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HomeMy WebLinkAboutCT 02-11; TUSCANY BY THE SEA TOWNHOMES; GEOTECHNICAL UPDATE; 2005-03-29RECEIVED ENGINEERING DEPARTMENT Geotechnical • Geologic • Environmental 5741 Palmer Way • Carlsbad, California 92008 • (760)438-3155 • FAX (760) 931-0915 March 29, 2005 W.0.3111-A2-SC Mr. Randall K. Locket 391 Tannarack Avenue Carlsbad, California 92008 Subject: Geotechnical Update, 391 Tamarack Avenue, Tuscany by the Sea Town Homes, Carlsbad, San Diego County, California Dear Mr. Locket In accordance with a request and authorization, GeoSoils, Inc. (GSI), has prepared this letter for the purpose of updating our previous referenced reports (seethe Appendix). This update is based on visual observations made during a site reconnaissance, performed on March 28,2005, and a review ofthe referenced plans and GSI's previous reports (see the Appendix). Recommendations contained in the previous reports, which are not specifically superceded by this review, should be properly incorporated into the design and construction phases of site development. CONCLUSiONS AND RECOMMENDATIONS Geotechnically, the subject site is in essentially the same condition as it appeared during the preparation of our previous reports (see the Appendix). Based upon our review of the current plans (see the Appendix), the proposed development ofthis site is consistent with that described in our previous reports. Therefore, the referenced geotechnical reports are considered relevant and applicable to the proposed construction. The conclusions and recommendations presented herein are professional opinions. These opinions have been derived in accordance with current standards of practice and no warranty is expressed or implied. Standards of practice are subject to change with time. GSI assumes no responsibility for work, testing or recommendations performed or provided by others. The opportunity to be of service is greatly appreciated. If you have any questions, please do not hesitate to call our office. Respectfully submitted^ loils, inc. n P. Franklin gineering Geologist, CET BV/DWS/JPF/jk Attachment: Appendix - References David W. Skelly Civil Engineer, RCE 47857 Distribution: (2) Addressee (2) Snipes-Dye Associates, Attention: Mr. Son Nguyen Mr. Randall K. Locket 391 Tamarack Avenue, Carlsbad File:e:\wp9\3100\3111 a2.gum3 W.O. 3111-A2-SC March 29. 2005 Page 2 GeoSoils, Inc. APPENDIX REFERENCES GeoSoils, Inc., 2005, Geotechnical review of grading plans, 391 Tamarack Avenue, Carlsbad, San Diego County, California, W.O. 3111-A1-SC, dated February 22. , 2001, Preliminary geotechnical evaluation, 391 Tamarack Avenue, Carlsbad, California, W.O. 3111-A-SC, dated August 31. 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. Snipes-Dye Associates, 2005, Grading and erosion plans for: Tuscany by the Sea Town Homes, Project no. CT-02-11, dated January 13. GeoSoils, Inc. 2S PRELIMINARY GEOTECHNiCAL EVALUATION 391 TAMARACK AVENUE CARLSBAD, CALIFORNIA FOR RANDALU K. LOCKETT 391 TAMARACK AVENUE CARLSBAD, CALiFORNIA 92008 W.O. 3111-A-SC jp r 0 j .1^ Geotechnical • Geologic • Environmental 5741 Palmer Way • Carlsbad, California 92008 • (760)438-3155 • FAX (760) 931-0915 August 31,2001 W.O. 3111-A-SC Randall K. Lockett 391 Tamarack Avenue Carlsbad, California 92008 Subject: Preliminary Geotechnical Evaluation, 391 Tamarack Avenue, Carlsbad, California Dear Mr. Lockett: In accordance with your authorization and request, GeoSoils, Inc. (GSI) has performed a preliminary geotechnical investigation of the subject property. The purpose of the study was to evaluate the onsite soils and geologic conditions and their effects on the proposed site development from a geotechnical viewpoint. EXECUTIVE SUMMARY Based on our review of the available data (Appendix A), field exploration, laboratory testing, and geologic and engineering analysis, the proposed development appears to be feasible from a geotechnical viewpoint, provided the recommendations presented in the text ofthis report are properly incorporated into the design and construction ofthe project. The most significant elements of this study are summarized below: • Removals of all existing fill and the upper 1 to 2 feet of weathered terrace deposits are recommended. Removal depths are anticipated to be on the order of 2 to 3 feet in areas proposed for settlement sensitive improvements. • Our laboratory test results indicate that soils onsite are generally low in expansion potential. Sulfate testing indicates that site soils have a negligible exposure to concrete per Table 19-A-4 ofthe 1997 UBC (sample=0.000 percent by weight). Corrosion testing (ph, resistivity) indicates that the soils are essentially neutral (pH=7.2) and moderately corrosive to ferrous metals (saturated resistivity=3,450 ohms-cm). Alternative methods and additional comments should be obtained by a qualified corrosion engineer. Subsurface water is not anticipated to affect site development, provided that 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 may be encountered during grading, or may occur after site development. Based on field mapping in the vicinity of the site, the presence of numerous paleoliquefaction features ("sand blows," liquefaction craters, sand filled fissures and injection dikes, sand vents, etc.), may exist within the site. Potential liquefaction of such areas in the future that may impact surface improvements is considered very low, provided that the recommendations presented in this report are incorporated into the design and construction of the project. Mitigation for structures may be provided by the use of post tensioned slabs. Mitigation in other areas may be accomplished by overexcavation and/or geotextiles, as evaluated in the field during grading, based on proposed development and use. Based on the presence of paleoliquefaction features that likely may exist, and potentially liquefiable soils in areas of the site, post tensioned foundations are most suitable for this project. However, conventional foundations may be suitable in some areas, based on conditions disclosed during grading. The seismicity acceleration values provided herein should be considered during the design of the proposed developmenL The geotechnical design parameters provided herein should be considered during project planning, design and construction by the project structural engineer and/or architects. Randall K. Lockett W.O. 3111 -A-SC File:e:\vi/p7\3100\3111 a.pge Page Two GcoSoils, Inc. The opportunity to be of service is greatly appreciated. If you have any questions concerning this report or if we may be of further assistance, please do not hesitate to contact any of the undersigned. Respectfully submitted, GeoSoils, Inc. Jryan voss Staff Geologist Reviewed by Engineering Geologist, BV/JPF/DWS/jh Distribution: (4) Addressee Reviewed by /DaMid W. Skel Skelly Civil Engineer, RCE Randall K. Lockett File:e:\wp7\3100\3111 a.pge W.O. 3111-A-SC Page Three GcoSoils, Inc. TABLE OF CONTENTS SCOPE OF SERVICES 1 SITE DESCRIPTION 1 PROPOSED DEVELOPMENT 1 FIELD STUDIES 3 REGIONAL GEOLOGY 3 EARTH MATERIALS 3 Artificial Fill - Undocumented (Not Mapped) 3 Terrace Deposits (Map Symbol - Qt) 4 FAULTING AND REGIONAL SEISMICITY 4 Faulting 4 Seismicity 6 Seismic Shaking Parameters 6 GROUNDWATER 7 UQUEFACTION 7 OTHER GEOLOGIC HAZARDS 8 LABORATORYTESTING .• 8 Classification 8 Laboratory Standard 8 Direct Shear Tests 9 Expansion Potential 9 Corrosivity 9 DISCUSSION AND CONCLUSIONS 10 General 10 Earth Materials 10 Expansion Potential 10 Corrosion/Sulfate Testing 11 Subsurface and Surface Water 11 Liquefaction 11 Regional Seismic Activity 11 GcoSoils, Inc. EARTHWORK CONSTRUCTION RECOMMENDATIONS 12 General 12 Site Preparation 12 Removals (Unsuitable Surficial Materials) 12 Fill Placement 13 Erosion Control 13 FOUNDATION RECOMMENDATIONS 13 Preliminary Foundation Design 14 Bearing Value 14 Lateral Pressure 14 Construction 14 Very Lowto Low Expansion Potential (Expansion Index 0 to 50) 14 PRELIMINARY POSTTENSIONED SLAB FORMATION SYSTEM RECOMMENDATIONS 15 General 15 Foundation Settlements 17 Subgrade Preparation 17 Perimeter Footings and Pre-Wetting 17 CONVENTIONAL RETAINING WALL RECOMMENDATIONS 18 General 18 Restrained Walls 19 Cantilevered Walls 19 Wall Backfill and Drainage 19 Retaining Wall Footing Transitions 23 FLATWORK AND ASSOCIATED IMPROVEMENTS 23 Tile Flooring 24 Gutters and Downspouts 24 Exterior Slabs and Walkways 25 ADDITIONAL RECOMMENDATIONS/DEVELOPMENT CRITERIA 25 Additional Site Improvements 25 Landscape Maintenance and Planting 26 Drainage 26 Footing Trench Excavation 27 Trench Backfill 27 PLAN REVIEW 28 LIMITATIONS 28 Randall K. Lockett Table of Contents File: e:\wp7\3100\3111 a.pge Page ii GcoSoils, Inc. FIGURES: Figure 1 - Site Location Map 2 Figure 2 - California Fault Map 5 Figure 3 -Schematic of Site Wall Drain Option A 20 Figure 4 -Schematic of Site Wall Drain Option B 21 Figure 5 -Schematic of Site Wall Drain Option C 22 ATTACHMENTS: Appendix A - References Rear of Text Appendix B - Boring Logs Rear of Text Appendix C - Laboratory Test Results Rear of Text Appendix D - General Earthwork and Grading Guidelines Rear of Text Plate 1 - Boring Location Map Rear of Text in Pocket Randall K. Lockett Table of Contents Rle: e:\wp7\3100\3111 a.pge Page iii GcoSoils, Inc. PREUMINARY GEOTECHNICAL EVALUATION 391 TAMARACK AVENUE CARLSBAD, CAUFORNIA SCOPE OF SERVICES The scope of our services has included the following: 1. Review of available soils and geologic data for the site area (Appendix A). 2. Geologic site reconnaissance and geologic mapping. 3. Subsurface exploration consisting of four hand auger exploratory borings for geotechnical logging and sampling (Appendix B). 4. Pertinent laboratory testing of representative soil samples collected during our subsurface exploration program (Appendix C). 5. General areal seismicity and liquefaction evaluation. 6. Appropriate engineering and geologic analysis of data collected and preparation of this report. SITE DESCRIPTION The subject site is located on the south side of Tamarack Avenue near Washington Street, in Carisbad, California (Figure 1). A residence, garage, and corrugated storage structure currently exist on the site. The lot is generally flat lying. According to a USGS 1968 (photo revised 1975) San Luis Rey Quadrangle map, the subject site is approximately 50 feet above Mean Sea Level (MSL). PROPOSED DEVELOPMENT It is our understanding that the structures will be demolished and proposed development would consist of a two-story 13 unit condominium complex and underground parking (three-story structure overall). Cut and fill grading techniques would be utilized to create design grades. It is anticipated that the planned development will consist of a three-story structure with continuous footings and slab-on-grade floors with wood-frame construction and/or masonry block construction. Building loads are assumed to be typical for this type of relatively light structures. Sewage disposal is proposed to be accommodated by tying into the regional system. The need for import soil is unknown. GcoSoils, Inc. Base Map: San Luis Rey Quadrangle, California—San Diego Co.,7.5 Minute Series (Topographic), 1968, (photo revised 1975), by USGS, 1"=2000" N 2000 Scale 4000 Feet W.O. 3111-A-SC SITE LOCATION MAP Figure 1 FIELD STUDIES Field studies conducted during our evaluation of the property for this study consisted of geologic reconnaissance, geologic mapping, and excavation of four exploratory hand auger borings for evaluation of near-surface soil and geologic materials. The borings were logged by a geologist from our firm, who collected representative samples from the excavations for appropriate laboratory testing. The logs of the borings are presented in Appendix B. Boring locations are presented on Plate 1. ^ REGIONAL GEOLOGY The subject property is located within a prominent natural geomorphic province in southwestern California known as the Peninsular Ranges. It is characterized by steep, elongated mountain ranges and valleys that trend northwesteriy. 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 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. EARTH MATERIALS Earth materials underlying the site consist of artificial fill underlain by Quaternary-age terrace deposits. These earth materials are described below: Artificiai Fill - Undocumented (Not Mapped) Artificial fill onsite was found to be discontinuously present, and generally consist of a brown, dry, loose, silty sand. Thickness of the material is approximately 2V2 feet. Artificial fill existing at the subject site is considered unsuitable for support of settlement sensitive improvements in its present state. Accordingly, these soils are considered unsuitable for support of additional fill and/or settlement sensitive improvements in their existing state. Randall K. Lockett W.O. 3111 -A-SC 391 Tamarack Avenue August 31, 2001 File: e:\wp7\3100\3111a.pge Page 3 GcoSoils, Inc. Terrace Deposits (Map Svmbol - Qt) The Quaternary-age terrace deposits underiie the entire site at depth. As encountered, the terrace deposits generally consist of red brown, dry to very moist, silty sand, and is medium dense. Due to the relatively soft and weathered condition of the upper ±1 to 2 feet, these materials should be removed, moisture conditioned, and recompacted and/or processed in place, should settlement-sensitive improvements be proposed. This unit typically has a low to medium expansion potential. FAULTING AND REGIONAL SEISMICITY Faulting The site is situated in an area of active as well as potentially-active faults. Our review indicates that there are no known active faults crossing the site within the areas proposed for development (Jennings, 1994), and the site is not within an Earthquake Fault Zone (Hart and Bryant, 1997). There are a number of faults in the southern California area that are considered active and would have an effect on the site in the form of ground shaking, should they be the source of an earthquake. 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-lnglewood-Rose Canyon fault zone. The location of these and other major faults relative to the site are indicated on Figure 2. The possibility of ground acceleration or shaking at the site may be considered as approximately similar to the southern California region as a whole. The following table lists the major faults and fault zones in southern California that could have a significant effect on the site should they experience significant activity. ABBREVIATED FAULT NAME APPROXIMATE DISTANCE MILES (KM) Coronado Bank- Agua Bianca 21 (33) Elsinore 25 (40) La Nacion 24 (39) Newport-lnglewood-Offshore 7(11) Rose Canyon 4(6) San Diego Trough-Bahia Sol 30 (48) Randall K. Lockett 391 Tamarack Avenue File: e:\wp7\3100\3111 a.pge W.O. 3111-A-SC August 31,2001 Page 4 GcoSoils, Inc. SAN Ff^NCISCO SITE LOCATION (-f): Latitude • Longitude Lockett W.O. 3111-A-SC 33.1492 N 117.3414 W CALIFORNIA FAULT Figure 2 GcoSoils, Inc. Seismicity The acceleration-attenuation relations of Joyner and Boore (1982) and Campbell and Bozorgnia (1994) have been incorporated into EQFAULT (Blake, 1997). For this study, peak horizontal ground accelerations anticipated at the site were determined based on the mean plus 1 sigma attenuation curves developed by Joyner and Boore (1982) and Campbell and Bozorgnia (1994). These acceleration-attenuation relations have been incorporated in EQFAULT, a computer program by Thomas F. Blake (1997), which performs deterministic seismic hazard analyses using up to 150 digitized California faults as earthquake sources. The program estimates the closest distance between each fault and a user-specified file. 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 the upper bound ("maximum credible") and "maximum probable" earthquakes on that fault. Site acceleration as a percentage of the acceleration of gravity (g) is computed by any of the 14 user-selected acceleration-attenuation relations that are contained in EQFAULT. Based on the above, peak horizontal ground accelerations from an upper bound event may be on the order of 0.42 g to 0.72 g, and a maximum probable event may be on the order of 0.23 g to 0.46 g on the Rose Canyon fault zone, located approximately 4 miles from the subject site. Seismic Shaking Parameters Based on the site conditions. Chapter 16 of the Uniform Building Code (International Conference of Building Officials, 1997) the following seismic parameters are provided. Seismic zone (per Figure 16-2*) 4 Seismic Zone Factor (per Table 16-1*) 0.40 Soil Profile Type (per Table 16-J*) SD Seismic Coefficient C^ (per Table 16-Q*) 0.44 N;^ Seismic Coefficient Cy (per Table 16-R*) 0.64 Nv Near Source Factor N^ (per Table 16-S*) 1.0 Near Source Factor Ny (per Table 16-T*) 1.15 Seismic Source Type (per Table 16-U*) B Distance to Seismic Source 4 mi. (6.4 km) Upper Bound Earthquake Mw 6.9 * Figure and table references from Chapter 16 ofthe Uniform Building Code (1997). Randall K. Lockett 391 Tamarack Avenue File: e:\wp7\3100\3111 a.pge W.O. 3111-A-SC August 31, 2001 Page 6 GcoSoils, Inc. GROUNDWATER Groundwater was not encountered feet during our investigation. Subsurface water is not anticipated to adversely affect site development, provided that the recommendations contained in this report are incorporated into final design and construction. These observations reflect site conditions at the time of our investigation and do not preclude future changes in local groundwater conditions from excessive irrigation, precipitation, or that were not obvious, at the time of our investigation. Perched groundwater conditions along fill/bedrock contacts and along zones of contrasting permeabilities should not be precluded from occurring in the future due to site irrigation, poor drainage conditions, or damaged utilities. 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 Liquefaction describes a phenomenon in which cyclic stresses, produced by earthquake induced ground motion, create excess pore pressures in relatively cohesionless soils. These soils may thereby acquire a high degree of mobility, which can lead to lateral movement sliding, consolidation and settlement of loose sediments, sand boils, and other damaging deformations. This phenomenon occurs only below the water table, but after liquefaction has developed, it can propagate upward into overiying, non-saturated soil, as excess pore water dissipates. Liquefaction susceptibility is related to numerous factors and the following conditions must exist for liquefaction to occur: 1) sediments must be relatively young in age and not have developed large amount of cementation: 2) sediments must consist mainly 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 seismic event of a sufficient duration and large enough magnitude, to induce straining of soil particles. At the subject site, three of the five conditions which are necessary for liquefaction to occur exist, and the site may experience the other two. One ofthe primary factors controlling the potential for liquefaction is depth to groundwater. Uquefaction susceptibility generally decreases as the groundwater depth increases for two reasons: 1) the deeper the water table, the greater normal effective stress acting on saturated sediments at any given depth and liquefaction susceptibility decreases with increased normal effective stress; and 2) age, cementation, and relative density of sediments generally increase with depth. Thus, as the depth to the water table increases, and as the saturated sediments become older, more cemented, have higher relative density, and confining normal stresses increase, the less likely they are to liquefy during Randall K. Lockett W.O. 3111 -A-SC 391 Tamarack Avenue August 31, 2001 File: e:\wp7\3100\3111 a.pge Page 7 GcoSoils, Inc. a seismic event. Typically, liquefaction has a relatively low potential where groundwater is greater than 30 feet deep and virtually unknown below 60 feet. OTHER GEOLOGIC HAZARDS Numerous sediment-defomriing features were mapped by Gerald Kuhn in the vicinity ofthe site. As indicated in Obermeier (1996), these features have: sedimentary characteristics that are consistent with an earthquake-induced liquefaction origin; namely, there is evidence of an upward-directed hydraulic force that was suddenly applied and was of short duration; sedimentary characteristics consistent with historically documented observations of the earthquake-induced liquefaction processes, in a similar physical setting (dikes, sills, vented sediment, lateral spreads, and some types of soft sediment deformations); occur in groundwater settings where suddenly applied, strong hydraulic forces of short duration could not be reasonably expected except from earthquake-induced liquefaction (i.e., non- artesian conditions and non-seismic landsliding are not present); similar features occur at multiple locations, in similar geologic and groundwater settings (Kuhn, et al, 1996); and the evidence for the age of the features supports the interpretation that they formed in one or more discreet, short episodes that individually affected a large area and that the episodes were separated by relatively long time periods during which no such features were formed. Based on our review, the sediment-deforming features are classified as paleoliquefaction features. LABORATORYTESTING Laboratory tests were performed on representative samples of representative site earth materials in order to evaluate their physical characteristics. Test procedures used and results obtained are presented below. Classification ^ Soils were classified visually in accordance with ASTM D-2487. The soil classifications are shown on the boring logs. Appendix B. Laboratorv Standard The maximum density and optimum moisture content was determined for the major soil type encountered in the borings. The laboratory standard used was ASTM D-1557. The moisture-density relationship obtained for this soil is shown on the following table: Randall K. Lockett W.O. 3111 -A-SC 391 Tamarack Avenue August 31, 2001 File: e:\wp7\3100\3111 a.pge PageB GcoSoils, Inc. LOCATION SOILTYPE . MAXIMUM DENSITY (PCF) OPTIMUM MOISTURE CONTENT (%) B-2 @ 0-1.5' Silty SAND, Brown 129.0 10.0 Direct Shear Tests Shear testing was perfomned on a representative undisturbed sample of terrace deposits in general accordance with ASTM test method D-3080. Test results are presented on the following table. SAMPLE LOCATION PRIMARY RESIDUAL SAMPLE LOCATION COHESION (PSF) FRICTION ANGLE (DEGREES) COHESION (PSF) FRICTION ANGLE (DEGREES) B-1 @ 2.5' 403 27 396 27 Expansion Potential Expansion index testing was performed on representative samples of the site materials in general accordance with Standard 18-2 ofthe Uniform Building Code (UBC). Results are presented in the following table. LOCATION SOIL TYPE EXPANSION INDEX EXPANSION POTENTIAL B-1 @ 0-2.0' Silty SAND, Brown <5 Very Low Corrosivity Sulfate testing indicates that site soils have a negligible exposure to concrete per Table 19- A-4 ofthe 1997 UBC (sample=0.000 percent by weight). Corrosion testing (ph, resistivity) indicates that the soils are essentially neutral (pH=7.2) and moderately corrosive to ferrous metals (saturated resistivity=3,450 ohms-cm). Alternative methods and additional comments should be obtained by a qualified corrosion engineer. Laboratory test results are presented in Plate C-1. Randall K. Lockett 391 Tamarack Avenue File: e:\wp7\3100\3111a.pge W.O. 3111-A-SC August 31.2001 Page 9 GcoSoils, Inc. DISCUSSION AND CONCLUSIONS General Based on our field exploration, laboratory testing and geotechnical engineering analysis, it is our opinion that the subject lots appear suitable for the proposed manufacturing development from a geotechnical engineering and geologic viewpoint, provided that the recommendations presented in the following sections are incorporated into the design and constnjction phases of site development. The primary geotechnical concerns with respect to the proposed development on the site are: • Depth to competent bearing material. • Expansion and corrosion potential of site soils. • Subsurface and perched water. • Liquefaction potential. • Regional seismic activity. 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 oflice. Foundation design parameters are considered preliminary until the foundation design, layout, and structural loads are provided to this office for review. Earth Materials Artificial fill and terrace deposits will be encountered during site earthwork. The artificial fill and the upper 1 to 2 feet of the weathered terrace deposits should be removed. Recommendations for the treatment ofthese soils are presented in the earthwork section of this report. Expansion Potential Our laboratory test results indicate that soils with a very low expansion potential underiie the site. This should be considered during project design. Foundation design and con.struction recommendations are provided herein for very low expansion potential classification. Randall K. Lockett W.O. 3111 -A-SC 391 Tamarack Avenue August 31, 2001 File: e:\vi/p7\3100\3111 a.pge Page 10 GcoSoils, Inc. Corrosion/Sulfate Testing Sulfate testing indicates that site soils have a negligible exposure to concrete per Table 19- A-4 of the 1997 UBC (sample=0.000 percent by weight). Corrosion testing (i.e., pH, resistivity) indicates that the soils are essentially neutral (pH=7.2) and moderately corrosive to ferrous metals (saturated resistivity=3,450 ohms-cm). Alternative methods and additional comments should be obtained by a qualified corrosion engineer. Subsurface and Surface Water Subsurface and surface water, as discussed previously, are not anticipated to significantly 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 fill/bedrock contacts and along zones of contrasting permeabilities, should not be precluded from occurring in the future due to site irrigation, poor drainage conditions, or damaged utilities. Should perched groundwater conditions develop, this office could assess the affected area(s) and provide the appropriate recommendations to mitigate the observed groundwater conditions. The groundwater conditions observed and opinions generated were those at the time of our investigation. Conditions may change with the introduction of irrigation, rainfall, or other factors that were not obvious at the time of our investigation. Liquefaction Liquefaction potential throughout a majority of the site is considered relatively low, assuming that the recommendations presented in this report are properly incorporated into the design and construction of the project. Previous liquefaction of terrace deposits, evidenced by the previous mapped paleoliquefaction features by Gerald Kuhn, is not anticipated to recur, primarily due to the observed cementation of the earth materials comprising the features and surrounding terrace deposits and the lack of groundwater. Design and construction within areas underiain by these features will likely need to consider additional subdrainage, as necessary, and/or other mitigative measures such as overexcavation and the use of geotextiles, or post tension slabs. Regional Seismic Activity The seismicity acceleration values provided herein should be considered during the design of the proposed development. Randall K. Lockett W.O. 3111 -A-SC 391 Tamarack Avenue August 31, 2001 File: e:\wp7\3100\3111a.pge Page 11 GcoSoils, Inc. EARTHWORK CONSTRUCTION RECOMMENDATIONS General All grading should conform to the guidelines presented in Appendix Chapter A33 of the Uniform Building Code (adopted and current edition), the requirements of the City of Carisbad, and the Grading Guidelines presented in this report as Appendix D, except where specifically superseded in the text of this report. Prior to grading, GSI's representative should be present at the preconstruction meeting to provide additional grading guidelines, if needed, and review the earthwork schedule. Earthwork beyond the limits of the surficial, remedial overexcavations or those indicated on the grading plan should be reviewed by the geologist and/or geotechnical consultant prior to and following these additional removals. 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 or if modifications are proposed to the rough grade or precise grading plan, 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, and the Construction Safety Act should be met. GSI does not consult in the area of safety engineering. Excavations into the granular material on this site may be unstable. Site Preparation Debris, vegetation, and other deleterious material should be removed from the improvement(s) area prior to the start of construction. Removals (Unsuitable Surficial Materials) Removals should consist of all existing fill or backfill (utilities), and the upper 1 to 2 feet of weathered terrace deposits, to competent formational sediments within areas proposed for settlement-sensitive improvements. Removals should be completed below a 1:1 (horizontal to vertical) projection down and away from the bottom outside edge of any settlement-sensitive improvement or fill area. Care should be taken when removing soil adjacent to or in close proximity to an existing foundation. Once these materials are removed, the bottom ofthe excavations should be observed and approved by a representative of GSI. The bottom areas approved to receive fill should be scarified in two perpendicular directions and moisture conditioned (at or above the soils optimum moisture content) to a depth of 12 inches and compacted to a minimum 90 percent relative compaction. At that time, the removed existing earth materiais may be re- Randall K. Lockett W.O. 3111 -A-SC 391 Tamarack Avenue August 31, 2001 File: e:\wp7\3100\3111 a.pge Page 12 GcoSoils, Inc. used as fill, provided the materials are moisture conditioned at or above the soils optimum moisture and compacted in accordance with the recommendations of this report. Fill Placement Subsequent to ground preparation, onsite soils may be placed in thin (6± inch) lifts, cleaned of vegetation and debris, brought to a least optimum moisture content, and compacted to achieve a minimum relative compaction of 90 percent. if fill materials are imported to the site, the proposed import fill should be submitted to GSI, so laboratory testing can be performed to verify that the intended import material is compatible with onsite material. 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. Erosion Control Onsite soils and formational sediments have a moderate erosion potential. Use of hay bales, silt fences, and/or sandbags should be considered, as appropriate during construction. Temporary grades should be constructed to drain at a minimum of 1 to 2 percent to a suitable temporary or permanent outlet. Precise grades should be evaluated by the design civil engineer to reduce concentrated flows to less than 6 feet per second and into lined or landscaped swales. Evaluation of cuts during grading will be necessary in order to identify any areas of loose or non-cohesive materials. Should any significant zones be encountered during earthwork construction, additional remedial grading may be recommended; however, only the remedial measures discussed herein are anticipated at this time. FOUNDATION RECOMMENDATIONS In the event that the information concerning the proposed development is not correct or any changes in the design, locafion, or loading conditions of the proposed structures are made, the conclusions and recommendations contained in this report are for the subject parcel 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 supersede 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. Randall K. Lockett W.O. 3111-A-SC 391 Tamarack Avenue August 31, 2001 File: e:\wp7\3100\3111a.pge Page 13 GcoSoils, Inc. Preliminarv Foundation Design Our review, field work, and laboratory testing indicates that onsite soils have a very low expansion potential. Final foundation recommendations should be provided at the conclusion of grading based on laboratory testing of fill materials exposed at finish grade. Bearing Value 1. The foundation systems should be designed and constructed in accordance with guidelines presented in the latest edition of the Uniform Building Code. 2. An allowable bearing value of 1500 pounds per square foot may be used for design of continuous footings 12 inches wide and 12 inches deep and for design of isolated pad footings 24 inches square and 24 inches deep founded entirely into compacted fill or competent bedrock material and connected by grade beam or tie beam in at least one direction. This value may be increased by 20 percent for each additional 12 inches in depth to a maximum value of 2500 pounds per square foot. The above values may be increased by one-third when considering short duration seismic or wind loads. No increase, in bearing, for footing width is recommended. Lateral Pressure 1. For lateral sliding resistance, a 0.35 coefficient of friction may be utilized for a concrete to soil contact when multiplied bythe dead load. 2. Passive earth pressure may be computed as an equivalent fluid having a density of 250 pounds per cubic foot with a maximum earth pressure of 2500 pounds per square foot. 3. When combining passive pressure and frictional resistance, the passive pressure component should be reduced by one-third. Construction The following foundation construction recommendations are presented as a minimum criteria from a soils engineering standpoint. The onsite soils expansion potentials are generally in the Very Low to Low (expansion index 0 to 50) range. Very Low to Low Expansion Potential (Expansion Index 0 to 50) 1. Exterior and interior footings should be founded at minimum depths of 12,18, or 24 inches for one, two, or three-story loads, respectively, below the lowest adjacent surface. Isolated column and panel pads or wall footings should be founded at a minimum depth of 24 inches and connected in one direction by a grade beam. All Randall K. Lockett """"" W.O. 3111-A-SC 391 Tamarack Avenue August 31. 2001 File: e:\wp7\3100\3111a.pge Page 14 GcoSoils, Inc. footings should be reinforced with a minimum of two No. 4 reinforcing bars, one placed near the top and one placed near the bottom of the footing, and in accordance with the recommendations width per UBC 1997. 2. A grade beam, reinforced as above, and at least 12 inches wide should be provided across large (e.g. doon/vays) entrances. The base ofthe grade beam should be at the same elevation as the bottom of adjoining footings. 3. Residential concrete slabs, where moisture condensation is undesirable, should be underiain with a vapor barrier consisting of a minimum of 6 mil polyvinyl chloride or equivalent membrane with all laps sealed. This membrane should be covered above and below with a minimum of 2 inches of sand (total of 4 inches) to aid in uniform curing ofthe concrete and to protect the membrane from puncture. 4. Residential concrete slabs should be a minimum of 4 inches thick, and should be reinforced with No. 3 reinforcing bar at 18 inches on center in both directions, per the UBC. All slab reinforcement should be supported to ensure placement near the vertical midpoint of the concrete. "Hooking" is not considered an acceptable method of positioning the reinforcement. 5. Residenfial 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 ft'om the footings should be maintained with expansion joint material to permit relafive movement. 6. Presaturation is not required for these soil conditions. The moisture content of the subgrade soils should be equal to or greater than optimum moisture content in the slab areas. Prior to placing visqueen or reinforcement, soil moisture content should be verified by this office within 72 hours of pouring slabs. PRELIMINARY POST TENSIONED SLAB FOUNDATION SYSTEM RECOMMENDATIONS Post tensioned slab foundation systems may be used to support the proposed buildings. Based on the potential differential settlement within areas ofthe site underiain by alluvium, post-tensioned slab foundations are recommended exclusively. General The information and recommendations presented in this section are not meant to supersede design by a registered structural engineer or civil engineer familiar with post- tensioned slab design or corrosion engineering consultant. Upon request, GSI could provide additional data/consultation regarding soil parameters as related to post-tensioned slab design during grading. The post tensioned slabs should be designed in accordance Randall K. Lockett W.O. 3111-A-SC 391 Tamarack Avenue August 31, 2001 File: e:\wp7\3100\3111 a.pge Page 15 GcoSoils, Inc. with the Post-Tensioning Institute (PTI) Method. Alternatives to the PTI method may be used if equivalent systems can be proposed which accommodate the angular distortions, expansion potential and settlement noted for this site. 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 Uniform Building Code Section 1816, based on design specifications ofthe 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 5 feet Constant Soil Suction (pf) 3.6 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 gutters and downspouts and posifive drainage 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, design values were obtained ft'om figures or tables of the 1997 Uniform Building Code Section 1816 and presented in Table 1. These values may not be appropriate to account for possible differential settlement of the slab due to other factors (i.e. fill settlement). If a stiffer slab is desired, higher values of ym may be warranted. TABLE 1 POSTTENSION FOUNDATIONS Expansion Potential Very Low''' to Low Expansive (EI = 0-50) em center lift 5.0 feet em edge lift 2.5 feet Ym center lift 1.1 inch Ym edge lift 0.35 inch Randall K. Lockett 391 Tamarack Avenue File: e:\wp7\3100\3111a.pge W.O. 3111-A-SC August 31, 2001 Page 16 GcoSoils, Inc. Expansion Potential Very Low**' to Low Expansive (El = 0-50) em center lift 5.0 feet Bearing Value 1200 psf Lateral Pressure 225 psf Subgrade Modulus (k) 100 pci/inch Minimum Slab Thickness 4.5 inches Perimeter footing embedment 12 inches '^'Internal bearing values within the perimeter of the post tension slab may be increased by 300 psf for each foot of embedment below the bottom of the slab, to a maximum of 2,500 psf. As measured below the lowest adjacent compacted subgrade surface. Foundations for very low expansive soil conditions may use the California Method (spanability method) Foundation Settlements In addifion to designing slab systems (PT or other) for the soil condifions, described herein, the esfimated settlement and angular distortion values that an individual structure could be subject to should be evaluated by a structural engineer. The levels of angular distortion were evaluated on to 40-feet length assumed as minimum dimension of single-family buildings and are anficipated to be on the order of inch in a 20-foot span. Although unlikely, should a large seismic event occur on blind thrust faults offshore, differential settlement may be on the order of 1 inch in 20 feet. If, from a structural standpoint, a decreased or increased length over which the differential is assumed to occur is justified, this change should be incorporated into the design. The settlement values should be revised and verified during grading. Subgrade Preparation The subgrade material should be compacted to a minimum 90 percent of the maximum laboratory dry density. Prior to placement of concrete, the subgrade soils should be well moistened to at least optimum moisture content and verified by our field representative. Perimeter Footings and Pre-Wetting From a soil expansion/shrinkage standpoint, a fairiy common contribufing factor to distress of structures using post tensioned slabs is a significant fluctuation in the moisture content of soils underiying the perimeter ofthe slab, compared to the center, causing a "dishing" Randall K. Lockett 391 Tamarack Avenue File: e:\wp7\3100\3111 a.pge W.O. 3111-A-SC August 31, 2001 Page 17 GcoSoils, Inc. or "arching" ofthe slabs. To mitigate this possible phenomenon, a combination of soil pre- wetting and construction of a perimeter cut-off wall grade beam should be employed. Deepened footings/edges around the slab perimeter must be used to minimize non- uniform surface moisture migration (from an outside source) beneath the slab. Embedment depths are presented in Table 1 for various soil expansion conditions. The bottom of the deepened footing/edge should be designed to resist tension, using cable or reinforcement per the structural engineer. Other applicable recommendations presented under conventional foundation recommendations in the referenced report should be adhered to during the design and construction phase of the project. Floor slab subgrade should be at, or above the soils optimum moisture content to a depth of 24 inches prior to pouring concrete, for exisfing soil conditions. Pre-wetting of the slab subgrade soil prior to placement of steel and concrete will likely be recommended and necessary, in order to achieve optimum moisture conditions. Soil moisture contents should be verified at least 72 hours prior to pouring concrete. CONVENTIONAL RETAINING WALL RECOMMENDATIONS General The design parameters provided below assume that very low expansive soils are used to backfill any standard retaining walls (i.e. no specialty walls, including crib walls, earthstone walls). The equivalent fluid pressure parameters provide for the use of very low expansive select granular backfill to be utilized behind the proposed walls. The very low expansive granular backfill should be provided behind the wall at a 1:1 (h:v) projection from the heel of the foundation system. Very low expansive fill is Class 3 aggregate baserock or Class 2 permeable rock. Wall backfilling should be performed with relatively light equipment within the same 1:1 projection (i.e., hand tampers, walk behind compactors). Highly expansive soils should not be used to backfill any proposed walls. During construction, materials should not be stockpiled behind nor in front of walls for a distance of 2H where H is the height of the wall. Foundation systems for any proposed retaining walls should be designed in accordance with the recommendations presented in the Foundation Design section of this report. Building walls, below grade, should be water-proofed or damp-proofed, depending on the degree of moisture protection desired. All walls should be properiy designed in accordance with the recommendations presented below. Some movement of the walls constructed should be anticipated as soil strength parameters are mobilized. This movement could cause some cracking depending upon the materials used to construct the wall. To reduce the potential for wall cracking, walls should be internally grouted and reinforced with steel. To mitigate this effect, the use of Randall K. Lockett W.O. 3111-A-SC 391 Tamarack Avenue August 31, 2001 File: e:\wp7\3100\3111 a.pge Page 18 GcoSoils, Inc. vertical crack control joints and expansion joints, spaced at 20 feet or less along the walls should be employed. Vertical expansion control joints should be infilled with a flexible grout. Wall footings should be keyed or doweled across vertical expansion joints. Walls should be internally grouted and reinforced with steel. Restrained Walls Any retaining walls that will be restrained prior to placing and compacting backfill material or that have re-entrant or male corners, should be designed for an at-rest equivalent fiuid pressures (EFP) of 65 pcf, plus any applicable surcharge loading. Expansive soils should not be used as backfill, only granular (very low expansive) backfill should be used. For areas of male or re-entrant corners, the restrained wall design should extend a minimum distance of twice the height of the wall laterally from the corner. Building walls below grade or greater than 2 feet in height should be water-proofed or damp-proofed, depending on the degree of moisture protection desired. The wall should be drained as indicated in the following section. For structural footing loads within the 1:1 zone of influence behind wall backfill, refer to the following section. Cantilevered Walls These recommendations are for cantilevered retaining walls up to 10 feet high. Active earth pressure may be used for retaining wall design, provided the top of the wall is not restrained from minor deflections. An empirical equivalent fluid pressure approach may be used to compute the horizontal pressure against the wall. Appropriate fluid unit weights are provided for specific slope gradients of the retained material. These do not include other superimposed loading conditions such as traffic, structures, seismic events, expansive soils, or adverse geologic conditions. If traffic is within a distance H behind any wall or a 1:1 projection from the heel of the wall foundation a pressure of 100 psf per foot in the upper 5 feet should be used. Structural loads ft'om adjacent properties and their influence on site walls should be reviewed by the structural engineer, if within a 1:1 projection behind any site wall. However, for preliminary planning purposes, one third of the footing contact pressure should be added to the wall in pounds per square foot below the bearing elevation and for a distance ofthree times the footing width along the wall alignment. Alternatively, a deepened footing beyond the 1:1 projection (up from the heel) behind the wall may be utilized. Wall Backfill and Drainage All retaining walls should be provided with an adequate backdrain and outlet system (a minimum two outlets per wall and no greater than 100 feet apart), to prevent buildup of hydrostatic pressures and be designed in accordance with minimum standards presented herein. See site wall drain options (Figure 3, Figure 4, and Figure 5). Drain pipe should Randall K. Lockett W.O. 3111 -A-SC 391 Tamarack Avenue August 31, 2001 File: e:\wp7\3100\3111a.pge Page 19 GcoSoils, Inc. Cop drain (cut off) 18" below soil line Waterproofing Manufactured drainage Geocomposite drain ( Mira drain 5000 equivalent ) Note: Filter fabric wraps completely aroijnd perforated pipe and behind core material, core material wraps beneath bottom of pipe. 4" dio. min. perforated pipe placed with holes down and sloped at 1-2% to suitable outlet 4 min. granular material — (class 2 permeable or 3/8-1" clean crushed rock wrapped in a filter fabric) Site retaining wall (structural design by others) Pavement section per t>SI recommendations — Parking lot surface i—Wall footing (designed by others) LOS ANGELES CO. RIVERSIDE CO. ORANGE CO. SAN OIEGO CO. ^SCHEMATIC OF SITE WALL DRAIN OPTION A Figure 3 w.o.. 3111-A-SC DATE 8/01 SCALE Kone 12 thick (min.) drain rock (class 2 permeable) or other acceptable granular material. 1/8-1" clean crushed rock wrapped in a filter fabric (Mirafi 140 or* equivalent) 4 dia. min. perforated pipe placed with holes down and sloped at 1-2% to a suitable outlet 1-" Min. —J Cap drain (cut off) 18' below soil line -Site retaining wall (structural design by others) Pavement section per GSI recomendations — Parking lot -surface 3 -VQU footing (designed by others) T LOS ANGELES CO. RIVERSIDE CO. ORANGE CO. SAN DEGO CO. ^SCHEMATIC OF SITE WALL DRAIN OPTION B Figure 4 w.o. 3111-A-SC DATE 8/01 SCALE rfone If^ finished surface is within 8 of top of footing wall drains shall be at 6' intervals along the length of the wall and located at the level of the bottom course of block. The drains shall be 4" in diameter 24" thick (min.) drain rock (class 2 permeable) or other acceptable granular material. 1/8-1" clean crushed rock wrapped in o filter fabric (Mirafi 140 or equivalent) Waterproofing X '4 • * tJ , • • » Cop drain (cut 18' below soii off) line -Site retaining wall (structural design by others) Pavement section per GSI recomendations •4" dia. pipe Parking lot surface , ».1o o, /'•«>, o» i . 4 * I ^ ' : rz 1 I -VQU. footing Cdesigned by others) LOSANGELES CO. RIVERSIDE CO. ORANGE CO. SAN DIEGO CO. SCHEMATIC OF SITE WALL DRAIN OPTION 0 Figure 5 consist of 4-inch diameter perforated schedule 40 PVC pipe embedded in gravel. Gravel used in the backdrain systems should be a minimum of 3 cubic feet per lineal foot of %- to 1-inch clean crushed rock wrapped in filter fabric (Mirafi 140 or equivalent) and 12 inches thick behind the wall. Where the void to be fitted is constrained by lot lines or property boundaries, the use of panel drains (Mirafi 5000 or equivalent) may be considered with the approval ofthe project geotechnical engineer. The surface ofthe backfill should be sealed by pavement or the top 18 inches compacted to 90 percent relative compaction with native soil. Proper surface drainage should also be provided. Weeping ofthe walls in lieu of a backdrain is not recommended for walls greater than 2 feet in height. For walls 2 feet or less in height, weepholes should be no greater than 6 feet on center in the bottom coarse of block and above the landscape zone. A paved drainage channel (v-ditch or substitute), either concrete or asphaltic concrete, behind the top of the walls with sloping backfill should be considered to reduce the potential for surface water penetration. For level backfill, the grade should be sloped such that drainage is toward a suitable outlet at 1 to 2 percent. Retaining Wall Footing Transitions Site walls are anticipated to be founded on footings designed in accordance with the recommendations in this report. Wall footings may transition from sedimentary bedrock to select fill. If this condition is present the civil designer may specify either: a) If transitions ft'om rock fill to select fill transect the wall footing alignment at an angle of less than 45 degrees (plan view), then the designer should perform a minimum 2-foot overexcavation for a distance of two times the height of the wall and increase overexcavation until such transition is between 45 and 90 degrees to the wall alignment. b) Increase of the amount of reinforcing steel and wall detailing (i.e., expansion joints or crack control joints) such that an angular distortion of 1/360 for a distance of 2H (where H=wall height in feet) on either side of the transition may be accommodated. Expansion joints should be sealed with a flexible, non-shrink grout. c) Embed the footings entirely into a homogeneous fill. FLATWORK AND ASSOCIATED IMPROVEMENTS 1. Planters and walls should not be tied to building(s). 2. Driveways, sidewalks, and patios adjacent to the building(s) should be separated from the building(s) with thick expansion joint filler material. In addition, all Randall K. Lockett ~ W.O. 3111-A-SC 391 Tamarack Avenue August 31, 2001 File: e:\wp7\3100\3111 a.pge Page 23 GcoSoils, Inc. sidewalks and driveways should be quartered and poured with expansion joints no farther apart than 8 feet for 4-inch slabs or 10 feet for 5-inch slabs, respectively. Consideration should additionally be given for the areas of the driveways and sidewalks adjacent to planters, lawns, and other landscape areas to have thickened edges, such that the edge is 4 to 6 inches thick and at least 6 inches below the adjacent landscaping zone (section). 3. Overhang structures should be structurally designed with continuous footings or grade beams tied in at least two directions. Footings that support overhang structures should be embedded a minimum of 24 inches from the lowest adjacent finished subgrade. 4. Any masonry landscape walls that are to be constructed throughout the property should be fully grouted and articulated in segments no more than 20 feet long. 5. Utilities should be enclosed within a closed vault or designed with flexible connections to accommodate differential settlement and expansive soil conditions. 6. Finish grade (Precise Grade Plan) on the lot should provide a minimum of 1 to 2 percent fall to the street. It should be kept in mind that drainage reversals could occur if relatively flat yard drainage gradients are not maintained due to landscaping work, modiflcations to flatwork, or post-sale owner modifications. Tile Flooring Tile flooring can crack, reflecting cracks in the concrete slab below the tile. Therefore, the designer should consider additional steel reinforcement of 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) is recommended between tile and concrete slabs on grade. Gutters and Downspouts Consideration should be given to the installation of gutters and downspouts to collect roof water that may otherwise infiltrate the soils adjacent to the structures. The downspouts should be drained away from the foundation and collected in drainage swales or other approved non-erosive drainage systems designed by a registered civil engineer (specializing in drainage) to convey water away from the foundation. Gutters and downspouts are not a geotechnical requirement, however, provided positive drainage is maintained in accordance with the recommendations of the design civil engineer. Randall K. Lockett W.O. 3111 -A-SC 391 Tamarack Avenue August 31, 2001 File: e:\wp7\3100\3111 a.pge Page 24 GcoSoils, Inc. Exterior Slabs and Walkways Exterior concrete slab on grade construction should be designed and constructed in accordance with the following criteria: 1. Driveway pavement and all other exterior flatwork should be a minimum 4 inches thick. A thickened edge should be considered for all flatwork adjacent to irrigated and landscape areas. 2. Slab subgrade should be scarified, moisture conditioned and compacted to a minimum 90 percent relative compaction. Subgrade should be moisture conditioned based on the representative expansion potential of the subgrade exposed (i.e. at or above optimum for low expansive. The subgrade moisture content should be maintained until the slab is poured. 3. The use of transverse and longitudinal control joints should be considered to help control slab cracking due to concrete shrinkage or expansion. Two of the best ways to control this movement is; 1) add a sufficient amount of reinforcing steel, increasing tensile strength of the slab, and/or 2) provide an adequate amount of control and/or expansion joints to accommodate anticipated concrete shrinkage and expansion. 4. No traffic should be allowed upon the newly poured concrete slabs until they have been properiy cured to within 75 percent of design strength. 5. Positive site drainage should be maintained at all times. Adjacent landscaping should be graded to drain into the street, parking area, or other approved area. All surface water should be appropriately directed to areas designed for site drainage. 6. Concrete compression strength should be a minimum of 2,500 psi. ADDITIONAL RECOMMENDATIONS/DEVELOPMENT CRITERIA Additional Site Improvements If in the ftjture, any additional improvements are planned for the site, recommendations concerning the geological or geotechnical aspects of design and construction of said improvements could be provided upon request this includes but not limited to appurtenant structures. This office should be notified in advance of any additional fill placement, regrading of the site, or trench backfilling after rough grading has been completed. This includes any grading, utility trench, and retaining wall backfills. Randall K. Lockett W.O. 3111-A-SC 391 Tamarack Avenue August 31, 2001 Rle: e:\wp7\3100\3111a.pge Page 25 GcoSoils, Inc. Landscape Maintenance and Planting Water has been shown to weaken the inherent strength of soil, and slope stability is significantly reduced by overly wet conditions. Positive surface drainage away ft'om graded slopes should be maintained and only the amount of irrigation necessary to sustain plant life should be provided for planted slopes. Over-watering should be avoided. Onsite soil materials should be maintained in a solid to semisolid state. Brushed native and graded slopes (constructed within and utilizing onsite materials) would be potentially erosive. Eroded debris may be minimized and surficial slope stability enhanced by establishing and maintaining a suitable vegetation cover soon after construction. Plants selected for landscaping should be light weight, deep rooted types that require little water and are capable of surviving the prevailing climate. Planting of large trees with potential for extensive root development should not be placed closer than 10 feet from the perimeter of the foundation or the anticipated height of the mature tree, whichever is greater. It order to minimize erosion on the slope face, an erosion control fabric (i.e. jute matting) should be considered. From a geotechnical standpoint, leaching is not recommended for establishing landscaping. If the surface soils area processed for the purpose of adding amendments they should be recompacted to 90 percent minimum relative compaction. Moisture sensors, embedded into fill slopes, should be considered to reduce the potential of overwatering from automatic landscape watering systems. The use of certain fertilizers may affect the corrosion characteristics of soil. Review of the type and amount (pounds per acre) of the fertilizers by a corrosion specialist should be considered. Recommendations for exterior concrete flatwork design and construction can be provided upon request. If in the future, any additional improvements are planned for the site, recommendations concerning the geological or geotechnical aspects of design and construction of said improvements could be provided upon request. This office should be notified in advance of any additional fill placement, regrading of the site, or trench backfilling after rough grading has been completed. This includes any grading, utility trench, and retaining wall backfills. Drainage Positive site drainage should be 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. Pad drainage should be directed toward the street or other approved area. Landscaping should be graded to drain into the street, or other approved area. All surface water should be appropriately directed to areas designed for site drainage. Randall K. Lockett W.O. 3111 -A-SC 391 Tamarack Avenue August 31, 2001 File: e:\wp7\3100\3111 a.pge Page 26 GcoSoils, Inc. Roof gutters and down spouts are recommended to control roof drainage. Down spouts should outlet a minimum of 5 feet firom proposed structures or tightiined into a subsurface drainage system. We 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 away ft'om structures or any exterior concrete flatwork. Drainage behind top of walls should be accomplished along the length of the wall with a paved channel drainage v-ditch or substitute. Footing Trench Excavation All footing trench excavations should be observed and approved by a representative ofthis office prior to placing reinforcement. 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. Trench Backfill All excavations should be observed by one of our representatives and conform to OSHA and local safety codes. Exterior trenches should not be excavated below a 1:1 projection from the bottom of any adjacent foundation system. If excavated, these trenches may undermine support for the foundation system potentially creating adverse conditions. 1. All utility trench backfill in slopes, structural areas and beneath hardscape features should be brought to near optimum moisture content and then compacted to obtain a minimum relative compaction of 90 percent of the laboratory standard. Observations, probing and, if deemed necessary, testing should be performed by a representative of this office to verify compactive efforts of the contractor. 2. Soils generated from utility trench excavations should be compacted to a minimum of 90 percent (ASTM D-1557) if not removed from the site. 3. Jetting of backfill is not recommended. 4. The use of pipe jacking to place utilities is not recommended on this site due to the presence of gravels and cobbles. 5. Bottoms of utility trenches should be sloped away from structures. Randall K. Lockett W.O. 3111 -A-SC 391 Tamarack Avenue August 31, 2001 File: e:\wp7\3100\3111 a.pge Page 27 GcoSoils, Inc. PLAN REVIEW Final site development and foundation plans should be submitted to this office for review and comment, as the plans become available, for the purpose of minimizing any misunderstandings between the plans and recommendations presented herein. In addition, foundation excavations and any additional earthwork construction performed on the site should be observed and tested by this office. If conditions are found to differ substantially from those stated, appropriate recommendations would be offered at that time. LIMITATIONS The materials encountered on the project site and utilized in our laboratory study are believed representative ofthe area; however, soil and bedrock materials vary in character between excavations and natural outcrops or conditions exposed during site grading, construction, and our post-grading study. Site conditions may vary due to seasonal changes or other factors. GSI assumes no responsibility or liability for work, testing, or recommendations performed or provided by others. Inasmuch as our study is based upon the site materials observed, selective laboratory testing and engineering analysis, the conclusion and recommendations are professional opinions. These opinions have been derived in accordance with current standards of practice, and no warranty is expressed or implied. Standards of practice are subject to change with time. During the field exploration phase of our study, odors or stained or discolored soils were not observed onsite or in our test pits or test pit spoils. However, these observations were made during our preliminary geotechnical study and should in no way be used in lieu of an environmental assessment. If requested, a proposal for a phase I preliminary environmental assessment could be provided. Randall K. Lockett W.O. 3111 -A-SC 391 Tamarack Avenue August 31, 2001 File: e:\wp7\3100\3111a.pge Page 28 GcoSoils, Inc. APPENDIX A REFERENCES APPENDIXA REFERENCES Blake, Thomas F., 1998, EQFAULT computer program and users manual for the deterministic prediction of horizontal accelerations from digitized California faults. Campbell, K.W. and Bozorgnia, Y., 1994, Near-Source attenuation of peak horizontal acceleration ft'om woridwide accelerograms recorded from 1957 to 1993: Proceedings, Fifth U.S. National Conference on Earthquake Engineering, vol. Ill, Earthquake Engineering Research Institute, pp. 293-292. Frankel, Arthur D., Perkins, David M., and Mueller, Charies S., 1996, Preliminary and working versions of draft 1997 seismic shaking maps for the United States showing peak ground acceleration (PGA) and spectral acceleration response at 0.3 and 1.0-second site periods for the Design Basis Earthquake (10 percent chance of exceedance in 50 years) for the National Earthquake Hazards Reduction Program (NEHRP): U.S. Geological Survey, Denver, Colorado. GeoSoils, Inc., Proprietary in-house information Greensfelder, R. W., 1974, Maximum credible rock acceleration from earthquakes in California: California Division of Mines and Geology, Map Sheet 23. Hart, E.W. and Bryant, W. A., 1997, Fault-rupture hazard zones in California: California Department of Consen/ation, Division of Mines and Geology, Special Publication 42. Housner, G. W., 1970, Strong ground motion in earthquake engineering, Robert Wiegel, ed., Prentice-Hall. International Conference of Building Officials, 1997, Uniform building code: Whittier, California, vol. 1, 2, and 3. Jennings, C.W., 1994, Fault activity map of California and adjacent areas: California Division of Mines and Geology, Map Sheet No. 6, scale 1:750,000. Joyner, W.B, and Boore, D.M., 1982a, Estimation of response-spectral values as functions of magnitude, distance and site conditions, in Johnson, J.A., Campbell, K.W., and Blake, eds., T.F., AEG Short Course, Seismic Hazard Analysis, June 18, 1994. , 1982b, Prediction of earthquake response spectra, in Johnson, J.A., Campbell, K.W., and Blake, eds., T.F., AEG Short Course, Seismic Hazard Analysis, June 18, 1994. GcoSoils, Inc. Krinitzsky, Ellis L, Gould, J.P., and Edinger, P.H., 1993, Fundamentals of earthquake resistant construction: John H. Wiley & Sons, Inc., 299 p. Kuhn, G.G., Legg, M.R., Johnson, J.A., Shiemon, R.G., and Frost, E.G., 1996, Paleo- liquefaction evidence for large pre-historic earthquakes(s) in north-coastal San Diego County, California, in Munasinghe, T., and Rosenberg, eds.. Geology and natural resources of coastal San Diego County, California, guidebook to accompany the 1996 annual field trip of the San Diego Association of Geologists, September. Obermeier, S.F., 1996, Using liquefaction-induced features for paleoseismic analysis, Chapter 7, in McCalpin, J.P., ed, Paleoseismology, Acedemic Press Petersen, Mark D., Bryant, W.A., and Cramer, C.H., 1996, Interim table of fault parameters used by the California Division of Mines and Geology to compile the probabilistic seismic hazard maps of California. Sadigh, K, Egan, J., and Youngs, R., 1987, Predictive ground motion equations reported in Joyner, W.B., and Boore, D.M., 1988, "Measurement, characterization, and prediction of strong ground motion", in Earthquake Engineering and Soil Dynamics II, Recent Advances in Ground Motion Evaluation, Von Thun, J.L., ed.: American Society of Civil Engineers Geotechnical Special Publication No. 20, pp. 43-102. Sowers and Sowers, 1979, Unified soil classification system (After U. S. WatenA/ays Experiment Station and ASTM 02487-667) in Introductory Soil Mechanics, New York. Tan, S.S and Kennedy, M.P., 1996, Geologic maps ofthe Northwestern part of San Diego County, California, DMG Open-File Report 96-02. United States Department of Agriculture, 1953, Black and white high altitude stereo photgraphs, AXN-14M-19 and -21. United States Geological Survey, 1968, San Luis Rey quadrangle, California - San Diego Co., 7.5 minute series (topographic), photo revised 1975. Weber, Harold F., 1982, Geologic map ofthe central-north coastal area of San Diego County, California, showing recent slope failures and pre-development landslides: United States Geologic Survey, Open-File Report 82-12. Randall K. Lockett Appendix A Rle: e:\wp7\3100\3111a.pge Page 2 GcoSoils, Inc. APPENDiX B BORING LOGS BORING LOG GeoSoils, Inc. P/?OJ£Cr; RANDALL LOCKETT 391 TAMARACK AVE. W.O. 3111-A-SC BORING B- 1 +-a. o a Sample I TJ 0 01 - n T3 L C 3 D -1- \ 01 3 O o M n U E 3 M SM 3 L a o L 3 4-01 O L 3 +• (0 M DyATTfXC/IVylT-fD SAMPLE METHOD: HAND AUGER SHEET_±_OF 1 8-10-01 Standard Penetration Test Undisturbed, Ring Sample Water Seepage into hole Description of Material @0' - FILL: Silty fine SAND, brown, dry, loose; fine grained. 5- 10- 15 20- 25 SM 102 4 14.0 @2' - WEATHERED TERRACE DEPOSITS: Silty fine SAND, \red brown, damp, medium dense. Total Depth: 2 1/2' No groundwater encountered Backfilled 08/10/01 391 TAMARACK AVE. GeoSoils, Inc. PLATE B-1 GeoSoils, Inc. P/?0.y£Cr; RANDALL LOCKETT 391 TAMARACK AVE. Q. 01 a Sample I Tl ttl a - n •D L C 3 3 +• 10- 15- 20- \ 3 0 o (A n U E W 3 3 W SM 25 3 L O O 391 TAMARACK AVE. (0 L 3 4-(0 (0 BORING LOG w.o. 3111-A-SC BORING B- 2 o/ir£fxc>iv/irfD SAMPLE METHOD: HAND AUGER SHEETJ[_PF 1 8-10-01 Standard Penetration Test Undisturbed, Ring Sample Water Seepage into hole Description of Material (5)0' - WEATHERED TERRACE DEPOSITS: Silty fine SAND, red brown, dry, medium dense; fine grained. \@^ 1/2' - As per 0', damp to moist, medium dense. Total Depth: 1 1/2' No groundwater encountered Backfilled 08/10/01 GeoSoils, Inc. PLATE B-2 GeoSoils, Inc. BORING LOG w.o. 3111-A-SC PROJECT: RANDALL LOCKETT 391 TAMARACK AVE. BORING B- 3 +- a ffi D- Sample I Tl U ffi - n XI L C 3 \ 01 3 o o CO Q U E Vt 3 3 W 3 L a o L 3 +- (0 M DATE EXCAVATED SAMPLE METHOD: HAND AUGER SHEET 1 OF 1 8-10-01 Standard Penetration Test Undisturbed, Ring Sample ^ Wafe/" Seepage into hole Description of Material SM 5- 10- 15- 20- 25 @0' - WEATHERED TERRACE DEPOSITS: Silty SAND, red brown, dry, medium dense; fine grained. Total Depth: 2' No groundwater encountered Backfilled 08/10/01 391 TAMARACK AVE. GeoSoils, Inc. PLATE B-3 BORING LOG GeoSoils, Inc. PROJECT: RANDALL LOCKETT 391 TAMARACK AVE. W.O. 3111-A-SC BORING B- 4 DATE EXCAVATED SAMPLE METHOD: HAND AUGER SHEET 1 OF 1 8-10-01 Standard Penetration Test Undisturbed, Ring Sample ^ Water Seepage into hole Description of Material g&O' - FILL (Garden): Silty SAND, red brown, moist, loose. @2' - Tiny pieces of asphalt. (5)2.5' - WEATHERED TERRACE DEPOSITS: Silty SAND, red brown, very moist, medium dense. Total Depth: 4' No groundwater encountered Backfilled 08/10/01 391 TAMARACK AVE GeoSoils, Inc. PLATE B-4 APPENDIX C LABORATORY TEST RESULTS M. J. Schiff & Associates, Inc. Consulting Corrosion Engineers - Since 1959 1308 Monte Vista Avenue, Suite 6 Upland, CA 91786-8224 Phone: 909/931-1360 Table 1 - Laboratory Tests on Soil Samples Locken Your UrSni-A-SC, MJS&A #01-0705LAB 16-Aug-Ol Sample ID Resistivity as-received saturated pH Electrical Conductivity Chemical Analyses • 2. Units ohm-cm ohm-cm mS/cm 53,000 3,450 7.2 0.14 Cations calcium Ca^" mg/kg 56 magnesium Mg^" mg/kg 7 sodium Na'" mg/kg ND Anions carbonate C03^" mg/kg ND bicarbonate HCO3' mg/kg 67 chloride ci'-mg/kg 20 sulfate S04'" mg/kg ND er Tests ammonium NH4'" mg/kg na nitrate NOJ'' mg/kg na sulfide qual na Redox mv na il^ti 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 Page 1 of 1 Plate C-1 APPENDiX D 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, placement of fill, installation of subdrains and excavations. The recommendations contained in the geotechnical report are part ofthe earthwork and grading guidelines and would supersede the provisions contained hereafter in the case of conflict. Evaluations performed by the consultant during the course of grading may resuft in new recommendations which could supersede these guidelines or the recommendations contained in the geotechnical report. The contractor is responsible for the satisfactory completion of all earthwork in accordance with provisions of the project plans and speciflcations. The project soil engineer and engineering geologist (geotechnical consultant) or their representatives should provide observation and testing services, and geotechnical consultation during the duration of the project. EARTHWORK OBSERVATIONS AND TESTING Geotechnical Consultant Priorto the commencement of grading, a qualified geotechnical consultant (soil engineer and engineering geologist) should be employed for the purpose of observing earthwork procedures and testing the fills for conformance with the recommendations of the geotechnical report, the approved grading plans, and applicable grading codes and ordinances. The geotechnical consultant should provide testing and observation so that determination may be made that the work is being accomplished as specified. It is the responsibility of the contractor to assist the consultants and keep them apprised of anticipated work schedules and changes, so that they may schedule their personnel accordingly. All clean-outs, prepared ground to receive fill, key excavations, and subdrains should be obsen/ed and documented by the project engineering geologist and/or soil engineer prior to placing and fill. It is the contractors's responsibility to notify the engineering geologist and soil engineer when such areas are ready for observation. Laboratorv and Field Tests Maximum dry density tests to determine the degree of compaction should be performed in accordance with American Standard Testing Materials test method ASTM designation D-1557-78. Random field compaction tests should be performed in accordance with test method ASTM designation D-1556-82, D-2937 or D-2922 and D-3017, at intervals of approximately 2 feet of fill height or every 100 cubic yards of fill placed. These criteria GcoSoils, Inc. would vary depending on the soil conditions and the size of the project. The location and frequency of testing would be atthe discretion ofthe 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 of the soil engineer. The contractor should also remove all major non- earth material considered unsatisfactory by the soil engineer. It is the sole responsibility ofthe 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 properiy 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 processing cannot adequately improve the condition should be overexcavated down to Randall K. Lockett Appendix D Rle: e:\wp7\3100\3111 a.pge Page 2 GcoSoils, Inc. firm ground and approved by the soil engineer before compaction and filling operations continue. Overexcavated and processed soils which have been properiy 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 ofthe 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 othenwise by the Soil Engineer, the minimum width of fill keys should be approximately equal to V2 the height ofthe 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 ofthe bench may exceed 4 feet. Pre-stripping may be considered for unsuitable materials in excess of 4 feet in thickness. All areas to receive fill, including processed areas, removal areas, and the toe of fill benches should be observed and approved by the soil engineer and/or engineering geologist prior to placement of fill. Fills may then be properiy placed and compacted until design grades (elevations) are attained. COMPACTED FILLS Any earth materials imported or excavated on the property may be utilized in the fill provided that each material has been determined to be suitable 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 Randall K. Lockett Appendix D File: e:\wp7\3100\3111 a.pge Page 3 GcoSoils, Inc. 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 greaterthan 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 ofthe soil engineer in areas designated as suitable for rock disposal. Oversized material should not be placed within 10 feet vertically of finish grade (elevation) or within 20 feet horizontally of slope faces. To facilitate future trenching, rock should not be placed within the range of foundation excavations, ftjture 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 ofthis material should be conducted by the soil engineer as soon as possible. Approved fill material should be placed in areas prepared to receive fill in near horizontal layers that when compacted should not exceed 6 inches in thickness. The soil engineer may approve thick lifts if testing indicates the grading procedures are such that adequate compaction is being achieved with lifts of greater thickness. Each layer should be spread evenly and blended to attain uniformity of material and moisture suitable for compaction. Fill layers at a moisture content less than optimum should be watered and mixed, and wet fill layers should be aerated by scarification or should be blended with drier material. Moisture condition, blending, and mixing of the fill layer should continue until the fill materials have a uniform moisture content at or above optimum moisture. After each layer has been evenly spread, moisture conditioned and mixed, it should be uniformly compacted to a minimum of 90 percent of maximum density as determined by ASTM test designation, D-1557-78, or as otherwise recommended 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. Randall K. Lockett Appendix D File: e:\wp7\3100\3111 a.pge Page 4 GcoSoils, Inc. 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 observation and/or testing of the finished slope face. Where compacted fill slopes are designed steeper than 2:1 (horizontal to vertical), specific material types, a higher minimum relative compaction, and special grading procedures, may be recommended. If an alternative to over-building and cutting back the compacted fill slopes is selected, then special effort should be made to achieve the required compaction in the outer 10 feet of each lift of fill by undertaking the following: 1. An extra piece of equipment consisting of a heavy short shanked sheepsfoot should be used to roll (horizontal) parallel to the slopes continuously as fill is placed. The sheepsfoot roller should 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 achieve compaction to the slope face. Final testing should be used to confirm compaction after grid rolling. 5. Where testing indicates less than adequate compaction, the contractor will be responsible to rip, water, mix and re-compact the slope material as necessary to achieve compaction. Additional testing should be performed to verify compaction. Randall K. Lockett Appendix D File: e:\wp7\3100\3111 a.pge Page 5 GcoSoils, Inc. 6. Erosion control and drainage devices should be designed by the project civil engineer in compliance with ordinances ofthe controlling governmental agencies, and/or in accordance with the recommendation ofthe soil engineer or engineering geologist. SUBDRAIN INSTALLATION Subdrains should be installed in approved ground in accordance with the approximate alignment and details indicated by the geotechnical consultant. Subdrain locations or materials should not be changed or modified without approval of the geotechnical consultant. The soil engineer and/or engineering geologist may recommend and direct changes in subdrain line, grade and drain material in the field, pending exposed conditions. The location of constructed subdrains should be recorded by the project civil engineer. EXCAVATIONS Excavations and cut slopes should be examined during grading by the engineering geologist. If directed by the engineering geologist, further excavations or overexcavation and re-filling of cut areas should be performed and/or remedial grading of cut slopes should be performed. When fill over cut slopes are to be graded, unless othenrt/ise approved, the cut portion of the 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 notified by the contractor when cut slopes are started. If, during the course of grading, unforeseen adverse or potential adverse geologic conditions are encountered, the engineering geologist and soil engineer should investigate, evaluate and make recommendations to treat these problems. The need for cut slope buttressing or stabilizing should be based on in-grading evaluation by the engineering geologist, whether anticipated or not. Unless OthenA/ise specified in soil and geological reports, no cut slopes should be excavated higher or steeper than that allowed by the ordinances of controlling governmental agencies. Additionally, short-term stability of temporary cut slopes is the contractors responsibility. Erosion control and drainage devices should be designed by the project civil engineer and should be constructed in compliance with the ordinances ofthe controlling governmental agencies, and/or in accordance with the recommendations of the soil engineer or engineering geologist. Randall K. Lockett Appendix D File: e:\wp7\3100\3111 a.pge Page 6 GcoSoils, Inc. COMPLETION Obsen/ation, testing and consultation bythe geotechnical consuftant should be conducted during the grading operations in order to state an opinion that all cut and filled areas are graded in accordance with the approved project specifications. After completion of grading and after the soil engineer and engineering geologist have finished their observations of the work, final reports should be submitted subject to review by the controlling governmental agencies. No further excavation or filling should be undertaken without prior notification 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 specifications and/or as recommended by a landscape architect. Such protection and/or planning should be undertaken as soon as practical after completion of grading. JOB SAFETY General At GeoSoils, Inc. (GSI) getting the job done safely is of primary concern. The following is the company's safety considerations for use by all employees on multi-employer construction sites. On ground personnel are at highest risk of injury and possible fatality on grading and construction projects. GSI recognizes that construction activities will vary on each site and that site safety is the prime responsibility of the contractor; however, everyone must be safety conscious and responsible at all times. To achieve our goal of avoiding accidents, cooperation between the client, the contractor and GSI personnel must be maintained. In an effort to minimize risks associated with geotechnical testing and observation, the following precautions are to be implemented for the safety of field personnel on grading and construction projects: Safety Meetings: GSI field personnel are directed to attend contractors regularly scheduled and documented safety meetings. Safety Vests: Safety vests are provided for and are to be worn by GSI personnel at all times when they are working in the field. Safety Flags: Two safety fiags 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. Randall K. Lockett Appendix D File: e:\wp7\3100\3111a.pge Page 7 GcoSoils, Inc. Flashing Lights: All vehicles stationary in the grading area shall use rotating or flashing amber beacon, or strobe lights, on the vehicle during all fleld testing. While operating 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 attention of our office. Test Pits Location, Orientation and Clearance The technician is responsible for selecting test pit locations. A primary concern should be the technicians's safety. Efforts will be made to coordinate locations with the grading contractors authorized representative, and to select locations following or behind the established traffic pattern, preferably outside of current traffic. The contractors authorized representative (dump man, operator, supervisor, grade checker, etc.) should direct excavation ofthe pit and safety during the test period. Of paramount concern should be the soil technicians safety and obtaining enough tests to represent the fill. Test pits should be excavated so that the spoil pile is placed away form oncoming traffic, whenever possible. The technician's vehicle is to be placed next to the test pit, opposite the spoil pile. This necessitates the fill be maintained in a driveable condition. Alternatively, the contractor may wish to park a piece of equipment in front of the test holes, particulariy in small fill areas or those with limited access. A zone of non-encroachment should be established for all test pits. No grading equipment should enter this zone during the testing procedure. The zone should extend approximately 50 feet outward ft'om the center of the test pit. This zone is established for safety and to avoid excessive ground vibration which typically decreased test results. When taking slope tests the technician should park the vehicle directly above or below the test location. If this is not possible, a prominent flag should be placed at the top of the slope. The contractor's representative should effectively keep all equipment at a safe operation distance (e.g. 50 feet) away from the slope during this testing. The technician is directed to withdraw ft'om the active portion of the fill as soon as possible following testing. The technician's vehicle should be parked at the perimeter of the fill in a highly visible location, well away from the equipment traffic pattern. The contractor should inform our personnel of all changes to haul roads, cut and fill areas or other factors that may affect site access and site safety. In the event that the 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 Randall K. Lockett Appendix D Rle: e:\wp7\3100\311 la.pge Page 8 GcoSoils, Inc. interim, no ftjrther testing will be performed until the situation is rectified. Any fill place can be considered unacceptable and subject to reprocessing, recompaction or removal. In the event that the soil technician does not comply with the above or other established safety guidelines, we request that the contractor brings this to his/her attention and notify this office. Effective communication and coordination between the contractors representative and the soils technician is strongly encouraged in order to implement the above safety plan. Trench and Vertical Excavation It is the contractor's responsibility to provide safe access into trenches where compaction testing is needed. Our personnel are directed not to enter any excavation or vertical cut which 1) is 5 feet or deeper unless shored or laid back, 2) displays any evidence of instability, has any loose rock or other debris which could fall into the trench, or 3) displays any other evidence of any unsafe conditions regardless of depth. All trench excavations or vertical cuts in excess of 5 feet deep, which any person enters, should be shored or laid back. Trench access should be provided in accordance with CAL-OSHA and/or state and local standards. Our personnel are directed not to enter any trench by being lowered or "riding down" on the equipment. If the contractor fails to provide safe access to trenches for compaction testing, our company policy requires that the soil technician withdraw and notify his/her supervisor. The 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 excavation, we have a legal obligation to put the contractor and owner/developer on notice to immediately correct the situation. If corrective steps are not taken, GSI then has an obligation to notify CAL-OSHA and/or the proper authorities. Randall K. Lockett Appendix D File: e:\wpA3100\311 la.pge Page 9 GcoSoils, Inc. CANYON SUBDRAIN DETAIL TYPE A PROPOSED COMPACTED FILL NATURAL GROUND COLLUVIUM AND ALLUVIUM IREMOVE) TYPICAL BENCHING "^^^^ ^ y\\V/ BEDROCK SEE ALTERNATIVES TYPE B \ N N PROPOSED COMPACTED RLL •NATURAL GROUND COLLUVIUM AND ALLUVIUM (REMOVE) BEDROCK lr TYPICAL BENCHING 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 AND FILTER MATERIAL A-1 MINIMUM 12' MINIMUM FILTER MATERIAL MINIMUM VOLUME OF 9 FT." -^i,-. /LINEAR FT. 6'i ABS OR PVC PIPE OR APPROVED ^''.V: SUBSTITUTE WITH MINIMUM 8 (1/A" (T) PERFS. ^'.'.'S LINEAR FT. IN BOTTOM HALF OF PIPE. \^ ASTM D2751. SDR 35 OR ASTM D1527. SCHD, .40 ASTM D3Q3A. SDR 35 OR ASTM D1785. SCHD. AO FOR CONTINUOUS RUN IN EXCESS OF 500 FT. USE8"JBfPIPE MINIMUM FILTER MATERIAL. SIEVE SIZE PERCENT PASSING IINCH .100 3/4 INCH ^°"''95 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. 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 COMPACTED RLL ORIGINAL GROUND SURFACE r ANTICIPATED ALLUVIAL REMOVAL DEPTH PER SOIL ENGMEER. BACKCUTV-VARIES. FOR DEEP REMOVALS.^ BACKCUT ^VKSHOULD BE MADE NO ^ STEEPER THAI^SI:! OR AS NECESSARY FOR SAFETY ^.^^ONSIDERATIONS^'^ '^v//^lP^ PROVIDE A 1:1 MINIMUM PROJECTION FROM TOE OF SLOPE AS SHOWN ON GRADING PLAN TO THE RECOHMENDEO REMOVAL DEPTH. SLOPE HEIGHT. SITE CONDITIONS AND/OR LOCAL CONDITIONS COULD DICTATE FLATTER PROJECTIONS. 1' REMOVAL ADJACENT TO EXISTING FILL ADJOINING CANYON FILL COMPACTED RLL LIMITS LINE (EXISTING.COMPACTED FILL) ^^^^ ' TO BE REMOVED BEFORE BEFORE PLACING ADDITIONAL COMPACTED RLL LEGEND Qaf ARTIFICIAL FILL Qal ALLUVIUM PLATE EG-3 TYPICAL STABILIZATION / BUTTRESS FILL DETAIL TJ > H m m o I OUTLETS TO BE SPACED AT 100'MAXIMUM INTERVALS, AND SHALL EXTEND 12- BEYOND THE FACE OF SLOPE AT TIME OF.ROUGH GRADING COMPLETION. DESIGN RNISH SLOPE 15'MINIMUM BLANKET FILL IF RECOMMENDED BY THE SOIL ENGINEER 10'MINIMUM 25'MAXIMUM TYPICAL BENCHING BUTTRESS OR SIDEHILL FILL .2% GRADIENT RLL I V L- HEEL ^ W = 15'MINIMUM OR H/2 BEDROCK DIAMETER NON-PERFORATED OUTLET PIPE AND BACKDRAIN (SEE ALTERNATIVESI 3'MINIMUM KEY DEPTH TYPICAL STABILIZATION / BUTTRESS SUBDRAIN DETAIL MINIMUM 2-MINIMUM PIPE MINIMUM PIPE r" > m m o I un 2- MINIMUM RLTER MATERIAL: MINIMUM OF FIVE R'/LINEAR R OF PIPF OR FOUR FP/LINEAR Fl OF PIPE WHEN PLACED IN SQUARE CUT TRENCH. ALTERNATIVE IN LIEU OF RLTER MATERIAL: GRAVEL MAY BE EI^CASED IN APPROVED RLTER FABRIC. RLTER FABRIC SHALL BE MIRAR 140 OR EQUIVALENT. RLTER FABRIC SHALL BE LAPPED A MINIMUM OF 12" ON ALL JOINTS. MINIMUM L-DIAMETER PIPE: ABS-ASTM D-2751. SDR 35 OR ASTM D-1527 SCHEDULE 40 PVC-ASTM D-3034, SpR 35 OR ASTM D-17B5 SCHEDULE AO 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. FILTER MATERIAL SHALL BE OF THE FOLLOWING SPECIFICATION OR AN APPROVED EQUIVALENT: SIEVE SIZE PERCENT PASSING 1 INCH 10 0 3/4 INCH 90-100 3/8 INCH 40-100 NO. 4 25-AO NO. 6 18-33 NO. 30 5-15 NO. 50 0--7 NO. 200 0--3 GRAVEL SHALL BE OF THE FOLLOWING SPECIFICATION OR AN APPROVED E.QUIVALENT: SIEVE SIZE PERCENT PASSING 1 1/2 INCH NO, A NO. 200 100 50 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 DESION TOE OF SLOPE TO TOE OF KEY AS SHOWN ON AS BUILT > m m o I cn NATURAL SLOPE TO BE RESTORED WITH COMPACTED FILL BACKCUT VARIES • \ lb'MINIMUM KEY WIDTH 2'X 3'MINIMUM KEY DEPTH 2'MINIMUM IN BEDROCK OR APPROVED MATERIAL. BENCH WIDTH MAY VARY "^•.MINIMUM f^OTE; 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 DISPOSl.TION OF DRAINS WOULD BE DETERMINED BY THE SOILS ENGINEER BASED UPON EXPOSED CONDITIONS. FILL OVER CUT DETAIL f^llT/RLL CONTACT 1. AS SHOWN ON GRADING PLAN 2. AS SHOWN ON AS BUILT MAINTAIN MINIMUM 15'RLL SECTION FROM BACKCUT TO FACE OF RNISH SLOPE •MINIMUM ^ _ ^ '^BEDROCK OR APPROVED MATERIAL LOWEST BENCH WIDTH 15'MINIMUM OR H/2 ^ TA'MINIMUM BENCH WIDTH MAY VARY > 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 > m m o I oo ^^^^^RJ^Pp^SED RNISHED GRADE j,i UNWEATHERED BEDROCK OR APPROVED MATERIAL "^^fH-^ COMPACTED STABILIZATION RLL — 7'Xl' 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 ENOINEER AND/OR ENGINEERING GEOLOGIST, 2 -Wr SHALL BE EQUIPMENT WIDTH CIS') FOR SLOPE HEIOHTS LESS THAN 25 FEET. FOR SLOPES GREATER- THAN 25 FEET -W- SHALL BE DETERMINED BY THE PROJECT SOILS ENOINEER AND /OR ENGINEERING GEOLOGIST. AT NO TIME SHALL "W BE LESS THAN H/2. SKIN RLL OF NATURAL GROUND ORIGINAL SLOPE 'ROPOSED FINISH GRADE 15'MINIMUM TO BE MAINTAINED FROM PROPOSED RNISH SLOPE FACE TO BACKCUT PROPOSED RNISH SLOPE T3N MINIMUM ^ BEDROCK OR APPROVED MATERIAL ^ fei 15'MtNIMUM K :EY WIDTH ^ 3'MINIMUM KEY DEPTH TI H m m CD I CD NOTE: 1. THE NEED AND DISPOSITION OF DRAINS WILL BE DETERMINED! BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST BASED ON FIELD CONDITIONS. 2. PAD OVEREXCAVATION AND RECOMPACTION SHOULD BE PERFORMED IF DETERMINED TO BE NECESSARY BY THE SOILS ENGINEER AND/OR ENGINEERINO GEOLOGIST. DAYLIGHT CUT LOT DETAIL RECONSTRUCT COMPACTED RLL SLOPE AT 2:1 OR FLATTER IMAY INCREASE OR DECREASE PAD AREA) OVEREXCAVATE AND RECOMPACT REPLACEMENT RLL AVOID AND/OR CLEAN UP SPILLAGE OF MATERIALS ON THE NATURAL SLOPE NATURAL GRADE TVPII BEDROCK OR APPROVED MATERIAL TYPICAL BENCHING % GRADIgNTi^x. T) > m rn o 1 NOTE: 1. SUBDRAIN AND KEY WIDTH REOUIREMENTS WILL BE DETERMINED BASED ON EXPOSED SUBSURFACE CONDITIONS AND THICKNESS OF OVERBURDEN. 2. PAD OVER EXCAVATION AND RECOMPACTION SHOULD BE PERFORMED IF DETERMINED NECESSARY BY THE SOILS ENGINEER AND/OR THE ENGINEERING GEOLOGIST. TRANSITION LOT DETAIL CUT LOT (MATERIAL TYPE TRANSITION) NATURAL GRADE COMPACTED RLL ^ I IMU ij^^jT^T^;;^^^^^;^^ 3-MimMUM^ ^ UNWEATHERED BEDROCK OR APPROVED MATERIAL TYPICAL BENCHING CUT-RLL LOT (DAYUGHT TRANSITION) PAD GRADE NATURAL GRADE -^^^^ -j^c.'V^J^-QYEREXCAVATE ^ AND RECOMPACT 5'MII^MUM 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-ir SETTLEMENT PLATE AND RISER DETAIL 2'X 2'X 1/A- STEEL PLATE STANDARD 3/A- PIPE NIPPLE WELDED TO TOP OF PLATE. 3/A- X 5'GALVANIZED PIPE. STANDARD PIPE THREADS TOP AND BOTTOM. EXTENSIONS THREADED ON BOTH ENDS AND ADDED IN 5* INCREMENTS. 3 INCH SCHEDULE AO PVC PIPE SLEEVE. ADD IN 5" INCREMENTS WITH GLUE JOINTS. RNAL GRADE MAINTAIN 5'CLEARANCE OF HEAVY EQUIPMENT. MECHANICALLY HAND COMPACT IN 2'VERTICAL -rV LIFTS OR ALTERNATIVE SUITABLE TO AND J ACCEPTED BY THE SOILS ENGINEER. MECHANICALLY HAND COMPACT THE INITIALS' VERTICAL WITHIN A 5'RADIUS OF PLATE BASE. ~ ~ \-. • • . • .. . . . • ••••./ BOTTOM DF CLEANOUT PROVIDE A MINIMUM 1* BEDDING OF COMPACTED SAND NOTE: 1. LOCATIONS OF SETTLEMENT PLATES SHOULD BE CLEARLY MARKED AND READILY VISIBLE (RED FLAGGED) TO EQUIPMENT OPERATORS. 2. CONTRACTOR SHOULD MAINTAIN CLEARANCE OF A 5'RADIUS OF PLATE BASE AND WITHIN 5'(VERTICAU FOR HEAVY EQUIPMENT. RLL WITHIN CLEARANCE AREA SHOULD BE HAND-COMPACTED TO PROJECT SPECIRCATIONS OR COMPACTED BY ALTERNATIVE APPROVED BY THE SOILS ENGINEER. r.^.r,....- 3. AFTER 5'(VERTICAL) OF RLL IS IN PLACE. CONTRACTOR SHOULD MAINTAIN A 5_RADIUS EQUIPMENT CLEARANCE FROM RISER. A. PLACE AND MECHANICALLY HAND COMPACT INITIAL 2" OF RLL PRIOR TO ESTABLISHING THE INITIAL READING. 5. IN THE EVENT OF DAMAGE TO THE SETTLEMENT PLATE OR EXTENSION RESULTING FROM EQUIPMENT OPERATING WITHIN THE SPECIFIED CLEARANCE AREA. CONTRACTOR SHOULD IMMEDIATELY NOTIFY THE SOILS ENGINEER AND SHOULO BE RESPONSIBLE FOR RESTORING THE SETTLEMENT PLATES TO WORKING ORDER. 5. 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 <-6- DIAMETER X 3 1/2* LENSTH HOLE CONCRETE BACKRLL PLATE EG-15 TEST PIT SAFETY DIAGRAM SIDE YIEW ( NOT TO SCALE ) I^RJkG- TOP VIEW 100 FEET 50 FEET ^TESTPITggiJI^^M lii u. a in 50 FEET V&BCLE APPROXIMATE CENTER OF TEST PIT J L { NOT TO SCALE ) PLATE EG-16 OVERSIZE ROCK DISPOSAL VIEW NORMAL TO SLOPE FACE 10'MINIMUM oo OS (B) _J5'MINIMUM (AX^ oo CX3 PROPOSED FINISH GRADE 10'MINIMUM (E) 15'MINIMUM (A) O oo OO oo (6) cao oolFl MINIMUM (C) V // i^r^r •\ \^ \- BEDROCK OR APPROVED MATERIAL VIEW PARALLEL TO SLOPE FACE PROPOSED RNISH GRADE FROM ____;fiiNiMUM to BEDROCK OR APPROVED MATERIAL NOTE- (AJ ONE EQUIPMENT WIDTH OR A MINIMUM OF 15 FEET. R HEIGHT /^ND WIDTH MAY VARY DEPENDING ON ROCK SIZE AND TYPE OF EQUIPMENT LENGTH OF WINDROW SHALL BE NO GREATER THAN 100'MAXIMUM. IC) 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 (D) 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. IE) CLEAR AREA FOR UTILITY TRENCHES. FOUNDATIONS AND SWIMMING POOLS. (F) ALL FILL OVER AND AROUND ROCK WINDROW SHALL BE COMPACTED TO 90% (G) JIIE^^'F^L BTTWEE^N^^IN^ COMPACTED WITH THE LIFT OF FILL COVERING WI^^^^^^ SHOULD BE PROOF ROLLED WITH A D-9 DOZER OR EQUIVALENT. VIEWS ARE DIAGRAMMATIC ONLY. ROCK SHOULD NOT TOUCH ATT^ ^ AND VOIDS SHOULD BE COMPLETELY RLLED IN. PLATE RD —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 r I I GRANULAR MATERIAL COMPACTED RLL SIZE OF EXCAVATION TO BE COMMENSURATE WITH ROCK SIZE ROCK DISPOSAL LAYERS GRANUUR SOIL TO RLL VOIDS.-v ^ COMPACTED RLL DENSIRED BY FLOODING ^""^ "-f LAYER ONE ROCK PROPOSED RNISH GRADE PROFILE ALONG UYER LOPE FACE ts'MINIMUM OOOOCOOOCXDOC5CG CLEAR ZONE 20'MINIMUM LAYER ONE ROCK HIGH PLATE RD-2