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HomeMy WebLinkAboutCT 02-10; VILLA FRANCESCA; PRELIMINARY GEOTECHNICAL EVALUATION; 2002-04-101 I I I I I I I I I I PRELIMINARY GEOTECHNICAL EVALUATION CARLSBAD SENIOR CONDOMINIUM PROJECT 2642 THROUGH 2646 JEFFERSON STREET CARLSBAD, SAN DIEGO COUNTY, CALIFORNIA FOR KARWIN COMPANY C/O KARNAK PLANNING & DESIGN 2802 STATE STREET CARLSBAD, CALIFORNIA 92008 W.O. 3256-A-SC APRIL 10, 2002 Geotechnical • Geologic • Environmental 5741 PalmerWay • Carlsbad, California 92008 • (760)438-3155 • FAX (760) 931-0915 April 10,2002 W.O. 3256-A-SC Karwin Company c/o Karnak Planning & Design 2802 State Street Carlsbad, Califomia 92008 Attention: Mr. Anthony De Leonardis Subject: Preliminary Geotechnical Evaluation, Carlsbad Senior Condominium Project, 2642 through 2646 Jefferson Street, Carlsbad, San Diego County, California Dear Mr. De Leonardis: In accordance with your request, GeoSoils. Inc. (GSI) has performed a geotechnical update evaluation ofthe subject site. The purpose ofthe study was to evaluate the onsite soils and geologic conditions and their effects on the proposed site development consisting of a three-story multi-residential structure over subterranean parking, from a geotechnical viewpoint. EXECUTIVE SUMMARY Based on our review ofthe available data (Appendix A), field exploration, laboratory testing, and geologic and engineering analysis, residential development of the property appears to be feasible from a geotechnical viewpoint, provided the recommendations presented in the text of this report are properly incorporated into the design and construction of the project. The most significant elements of this study are summarized below: • Based on our review of the grading and private improvement plans provided by Karnak Planning and Design, it appears that the proposed development would consist of a 52 unit mix of senior housing, in three story buildings over subterranean parking, with typical light multi-story loads, utilizing conventional foundations with continuous footings and slabs on grade, including underground utility improvements. All existing colluvium and near surface weathered terrace deposits are generally loose and potentially compressible, and are not suitable for the support of settlement sensitive improvements. These materials will require removal and recompaction if settlement sensitive improvements are proposed within their influence. Depth of removals are outlined in the conclusions and recommendations section of this report. In general, removals will be on the order of ±2 to ±3V2 feet across a majority of the site. Our laboratory test results indicate that soils onsite are generally very low to 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 medium acidic (pH=6.0) and moderately corrosive to ferrous metals (saturated resistivity=7,500 ohms-cm). Alternative methods and additional comments should be obtained by a qualified corrosion engineer. Groundwater was not encountered onsite during our subsurface investigation and is generally not anticipated to affect site development, providing that the recommendations contained in this report are incorporated into final design and construction and that prudent surface and subsurface drainage practices are incorporated into the construction plans. Perched groundwater conditions along zones of contrasting permeabilities 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 grounciwater conditions. Field mapping in the site vicinity, noted the presence of numerous paleoliquefaction features ("sand blows," liquefaction craters, sand filled fissures and injection dikes, sand vents, etc.), which may also exist within the site. Potential liquefaction in such areas (in the future) impacting surface improvements is considered very low, provided that the recommendations presented in this report are incorporated into design and construction of the project. Isolated spread/continuous footings or mat foundation may be used onsite. The seismic design parameters presented herein should be considered during project planning and design. The geotechnical design parameters presented herein should be incorporated into project planning, design, and construction by the project structural engineer and architect. Karwin Compatny W.O. 3256-A-SC File:e:\wp7\3200\3256a.pge Page Two GeoSoils, Inc. The opportunity to be of service is greatly appreciated. If you have any questions concerning this report or if we may be of further assistance, please do not hesitate to contact any of the undersigned. Respectfully submitted, GeoSoils, Inc. Bpyan Voss Staff Geologist ll J 'SO. 1934 ertG. Crisman y^'J^s/wJ ineering Geologist,X^Q^9; Engine Reviewed by: Franklin (/ Engineering Geoloc BV/JPF/RGC/DWS/BS/jh Distribution: (4) Addressee David W. Skelly Civil Engineer, Karwin Company File:e:\wp7\3200\3256a.pge W.O. 3256-A-SC Page Three GeoSoils, Inc. TABLE OF CONTENTS SCOPE OF SERVICES 1 SITE CONDITIONS/PROPOSED DEVELOPMENT 1 SITE EXPLORATION 3 REGIONAL GEOLOGY 3 SITE GEOLOGIC UNITS 3 Colluvium (Unmapped) 3 Quaternary-age Terrace Deposits (Map Symbol - Qt) 4 LABORATORYTESTING 4 General 4 Laboratory Standard 4 Expansion Potential 4 Shear Testing 5 Corrosion/Sulfate Testing 5 FAULTING AND REGIONAL SEISMICITY 5 Faulting 5 Seismicity 6 Seismic Shaking Parameters 8 Seismic Hazards 8 LIQUEFACTION 9 SEISMIC SETTLEMENT 10 OTHER GEOLOGIC HAZARDS 10 CONCLUSIONS 10 EARTHWORK CONSTRUCTION RECOMMENDATIONS 10 General 10 Site Preparation 11 Removals (Unsuitable Surficial Materials) 11 Fill Placement 11 Transitions/Overexcavation 11 GcoSoils, Inc. RECOMMENDATIONS - FOUNDATIONS 12 Deep Isolated Spread/Continuous Footings 12 Mat Foundations Construction 13 Lateral Earth Pressures 14 Corrosion and Concrete Mix 18 RECOMMENDATIONS-POST EARTHWORK 18 Planting and Landscape Maintenance 18 Additional Site Improvements 18 Additional Grading 19 Footing Trench Excavation 19 Drainage 19 TRENCH BACKFILL 19 PLAN REVIEW 20 INVESTIGATION LIMITATIONS 20 DEVELOPMENT CRITERIA 20 Landscape Maintenance and Planting 20 Additional Site Improvements 20 Trenching 21 Drainage 21 Utility Trench Backfill 21 PLAN REVIEW 22 LIMITATIONS 22 FIGURES: Figure 1 - Site Location Map 2 Figure 2 - California Fault Map 7 Figure 3 - Schematic of Site Wall Drain Option A 15 Figure 4 - Schematic of Site Wall Drain Option B 16 Figure 5 - Schematic of Site Wall Drain Option C 17 ATTACHMENTS: Plate 1 - Boring Location Map Rear of Text Appendix A - References Rear of Text Appendix B - Borings Logs Rear of Text Appendix C - Laboratory Data Rear of Text Appendix D - General Earthwork and Grading Guidelines Rear of Text Karwin Company Table of Contents Flle:e:\wp7\3200\3256a.pge Page 11 GcoSoils, Inc. PRELIMINARY GEOTECHNICAL EVALUATION CARLSBAD SENIOR CONDOMINIUM PROJECT 2642 THROUGH 2646 JEFFERSON STREET CARLSBAD, SAN DIEGO COUNTY, CALIFORNIA SCOPE OF SERVICES The scope of our services has included the following: 1. Review of the available geologic literature for the site (Appendix A). 2. Geologic site reconnaissance, subsurface exploration, sampling and mapping. 3. General areal seismicity evaluation. 4. Appropriate laboratory testing, engineering and geologic analysis of data coiiected and preparation of this report. SITE CONDITIONS/PROPOSED DEVELOPMENT The site is an approximately rectangular shaped parcel located on the east side of Jefferson Street, in Carlsbad, California. The relatively level site is situated south of Knowles Street and approximately 30 feet north of Laguna Drive, (see Figure 1, Site Location Map). The property is bordered on the north by a multi-family-house, on the south by a single-family residence, and on the west by Jefferson Street. Overall, the property is relatively level with a gently sloping gradient to the southwest. The site drainage is generally via sheet flow to the southwest. According to a 1968 topographic map, the subject site is approximately 64 feet above Mean Sea Level (MSL). Based on our review of the tentative plans (Karnak Planning and Design), it is our understanding thatthe proposed project would consist of residential development of 52 unit mix of moderate and standard senior housing, in a three story building over subterranean parking structure with underground main-line and onsite utility improvements. It is our understanding that design grades will essentially be the same as existing grades, and that grading operations atthe site will be remedial in nature. Cut and fill grading techniques are anticipated to create design grades for the proposed multi-family residential structure. It is anticipated that the residential development would consist of a multi-story structure with slab-on-grade floors and continuous footings, utilizing masonry and steel types of construction, with underground utility improvements. Estimated average and maximum column loads are assumed to be typical for a three-story building within a subterranean garage. We have also assumed that the below grade parking will be about 5 feet below existing grade. GcoSoils, Inc. 3p TopoQuads Copyright © 1999 DtUrmt Yarmoutfi, ME 04096 Source Data: USGS Base Map: San Luis Rey Quadrangle, California~San Diego Co., 7.5 Minute Series (Topographic 1968, by USGS, r =20d0' 1/2 Scale Miles N Reproducvd with p«rmf«tion aranted by Thomas Btos. Maps. This map is copyrlflhtsd by Thomas Bros. Maps. It Is unlawful to copy or reproduce all or any part thereof, whether for persons! use or resale, without permission. All rights reserved. W.O. 3256-A-SC SITE LOCATION MAP Figure 1 SITE EXPLORATION Surface observations and subsurface exploration were performed on March 18,2002, by a representative of this office. A survey of line and grade for the subject lot was not conducted by this firm at the time of our site reconnaissance. Near surface soil conditions were explored with five hand auger borings within the site to evaluate soil and geologic\conditions. The approximate location of each boring are shown on the attached boring location map (Plate 1). Boring logs are presented in Appendix B. REGIONAL GEOLOGY The subject property is located within a prominent natural geomorphic province in southwestern California known as the Peninsular Ranges. It is characterized by steep, elongated mountain ranges and valleys that trend northwesterly. The mountain ranges are underlain by basement rocks consisting of pre-Cretaceous metasedimentary rocks, Jurassic metavolcanic rocks, and Cretaceous plutonic rocks of the southern California batholith. In the San Diego County region, deposition occurred during the Cretaceous period and Cenozoic era in the continental margin of a forearc basin. Sediments, derived from Cretaceous-age plutonic rocks and Jurassic-age volcanic rocks, were deposited into the narrow, steep, coastal plain and continental margin ofthe basin. These rocks have been uplifted, eroded and deeply incised. During early Pleistocene time, a broad coastal plain was developed from the deposition of marine terrace deposits. During mid- to late- Pleistocene time, this plain was uplifted, eroded and incised. Alluvial deposits have since filled the lower valleys, and young marine sediments are currently being deposited/eroded within coastal and beach areas. SITE GEOLOGIC UNITS The site geologic units encountered during our subsurface investigation and site reconnaissance included colluvium and terrace deposits. The earth materials are generally described below from the youngest to the oldest. The distribution of these materials is shown on Plate 1. Colluvium (Unmapped) The site colluvium materials are mostly residual, having developed through weathering and decomposition of the underlying terrace deposits. Thickness of the colluvium is approximately 1 foot. These materials generally consist of reddish brown to dark brown, silty sand with roots and rootlets. A thin veneer of crushed aggregate was noted on the north side of the property. These materials were generally observed to be dry to damp, Karwin Company W.O. 3256-A-SC 2642 through 2646 Jefferson Street April 10,2002 Rle:e:\wp7\3200\3256a.pge Page 3 GcoSoils, Inc. loose, porous, and are considered compressible. These materials are considered unsuitable for structural support in its present conditioned and should be removed and recompacted. Quaternarv-aae Terrace Deposits (Map Svmbol - Qt) Terrace deposits were observed to underlie the site and consist of dense silty sand. These deposits are generally orange brown to reddish brown in color, and damp to moist in their moisture content. As a result ofthe relatively loose and weathered condition ofthe upper ±1 to ±2V2 feet, these materials should be removed, moisture conditioned, and recompacted and/or processed in place, should settlement-sensitive improvements be proposed. LABORATORY TESTING General Laboratory tests were performed on representative samples of the onsite earth materials in order to evaluate their physical characteristics. The test procedures used and results obtained are presented below. Laboratorv Standard The maximum dry density and optimum moisture content was determined forthe major soil type encountered in the trenches. The laboratory standard used was ASTM D-1557. The moisture-density relationship obtained for this soil is shown below: SOIL BORING OR TEST MAXIMUM DRY OPTIMUM ^TYPE:;.. PIT AND DEPTH DENSITY (pcf) MOISTURE (ft.) DENSITY (pcf) CONTENT (%) Silty SAND, dark brown B-3 @ 1-3 130.0 10.0 Expansion Potential Expansion testing was performed on a representative sample of site soil in accordance with UBC Standard 18-2. The results of expansion testing are presented in the following table. Karwin Company 2642 through 2646 Jefferson Street Rle:e:\wp7\3200\3256a.pge W.O. 3256-A-SC April 10, 2002 Page 4 GcoSoils, Inc. 1 LOCATION EXPANSION INDEX EXPANSION POTENTIAL 1 B-3@1'-3" 5 Very Low Shear Testina Shear testing was performed on a representative, undisturbed and remolded sample of site soil in general accordance with ASTM test method D-3080 in a Direct Shear Machine ofthe strain control type. Shear test results are presented as Plates C-1 and C-2 in Appendix C, and as follows: SAMPLE LOCATION PRIMARY RESIDUAL SAMPLE LOCATION COHESION (PSF) FRICTION ANGLE (DEGREES) COHESION (PSF) FRICTION ANGLE (DEGREES) B-1@1' (undisturbed) 70 33 52 33 B-3@1'-3' (remolded) 144 35 27 33 Corrosion/Sulfate Testing Sulfate testing indicates that site soils have a negligible exposure to concrete per Table 19- A-4 of the 1997 UBC (water extractable sulfate = 0.000 percent by weight). Corrosion testing (pH, resistivity) indicates that soils are medium acidic (pH = 6.0) and moderately corrosive (saturated resistivity = 7,500 ohms-cm) to ferrous metals. Test results are presented as Plate C-3 in Appendix C. FAULTING AND REGIONAL SEISMICITY Faulting The site is situated in a region 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). Karwin Company 2642 through 2646 Jefferson Street File:e:\wp7\3200\3256a.pge W.O. 3256-A-SC April 10,2002 Page 5 GcoSoils, Inc. 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 (Figure 2). These faults include-but are not limited to-the San Andreas fault, the San Jacinto fault, the Elsinore fault, the Coronado Bank fault zone, and the Newport-Inglewood - Rose Canyon fault zone. 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(34) Elsinore 24(39) La Naci6n 25(41) Newport-lnglewood-Offshore 7(12) Rose Canyon 4(7) 1 San Diego Trough-Bahia Sol. 30(49) Seismicitv The acceleration-attenuation relations of Joyner and Boore (1982), Campbell and Bozorgnia (1994), and Sadigh and others (1987) have been incorporated into EQFAULT (Blake, 1997). Forthis study, peak horizontal ground accelerations anticipated atthe site were determined based on the random mean and mean plus 1 sigma attenuation curves developed by Joyner and Boore (1982), Campbell and Bozorgnia (1994), and Sadigh and others (1989). 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. Karwin Company 2642 through 2646 Jefferson Street Fil6:e:\wp7\3200\3256a.pge W.O. 3256-A-SC April 10, 2002 Page 6 GcoSoils, Inc. SAN FRANCISCO SITE LOCATION ( + ): Latitude - 33.1658 N Longitude - 117.3481 W karwin CALIFORNIA FAULT w.o. 3256-A-SC Figure 2 Site acceleration, as a percentage ofthe 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 (maximum credible) event may be on the order of 0.64 g to 0.78 g, and a maximum probable event may be on the order of 0.32 g to 0.44 g, assuming upper bound (maximum credible) and maximum probable event of a magnitude about 6.9, on the Rose Canyon fault zone, located approximately 4.2 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) and Peterson and others (1996), 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 C^ (per Table 16-R*) 0.64 N^ Near Source Factor N, (per Table 16-S*) 1.0 Near Source Factor N^ (per Table 16-T*) 1.1 Seismic Source Type (per Table 16-U*) B Distance to Seismic Source 4.2 mi. (6.8 km) Upper Bound Earthquake M„ 6.9 * Figure and table references fi'om Chapter 16 ofthe Uniform Building Code (1997). Seismic Hazards The following list includes other seismic related hazards that have been considered during our evaluation ofthe site. The hazards listed are considered negligible and/or completely mitigated as a result of site location, soil characteristics, and typical site development procedures: Liquefaction Tsunami Dynamic Settlement Surface Fault Rupture Ground Lurching or Shallow Ground Rupture Karwin Company 2642 through 2646 Jefferson Street File:e:\wp7\3200\3256a.pge W.O. 3256-A-SC April 10,2002 Page 8 GcoSoils, Inc. It is important to keep in perspective that in the event of a maximum probable or credible earthquake occurring on any ofthe nearby major faults, strong ground shaking would occur in the subject site's general area. Potential damage to any structure(s) would likely be greatest from the vibrations and impelling force caused by the inertia of a structure's mass, than from those induced by the hazards considered above. This potential would be no greater than that for other existing structures and improvements in the immediate vicinity. 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 overlying, 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 or may not experience the other two (Kuhn, Legg, Shiemon, Bauer, 2000b). Therefore, although remote, the possibility for liquefaction to occur cannot be entirely precluded, however, should not pose an undue constraint to development. One ofthe primary factors controlling the potential for liquefaction is depth to groundwater. Liquefaction 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 watertable 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 a seismic event. Typically, liquefaction has a relatively low potential where groundwater is greaterthan 30 feet deep, and virtually unknown below 60 feet. Mitigation ofthe impacts from liquefaction would be provided by the recommended removal and recompaction discussed herein. Karwin Company W.O. 3256-A-SC 2642 through 2646 Jefferson Street April 10, 2002 File:e:\wp7\3200\3256a.pge Pagg g GcoSoils, Inc. SEISMIC SETTLEMENT Some settlement of underlying granular terrace deposits should be expected during a seismic event. The magnitude of this settling is a junction of relative density of the underlying terrace, depth of groundwater, and the magnitude and duration ofthe event. For preliminary purposes a seismic settlement on the order of 2 inches should be planned for in the structural design. OTHER GEOLOGIC HAZARDS Mass wasting refers to the various processes by which earth materials are moved down slope in response to the force of gravity. Examples ofthese processes include slope creep, surficial failures, and deep-seated landslides. Creep is the slowest form of mass wasting and generally involves the outer 5 to 10 feet of a slope surface. During heavy rains, such as those in 1969,1978,1980,1983,1993, and 1998 creep-affected materials may become saturated, resulting in a more rapid form of downslope movement (i.e., landslides and/or surficial failures). The site topography is very flat lying, no such slopes are proposed, and indications of deep seated landsliding on the site were not observed during our site reconnaissance. Therefore, the potential for seismically induced landsliding is considered nil. CONCLUSIONS Based upon our site reconnaissance, test results, and review ofthe previous report, it is our opinion that the subject site appears suitable for the proposed residential development. The following recommendations should be incorporated into the construction details. EARTHWORK CONSTRUCTION RECOMMENDATIONS General All grading should conform to the guidelines presented in Appendix Chapter A33 of the Uniform Building Code, the requirements of the City of Carlsbad, and the Grading Guidelines presented in Appendix D, except where specifically superseded in the text of this report. Prior to grading, a GSI representative should be present at the preconstruction meeting to provide additional grading guidelines, if needed, and review the earthwork schedule. During earthwork construction all site preparation and the general grading procedures of the contractor should be observed and the fill selectively tested by a representative(s) of GSI. If unusual or unexpected conditions are exposed in the field, they should be reviewed Karwin Company W.O. 3256-A-SC 2642 through 2646 Jefferson Street April 10,2002 File:e:\wp7\3200\3256a.pge Page 10 GcoSoils, Inc. 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. Site Preparation Debris, vegetation and other deleterious material should be removed from the building area prior to the start of construction. Sloping areas to receive fill should be properly benched in accordance with current industry standards of practice and guidelines specified in the Uniform Building Code. Removals (Unsuitable Surficial Materials) As a result of the relatively loose/soft condition of colluvium and weathered terrace deposits, these materials should be removed and recompacted in areas proposed for settlement sensitive structures or areas to receive compacted fill. At this time, removal depths on the order of ±1 to ±2 feet should be anticipated; however, locally deeper removals may be necessary. Removals should be completed below a 1:1 projection down and away from the edge of any settlement sensitive structure and/or limit of proposed fill. Once removals are completed, the exposed bottom should be reprocessed and compacted 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 soil importation is planned, a sample ofthe soil import should be evaluated by this office prior to importing, in order to assure compatibility with the onsite site soils and the recommendations presented in this report. Import soils for a fill cap should be low expansive (expansion index [E.I.] less than 50). The use of subdrains at the bottom of the fill cap may be necessary, and subsequently recommended based on compatibility with onsite soils. Transitions/Overexcavation Cut portions of cut/fill transition pads should be overexcavated a minimum 3 feet below pad grade. Areas with planned fills less than 3 feet shouid be over excavated in order to provide to minimum fill thickness. Overexcavation of native soils due to the presence of heterogenous stratigraphy (i.e., sand/clay) may be warranted and will be evaluated on a lot-by-lot basis during grading. Where the ratio of maximum to minimum fill thickness below a given structure exceeds 3:1, overexcavation should be completed to reduce this ration to 3:1, or less. Karwin Company W.O. 3256-A-SC 2642 through 2646 Jefferson Street April 10,2002 File:e:\wpA3200\3256a.pge Page 11 GcoSoils, Inc. RECOMMENDATIONS - FOUNDATIONS In the event that the information concerning the proposed development plan is not correct or any changes in the design, location, or loading conditions ofthe proposed structure are made, the conclusions and recommendations contained in this report are for the subject site only and shall not be considered valid unless the changes are reviewed and conclusions of this report are modified or approved in writing by this office. The information and recommendations presented in this section are considered minimums and are not meant to 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 recommendationsfor proposed construction, in consideration of our field investigation, laboratory testing, and engineering analysis. The lowest finished floor level is anticipated to be at an elevation of about 60 feet MSL. Based on the above, we have considered the following design alternatives: • Isolated spread/continuous footings. • Mat foundation Deep Isolated Spread/Continuous Footings Based on the anticipated foundation loads and preliminary design information provided us, it is our opinion that the proposed structure can favorably be supported on the dense soils which underlie the site at a depth of about 5 feet. Building loads may be supported on continuous or isolated spread footings (elevation ±60 feet MSL) designed in accordance with the following recommendations. ALLOWABLE BEARING VALUES FOR FOOTINGS DEPTH BELOW LOWEST ADJACENT FINISHED GRADE (Inches) ALLOWABLE BEARING CAPACITY FOR SPREAD FOOTINGS (Minimum Width = 4 Feet) ALLOWABLE BEARING CAPACITY FOR CONTINUOUS WALL FOOTINGS (Minimum Width=2 Feet) 24 2.2 ksf 2.0 ksf 36 3.0 ksf 2.5 ksf 48 3.5 ksf 3.0 ksf Karwin Company 2642 through 2646 Jefferson Street File:e:\wp7\3200\3256a.pge w.o. 3256-A-SC April 10,2002 Page 12 GcoSoils, Inc. The above values are for dead plus live loads and may be increased by one-third for short- term wind or seismic loads. Foundation elements supported in compacted fill soils (90 percent relative compaction based on ASTM Dl 557) or above an elevation of ±70 feet MSL may be designed for a maximum allowable dead plus live load bearing value of 2.0 ksf for a minimum footing width and depth of embedment of 24 inches. Where column or wall spacings are less than twice the width of the footing, some reduction in bearing capacity may be necessary to compensate for the effects of group action. Reinforcement should be designed in accordance with local codes and structural considerations. The recommended allowable bearing capacity is generally based on maximum total and differential settlements of 1 inch and % inch, respectively. Actual settlement can be estimated on the basis that settlement is roughly proportional to the net contact bearing pressure. The majority of the settlement should occur during construction. Since settlement is a function of footing size and contact bearing pressure, some differential settlement can be expected between adjacent columns or walls where a large differential loading condition exists. However, for most cases, differential settlements are considered unlikely to exceed Vz inch. With increased footing depth/width ratios, differential settlement should be less. For structures founded in firm formational soils or properly compacted fill soils, the floor slabs should have a minimum thickness of 5 inches and be reinforced (at a minimum) with No. 4 rebars at 18 inches on center (each way), placed at mid-height in the slab. Actual thickness and reinforcement should be based on structural considerations and local codes. Concrete shrinkage cracking may be reduced by addition of fiber mesh into the concrete and careful control of concrete water-to-cement ratios. If moisture-sensitive equipment or floor coverings are used, we recommend that a 10-mil thick moisture barrier (with all laps sealed) be placed beneath slabs. A 4-inch layer of clean crushed gravel (% inch maximum) between the slab and the barrier is recommended to aid in concrete curing. Soils underlying the slabs should be moisture conditioned to 130 percent of optimum moisture content prior to moisture barrier and concrete placement. Slabs should have crack control joints with appropriate spacings as designed by the structural engineer. Mat Foundations Construction A mat foundation also appears to be a favorable consideration forthe proposed structure considering the anticipated column loads and the proposed depth of the lowest finished floor. A mat foundation by its very nature is typically easier to waterproof, and this fact should be taken into account in evaluating the foundation design alternatives. For a mat foundation bearing uniformly in competent soils at an elevation of ±60 feet MSL (about 10 feet below existing grade), a maximum allowable bearing capacity of 4,000 psf is recommended. This value may be increased by one-third for short-term loads including wind or seismic. Reinforcement should be designed in accordance with local codes and structural considerations. Karwin Company W.O. 3256-A-SC 2642 through 2646 Jefferson Street April 10,2002 File:e:\wp7\3200\3256a.pge Page 13 GcoSoils, Inc. The recommended bearing capacity is based on an anticipated maximum total and differential settlement of 2 inches and 1 inch, respectively. The majority ofthe settlement should occur during construction. For foundation design, a modulus of subgrade reaction (k) of 100 pounds per square inch per inch of depth may be utilized. Floor slabs should be a minimum of 5 inches in thickness and be reinforced with rebars at the spacing recommended by the structural engineer, in light of expansive soil conditions. If moisture sensitive improvements are proposed, then a 10-mil thick visqueen (or equivalent) moisture barrier, with all laps sealed, should be placed on the subgrade. Two inches of clean sand should undertie the slab, and overlie the moisture barrier (if utilized). Nuisance cracking may be lessened by the addition of engineered reinforcing fibers in the concrete and careful control of water/cement ratios. Lateral Earth Pressures The recommended lateral earth pressures for the site soils and level backfill are as follows: EQUIVALENT FLUID WEIGHT (PCF) CONDITIONS LEVEL Active 40 At Rest 60 Passive 250 To design an unrestrained wall, such as a cantilever wall, the active earth pressure may be used. For a restrained wall (a wall that is not free to rotate greater than 0.002 times the wall height), the at-rest pressure should be used. Passive pressure is used to compute lateral soils resistance developed against lateral structural movement. Further, for sliding resistance, the friction coefficient of 0.35 may be used at the concrete and soil interface. In combining the total lateral resistance, the passive pressure or the frictional resistance should be reduced by 50 percent. The total depth of retained earth for design of cantilever walls should be the vertical distance below the ground surface measured at the wall face for stem design or measured at the heel of the footing for overturning and sliding. Wall footings should be designed in accordance with structural considerations. The passive resistance value may be increased by one-third when considering loads of short duration including wind or seismic loads. The horizontal distance between foundation elements providing passive resistance should be aminimum of three times the depth ofthe elements to allow full development of these passive pressures. All retaining structures should be provided with a drainage blanket and drains (Figures 3,4 and 5). As an alternative, a Mirafi drainage board may be utilized, with perforated pipe surrounded by gravel and filter fabric, such as Mirafi 140N or approved equivalent. Surcharge loading from adjacent structures Karwin Company W.O. 3256-A-SC 2642 through 2646 Jefferson Street April 10,2002 File:e:\wp7\3200\3256a.pge Page 14 GcoSoils, Inc. Cop drain (cut off) 18" below soil line Manufactured drainage Geocomposite drain ( Mira drain 5000 or equivalent ) Note: Filter fabric wraps completely around perforated pipe and behind core material, core moterial wraps beneath bottom of pipe. Site retaining wall (structural design by others) 4 dia. 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) '— Wall footing (designed by others) _• Figure 3 L08AI4GELESCO. FUVERSIOECa ORANGE ca aM DIEGO CO. SCHEMATIC OF SITE WALL DRAIN OPTION A w.o.3256i-A-SC DATE 4/02 SCALE^ none 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 4" Min. —I Cop drain (cut off) 18' below soil line "Site retaining wall (structural design by others) Pavement section per GSI recomendations — Parking lot •surface 3- T ' I o f m , / • Wall footing (designed by others) Figure 4 LOSANGELES CO. RIVERSlOE CO. ORANGE CO. SAN DIEGO CO SCHEMATIC OF SITE WALL DRAIN OPTION B w.o. 3256'-A-SC DATE 4/02 SCALE none 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 bottonn course of block. The drains shall be 4" in diameter. Cap drain (cut off) 18' below soil line 24" thick (nnin.) drain rock (class 2 pemneable) or other acceptable granular material, 1/8-1" clean crushed rock wrapped in a filter fabric (Mirafi 140 or equivalent) Waterproofing * • • Site retaining wall (structural design by others) Pavement section per GSI recomendations dia. pipe Parking lot surface iriace v. \ .Wall footing (designed by others) Figure 5 LOS ANGELES CO. RIVERSIDE CO. ORANGE CO. SAN DIEGO CO. SCHEMATIC OF SITE WALL DRAIN OPTION 0 w.o. 3256-A-SC DATE 4/02 SCALE' none should also be taken into account during wall design. Please note that to properly drain retaining walls, a sump pump will likely be necessary. Corrosion and Concrete Mix Upon completion of grading, laboratory testing should be performed of site materials for corrosion to concrete and corrosion to steel. Additional comments may be obtained from a qualified corrosion engineer at that time. RECOMMENDATIONS-POST EARTHWORK Planting and Landscape Maintenance Graded slopes constructed within and/or exhibiting or exposing weathered formational materials are considered erosive. Eroded debris may be minimized and surficial slope stability enhanced by establishing and maintaining a suitable vegetation cover soon after construction. Plants selected by the project landscape architect should be light weight, deep-rooted types that require little water and are capable of surviving the prevailing climate. Graded cut slopes exposing less weathered formational materials are expected to be relatively non-erosive and will present difficulty for establishment of vegetation on the dense formational materials. Jute-type matting or other fibrous covers may aid in allowing the establishment of a sparse plant cover. Water can weaken the inherent strength of all earth materials. Positive surface drainage away from graded slopes should be maintained and only the amount of water necessary to sustain plant life should be provided for planted slopes. Overwatering should be avoided as ovenwatering the landscape area could adversely affect the proposed site improvements. Additional Site Improvements Recommendations for exterior concrete flat work design and construction can be provided upon request, after site earthwork is complete. If, in the future, any additional improvements are planned for the site in general or individual areas, recommendations concerning the geological or geotechnical aspects of design and constmction of said improvements may be provided upon request. Karwin Company W.O. 3256-A-SC 2642 through 2646 Jefferson Street April 10,2002 File:e:\wp7\3200\3256a.pge Page 18 GcoSoils, Inc. Additional Grading This office should be notified in advance of any additional fill placement, supplemental regrading ofthe site, or trench backfilling after rough grading has been compacted. This includes completion of grading in the street and parking areas and utility trench and retaining wall backfills. Footing Trench Excavation All footing trench excavations should be observed by a representative of this 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 the site. Drainage Positive site drainage should be maintained at all times. Drainage should not flow uncontrolled down any descending slope. Water should be directed awayfrom foundations and not allowed to pond and/or seep into the ground. Pad drainage should be directed toward the street or other approved area. Due to the nature of on-site soils, combined with the hardness and permeability of the formational materials, local areas of seepage may develop due to irrigation or heavy rainfall. Minimizing irrigation will lessen this potential. If areas of seepage develop, remedial recommendations for minimizing this effect could be provided upon request. TRENCH BACKFILL 1. All utility trench backfill in structural areas, slopes, and beneath hard scape features should be brought to at least optimum moisture content and then compacted to obtain a minimum relative compaction of 90 percent of the laboratory standard. Flooding/jetting is not recommended for the site soil materials. As an alternative, soil expansion (S.E.) 30 or greater sand, may be flooded/jetted in shallow under-slab interior trenches. 2. Sand backfill should not be allowed in exterior trenches adjacent to and within an area extending below a 1:1 plane projected from the outside bottom edge of the footing. 3. All trench excavations should conform to CAL-OSHA and local safety codes. Karwin Company W.O. 3256-A-SG 2642 through 2646 Jefferson Street April 10, 2002 File:e:\wp7\3200\3256a.pge Page 19 GcoSoils, Inc. PLAN REVIEW Project plans should be reviewed by this office priorto construction, so that GSI can verify proposed construction is in accordance with this report. Based on our review, supplemental recommendations and/or further geotechnical studies may be warranted. INVESTIGATION LIMITATIONS 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. DEVELOPMENT CRITERIA 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 from graded slopes should be maintained and oniy the amount of irrigation necessary to sustain plant life should be provided for planted slopes. Overwatering should be avoided. Graded slopes constructed within and utilizing onsite materials would be erosive. Eroded debris may be minimized and surficial slope stability enhanced by establishing and maintaining a suitable vegetation cover soon after construction. Plants selected for landscaping should be light weight, deep rooted types which require little water and are capable of surviving the prevailing climate. Compaction to the face of fill slopes would tend to minimize shortterm erosion until vegetation is established. In orderto minimize erosion on a 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 relative compaction. Additional Site Improvements Recommendations for additional grading, exterior concrete flatwork design and construction, including driveways, 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 ofsaid improvements could be provided upon request. Karwin Company W.O. 3256-A-SC 2642 through 2646 Jefferson Street April 10, 2002 Rle:e:\wp7\3200\3256a.pge Page 20 GcoSoils, Inc. Trenching All footing trench excavations for structures and walls should be observed and approved by a representative ofthis office priorto 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. All excavations should be observed by one of our representatives and conform to CAL-OSHA and local safety codes. GSI does not consult in the area of safety engineers. In addition, the potential for encountering hard spots during footing and utility trench excavations should be anticipated. If these concretions are encountered within the proposed footing trench, they should be removed, which could produce larger excavated areas within the footing or utility trenches. 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. Roof gutters and down spouts should be considered to control roof drainage. Down spouts should outlet a minimum of 5 feet from the proposed structure or into a subsurface drainage system. We would recommend that any proposed open bottom planters adjacent to proposed structures be eliminated for a minimum distance of 10 feet. As an alternative, closed bottom type planters could be utilized. An outlet placed in the bottom ofthe planter, could be installed to direct drainage away from structures or any exterior concrete flatwork. Utilitv Trench Baclcflll 1. All utility trench backfill in structural areas, slopes, 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. Flooding/jetting is not recommended for the site soil materials. As an alternative, imported sandy material with an S.E. of 30 or greater, may be flooded/jetted in shallow (12± inches or less) under-slab interior trenches, only. 2. Sand backfill, unless trench excavation material, should not be allowed in exterior trenches adjacent to and within an area extending below a 1:1 plane projected from the outside bottom edge of the footing. 3. All trench excavations should minimally conform to CAL-OSHA and local safety codes. Karwin Company W.O. 3256-A-SC 2642 through 2646 Jefferson Street April 10, 2002 Flle:e:\wp7\3200\3256a.pge Page 21 GcoSoils, Inc. Soils generated from utility trench excavations to be used onsite should be compacted to 90 percent minimum relative compaction. This material must not alter positive drainage patterns that direct drainage away from the structural area and towards the street. PLAN REVIEW Finai 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 atthattime. 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 mass grading, 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. The scope of work was performed within the limits of a budget. 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. Karwin Company W.O. 3256-A-SC 2642 through 2646 Jefferson Street April 10, 2002 Flle:e:\wp7\3200\3256a.pge Page 22 GcoSoils, Inc. ot Approximate location of boring test, with total depth Quaternary terrace deposits Base map adapted from, "Carlsbad Senior Citizen Condominium Complex Project Plans, Cover Sheet Site Plan", sheet C-2.0, by Karnalc Planning & Design, dated 10-01-01 —e LOS ANGELES CO. RIVERSIDE CO. ORANGE CO. SAN DIEGO CO. BORING LOCATION MAP . Plate 1 W:0^256-A-SC DATE 4/02 SCALE 1-=20' APPENDIX A REFERENCES APPENDIX A REFERENCES Blake, Thomas F., 1997, EQFAULT computer program 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 from worldwide accelrograms recorded from 1957 to 1993; Proceedings, Fifth U.S. National Conference on Earthquake Engineering, volume III, Earthquake Engineering Research Institute, pp 292-293. Hart, E.W. and Bryant, W.A. 1997, Fault-rupture Hazard Zones in California, Alquist-Priolo Earthquake Fault Zoning act with Index to Earthquake Fault Maps; California Division of Mines and Geology Special Publication 42. International Conference of Building Officials, 1997, Uniform buiiding 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., 1994, Estimation of response-spectral values as functions of magnitude, distance and site conditions, jn eds., Johnson, J.A., Campbell, K.W., and Blake, T.F., AEG short course, seismic hazard analysis, dated June 18. Kuhn, G.G., and Shepard, F.P., 2000a, Sea Cliff, Canyon and Coastal Terrace Erosion between 1887 and 2000: San Onofre State Beach, Camp Pendleton Marine Corps Base, San Diego County, California: 51 pp., 30figs., 5 plates, p.l-31: in R.J. Shiemon G.G. Kuhn, and M.R. Legg, eds., Neotectonics and Coastal Instability Orange and Northern San Diego Counties, California, Joint Field Conference, Volume 1, AAPG, Pacific Section SPE, Western Section Held in Long Beach, California, June 19-22. , 2000b, Neotectonics in the North Coastal Area, San Diego County, California: p.l- 88: in R.J. Shiemon G.G. Kuhn, and M.R. Legg, eds., Neotectonics and Coastal Instability Orange and Northern San Diego Counties, California, Joint Fieid Conference, Volume 1, AAPG, Pacific Section SPE, Western Section Held in Long Beach, California, June 19-22. , 1984, Sea Cliffs, beaches and coastal valleys of San Diego County: some amazing histories and some horrifying implications: University of California Press, Berkeley, California, and London, England. , 1983, Newly discovered Evidence from the San Diego County area of some principles of coastal retreat: Geological Society of America Bulletin, Shore and Beach, January. GcoSoils, Inc. , 1981, Should Southern California build defenses against violent storms resulting in lowland flooding as in records of past century: Geological Society of America Bulletin , 1980a, Greatly accelerated man-induced coastal erosion and new sources of beach sand, San Onofre State Park and Camp Pendleton, northen San Diego County, California: Geological Society of America Bulletin, Shore and Beach, October. , 1980b Coastal erosion in San Diego County, California, jn Edge, B.L, ed.. Coastal Zone '80, Proceedings of second Symposium on Coastal and Ocean Management held in Hollywood, Florida, on 17-20 November, 1980: American Society of Civil Engineers, V. III. , 1979a, Accelerated beach-cliff erosion related to unusual storms in southern California: California Geology, March. , 1979b, Coastal erosion in San Diego County, California, jn Abbott, P.L. and Elliott, W.J., eds.. Earthquakes and other perils San Diego region. 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 Califomia. Sadigh, K., Egan, J., and Youngs, R., 1989, Predictive ground motion equations reported in Joyner, W.B., and Boore, D.M., "Measurement, characterization, and prediction of strong ground motion", jjn 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. Tan, S.S., and Kennedy, Michael P., 1996, Geologic maps ofthe northwestern part of San Diego County, Caiifornia: California Division of Mines and Geology, Open File Report 96-02. Karwin Company Appendix A File:e:\wp7\3200\3256a.pge Page 2 GcoSoils, Inc. APPENDIX B BORING LOGS BORING LOG GeoSoils, Inc. w.o. 3256-A-SC PROJECT: KARWIN COMPANY CARLSBAD SENIOR FACILITY BORING B-1 DATE EXCAVATED SHEET 10F 1 3-18-02 8 Sample II CO >. 303 => o c o C 3 a V) 10^ SAMPLE METHOD: HAND AUGER/RING SAMPLER Standard Penetration Test Undisturt)ed, Ring Sample ^ Water Seepage into hole Description of Material GW SM COLLUVIUM: \@ 0' CRUSHED AGGREGATE ^ YA SILTY SAND, reddish brown, damp, loose; abundant organics. SM 109.5 3.6 18.8 WEATHERED TERRACE DEPOSITS: @ 1' SILTY SAND, reddish brown, damp, medium dense. SM TERRACE DEPOSITS: @ lYz SILTY SAND, reddish brown, damp, dense. Practical Refusal @ 2!4' No Groundwater Encountered or Caving Backfilled 3-18-02 5- CARLSBAD SENIOR FACILITY GeoSoils, Inc. PLATE B-1 BORING LOG GeoSoils, Inc. w.o. 3256-A-SC PROJECT: KARWIN COMPANY CARLSBAD SENIOR FACILITY BORING B-2 DATE EXCAVATED SHEET 10F 1 3-18-02 t 8 Sample (0 >. 3 W c s » o c 3 n CO 10^ £1 SAMPLE METHOD: HAND AUGER/RING SAMPLER Standard Penetration Test Undisturbed, Ring Sample ^ Water Seepage into hole Description of Material GW ML COLLUVIUM: \@ 0' CRUSHED AGGREGATE %' CLAYEY SANDY SILT, dari< brown, wet, loose; abundant organics. SM 122.5 10.2 77.1 WEATHERED TERRACE DEPOSITS: @ 1' SILTY SAND, reddish brown, moist, medium dense; trace organics. SM TERRACE DEPOSITS: @ 2' SILTY SAND, reddish brown, moist, medium dense. Total Depth = 5" No Groundwater Encountered or Caving Backfilled 3-18-02 CARLSBAD SENIOR FACILITY GeoSoils, Inc. PLATE B-2 BORING LOG GeoSoils, Inc. 1^.0. 3256-A-SC PROJECT: KARWIN COMPANY CARLSBAD SENIOR FACILITY BORING B-3 DATE EXCAVATED SHEET 10F 1 3-18-02 a. Sample CO >. 3 CO 3 S I o c 3 IS CO SAMPLE METHOD: HAND AUGER/RING SAMPLER Standard Penetration Test Undisturbed, Ring Sample ^ Water Seepage into hole Description of Material SM COLLUVIUM: @ 0' SILTY SAND, reddish brown, dry, loose; roots and rootlets, trace trash (glass, coin). SP WEATHERED TERRACE DEPOSITS: @ T SAND, reddish brown, damp to moist, medium dense; fine to medium grained, trace organics. 5- SM TERRACE DEPOSITS: @ 3' SILTY SAND, reddish brown, moist, medium dense. Total Depth = 6" No Groundwater Encountered or Caving Backfilled 3-18-02 CARLSBAD SENIOR FACILITY GeoSoils, Inc. PLATE B-3 BORING LOG GeoSoils, Inc. IV. 0. 3256-A-SC PROJECT: KARWIN COMPANY CARLSBAD SENIOR FACILITY BORING B-4 DATE EXCAVATED SHEET 10F 1 3-18-02 £ a. E Sample ffi O E CO >. 3 CO c ~ 3 s c IS CO SAMPLE METHOD: HAND AUGER/RING SAMPLER Standard Penetration Test ^ Undishtrbed, Ring Sample ^ Water Seepage into hole Description of Material SM COLLUVIUM: @ 0' SILTY SAND, dark reddish brown, dry to damp, loose; roots and rootlets, trace trash (glass). SM WEATHERED TERRACE DEPOSITS: @ 1' SILTY SAND, orange brown to reddish brown, damp to moist, medium dense to dense; trace organics. SM 5- TERRACE DEPOSITS: @ 3%' SILTY SAND, orange brown to reddish brown, moist, dense; trace organics. Practical Refusal @ ZYz No Groundwater Encountered or Caving Backfilled 3-18-02 CARLSBAD SENIOR FACILITY GeoSoils, Inc. PM7E B-4 BORING LOG GeoSoils, Inc. w.o. 3256-A-SC PROJECT: KARWIN COMPANY CARLSBAD SENIOR FACILITY BORING B-5 DATE EXCAVATED SHEET 10F 1 3-18-02 t Sample 33 CD CO £. 3 CO C ' 3 £• Q a. e IO o IS CO SAMPLE METHOD: HAND AUGER/RING SAMPLER Standard Penetration Test ^ Undisturbed, Ring Sample ^ Water Seepage into hole Description of Material SM COLLUVIUM: @ 0' SILTY SAND, dark brown, moist, loose; roots and rootlets. SM WEATHERED TERRACE DEPOSITS: @ 1' SILTY SAND, orange brown to reddish brown, moist, medium dense; trace organics, dari^ oxide staining (manganese?) SM TERRACE DEPOSITS: @ 3' SILTY SAND, orange brown to reddish brown, damp to moist, dense to very dense. Practical Refusal @ 5' No Groundwater Encountered or Caving Backfilled 3-18-02 CARLSBAD SENIOR FACILITY GeoSoils, Inc. PLATE B-5 APPENDIX C LABORATORY DATA 1,000 1,500 NORMAL PRESSURE, psf 2,000 2,500 3,000 Sample Depth/El. Primary/Residual Shear Sample Type Yd MC% C • B-1 1.0 Primary Shear Undisturbed 108.6 3.6 70 33 § • B-1 1.0 Residual Shear Undisturbed 108.6 3.6 52 33 • Note: Sample Innundated priorto testing ^^^^^^^^^^^^^^^^ IB 3 GeoSoils, Inc. 5741 PalmerWay Carisbad, CA 92008 Telephone: (760)438-3155 Fax: (760)931-0915 DIRECT SHEAR TEST Project: KARWIN Number: 3256-A-SC Date: March 2002 Plate; C -1 3.000 2,500 2,000 1 z Ul Q: m X (0 1,500 1,000 500 i soo 1,000 1,500 NORMAL PRESSURE, psf 2,000 2,500 3,000 Sample Depth/El. Primary/Residual Shear Sample Type Yd MC% 0 4> • B-3 1.0 Primary Shear Remolded 117.0 10.0 144 35 § g • B-3 1.0 Residual Shear Remolded 117.0 10.0 27 33 § g (9 Note: Sample Innundated priorto testing ^^^^^^^^^^^^^^^^ GeoSoils, Inc. 5741 Palmer Way Carisbad, CA 92008 Telephone: (760)438-3155 Fax: (760)931-0915 DIRECT SHEAR TEST Project: KARWIN Number: 3256-A-SC Date: March 2002 Plate C-2 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 Karwin Your #3256-ASC, MJS&A #02-02 71LAB 20-Mar-02 Sample ID B-3 @l-3 Resistivity as-received saturated pH Electrical Conductivity Chemical Analyses Cations calcium Ca^ magnesium Mg sodium Na Anions carbonate CO^' bicarbonate HCO3 chloride Cl'' sulfate Other Tests ammonium nitrate sulfide Redox 2+ 1+ SO4 NH4 NO, 1+ Units ohm-cm ohm-cm mS/cm mg/kg mg/kg mg/kg mg/kg • mg/kg mg/kg mg/kg mg/kg mg/kg qual mv 135,000 7,500 6.0 0.14 64 7 ND ND 98 40 ND na na na na Electrical conductivity in millisiemens/cm and chemical analysis were made on a 1:5 soil-to-water extract, mg/kg = milligrams per kilogram (parts per million) of dry soil. Redox = oxidation-reduction potential in millivolts ND = not detected na = not analyzed Page 1 ofl Plate C-3 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 result in new recommendations which could supersede these guidelines orthe recommendations contained in the geotechnical report. The contractor is responsible for the satisfactory completion of all earthwork in accordance with provisions of the project plans and specifications. The project soil engineer and engineering geologist (geotechnical consultant) or their representatives shouid provide observation and testing services, and geotechnical consultation during the duration ofthe project. EARTHWORK OBSERVATIONS AND TESTING Geotechnical Consultant Priorto the commencement of grading, a qualified geotechnical consultant (soil engineer and engineering geologist) should be employed for the purpose of observing earthwork procedures and testing the fills for conformance with the recommendations of the geotechnical report, the approved grading plans, and applicable grading codes and ordinances. The geotechnical consultant should provide testing and observation so that determination may be made that the work is being accomplished as specified. It is the responsibility of the contractor to assist the consultants and keep them apprised of anticipated work schedules and changes, so that they may schedule their personnel accordingly. All clean-outs, prepared ground to receive fill, key excavations, and subdrains should be observed and documented bythe project engineering geologist and/or soil engineer prior to placing and fill. It is the contractors's responsibility to notify the engineering geologist and soil engineer when such areas are ready for observation. 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 would vary depending on the soil conditions and the size ofthe project. The location and fi'equency of testing would be at the discretion of the geotechnical consultant. GcoSoils, Inc. Contractor's Responsibility All clearing, site preparation, and earthwork performed on the project should be conducted bythe contractor, with observation by geotechnical consultants and staged approval bythe governing agencies, as applicable. It isthe 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 bythe contractor with due consideration forthe fill material, rate of placement, and climatic conditions. If, in the opinion ofthe geotechnical consultant, unsatisfactory conditions such as questionable weather, excessive oversized rock, or deleterious material, insufficient support equipment, etc., are resulting in a quality of work that is not acceptable, the consultant will inform the contractor, and the contractor is expected to rectify the conditions, and if necessary, stop work until conditions are satisfactory. During construction, the contractor shall properly grade all surfaces to maintain good drainage and prevent ponding of water. The contractor shall take remedial measures to control surface water and to prevent erosion of graded areas until such time as permanent drainage and erosion control measures have been installed. SITE PREPARATION 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 priorto grading are to be removed or treated in a manner recommended bythe soil engineer. Soft, dry, spongy, highly fractured, or othen/vise unsuitable ground extending to such a depth that surface processing cannot adequately improve the condition should be overexcavated down to firm ground and approved by the soil engineer before compaction and filling operations continue. Overexcavated and processed soils which have been properly mixed and moisture Karwin Company Appendix D File:e:\wp7\3200\3256a.pge Page 2 GcoSoils, Inc. 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 fi'om 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 y2the 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 of the bench may exceed 4 feet. Pre-stripping may be considered for unsuitable materials in excess of 4 feet in thickness. All areas to receive fill, including processed areas, removal areas, and the toe of fill benches should be observed and approved by the soii engineer and/or engineering geologist priorto placement of fill. Fills may then be properly placed and compacted until design grades (elevations) are attained. COMPACTED FILLS Any earth materials imported or excavated on the property may be utilized in the fill provided that each material has been determined to be suitable bythe soil engineer. These materials should be free of roots, tree branches, other organic matter or other deleterious materials. All unsuitable materials should be removed from the fill as directed by the soil engineer. Soils of poor gradation, undesirable expansion potential, or substandard strength Kanivin Company Appendix D File:e:\wpA3200\3256a.pge Page 3 GcoSoils, Inc. 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 fi'om 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, future utilities, or underground construction unless specifically approved by the soil engineer and/or the developers representative. If import material is required for grading, representative samples of the materials to be utilized as compacted fill should be analyzed in the laboratory by the soil engineer to determine its physical properties. If any material other than that previously tested is encountered during grading, an appropriate analysis 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 horizontai 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. Karwin Company Appendix D File:e:\wp7\3200\3256a.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 soii engineer. Compaction of slopes should be accomplished by over-building a minimum of 3 feet horizontally, and subsequentiy 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. Ifan 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. Karwin Company Appendix D Flle:e:\wp7\3200\3256a.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 otherwise approved, the cut portion ofthe slope should be observed bythe engineering geologist priorto 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 otherwise specified in soil and geological reports, no cut slopes should be excavated higher or steeper than that allowed by the ordinances of controlling governmental agencies. Additionally, short-term stability of temporary cut slopes is the contractors responsibility. Erosion control and drainage devices should be designed 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. Karwin Company Appendix D Rle:e:\wp7\3200\3256a.pge Page 6 GcoSoils, Inc. COMPLETION Observation, testing and consultation bythe geotechnical consultant should be conducted during the grading operations in order to state an opinion that all cut and filled areas are graded in accordance with the approved project specifications. Afl:er 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 ail 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 forthe 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 flags are provided to GSI field technicians; one is to be affixed to the vehicle when on site, the other is to be placed atop the spoil pile on all test pits. Karwin Company Appendix D File:e:\wp7\3200\3256a.pge Page 7 GcoSoils, Inc. Flashing Lights: All vehicles stationary in the grading area shall use rotating or fiashing amber beacon, or strobe lights, on the vehicle during all field testing. While operating a vehicle in the grading area, the emergency flasher on the vehicle shall be activated. 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 Ciearance The technician is responsible for selecting test pit locations. A primary concern should be the technicians's safety. Efforts will be made to coordinate locations with the grading contractors authorized representative, and to select locations following or behind the established traffic pattern, preferably outside of current traffic. The contractors authorized representative (dump man, operator, supervisor, grade checker, etc.) should direct excavation ofthe pit and safety during the test period. Of paramount concern should be the soil technicians safety and obtaining enough tests to represent the fill. Test pits should be excavated so that the spoil pile is placed away form oncoming traffic, whenever possible. The technician's vehicle is to be placed next to the test pit, opposite the spoil pile. This necessitates the fill be maintained in a driveable condition. Alternatively, the contractor may wish to park a piece of equipment in front of the test holes, particularly in small fill areas or those with limited access. A zone of non-encroachment should be established for all test pits. No grading equipment should enter this zone during the testing procedure. The zone should extend approximately 50 feet outward fi'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 fiag should be placed at the top of the slope. The contractor's representative should effectively keep all equipment at a safe operation distance (e.g., 50 feet) away from the slope during this testing. The technician is directed to withdraw from the active portion 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 ft'om the equipment traffic pattern. The contractor should inform our personnel of all changes to haul roads, cut and fill areas or other factors that may affect site access and site safety. In the event that the technicians safety is jeopardized or compromised as a 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 Karwin Company Appendix D File:e:\wp7\3200\3256a.pge Page 8 GcoSoils, Inc. interim, no further 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. Ifthe contractorfails to provide safe access to trenches for compaction testing, our company policy requires that the soil technician withdraw and notify his/her supen/isor. 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. Karwin Company Appendix D Rle:e:\wp7\3200\3256a.pge Page 9 GcoSoils, Inc. CANYON SUBDRAIN DETAIL TYPE A PROPOSED COMPACTED FILL •NATURAL OROUND A N ^COLLUVIUM AND ALLUVIUM (REMOVEl WWH/ TYPICAL BENCHING ^''^^^ "^W^I BEDROCK SEE ALTERNATIVES \ \ \ TYPE B PROPOSED COMPACTED RLL •NATURAL GROUND '''' )^ ^COLLU/IUM AND ALLUVIUM (REMOVE! J^s" TYPICAL BENCHING l///i^\V SEE ALTERNATIVES BEDROCK NOTE: ALTERNATIVES. LOCATION 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-l MINIMUM FILTER MATERIAL MINIMUM VOLUME OF 9 FT.> -^.-.ij.. /LINEAR FT. 6" i ABS OR PYC PIPE OR APPROVED 2'•'.'.i/.-.* SUBSTITUTE WITH MINIMUM 8 11/4'/ PERFS. ^-V.?^ UNEAR FT. IN BOTTOM HALF OF PIPE. ASTM D2751. SDR 35 OR ASTM D1527. SCHD, AO ASTM D3Q34. SDR 35 OR ASTM D17B5. SCHD. 10 FOR CONTINUOUS RUN IN EXCESS OF 500 FT. USE B'fi PIPE 6-MINIMUM B-1 FILTER MATERIAL. SIEVE SIZE PERCENT PASSING t INCH .100 3/4 INCH .90-100 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 OVERLAP 6-MINIMUM COVER = 4- MINIMUM BEDDING A-2 B-2 4' MINIMUM BEDDING GRAVEL MATERIAL 9 FP/UNEAR FT. PERFORATED PIPE SEE ALTERNATE 1 GRAVEL- CLEAN 3/4 INCH ROCK OR APPROVED SUBSTITUTE FILTER FABRIC MIRAFI 140 OR APPROVED SUBSTITUTE PUTE 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 BACKCUTS^ARIES. FOR DEEP REMOVALS. ^ BACKCUT ^VKSHOULD BE MADE NO STEEPER THAIKJ:! OR AS NECESSARY FOR SAFETY r»/supincB»TiniJc ' CONSIDERATIONS, ORIGINAL GROUND SURFACE COMPACTED RLL ANTICIPATED ALLUVIAL REMOVAL 1 DEPTH PER SOIL ENGMCER. PROVIDE A 1:1 MINIMUM PROJECTION FROM TOE OF SLOPE AS SHOWN ON GRADING PLAN TO THE RECOHMENDEO REMOVAL DEPTH. SLOPE HEIGHT. SITE CONDITIONS ANO/OR LOCAL CONDITIONS COULD DICTATE FLATTER PROJECTIONS. REMOVAL ADJACENT TO EXISTING FILL ADJOINING CANYON RLL COMPACTED RLL LIMITS LIME rx TEMPORARY COMPACTED RLL \FOR DRAINAGE ONLY '^'^^ Qaf XQQI ITO BE REMOVEDL lEXISTING.COMP ACTED FILU ^\ Qaf TO BE REMOVED BEFORE PLACING ADDITIONAL COMPACTED RLL LEGEND Qaf ARTIFICIAL RLL Qal ALLUVIUM PLATE EG-3 TYPICAL STABILIZATION / BUTTRESS FILL DETAIL OUTLETS TO BE SPACED AT 100'MAXIMUM INTERVALS. AND SHALL EXTEND 12- BEYOND THE FACE OF SLOPE AT TIME OF.ROUGH GRADING COMPLETION. > H m m o I BLANKET FILL IF RECOMMENDED BY THE SOIL ENGINEER TYPICAL BENCHING 4" DIAMETER NON-PERFORATED OUTLET PIPE AND BACKDRAIN (SEE ALTERNATIVESI 3'MINIMUM KEY DEPTH ^ W=15"MINIMUM I OR H/2 Lll Q < Ql Q m CO to CO LU 01 OQ < if) < o CL >- LU O UJ m < X < o: UJ I- < tr UJ u. z o < U u. u UJ 0. U) (9 z i o o u. UJ X Z UJ -J < > 5 a UJ o UJ > o a. a. < z < tr o u z to I/) < Q. H Z UJ u cr UJ Q. UJ N to UJ > UJ tn ° o ^ o ^ rj o I I I I a o tn 00 !2 I I in o n I o at X X o u z Z ~" CN -r- o o o o g in ^ o o ^ Z Z 2 cr o z o < u E UJ 0. < « -i ^ Ul o 5 II cr o UJ X h- U. o UJ CO C2 z z < UJ .CL < > 5 a. UJ a UJ > o z UJ c cr UJ QL UJ CL UJ < > z y a u. < (/) ° s « X u z •<» fN o O . fM o z o in u. o ZD z UJ -J =3 a UJ < WJ UJ u. cr a. < ^ i U. w) ° z cr £ < o UJ < Z wi • OL z n: X LL >^ O t^ Z cr "E cn >- ^ 5 ^ -J 5 m w UJ ?t 2 »-S u. < ^ 2 u. 5 K HJ cr -1 tn n < < Ul 3E. 3 cr UJ u. < cr UJ cr UI u. o UJ UJ o u. cr o u z ?=| cr <l 3 u E cn if cr UJ o UJ > o cr CL Q. < z UJ u. o a Ul tn- oa < Ul < > a =} UJ 2 cr z ° 5 < i< ID UJ ts m «* r> o r> s ° t~ in I/) < I o a > 3E °-I- < I o iJ? ° cn < Ul u Q. CL UJ < < < l/l I/) -I 3 a Ul X u in fN in T a z »- in < <r o o z u. X O Ul </) «r & 3 3 CL 1 o b < £ z K o < w ^ .11. -1 i 3 S S O Z H Ul ? < X ^ oe CJ w o to • li; Z t£ in 5 Ul " 1 °' ^ O. Q I O UJ o o " 2 °. ^ »— W) to u. < o 5 fN P a. < a. Ul 2 w u. u. o LO z o cc o s i o o . u = tr cr -3 tO (O 00 a z Ul ce Ul cr I/) Ul (L n. 3 X H H- < a u Ul Il Ul -J a II a Ul U UJ z z o u Ul cn . I- m Ul —I a. Ul o. cr I- o Ul Ul —I Ul o X. ul ^ CL Ul E & I- °- Ul z H < IT = 3 « CD O 3 I- Ui a Ul 2^ u < • cn lu cn to Ul a. CL. I- Ul 3 O cr o X CJ z Ul cr Ul I- Ul cn z < cr C3 < z X Ul tn m m z < cr a < cr UJ >-cr UJ > UJ U. o -i < S 5 ^ in Q Ul Ul ^ a, ? i < Z < C3 0 o= Ul ^ a I- 1 < 5 < R > m -I fN UJ o S < >• 3 in -> z S < o cc > UJ z -J o Ul f-- • < lii u a o < -I cr cs 5 I-< o cr -J ° cr Ul Ui > E o LL -J to o tn «n 3 UJ 9 r- u U. O" O o z 5 2 IC H- IU UJ UJ DC Z U o i2 z a Ul Ul oc X o :! < < a cr Ul UJ cr Ul 3 5 a o UJ z cr UJ wnwiNiw.z PLATE EG-5 FILL OVER NATURAL DETAIL SIDEHILL FILL PROPOSED GRADE TOE OF SLOPE AS SHOWN ON GRADING PLAN PROVIDE A 1:1 MINIMUM PROJECTION FROM DESIGN TOE OF SLOPE TO TOE OF KEY AS SHOWN ON AS BUILT r- > m m o I cn NATURAL SLOPE TO BE RESTORED WITH COMPACTED FILL BACKCUT VARIES l6'MINIMUM KEY WIDTH 2'X 3'MINIMUM KEY DEPTH 2'MINIMUM IN BEOROCK OR APPROVED MATERIAL BENCH WIDTH MAY VARY "^3'. MINIMUM NOTE: 1. WHERE THE NATURAL SLOPE APPROACHES OR EXCEEDS THE DESIGN SLOPE RATIO. SPECIAL RECOMMENDATIONS WOULD BE PROVIDED BY THE SOILS ENGINEER. 2. THE NEED FOR AND DISPOSl.TION OF DRAINS WOULD BE DETERMINED BY THE SOILS ENOINEER BASED UPON EXPOSED CONDITIONS. FILL OVER CUT DETAIL riiT/FHi noNTACT 1, AS SHOWN ON GRADING PLAN 2. AS SHOWN ON AS BUILT MAINTAIN MINIMUM 15'RLL SECTION FROM BACKCUT TO FACE OF FINISH SLOPE BENCH WIDTH MAY VARY ^^/^ BEDROCK OR APPROVED MATERIAL LOWEST BENCH WIDTH 15'MiNIMUM OR H/2 Tl > -I m m o I NOTE; THE CUT PORTION OF THE SLOPE SHOULD BE EXCAVATED AND EVALUATED BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST PRIOR TO CONSTRUCTING THE RLL PORTION. STABILIZATION FILL FOR UNSTABLE MATERIAL EXPOSED IN PORTION OF CUT SLOPE TJ r- > -H m m o I CO . -pftr^ffRTT nr^lSHED GRADE <^,„ UNWEATHERED BEDROCK ^ OR APPROVED MATERIAL COMPACTED STABILIZATION RLL • 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, • 'W LALL BE EQUIPMENT WIDTH .IB'. FDR SLOPE HEIOHTS LESS THAN 25 FEET, FOR SLOPES GREATER- THAN 25 FEET SHALL BE DETERMINED BY THE PROJECT SOILS ENGINEER AND /OR ENGINEERING GEOLOGIST. AT NO TIME SHALL "W BE LESS THAN H/2. SKIN RLL OF NATURAL GROUND ORIGINAL SLOPE 15'MINIMUM TO BE MAINTAINED FROM PROPOSED RNISH SLOPE FACE TO BACKCUT PROPOSED FINISH SLOPE TJ ROPOSED FINISH GRADE J3'MINIMUM BEDROCK OR APPROVED MATERIAL 2'MINIMUM KEY DEPTH ^/[^!ii^yM\%^^//^K^^^^^ MINIMUM KEY DEPTH m m o I UD fNIMUM KEY WIDTH ' NECESSARY BY THE SOILS ENOINEER AND/OR ENOINEERINO GEOLOGIST. DAYLIGHT CUT LOT DETAIL RECONSTRUCT COMPACTED RLL SLOPE AT 211 OR FLATTER IMAY INCREASE OR DECREASE PAD AREA). NATURAL GRADE OVEREXCAVATE AND RECOMPACT REPLACEMENT RLL AVOID AND/OR CLEAN UP SPILLAGE OF MATERIALS ON THE NATURAL SLOPE 45'/ PROPOSED RNISH GRADE fr MINIMUM BLANKET FILL BEDROCK OR APPROVED MATERIAL TYPICAL BENCHING Ul 2'MINIMUM. KEY DEPTH T) r" > -H m m o I NOTE: 1. SUBDRAIN AND KEY WIDTH REQUIREMENTS WILL BE DETERMINED BASED ON EXPOSED SUBSURFACE CONDITIONS AND THICKNESS OF OVERBURDEN. „..rcrou.M.rn KIFPESSARY BY 2 PAD OVER EXCAVATION AND RECOMPACTION SHOULD BE PERFORMED IF DETERMINED NECESSARY THE SOILS ENGINEER AND/OR THE ENGINEERINO GEOLOGIST. TRANSITION LOT DETAIL CUT LOT (MATERIAL TYPE TRANSITION) NATURAL GRADE COMPACTED RLL OVEREXCAVATE AND RECOMPACT _ /^V/^^^xVW^^ J-MINIMUM* ^ UNWEATHERED BEDROCK OR APPROVED MATERIAL TYPICAL BENCHING CUT-RLL LOT (DAYUGHT TRANSITION) NATURAL GRADE jjJjS^ 5; MINIMUM -«^5A^>-r OVEREXCAVATE AND RECOMPACT \5 y UNWEATHERED BEDROCK OR APPROVED MATERIAL ^1. TYPICAL BENCHING NOTE- * DEEPER OVEREXCAVATION MAY BE RECOMMENDED BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST IN STEEP CUT-RLL TRANSITION AREAS. PLATE EG-11 SETTLEMENT PLATE AND RISER DETAIL 2'X 2'X 1/4- STEEL PLATE STANDARD 3/4- PIPE NIPPLE WELDED TO TOP OF PLATE. 3/4" X 5" GALVANIZED PIPE. STANDARD PIPE THREADS TOP AND BOTTOM. EXTENSIONS THREADED ON BOTH ENDS AND ADDED IN 5' INCREMENTS. 3 INCH SCHEDULE 40 PVC PIPE SLEEVE. ADD IN 5*INCREMENTS WITH GLUE JOINTS. RNAL GRADE I I 5' —rV" I I I I I 5' 1" ' I* • • • • . ^ • • 5* MAINTAIN 5'CLEARANCE OF HEAVY EQUIPMENT. ^MECHANICALLY HAND COMPACT IN 2'VERTICAL -T-V UFTS OR ALTERNATIVE SUITABLE TO AND J ACCEPTED BY THE SOILS ENGINEER. MECHANICALLY HAND COMPACT THE INITIAL 5' VERTICAL WITHIN A 5'RADIUS OF PLATE BASE. BOTTOM OF CLEANOUT PROVIDE A MINIMUM 1'BEDDING OF COMPACTED SAND NOTE: 1 LOCATIONS OF SETTLEMENT PLATES SHOULD BE CLEARLY MARKED AND READILY 2 S^A^TiS ItA5lD°Ml?NlATN^c"J!i^^^^^^^ RADIUS OF PLATE BASE AND ^ ^MTWs-'ivERTI^Au"^^^ KP'A'^T^E'D'B^AlTERNrSvE^ BE HAND COMPACTED TO PROJECT SPECIRCATIONS OR COMPACTED BY ALTERNATIVE 3 AFTER's^-r/rRTIcluSV'RLU CONTRACTOR SHOULD MAINTAIN A SlRADIUS EQUIPMENT CLEARANCE FROM RISER. CCTADI icuiwr 4. PLACE AND MECHANICALLY HAND COMPACT INITIAL 2* OF RLL PRIOR TO ESTABUSHING THE INITIAL READING. 5. IN THE EVENT OF DAMAGE TO THE SETTLEMENT PLATE OR EXTENSION RESVLTING FROM EQUIPMENT OPERATING WITHIN THE SPECIRED CLEARANCE AREA. CONTRACTOR SHOULD IMMEDIATELY NOTIFY THE SOILS ENGINEER AND SHOULD BE RESPONSIBLE FOR RESTORING THE SETTLEMENT PLATES TO WORKING ORDER. 6. AN ALTERNATE DESIGN AND METHOD OF INSTALLATION MAY BE PROVIDED AT THE DISCRETION OF THE SOILS ENGINEER. PLATE EG-U TYPICAL SURFACE SETTLEMENT MONUMENT RNISH GRADE •3'-6' 4-6- DIAMETER X 3 1/2'LENGTH HOLE 3/8" DIAMETER X 6" LENGTH CARRIAGE BOLT OR EQUIVALENT CONCRETE BACKRLL PLATE EG-15 TEST PIT SAFETY DIAGRAM SIDE VIEW ( NOT TO SCALE ) TOP VIEW 100 FEET APPROXIMATE CENTER OF TEST PIT ( NOT TO SCALE ) PLATE EG-16 OVERSIZE ROCK DISPOSAL VIEW NORMAL TO SLOPE FACE 20'MINIMUM 03 M (B) PROPOSED RNISH GRADE MINIMUM (E) 15'MINIMUM (A) oo oo (G) aoUri 15-MINIMUM (AJ^ oo oo Ts* MINIMUM (C) _____,._„^__^ /i\p/msU/m>^/-i-''/A^^^^ BEDROCK OR APPROVED MATERIAL VIEW PARALLEL TO SLOPE FACE PROPOSED RNISH GRADE FRDM - .' IXINIMUM (C» BEDROCK OR APPROVED MATERIAL NOTE: lAl ONE EQUIPMENT WIDTH OR A MINIMUM OF 15 fEET. B HEIGHT AND WIDTH MAY VARY DEPENDING ON ROCK SEE A^^^^ POUIPMPNT LENGTH OF WINDROW SHALL BE NO GREATER THAN 100 MAXIMUM, tci 1°XPPRO'JED BY T^E ioiLS ENGINEER AND/OR ENGlNKRING GEOLOa|T '°'?5IS5f^°E''NSrN^rR°l°N^/MN%VRKl^elf^^ ,E. S°A*lkSTu^'.EpT¥tS^NrHfs'lgu~^ SWIMMING POOLS. IFI ALL RL^ OVER AND AROUND ROCK WINDROW SHALL BE COMPACTED TO 90% IGI ll'r^l%l?°i^-^lEHZD^^^^ COMPACTED WITH THE UFT OF ffi."0VERING%DROW: WINDROW SHOULD BE PROOF ROLLED WITH A ?0(S °Are''DlAGlAXTic ONLY. ROCK SHOULD NOT TOUCH „, . -.j- pp-l AW VOIDS SHOULD BE COMPLETELY FILLED IN. PLATE RO —1 ROCK DISPOSAL PITS VIEWS ARE DIAGRAMMATIC ONLY. ROCK SHOULD NOT TOUCH AND VOIDS SHOULD BE COMPLETELY RLLED IN. RLL UFTS COMPACTED OVER ROCK AFTER EMBEDMENT r I I GRANULAR MATERIAL I I j COMPACTED RLL SIZE OF EXCAVATION TO BE COMMENSURATE WITH ROCK SIZE ROCK DISPOSAL UYERS GRANULAR SOIL TO RLL VOIDS. DENSIRED BY FLOODING ^ - LAYER ONE ROCK HIGH COMPACTED nu PROPOSED RNISH GRADE tlO'MINIMUM OR BELOW LOWEST UTIU 0CXDOcDGC3CCDaOc OVERSIZE LAYER PROFILE ALONG LAYER LOPE FACE COMPACTED RLL T3'MINIMUM CLEAR ZONE 20'MINIMUM LAYER ONE ROCK HIGH PLATE RD-2