concrete shrinkage and expansion. In order to reduce the potential for unsightly cracks, slabs should be reinforced at mid-height with a minimum of No. 3 bars placed at 18 inches on center, in each direction. If subgrade soils within the top 7 feet from finish grade are very low expansive soils (i.e., E.I. <20), then 6x6-W1.4xW1.4 welded-wire mesh may be substituted for the rebar, provided the reinforcement is placed on chairs, at slab mid-height. The exterior slabs should be scored or saw cut, Vz to ¥8 inches deep, often enough so that no section is greater than 10 feet by 10 feet. For sidewalks or narrow slabs, control joints should be provided at intervals of every 6 feet. The slabs should be separated from the foundations and sidewalks with expansion joint filler material. 5. No traffic should be allowed upon the newly poured concrete slabs until they have been properly cured to within 75 percent of design strength. Concrete compression strength should be a minimum of 2,500 psi. 6. Driveways, sidewalks, and patio slabs adjacent to the house should be separated from the house with thick expansion joint filler material. In areas directly adjacent to a continuous source of moisture (i.e., irrigation, planters, etc.), all joints should be additionally sealed with flexible mastic. 7. Planters and walls should not be tied to the house. Kokopelli Builders, Inc. W.O. 4646-A-SC Kokopelli Residence, Carlsbad January 21, 2005 File:e:\wp9\4600\4646a.pge Page 27 GeoSoils, Inc. 8. Overhang structures should be supported on the slabs, or structurally designed with continuous footings tied in at least two directions. If very low expansion soils are present, footings need only be tied in one direction. 9. 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. 10. Utilities should be enclosed within a closed utilidor (vault) or designed with flexible connections to accommodate differential settlement and expansive soil conditions. 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 homeowner or homeowners association. 12. 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 water lines should be drained to a suitable non-erosive outlet. 13. 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. DEVELOPMENT CRITERIA 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 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 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 from 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 from the structure. We recommend that unpaved lawn and landscape areas have a minimum Kokopelli Builders, Inc. W.O. 4646-A-SC Kokopelli Residence, Carlsbad January 21, 2005 File:e:\wp9\4600\4646a.pge Page 28 GeoSoils, Inc. gradient of 1 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. 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 10 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 awayfrom 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 barrier to prevent 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. 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 house, 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). Kokopelli Builders, Inc. ~ W.O. 4646-A-SC Kokopelli Residence, Carlsbad January 21, 2005 File:e:\wp9\4600\4646a.pge ^ m* w Page 29 GeoSoils, inc. 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 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 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. Pools and/or spas should not be constructed without specific design and construction recommendations from GSI, and this construction recommendation should be provided to the homeowners, any homeowners association, and/or other interested parties. This office should be notified in advance of any fill placement, grading ofthe 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 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, driveway approaches, driveways, parking areas, and utility trench and retaining wall backfills. Kokopelli Builders, Inc. W.O. 4646-A-SC Kokopelli Residence, Carlsbad January 21, 2005 Flle;e:\wp9\4600\4646a.pge Page 30 GeoSoils, Inc. 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 90 percent, if not removed from the site. 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 homeowners, etc., that may perform such work. Utilitv 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 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 ali trenches beneath hardscape features and in slopes, should be compacted to at least 90 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. Kokopelli Builders, Inc. W.O. 4646-A-SC Kokopelli Residence, Carlsbad January 21, 2005 File:e:\wp9\4600\4646a.pge Page 31 GeoSoils, Inc. 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. • 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 barriers (i.e., visqueen, etc.). 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 developer or homeowner improvements, such as flatwork, spas, pools, walls, etc., are constructed, priorto 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. • GSI should review project sales documents to homeowners/homeowners associations for geotechnical aspects, including irrigation practices, the conditions outlined above, etc., prior to any sales. At that stage, GSI will provide homeowners maintenance guidelines which should be incorporated into such documents. Kokopelli Builders, Inc. W.O. 4646-A-SC Kokopelli Residence, Carlsbad January 21, 2005 File:e:\wp9\4600\4646a.pge ^ «« » Page 32 &eo90fis. Inc. 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. This report presents minimum 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 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, 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. Kokopelli Builders, Inc. W.O. 4646-A-SC Kokopelli Residence, Carlsbad January 21, 2005 File:e:\wp9\4600\4646a.pge Page 33 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, 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 GSI 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 ofthe project. All samples will be disposed of after 30 days, unless specifically requested by the client, in writing. Kokopelli Builders, Inc. W.O. 4646-A-SC Kokopelli Residence, Carlsbad January 21, 2005 Flle:e:\wp9\4600\4646a.pge Page 34 GeoSoils, Inc. APPENDIX A REFERENCES APPENDIXA REFERENCES 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 June, 2003, Windows 95/98 version. , 2000c, FRISKSP, A computer program for the probabilistic estimation of peak acceleration and uniform hazard spectra using 3-D faults as earthquake sources; Windows 95/98 version. Boore, D.M., Joyner W.B., and Fumal, T.E., 1997, Equations for estimating horizontal response spectra and peak acceleration from Western North American Earthquakes: A summary of recent work, Seismological Research Letters, vol. 68, no.l, pp. 128-153. 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. Campbell, K.W. and Bozorgnia, Y., 1997, Attenuation relations for soft rock conditions; in EQFAULT, A computer program for the estimation of peak horizontal acceleration from 3-D fault sources; Windows 95/98 version, Blake, 2000a. Franklin, J.P., and Kuhn, G.G., 2000, Paleoseismic features exposed by trenching the lowest coastal terrace at Carlsbad, California, in Shiemon, R.J., Kuhn, G.G., and Legg, M.R., eds., Neotectonics and coastal instability. Orange and Northern San Diego Counties, California, jointfield conference. Vol. I, AAPG, Pacific Section, SPE, Western Section, Long Beach, California, June 19-22, 2000. 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, 2001, California building code, California code of regulations title 24, part 2, volume 1 and 2. , 1997, Uniform building code: Whittier, California, vol. 1, 2, and 3. GeoSoils, Inc. 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. JL Design, undated. Site plan. Northeast corner of Carlsbad Boulevard and Cerezo Drive, Carlsbad, California, 50-scale. Sowers and Sowers, 1979, Unified soil classification system (After U. S. Watenways Experiment Station and ASTM 02487-667) jn Introductory Soil Mechanics, New York. Kokopelli Builders, Inc. Appendix A File:e:\wp9\4600\4646a.pge Page 2 GeoSoils, Inc. APPENDIX B TEST PIT LOGS UNIFIED SOIL CLASSIFICATION SYSTEM CONSISTENCY OR RELATIVE DENSITY Maior Divisions Group Symbols Typical Names CRITERIA CO o o CM ^ 6 o z to ^ TJ O •i <" o St i> £ o c (0 n o o o sa CM "o d OT i 0} S C to C3 Q. <b <o .E o E <i> > o •5 c •» X, o ^ o 9, ° i ^^1 I ° 2 ° Co •ffi ._ (D 5 " s ^ OT i= 2 (0 (DOS o 8 « C " CO Q. GW Well-graded gravels and gravel- sand mixtures, little or no fines Standard Penetration Test GP Poorly graded gravels and gravel-sand mixtures, little or no fines (0 g C5 * GM Silty gravels gravel-sand-siit mixtures GC Clayey gravels, gravel-sand-clay mixtures sw O CO Well-graded sands and gravelly sands, little or no fines Penetration Resistance N (blows/ft) Relative Density 0-4 Very loose 4-10 Loose 10-30 Medium 30-50 Dense > 50 Very dense SP Pcxjriy graded sands and gravelly sands, little or no fines CO SM Silty sands, sand-silt mixtures sc Clayey sands, sand-clay mixtures ML Inorganic silts, very fine sands, rock flour, silty or clayey fine sands Standard Penetration Test « g U> O .E .2 FT a •-. <=> — —• tn CL Inorganic clays of low to medium plasticity, gravelly clays, sandy clays, silty clays, lean clays OL Organic silts and organic silty clays of low plasticity " ^ S CO .-^ in "1 i "g -g £ MH Inorganic silts, micaceous or diatomaceous fine sands or silts, elastic silts CH Inorganic clays of high plasticity, fat clays OH Organic clays of medium to high plasticity Penetration Resistance N (blows/ft) Consistent:y UncMnfined Compressive Strength (tons/ft^ <2 Very Soft <0.25 2-4 Soft 0.25 - .050 4-8 Medium 0.50-1.00 8-15 Stiff 1.00-2.00 15-30 Very Stiff 2.00 - 4.00 >30 Hard >4.00 Highly Organic Soils PT Peat, mucic, and other highly organic soils 3/4" #4 #10 #40 #200 U.S. Standard Sieve Unified Soil Classific:ation Cobbles Gravel cx)arse fine Sand coarse medium fine Silt or Clay IVIOISTURE CONDITIONS Dry Absence of moisture: dusty, dry to the touch Slightly Moist Below optimum moisture content for compaction Moist Near optimum moisture content Very Moist Above optimum moisture content Wet Visible free water; below water table MATERIAL QUANTITY trace 0 - 5 % few 5-10% little 10-25% some 25 - 45 % OTHER SYMBOLS 0 S B T Gore Sample SPT Sample Bulk Sample Groundwater 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;\SQilClassif.wpd PLATE B-1 W.O. 4646-A-SC Kokopelli Builders, Inc. Carlsbad Blvd. and Cerezo Dr. January 6, 2005 LOG OF EXPLORATORY TEST PITS TEST PIT NO. DEPTH (ft.) GROUP SYMBOL SAMPLE DEPTH (ft.) MOISTURE (%) FIELD DRY DENSITY (pcf) DESCRIPTION TP-1 0-% SP TOPSOIL/COLLUVIUM: SAND w/SILT. dark red brown, moist, loose; porous, rootlets. % - 272 SP WEATHERED TERRACE DEPOSITS: SAND w/SILT. dark red brown, moist, medium dense; slightly porous. 272 - 5 SM Undisturbed @5 76 112.2 QUATERNARY TERRACE DEPOSITS: SILTY SAND w/minor CLAY, oranae brown, moist, dense; massive. Total Depth = 5' No Groundwater/Caving Encountered Backfilled 1-6-2005 TP-2 0-% SP TOPSOIL/COLLUVIUM: SAND w/SlLT, dark red brown, moist, loose: porous, roots/rootlets. %-3 SP Bulk® 1 - 272 WEATHERED TERRACE DEPOSITS: SAND w/SILT. dark red brown, moist, medium dense; slightly porous, occasional roots/rootlets. 3-13 SM Undisturbed @3 QUATERNARY TERRACE DEPOSITS: SILTY SAND, oranae brown, moist, dense; massive. Total Depth = 13' No Groundwater/Caving Encountered Backfilled 1-6-2005 PLATE B-2 W.O. 4646-A-SC Kokopelli Builders, Inc. Carlsbad Blvd. and Cerezo Dr. January 6, 2005 LOG OF EXPLORATORY TEST PITS TEST PIT NO. DEPTH (ft.) . GROUP SYMBOL SAMPLE DEPTH (ft.) MOISTURE (%) FIELD DRY DENSITY (pcf) DESCRIPTION TP-3 0-% SP TOPSOIL/COLLUVIUM: SAND w/SILT, brown, moist, loose. 3/4-3 SP WEATHERED TERRACE DEPOSITS: SAND w/SILT. dark red brown, moist, medium dense; slightly porous. 3 - 372 SM QUATERNARY TERRACE DEPOSITS: SILTY SAND, oranae brown, moist, dense; massive. Total Depth = 372 No Groundwater/Caving Encountered Backfilled 1-6-2005 TP-4 0-% SP TOPSOIL/COLLUVIUM: SAND w/SILT. brown, moist, loose; porous, abundant roots/rootlets. %-3 SP WEATHERED TERRACE DEPOSITS: SAND w/SILT. dark red brown, moist, medium dense; slightly porous, occasional roots. 3 - 372 SM QUATERNARY TERRACE DEPOSITS: SILTY SAND, oranae brown, damp, very dense; massive. Total Depth = 372' No Groundwater/Caving Encountered Backfilled 1-6-2005 PLATE B-3 APPENDIX 0 EQFAULT, EQSEARCH, AND FRISKSP Ui c o •••1 *^ (0 o o < MAXIMUM EARTHQUAKES KOKOPELLI BUILDERS, INC. .01 .001 X X Illll llll X X X ,1 1 10 Distance (mi) X X X i_LL 100 W.O. 4646-A-SC Plate C-1 CO 0) >- ili c 0) > UJ d) E 3 z 0) > w 3 E E 3 o EARTHQUAKE RECURRENCE CURVE KOKOPELLI BUILDERS, INC. 100 10 .01 .001 \ { \ < { i llll llll llll llll llll llll WW llll llll llll 1 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. 4646-A-SC Plate 0-2 EARTHQUAKE EPICENTER MAP KOKOPELLI BUILDERS, INC. 1100 1000 -• 900 -- 800 -- -400 -300 -200 -100 100 200 300 400 500 600 W.O. 4646-A-SC Plate C-3 PROBABIUTY OF EXCEEDANCE BOORE ETAL. (1997) SOIL (310)1 100 n (0 o 0 o c (0 •D 0) 0) O X LU 25 yrs 75 yrs 50 yrs 100 yrs ilil 1 0.00 0.25 0.50 0.75 1.00 1.25 1.50 Acceleration (g) W.O. 4646-A-SC Plate C-4 p 0) o> > I . (0 o RETURN PERIOD vs. ACCELERATION BOORE ETAL. (1997) SOIL (310)1 100000 (0 >* o 0) a. c 1- 3 10000 1000 100 2 (0 o I Ol 0.00 0,25 0.50 0.75 1,00 Acceleration (g) 1,25 1,50 APPENPIX D LABORATORY DATA 3,000 2,500 2,000 I I-C3 Z ai cc i- OT CC S5 X OT 1,500 1,000 500 1 1 i NORMAL PRESSURE, psf Sample Depth/El. Primary/Residual Shear Sample Type \ MC% C <!• • TP-1 5.0 Primary Shear Undisturbed 111.8 7.6 120 35 • TP-1 5.0 Residual Shear Undisturiaed 111.8 7.6 92 33 Note: Sample Innundated prior to testing 05 tu CC GeoSoils, Inc. 5741 Palmer Way Carlsbad, CA 92008 Telephone: (760)438-3155 Fax: (760)931-0915 DIRECT SHEAR TEST Project: KOKO PELLI BUILDERS, INC. Number: 4646-A-SC Date: January 2005 Plate: D -1 M. J. Schiff & Associates, Inc. Consulting Corrosion Engineers - Since 1959 431 W. Baseline Road Claremont, CA 91711 Phone: (909) 626-0967 Fax: (909) 626-3316 E-mail lab@mjschiff.com website: mjschiff.com Table 1 - Laboratory Tests on Soil Samples GeoSoils, Inc. KoKo Pelli Builders Your «4646-ASC, MJS&A #05-0019LAB 7-Jan-05 Sample ID TP-2 1-2.5' Resistivity as-received saturated pH Electrical Conductivity Chemical Analyses Units ohm-cm ohm-cm mS/cm 20,000 5,900 5.2 0.10 Cations calcium Ca^" mg/kg 16 magnesiimi mg/kg 24 sodium Na'" mg/kg ND Anions carbonate COy' mg/kg ND bicarbonate HCO3' mg/kg 15 chloride ci'-mg/kg 35 sulfate S04^' mg/kg 65 ler Tests ammonium NH4'" mg/kg na nitrate N03'" mg/kg na sulfide qual na Redox mV na Electrical conductivity in millisiemens/cm and chemical analysis were made on a 1:5 soil-to-water extract, mg/kg = milligrams per kilogram (parts per million) of dry soil. Redox = oxidation-reduction potential in millivolts ND = not detected na = not analyzed W.O. 4646-A-SC Page 1 of 1 Plate D-2 APPENDIX E GENERAL EARTHWORK AND GRADING GUIDELINES GENERAL EARTHWORK AND 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, placerTient 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 supercede these guidelines or the recommendations contained in the geotechnical report. The contractor is responsible forthe 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 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 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 bythe 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. 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-1557-78. 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 intervals 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. Contractor's Responsibility All clearing, site preparation, and earthwork performed on the project should be conducted by the contractor, with observation by geotechnical consultants and staged approval by the 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 ofthe soil engineer. The contractor should also remove all major non- earth material considered unsatisfactory by the soil engineer. It is the sole responsibility of the contractor to 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 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. 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 by the soil engineer. Soft, dry, spongy, highly fractured, or otherwise unsuitable ground extending to such a depth that surface Kokopelli Builders, Inc. Appendix E File:e:\wp9\4600\4646a.pge Page 2 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. Existing ground which is determined to be satisfactory for support of the fills should be scarified to a minimum depth of 6 inches or as directed by the soil engineer. 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 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 inhibit 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 by the 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 priorto placement of fill. Fills may then be properly placed and compacted until design grades (elevations) are attained. Kokopelli Builders, Inc. Appendix E File:e:\wp9\4600\4646a.pge Page 3 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 by the 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 soil 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 serve as a satisfactory fill material. Fill materials derived from benching operations should be dispersed throughout the 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 be taken off-site or placed in accordance with recommendations of the 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, future utilities, or underground 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 of this 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. Kokopelli Builders, Inc. Appendix E File:e:\wp9\4600\4646a.pge PaQe 4 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 othenwise recommended by the 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 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 compaction should be based on obsen/ation 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 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. 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 verify compaction, the slopes should be grid-rolled to Kokopelli Builders, Inc. ~ Appendix E File:e:\wp9\4600\4646a.pge Page 5 achieve compaction to the slope face. Final testing should be used to confirm compaction after grid rolling. 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 compacfion. Addifional tesfing should be performed to verify compacfion. 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 recommendafion ofthe soil engineer or engineering geologist. SUBDRAIN INSTALLATION Subdrains should be installed in approved ground in accordance with the approximate alignment and details indicated by the geotechnical consultant. Subdrain locafions 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 the field, pending exposed condifions. The locafion of constructed subdrains should be recorded bythe project civil engineer. EXCAVATIONS Excavafions and cut slopes should be examined during grading by the engineering geologist. If directed by the engineering geologist, further excavations or overexcavafion 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 by the engineering geologist prior to placement of materials for construction of the fill portion of the slope. The engineering geologist should observe all cut slopes and should be nofified by the contractor when cut slopes are started. If, during the course of grading, unforeseen adverse or potenfial adverse geologic condifions are encountered, the engineering geologist and soil engineer should investigate, evaluate and make recommendafions to treat these problems. The need for cut slope buttressing or stabilizing should be based on in-grading evaluafion by the engineering geologist, whether anficipated or not. 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. Addifionally, short-term stability of temporary cut slopes is the contractors responsibility. Kokopelli Builders, Inc. Appendix E File:e:\wp9\4600\4646a.pge Page 6 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 recommendafions of the soil engineer or engineering geologist. COMPLETION Obsen/afion, testing and consultafion bythe geotechnical consultant should be conducted during the grading operafions in order to state an opinion that all cut and filled areas are graded in accordance with the approved project specificafions. After complefion of grading and after the soil engineer and engineering geologist have finished their obsen/afions ofthe work, final reports should be submitted subject to review by the controlling governmental agencies. No further excavafion or filling should be undertaken without prior notificafion of the soil engineer and/or engineering geologist. All finished cut and fill slopes should be protected from erosion and/or be planted in accordance with the project specificafions and/or as recommended by a landscape architect. Such protecfion and/or planning should be undertaken as soon as pracfical after complefion 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 construcfion sites. On ground personnel are at highest risk of injury and possible fatality on grading and construcfion projects. GSI recognizes that construcfion activifies 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 fimes. To achieve our goal of avoiding accidents, cooperafion between the client, the contractor and GSI personnel must be maintained. In an effort to minimize risks associated with geotechnical testing and observafion, 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 meefings. Safety Vests: Safety vests are provided for and are to be worn by GSI personnel at all fimes when they are working in the field. Kokopelli Builders, Inc. Appendix E Flle:e:\wp9\4600\4646a.pge Page 7 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 stafionary in the grading area shall use rotafing or flashing amber beacon, or strobe lights, on the vehicle during all field tesfing. While operafing a vehicle in the grading area, the emergency flasher on the vehicle shall be activated. In the event that the contractor's representative observes any of our personnel not following the above, we request that it be brought to the attenfion of our office. Test Pits Location. Orientation and Ciearance The technician is responsible for selecting test pit locafions. A primary concern should be the technicians's safety. Efforts will be made to coordinate locafions with the grading contractors authorized representative, and to select locafions following or behind the established traffic pattern, preferably outside of current traffic. The contractors authorized representafive (dump man, operator, supervisor, grade checker, etc.) should direct excavafion of the 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. Alternafively, 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 tesfing procedure. The zone should extend approximately 50 feet outward from the center ofthe test pit. This zone is established for safety and to avoid excessive ground vibrafion 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 flag should be placed at the top of the slope. The contractor's representafive 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 tesfing. The technician's vehicle should be parked at the perimeter of the fill in 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. Kokopelli Builders, Inc. Appendix E File:e:\wp9\4600\4646a.pge Page 8 In the event that the technicians safety is jeopardized or compromised as a result 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 tesfing will be performed unfil the situafion is rectified. Any fill place can be considered unacceptable and subject to reprocessing, recompacfion 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 attenfion and notify this office. Effective communicafion and coordination between the contractors representative and the soils 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 compacfion tesfing is needed. Our personnel are directed not to enter any excavafion 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 condifions regardless of depth. All trench excavafions 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 compacfion tesfing, 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 GSI personnel become aware of anyone working beneath an unsafe trench wall or vertical excavafion, we have a legal obligafion to put the contractor and owner/developer on nofice to immediately correct the situafion. If corrective steps are not taken, GSI then has an obligation to notify CAL-OSHA and/or the proper authorifies. Kokopelli Builders, Inc. Appendix E Flle:e:\wp9\4600\4646a.pge F^ge 9 CANYON SUBDRAIN DETAIL TYPE A PROPOSED COMPACTED FILL NATURAL GROUND COLLUVIUM AND ALLUVIUM (REMOVEJ^, 11 TYPICAL BENCHING ^^'^^y. x\\l// BEDROCK SEE ALTERNATIVES TYPE B PROPOSED COMPACTED RLL NATURAL GROUND COLLUVIUM AND ALLUVIUM IREMOVE) T BEDROCK lr TYPICAL BENCHING l///i^\V SEE ALTERNATIVES NOTE: ALTERNATIVES. LOCATICN AND EXTENT OF SUBDRAINS SHOULD BE DETERMINED BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST DURING GRADING. PLATE EG-1 CANYON SUBDRAIN ALTERNATE DETAILS ALTERNATE 1: PERFORATED PIPE ANO FILTER MATERIAL A-1 MINIMUM 12' MINIMUM FILTER MATERIAL: MINIMUM VOLUME OF 9 FT.> -^i.-.ii^.. /LINEAR FT. 6" i ABS OR PVC PIPE OR APPROVED lS4'--'.-c-iiDCTiTiiTc u/iTu MiMiuiiu ft il// • (/I PtTDcc ^ .'.^n*;;^ SUBSTITUTE WITH MINIMUM 8 PERFS LINEAR FT. IN BOTTOM HALF OF PIPE. ASTM 02751. SDR 35 OR ASTM D1527. SCHD, 40 ASTM D303A. SDR 35 OR ASTM D1785. SCHD, 10 FOR CONTINUOUS RUN IN EXCESS OF 500 FT. USE 8*^r PIPE ^ 5* MINIMUM B~1 FILTER MATERIAL. SIEVE SIZE Pt^RgENT PA??|N(? 1INCH .100 3/4 INCH ?5~329 3/8 INCH 40-100 NO.4 25-40. NO. 8 18-33 .NO. 30 -.5-15 "NO. 50 .0-7 NO. 200 0-3 ALTERNATE 2: PERFORATED PIPE. GRAVEL AND.FILTER FABRIC 6* MINIMUM OVERLAP 6' MINIMUM COVER 4* MINIMUM BEDDING 6' MINIMUM OVERLAP A-2 4" MINIMUM BEDDING" GRAVEL MATERIAL 9 FP/LINEAR FT. B'-l PERFORATED PIPE: SEE ALTERNATE 1 GRAVEL CLEAN 3/4 INCH ROCK OR APPROVED SUBSTITUTE FILTER FABRIC MIRAFI 140 OR APPROVED SUBSTITUTE PLATE EG-2 DETAIL FOR FILL SLOPE TOEING OUT ON FLAT ALLUVIATED CANYON TOE OF SLOPE AS SHOWN ON GRADING PLAN ORIGINAL GROUND SURFACE TO BE RESTORED WITH COMPACTED FILL BACKCUT\,^ARIES. FOR DEEP REMOVALS. ^ BACKCUT ^VKSHOULD BE MADE NO STEEPER THAlK^II OR AS NECESSARY, FOR SAFETY CONSIDERATIONS, COMPACTED RLL ORIGINAL GROUND SURFACE r ANTICIPATED ALLUVIAL REMOVAL i DEPTH PER SOIL ENGINEER. PROVIDE A 1:1 MINIMUM PROJECTION FROM TOE OF SLOPE AS SHOWN ON GRADING PLAN TO THE RECOMMEMDED REMOVAL DEPTH. SLOPE HEIGHT. SITE CONDITIONS AMD/OR LOCAL CONDITIONS COULD DICTATE FLATTER PROJECTIONS. REMOVAL ADJACENT TO EXISTING FILL ADJOINING CANYON RLL COMPACTED RLL LIMITS LINE (EXISTING COMPACTED FILL) x TEMPORARY COMPACTED RLL "^^FOR DRAINAGE ONLY ^<bx Onf ./Qal (TO BE REMOVED) BE REMOVED BEFORE PLACING ADDITIONAL COMPACTED RLL LEGEND Qaf ARTIFICIAL FILL Qai ALLUVIUM PL4TE EG-3 TYPICAL STABILIZATION / BUTTRESS FILL DETAIL 15" TYPICAL 1-2' CLEA > H m m o I ILEAR — " OUTLETS TO BE SPACED AT 100* MAXIMUM INTERVALS. AND SHALL EXTEND 12- BEYOND THE FACE OF SLOPE AT TIME OF.ROUGH GRADING COMPLETION. DESIGN FINISH SLOPE 15'MINIMUM BLANKET FILL IF RECOMMENDED BY THE SOIL ENGINEER 10'MINIMUM 25'MAX IMU TOE W=15'MINIMUM OR H/2 TYPICAL BENCHING BUTTRESS OR SIDEHILL FILL ,2% GRADIENT 4" DIAMETER NON-PERFORATED OUTLET PIPE ANO BACKDRAIN ISEE ALTERNATIVES) BEDROCK HEEL 3'MINIMUM KEY DEPTH TYPICAL STABILIZATION / BUTTRESS SUBDRAIN DETAIL MINIMUM 2" PIPE INIMUM MINIMUM PIPE 1— > m m I Ln 2- MINIMUM RLTER MATERIAL: MINIMUM OF FIVE R'/LINEAR R OF PIPF OR FOUR Fl'/LINEAR Fl OF PIPE WHEN PLACED IN SQUARE CUT TRENCH. ALTERNATIVE IN LIEU OF RLTER MATERIAL: GRAVEL MAY BE ENCASED IN APPROVED RLTER FABRIC. RLTER FABRIC SHALL BE MIRAR 140 OR EQUIVALENT. RLTER FABRIC SHIALL BE LAPPED A MINIMUM OF 12" ON ALL JOINTS. MINIMUM 4- DIAMETER PIPE: ABS-ASTM D-2751. SDR 35 OR ASTM D-1527 SCHEDULE 40 PVC-ASTM D-3034. SpR 3S OR ASTM D-17B5 SCHEDULE 40 WITH A CRUSHING STRENOTH OF 1.000 POUNDS MINIMUM. AND A MINIMUM OF 8 UNIFORMLY SPACED PERFORATIONS PER FOOT OF PIPE INSTALLED WITH PERFORATIONS OF BOTTOM OF PIPE. PROVIDE CAP AT UPSTREAM END OF PIPE. SLOPE AT 2% TO OUTLET PIPE. OUTLET PIPE TO BE CONNECTED TO SUBDRAIN PIPE WITH TEE OR ELBOW. NOTE: 1. TRENCH FOR OUTLET PIPES TO BE BACKRLLED WITH ON-SITE SOIL 2. BACKDRAINS AND LATERAL DRAINS SHALL BE LOCATED AT ELEVATION OF EVERY BENCH DRAIN. RRST DRAIN LOCATED AT ELEVATION JUST ABOVE LOWER LOT GRADE. ADDITIONAL DRAINS MAY BE REQUIRED AT THE DISCRETION OF THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST. Fll TER MATERIAL SHALL BE OF THE FOLLOWING SPECIFICATION OR AN APPROVED EQUIVALENT: SIEVE SIZE PERCENT PASSING 1 INCH 3/4 INCH 3/8 INCH NO. 4 NO. 8 NO. 30 NO. 50 NO. 200 100 90-100 40-100 25-40 18-33 5-15 0-7 0-3 GRAVEL SHALL BE OF THE FOLLOWING SPECIFICATION OR AN APPROVED E.QUIVALENT: SIEVE SIZE PERCENT PASSING 1 1/2 INCH. 100 NO. 4 50 NO.200 8 SAND EQUIVALENT: MINIMUM OF 51 FILL OVER NATURAL DETAIL SIDEHILL FILL PROPOSED GRADE TOE OF SLOPE AS SHOWN ON GRADING PLAN PROVIDE A 1:1 MINIMUM PROJECTION FROM DESIGN TOE OF SLOPE TO TOE OF KEY AS SHOWN ON AS BUILT NATURAL SLOPE TO BE RESTORED WITH COMPACTED FILL . j^V/AWW// T4-MINIMUM BACKCUT VARIES Ti r— > m m o I cn it'MINIMUM KEY WIDTH 2'X 3'MINIMUM KEY DEPTH 2* MINIMUM IN BEDROCK OR APPROVED MATERIAL. BENCH WIDTH MAY VARY "^'.MINIMUM NOTE- 1 WHERE THE NATURAL SLOPE APPROACHES OR EXCEEDS THE DESIGN SLOPE RATIO. SPECIAL RECOMMENDATIONS WOULD BE PROVIDED BY THE SOILS ENGINEER. 2. THE NEED FOR AND DISPOSITION OF DRAINS WOULD BE DETERMINED BY THE SOILS ENGINEER BASED UPON EXPOSED CONDITIONS. FILL OVER CUT DETAIL H niT/FIII r^oNTACT 1. AS SHOWN ON GRADING PLAN 2. AS SHOWN ON AS BUILT ORIGINAL TOPOGRAPHY MAINTAIN MINIMUM 15'RLL SECTION FROM BACKCUT TO FACE OF RNISH SLOPE CUT SLOPE m^^^^j BENCH WIDTH MAY VARY ^4 ^ LOWEST BENCH WIDTH [4'MINIMUM 15'MINIMUM OR H/2 ^^/^ BEDROCK OR APPROVED MATERIAL r" > -I m m o I NOTE: THE CUT PORTION OF THE SLOPE SHOULD BE EXCAVATED AND EVALUATED BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST PRIOR TO CONSTRUCTING THE RLL PORTION. STABILIZATION FILL FOR UNSTABLE MATERIAL EXPOSED IN PORTION OF CUT SLOPE "D r- > m m o I 00 "^^...l^/ UNWEATHERED BEDROCK OR APPROVED MATERIAL COMPACTED STABILIZATION RLL y MINIMUM TILTED BACK IF RECOMMENDED BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST. THE REMAINING CUT PORTION OF THE SLOPE MAY REQUIRE REMOVAL AND REPLACEMENT WITH COMPACTED RLL NOTE: 1 SUBDRAINS ARE NOT REQUIRED UNLESS SPECIFIED BY SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST, 2 -Wr SHALL BE EQUIPMENT WIDTH 115') FOR SLOPE HEIGHTS LESS THAN 25 FEET. FOR SLOPES GREATER' ' THAN 25 FEET 'W SHALL BE DETERMINED BY THE PROJECT SOILS ENGINEER AND /OR ENGINEERING GEOLOGIST. AT NO TIME SHALL "W BE LESS THAN H/2. SKIN RLL OF NATURAL GROUND ORIGINAL SLOPE ROPOSED RNISH GRADE 15'MINIMUM TO BE MAINTAINED FROM PROPOSED RNISH SLOPE FACE TO BACKCUT PROPOSED FINISH SLOPE MINIMUM ^ BEDROCK OR APPROVED MATERIAL 2'MINIMUM! _.. VV? KEY DEPTH 3'MINIMUM KEY DEPTH H m m o I ID (NIMUM KEY WIDTH NOTE: 1. THE NEED AND DISPOSITION OF DRAINS WILL BE DETERMINED! BY THE SOILS ENOINEER ANO/OR ENGINEERING GEOLOGIST BASED ON FIELD CONDITIONS. . PAD OVFREXCAVATION AND RECOMPACTION SHOULD BE PERFORMED IF DETERMINED TO BE NECESSARY BY THE SOILS ENOINEER AND/OR ENGINEERING OEOLOOIST. DAYLIGHT CUT LOT DETAIL RECONSTRUCT COMPACTED RLL SLOPE AT 2:1 OR FLATTER IMAY INCREASE OR DECREASE PAD AREA). NATURAL GRADE OVEREXCAVATE AND RECOMPACT REPLACEMENT RLL AVOID AND/OR CLEAN UP SPILLAGE OF MATERIALS ON THE NATURAL SLOPE PROPOSED FINISH GRADE MINIMUM BLANKET RLL /// 2'MINIMUM KEY DEPTH !%ORADIENT>xx. ^rrW BEDROCK OR APPROVED MATERIAL TYPICAL BENCHING r- > m m o I .OTE: 1. SUBDRAIN AND KEY WIDTH REQUIREMENTS WILL BE DETERMINED BASED ON EXPOSED SUBSURFACE CONDITIONS AND THICKNESS OF OVERBURDEN. ncTPPMINED NECESSARY BY 2 PAD OVER EXCAVATION AND RECOMPACTION SHOULD BE PERFORMED IF DETERMINED NECESSARY THB SOILS ENGINEER AND/OR THE ENGINEERING GEOLOGIST. TRANSITION LOT DETAIL CUT LOT (MATERIAL TYPE TRANSITION) NATURAL GRADE PAD GRADE COMPACTED RLL \^^'^y 3* MINIMUM^ ^ UNWEATHERED BEDROCK OR APPROVED MATERIAL TYPICAL BENCHING CUT-FIU LOT (DAYUGHT TRANSITION) PAD GRADE 5; MlhyMUM NATURAL GRADE -<f?^5' •^^^^ 'OVEREXCAVATE w AND RECOMPACT sS^""^ >h;^//^r/^^^^ d' 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-RLL TRANSITION AREAS. PLATE EG-11 SETTLEMENT PLATE AND RISER DETAIL 2'X 2'X 1/4- STEEL PLATE STANDARD 3/4" PIPE NIPPLE WELDED TO TOP OF PLATE. 3/4- X 5-GALVANIZED RPE. STANDARD PIPE THREADS TOP AND BOTTOM. EXTENSIONS THREADED ON BOTH ENDS AND ADDED IN 5' INCREMENTS. 3 INCH SCHEDULE 40 PVC PIPE SLEEVE. ADD IN 5* INCREMENTS WITH GLUE JOINTS. RNAL GRADE MAINTAIN 5'CLEARANCE OF HEAVY EQUIPMENT. MECHANICALLY HAND COMPACT IN 2*VERTICAL -rAr LIFTS OR ALTERNATIVE SUITABLE TO AND ACCEPTED BY THE SOILS ENGINEER. I I MECHANICALLY HAND COMPACT THE INITIAL 5* VERTICAL WITHIN A 5'RADIUS OF PLATE BASE. 1' NOTE: \ i / I • - • • • • • • " • • • mi \« • - ....» • • . » .'»•. » «* BOTTOM OF CLEANOUT PROVIDE A MINIMUM 1'BEDDING OF COMPACTED SAND 1. 3. 5. LOCATIONS OF SETTLEMENT PLATES SHOULD BE CLEARLY MARKED AND READILY C«,i?lg M{<I?NIATN'S»{ W BASE AND ^rHrN§'Ktk'D^?Sp"R%Tci°s"p'^ |r ^EJOILS^ENsmE^^^ CONTRACTOR SHOULD MAINTAIN A SlflADIUS I?AC'E"I!!S SSCAL[Y°HASD'COMPACT INITIAL r OF FILL PRIOR TO ESTABUSHING THE INITIAL READING. IN THE EVENT OF DAMAGE TO THE SETTLEMENT PLATE OR EXTENSION RESULTING FROM EQUIPMENT OPERATING WITHIN THE SPECIFIED CLEARANCE AREA CONTRACTOR SHOULD IMMEDUTELY NOTIFY THE SOILS ENGINEER AND SHOULD BE RESPONSIBLE FOR RESTORING THE SETTLEMENT PLATES TO WORKING ORDER. AN ALTERNATE DESIGN AND METHOD OF INSTALLATION MAY BE PROVIDED AT THE DISCRETION OF THE SOILS ENGINEER. PLATE EG-U TYPICAL SURFACE SETTLEMENT MONUMENT RNISH GRADE 3'-6' 3/8- DIAMETER X 6" LENGTH CARRIAGE BOLT OR EQUIVALENT DIAMETER X 3 1/2'LENGTH HOLE ^ CONCRETE BACKFILL PLATE EG~15 TEST PIT SAFETY DIAGRAM SIDE VIEW { NOT TO SCALE ) TOP VIEW 100 FEET APPROXIMATE CENTER OF TEST PIT ( NOT TO SCALE ) PLATE EG-16 OVERSIZE ROCK DISPOSAL VIEW NORMAL TO SLOPE FACE ••oo 20'MINIMUM _J 5'MINIMUM (A)^ CO oO oolFl MINIMUM (C) 03 M (Bl oo PROPOSED RNISH GRADE MINIMUM (E) oo 15'MINIMUM (A) oa C30 (G) C30 BEDROCK OR APPROVED MATERIAL VIEW PARALLEL TO SLOPE FACE PROPOSED FINISH GRADE 10'MINIMUM (E) 100'MAXIMUM (B ' |3' MINIMUM (Qj >5*MINIMUM (Ci FROM CATIYOALWALL ^ /// ^ ,^' MINIMUM (C) BEDROCK OR APPROVED MATERIAL NOTE: (A) (B) (C) (D) (E) in (G) ONE EQUIPMENT WIDTH OR A MINIMUM OF 15 FEET. HEIGHT AND WIDTH MAY VARY DEPENDING ON ^OCK SEE AND TYPE OF EQUIPMENT LENGTH OF WINDROW SHALL BE NO GREATER THAN 100 MAXIMUM. IF APPROVED BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST. WINDROWS MAY BE PLACED DIRECTLY ON COMPETENT MATERIAL OR BEDROCK PROVIDED ADEQUATE SPACE IS AVAILABLE FOR COMPACTION ORIENTATION OF WINDROWS MAY VARY BUT SHOULD BE AS RECOMMENDED BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST. STAGGERING OF WINDROWS IS NOT NECESSARY UNLESS RECOMMENDED.^ CLEAR AREA FOR UTILITY TRENCHES. FOUNDATIONS AND SWIMMING POOLS. ALL RLL OVER AND AROUND ROCK WINDROW SHALL BE COMPACTED TO 90% RELATIVE COMPACTION OR AS RECOMMENDED. AFTER FILL BETWEEN WINDROWS IS PLACED AND COMPACTED WITH THE LIFT OF FILL COVERING Wl^^^^^ SHOULD BE PROOF ROLLED WITH A D-9 DOZER OR EQUIVALENT. VIEWS ARE DIAGRAMMATIC ONLY. ROCK SHOULD NOT TOUCH p^, » ^-r- or» -i AND VOIDS SHOULD BE COMPLETELY RLLED IN. PLATE RU"-1 ROCK DISPOSAL PITS VIEWS ARE DIAGRAMMATIC ONLY. ROCK SHOULD NOT TOUCH AND VOIDS SHOULD BE COMPLETELY RLLED IN. RLL LIFTS COMPACTED OVER ROCK AFTER EMBEDMENT / \. GRANULAR MATERIAL I • 1 • • \ • I 1 1 COMPACTED RLL J SIZE OF EXCAVATION TO BE , ! COMMENSURATE WITH ROCK SIZE | ROCK DISPOSAL UYERS GRANULAR SOIL TO RLL VOIDS.^OMPACTED RLL DENSIRED BY FLOODING "^"^ ' LAYER ONE ROCK HIGH V PROPOSED FINISH GRADE 10'MINIMUM OR BELOW LOWEST UTIU 0CX3OCXX3CQ; OVERSIZE LAYER Fl COMPACTED FILL PROFILE ALONG LAYER LOPE FACE ^CLEAR ZONE 20'MINIMUM LAYER ONE ROCK HIGH PLATE RD-2 i