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MS 06-11; 996-998 PINE AVENUE; PRELIMINARY GEOTECHNICAL INVESTIGATION; 2006-05-08
PRELIMINARY GEOTECHNICAL INVESTIGATION, 996 AND 998 PINE AVENUE, CARLSBAD, CALIFORNIA Prepared or. MR. BARRY COLLINS do Nowell and Associates 4010 Goldfinch Street ___ San Diego, California 92103 LJL— Project No. 041908-001 0 May 8, 2006 (revised August 21, 2007) I I © II II , II=I 1' Leighton and Associates, Inc. A LEIGHTON GROUP COMPANY (V JJ7 William D. Olson, RCE 45283 Senior Project Engineer D. Jensen, CEG 2547 A Geologist nE Leighton and Associates, Inc. A LEIGHTON GROUP COMPANY May 8, 2006 (revised August 21, 2007) Project No. 041908-001 To: Mr. Barry Collins do Newell and Associates 4010 Goldfinch Street San Diego, California 92103 Attention: Mr. Jeff Howard Subject: Preliminary Geotechnical Investigation, 996 and 998 Pine Avenue, Carlsbad, California In accordance with your request and authorization, we have prepared a preliminary geotechnical investigation report for the proposed residential development at 996 and 998 Pine Avenue located in Carlsbad, California. Based on the results of our study, it is our professional opinion that the residential development of the site is geotechnically feasible provided the recommendations provided herein are incorporated into the design and construction of the proposed improvements. The accompanying report presents a summary of the existing conditions of the site, the results of our field investigation and laboratory testing, and provides geotechnical conclusions and recommendations relative to the proposed residential development. If you have any questions regarding our report, please do not hesitate to contact this office. We appreciate this opportunity to be of service. Respectfully submitted, Ue NO. 2457 CERTIFIED Z LEIGHTON AND ASSOCIATES, INC Distribution: (6) Addressee 3934 Murphy Canyon Road, Suite B205 • San Diego, CA 92123-4425 858.292.8030 • Fax 858.292.0771 • www.leightongeo.com 041908-001 TABLE OF CONTENTS Section Page 1.0 INTRODUCTION..........................................................................................................1 1.1 PURPOSE AND SCOPE...............................................................................................1 1.2 SITE LOCATION AND DESCRIPTION .............................................................................. 1 1.3 PROPOSED DEVELOPMENT -------- --------- --- - - - - - - - - - - - - - - - - - -------- 2.0 SUBSURFACE EXPLORATION AND LABORATORY TESTING .............................................4 3.0 SUMMARY OF GEOTECHNICAL CONDITIONS ................................................................. 5 3.1 - REGIONAL GEOLOGY ................................................................................................5 3.2 SITE GEOLOGY .......................................................................................................5 3.2.1 Topsoil (Unmapped) ......................................................................................... 5 3.2.2 Quaternary Terrace Deposits (Map Symbol Qt)...................................................6 3.2.3 Tertiary Santiago Formation (Map Symbol Ts)......................................................6 3.3 GEOLOGIC STRUCTURE .............................................................................................6 3.4 GROUND WATER ....................................................................................................6 3.5 ENGINEERING CHARACTERISTICS OF ONSITE SOILS .........................................................7 3.5.1 Expansion Potential..........................................................................................7 3.5.2 Soil Corrosivity.................................................................................................7 3.5.3 Excavation Characteristics.................................................................................8 4.0 FAULTING AND SEISMICITY.........................................................................................9 4.1 FAULTING .............................................................................................................9 4.2 SEISMICITY ........................................................................................................... 9 4.2.1 Shallow Ground Rupture..................................................................................11 4.2.2 Liquefaction....................................................................................................11 4.2.3 Earthquake-Induced Settlement.......................................................................12 4.2.4 Tsunamis and Seiches.....................................................................................12 5.0 CONCLUSIONS...........................................................................................................13 6.0 RECOMMENDATIONS .................................................................................................14 6.1 EARTHWORK.........................................................................................................14 6.1.1 Site Preparation ................................................................................................ 14 6.1.2 Removal of Potentially Compressible Soils...........................................................14 6.1.3 Excavations and Oversize Material .................................................................... i5 6.1.4 Fill Placement and Compaction.........................................................................15 6.2 TREATMENT OF CUT/FILL TRANSITION ........................................................................15 6.3 FOUNDATION DESIGN CONSIDERATIONS.......................................................................16 6.3.1 Post-Tensioned Foundation Design...................................................................16 6.3.2 Conventionally Reinforced Foundation Design Foundation Design..........................18 6.3.3 Slab Subgrade Moisture Conditioning .................................................................20 Leighton 041908-001 TABLE OF CONTENTS (Continued) Section Page 6.4 LATERAL EARTH PRESSURES AND RETAINING WALL DESIGN CONSIDERATIONS.........................21 6.5 CEMENT TYPE FOR CONSTRUCTION .............................................................................22 6.6 CONCRETE FLATWORK.............................................................................................22 6.7 CONTROL OF GROUND WATER AND SURFACE WATER........................................................23 6.8 PRELIMINARY PAVEMENT DESIGN CONSIDERATIONS........................................................23 6.9 LANDSCAPING AND POST-CONSTRUCTION .....................................................................24 6.10 CONCRETE FLATWORK.............................................................................................26 6.11 CONSTRUCTION OBSERVATION AND PLAN REVIEW .......................................................... 26 7.0 LIMITATIONS ............................................................................................................27 TABLES TABLE 1 - SEISMIC PARAMETERS FOR ACTIVE FAULTS - PAGE 10 TABLE 2- POST-TENSIONED FOUNDATION DESIGN RECOMMENDATIONS - PAGE 16 TABLE 3- MINIMUM FOUNDATION AND SLAB DESIGN RECOMMENDATIONS FOR CONVENTIONALLY REINFORCED FOUNDATIONS - PAGE 19 TABLE 4- PRESOAKING RECOMMENDATIONS BASED ON FINISH GRADE SOIL EXPANSION POTENTIAL - PAGE 20 TABLE 5- LATERAL EARTH PRESSURES - PAGE 21 TABLE 6- PRELIMINARY PAVEMENT SECTIONS - PAGE 23 FIGURES FIGURE 1 - SITE LOCATION - PAGE 2 FIGURE 2- GEOTECHNICAL MAP - REAR OF Tocr APPENDICES APPENDIX A - REFERENCES APPENDIX B - BORING LOGS APPENDIX C - SUMMARY OF LABORATORY TESTING APPENDIX D - SEISMIC AND LIQUEFACTION ANALYSIS APPENDIX E - GENERAL EARTHWORK AND GRADING SPECIFICATIONS FOR ROUGH GRADING Leighton 041908-001 1.0 INTRODUCTION 1.1 Purpose and ScOpe This report presents the results of our preliminary geotechnical investigation for the proposed residential development at 996 and 998 Pine Avenue in Carlsbad, California (Figure 1). The purpose of our investigation was to evaluate the geotechnical conditions at the site and provide conclusions and recommendations relative to the proposed development. Our scope of services included the following: Review of published and unpublished geotechnical reports, maps and aerial photographs (Appendix A). Site reconnaissance. Coordination with Underground Services Alert (USA) to locate potential underground utilities on site. Excavation, logging and sampling of three exploratory borings. The boring logs are presented in Appendix B. Laboratory testing of representative soil samples obtained from the subsurface exploration program. Results of these tests are presented in Appendix C. Preparation of this report presenting our findings, conclusions, and geotechnical recommendations with respect to the proposed design, site grading and general construction considerations. 1.2 Site Location and Description The proposed residential development is located, in a previously developed area of Carlsbad, California. Currently, the site is occupied by two residential structures, one structure on the western portion of the site and the other on the southeastern portion of the site. Vegetation consists of citrus trees, grass, and light shrubs. The site is adjacent to existing residential properties on the east and the west, Pine Avenue to the south, and an apartment complex to the north. The existing surface elevation of the site ranges from an estimated 71 feet above mean sea level (msl) at the northeast corner of the site to approximately 69 feet msl at the southwest corner of the site. 4 -1- Leighton 0 .1,200 2,400 Scale in Feet Project No. Barry Collins I 996 and 998 Pine Avenue . LOCATION AII" &I 041908-001 Carlsbad, California Date MAP May 2006 Figure No.1 041908-001 1.3 Proposed Development We understand that the proposed residential development at 996 to 998 Pine Avenue will consist of four single-family condos. The residential structures will be two-stories wood- framed, with slab-on-grade construction. A private driveway will enter the site on the west side of the property from Pine Avenue. Associated improvements will include, retaining walls, underground utilities, hardscaping and landscaping. Grading plans and building foundation plans were reviewed to identify potential conflicts with the project geotechnical report (Leighton, 2007). -3- Leighton 041908-001 2.0 SUBSURFACE EXPLORATION AND LABORATORY TESTING Our subsurface exploration consisted of the excavation of three (3) exploratory borings. The approximate locations of the borings are shown on the Geotechnical Map, Figure 2. The purpose of these excavations was to evaluate the physical characteristics of the onsite soils pertinent to the proposed improvements. The borings allowed evaluation of the soils encountered within proposed excavation area, beneath the proposed subsurface structures, and provided representative samples for laboratory testing. Prior to drilling the exploratory excavations, Underground Service Alert was contacted to coordinate location and identification of nearby underground utilities. It should also be noted that no indications (odors, staining, etc.) of hydrocarbon impacted soils were observed during drilling. The exploratory excavations were logged by a project geologist from our firm. Representative bulk and undisturbed samples were obtained at frequent intervals for laboratory testing, logs of the borings are presented in Appendix B. Subsequent to logging and sampling, the current borings were backfilled with bentonite. Laboratory testing was performed on representative samples to evaluate the moisture, density, hydro-collapse potential, particle size, expansion potential and geo-chemical (corrosion) characteristics of the subsurface soils. A discussion of the laboratory tests performed and a summary of the laboratory test results are presented in Appendix C. In-situ moisture and density test results are provided on the boring logs (Appendix B). Leighton 041908-001 3.0 SUMMARY OF GEOTECHNICAL CONDiTIONS 3.1 Regional Geology The subject site is located in the coastal section of the Peninsular Range Province, a geomorphic province with a long and active geologic history throughout Southern California. Throughout the last 54 million years, the area known as the "San Diego Embayment" has undergone several episodes of marine inundation and subsequent marine regression, resulting in the deposition of a thick sequence of marine and nonmarine sedimentary rocks on the basement rock of the Southern California batholith. Gradual emergence of the region from the sea occurred in Pleistocene time, and numerous wave-cut platforms, most of which were covered by relatively thin marine and nonniarine terrace deposits, formed as the sea receded from the land. Accelerated fluvial erosion during periods of heavy rainfall, coupled with the lowering of the base sea level during Quaternary time, resulted in the rolling hills, mesas, and deeply incised canyons which characterize the landforms we see in the general site area today. 3.2 Site Geology Based on subsurface exploration, aerial photographic analysis, and review of pertinent geologic literature and maps, the geologic unit underlying the site consists of Quaternary- aged Terrace Deposits which overlies the Tertiary-aged Santiago Formation. The approximate areal distribution of this unit is depicted on the Geotechnical Exploration Map (Figure 2). A brief description of the geologic unit encountered on the site is presented below. 3.2.1 Topsoil (Unmapped) The topsoil encountered during our field investigation mantles the majority of the site. The topsoil, as observed, consisted predominantly of a light-brown to brown, damp to moist, loose, clayey to silty sands. These soils were generally massive, porous, and contained scattered roots and organics. The unsuitable topsoil is estimated to be from 2 to 3 feet in thickness; however, localized areas of thicker accumulations of topsoil may be encountered during grading. -5- S Leighton 041908-001 3.2.2 Quaternary Terrace DeDosits (Mao Symbol Qt Quaternary-aged Terrace Deposits were encountered at shallow depths during our investigation. As encountered, these soils were observed to generally consist of orange-brown, damp to slightly moist, medium dense to dense silty fine to medium grained sands. A relatively thin loose layer of friable sand was located 10 to 13 feet below existing ground surface (bgs). This unit was massive and abundant iron-oxide staining was visible within the samples. These deposits are considered suitable for support of fills and anticipated loads. 3.2.3 Tertiary-aged Santiago Formation (MaD Symbol Ts) The Tertiary-aged Santiago Formation underlies the entire site at depth. As encountered, the Santiago Formation generally consists of light brown to light gray silty sandstones. These materials are generally very dense although localized cemented zones may be present. These materials will likely not be encountered during site development 3.3 Geologic Structure Based on the results of our current investigation, literature review, and our professional experience on nearby sites, the Terrace Deposits are generally massive with no apparent bedding. 3.4 Ground Water Ground water was encountered in all borings during our investigation of the site. The ground water encountered at the site is likely perched on dense relatively impermeable Santiago Formation. Ground water was encountered at of depth 12 feet bgs (i.e., an approximate elevation of 58 feet msl). Ground water is not expected to impact the proposed development. However, seepage conditions may locally be encountered after periods of heavy rainfall or irrigation. These conditions can be treated on an individual basis if they occur. -6- Leighton 041908-001 3.5 Engineering Characteristics of Onsite Soils Based on the results of our current geotechnical investigation, laboratory testing of representative onsite soils, and our professional experience on adjacent sites with similar soils, the engineering characteristics of the onsite soils are discussed below. 3.5.1 Expansion Potential Based on laboratory test results and visual classification of the upper onsite soils are anticipated to be in the very low to low expansion range. Geotechnical observations and/or laboratory testing during site grading is recommended to determine the actual expansion potential of near-surface soils beneath the proposed building pads. 3.5.2 Soil Corrosivity The National Association of Corrosion Engineers (NACE) defines corrosion as "a deterioration of a substance or its properties because of a reaction with its environment". From a geotechnical viewpoint, the "environment" is the prevailing foundation soils and the "substances" are reinforced concrete foundations or various types of metallic buried elements such as piles, pipes, etc. that are in contact with or within close vicinity of the soil. In general soil environments that are detrimental to concrete have high concentrations of soluble sulfates and/or pH values of less than 5.5. Table 19A-4 of the 1997 UBC provides specific guidelines for the concrete mix-design when the soluble sulfate content of the soil exceeds 0.1 percent by weight or 1000 parts per million (j)pm). The minimum amount of chloride ions in the soil environment that are corrosive to steel, either in the form of reinforcement protected by concrete cover, or plain steel substructures such as steel pipes or piles is 500 ppm per California Test 532. The results of our laboratory tests on representative formational soils from the site indicated a soluble sulfate content of less than 0.015 percent and a pH of 7.4 which suggests that the concrete should be designed minimally in accordance with the negligible category of Table 19A-A-4 of the 2001 CBC. The test results also indicate a chloride content of 104 ppm, which is considered a threshold potential for chloride attack and a minimum resistivity value of 4,925 ohm-cm indicating a fair degree of corrOsivity. These findings indicate that the corrosive effects of the on-site soils on buried metal to be moderate and the corrosive effects on concrete are expected to be low to moderate. Laboratory testing should be performed on the soils placed at or near finish grade after completion of site grading to ascertain the actual corrosivity characteristics. We recommend that a corrosion engineer be -7- Leighton 041908-001 retained to design mitigative measures for materials that will be in contact with corrosive soils at the site. The test results are provided in Appendix C. 3.5.3 Excavation Characteristics It is anticipated the onsite soils can be excavated with conventional heavy-duty construction equipment. If oversize material (larger than 6 inches in maximum dimensions) is encountered, it should be placed in non-structural areas or hauled off site. -8- Leighton 041908-001 4.0 FAULTING AND SEISMICITY 4.1 Faulting Our discussion of faulting on the site is prefaced with a discussion of California legislation and state policies concerning the classification and land-use criteria associated with faults. By definition of the California Mining and Geology Board, an active fault is a fault which has had surface displacement within Holocene time (about the last 11,000 years). The State Geologist has defined a potentially active fault as any fault considered to have been active during Quaternary time (last 1,6000,000 years) but that has not been proven to be active or inactive. This definition is used.in delineating Fault-Rupture Hazard Zones as mandated by the Aiquist-Priolo Earthquake Fault Zoning Act of 1972 and as revised in 1997 (Hart, 1997). The intent of this act is to assure that unwise urban development does not occur across the traces of active faults. Based on our review of the Fault-Rupture Hazard Zones, the site is not located within a Fault-Rupture Hazard Zone as created by the Alquist-Priolo Act (Hart, 1997) and recently modified. Our review of available geologic literature (Appendix A) indicates that there are no known major or active faults on or in the immediate vicinity of the site. The nearest active regional fault is the Newport-Inglewood Fault Zone located offshore approximately 5.0 miles west of the site. 4.2 Seismicity The site can be considered to lie within a seismically active region, as can all of Southern California. Table 1 (below) identifies potential seismic events that could be produced by the maximum moment magnitude earthquake. A maximum moment magnitude earthquake is the maximum expectable earthquake given the known tectonic framework. Site-specific seismic parameters included in Table 1 are the distances to the causative faults, earthquake magnitudes, and expected ground accelerations. The ground motion was calculated using the computer software EQFAULT (Blake, 2000) and the attenuation relationship by Abrahamson & Silva (1997) for a soil site profile. 4 -9- Leighton 041908-001 Table 1 Seismic Parameters for Active Faults Distance Maximum Peak One Standard Potential from Fault Credible Horizontal Deviation of Peak Causative to Site Earthquake Ground Horizontal Ground Fault (Miles/kin) (Moment Acceleration Acceleration Magnitude) (g) (g) Newport- 5.0/8.1 7.1 0.35 0.19 Inglewood Rose Canyon 5.3/8.6 7.2 0.34 0.19 Fault Zone Coronado 21.1/34.0 7.6 0.15 0.08 Bank Elsinore - Julian. 24.2/39.0 7.1 0.11 0.06 As indicated in Table 1, the Newport-Inglewood Fault Zone is the 'active' fault considered having the most significant effect at the site from a design standpoint. A maximum credible earthquake of moment magnitude M7.1 on the fault could produce an estimated peak horizontal ground acceleration of 0.35g at the site (0.19g at one standard deviation). The Newport-Inglewood Fault Zone is considered to be a Type B seismic source according to the California Building Code (CBSC, 2001) and the California Division of Mines and Geology (CDMG, 2002). Summary printouts of the deterministic analyses are provided in Appendix D of this report. From a probabilistic standpoint, the design ground motion is defined as the ground motion having a 10 percent probability of exceedance in 50 years. This ground motion is referred to as the maximum probable ground motion (CBSC, 2001). Based on review of statewide mapping at the California Geological Survey website (www.consrv.ca.gov/cgs/rghmlpshamap/pshamain.html), the maximum probable ground motion at the site is postulated to be 0.30g (CGS, 2004). Site-specific analysis should be performed if this value is utilized in structural design. The effect of seismic shaking may be mitigated by adhering to the California Building Code or state-of-the-art seismic design parameters of the Structural Engineers -10- Leighton 041908-001 Association of California. The site is located within Seismic Zone 4. The soil profile type for the site is considered Type Sc(CBSC, 2001). Site coefficients Na of 1.0 and N of 1.1 are considered appropriate based on proximity to seismic sources. Secondary effects that can be associated with severe ground shaking following a relatively large earthquake include shallow ground rupture, soil liquefaction and dynamic settlement, seiches and tsunamis. These secondary effects of seismic shaking are discussed in the following sections. 4.2.1 Shallow Ground Rupture Ground rupture because of active faulting is not likely to occur on site due to the absence of known active faults. Cracking due to shaking from distant seismic events is not considered a significant hazard, although it is a possibility at any site in Southern California. 4.2.2 Uauefaction Liquefaction and earthquake-induced settlement of soils can be caused by strong vibratory motion due to earthquakes. Research and historical data indicate that loose granular soils underlain by a near surface ground water table are most susceptible to liquefaction, while the stability of most clayey material are not adversely affected by vibratory motion. Liquefaction is characterized by a loss of shear strength in the affected soil layer, thereby causing the soil to behave as a viscous liquid. This effect may be manifested at the ground surface by settlement and, possibly, sand boils where insufficient confining overburden is present over liquefied layers. Where sloping ground conditions are present, liquefaction- induced instability can result. Liquefaction potential analyses and earthquake-included settlement calculations were performed utilizing the computer program LiquefyPro (CivilTech, 2002) considering the ground motions resulting from an earthquake (i.e., PGA = 0.3g) and a maximum moment magnitude event for the Newport-Inglewood Fault of M7. 1. The program follows procedures suggested by the most recent publications of the NCEER Workshop (NCEER, 1997) and SP 117 Implementation (CDMG, 1997) based on SPT blow counts recorded during our subsurface exploration program and grain size characteristics of the subsurface soils. Based on the results of our subsurface exploration, geotechnical analysis and dynamic settlement calculations, it is our professional opinion that the overall -11- Leighton 041908-001 liquefaction hazard to the proposed development is considered low. A discussion on earthquake-induced settlement is presented in the following section. 4.2.3 Earthquake-Induced Settlement Based on the results of our subsurface exploration and the results of our analysis, a total and differential dynamic settlement at the site as a result of a maximum moment magnitude earthquake of M7.1 and the ground motions resulting from an earthquake is estimated at less than 1 inch and 1/2 inch, respectively. Summary plots showing idealized profiles, fines content, calculated cyclic stress and resistance ratio, factor of safety, and liquefaction-induced settlement are provide in Appendix E. 4.2.4 Tsunamis and Seiches Based on the distance between the site and large, open bodies of water, and the elevation of the site with respect to sea level, the possibility of seiches and/or tsunamis is considered to be low. -12- Leighton 041908-001 5.0 CONCLUSIONS . S Based on the results of our geotechnical investigation of the site, it is our professional opinion that the proposed residential development is feasible from a geotechnical standpoint, provided the following conclusions and recommendations are implemented during the design and construction of the project. The following is a summary of the significant geotechnical factors that may affect development of the site. Based on laboratory testing and visual classification, the onsite soils generally possess a very low to low expansion potential. The existing onsite soils appear to be suitable material for use as compacted fill provided they are relatively free of organic material, debris, and rock fragments larger than 8 inches in maximum dimension. Based on laboratory testing, the onsite soils are expected to have a negligible potential for sulfate attack on concrete. These soils are also considered to have a low to moderate potential for corrosion to buried uncoated metal conduits. Laboratory testing should be performed on the finish grade soils to verify the corrosivity characteristics. Based on the results of our exploration, we anticipate that the onsite materials can be excavated with conventional heavy-duty earthwork equipment. Perched ground water was encountered at a depth of approximately 12 feet below the ground surface during our investigation. Active or potentially active faults are not known to exist on or in the immediate vicinity of the site. -13- Leighton 041908-001 6.0 RECOMMENDATIONS 6.1 Earthwork We anticipate that earthwork at the site will consist of site preparation, removals of potentially compressible soil, undercutting the building pad for transitional areas, fill placement, and trench excavation and backfill. We recommend that earthwork on site be performed in accordance with the following recommendations, the City of Carlsbad grading requirements, and the General Earthwork and Grading Specifications for Rough-Grading (GEGS) included in Appendix E. In case of conflict, the following recommendations shall supersede those included as part of Appendix E. 6.1.1 Site Preparation Prior to the grading of areas to receive structural fill or engineered structures, the areas should be cleared of surface obstructions, debris, vegetation, and potentially compressible material. Vegetation and debris should be removed and properly disposed of offsite. Holes results from the removal of buried obstructions which extend below finished site grades should be replaced with suitable compacted fill material. Areas to receive fill should be scarified to a minimum depth of 12 inches, brought to optimum or above optimum moisture condition, and recompacted to at least 90 percent relative compaction (based on American Standard of Testing and Materials [ASTM] Test Method D1557). 6.1.2 Removal of Potentially Compressible Soils Portions of the site are underlain by potentially compressible soils that may settle under the surcharge of fill and/or foundation loads. These materials include topsoil and weathered formational material. Compressible materials not removed by the planned grading should be excavated to either competent material beneath the proposed building footprint and proposed private drive. We estimate removals will be on the order of 2 to 3 feet. The actual depth and extent of the required removals should be determined during grading operations by the geotechnical consultant. The excavated soil may be reused as fill provided it is moisture conditioned optimum or above optimum moisture content (see Section 6.1.4 below for fill placement and compaction requirements). 4 -14- Leighton 041908-001 6.1.3 Excavations and Oversize Material Excavations of the onsite materials may generally be accomplished with conventional heavy-duty earthmoving equipment. In accordance with OSHA requirements, utility excavations between 5 and 15 feet in depth should be shored or laid back to inclinations of 1:1 (horizontal to vertical) if workers are to enter such excavations. For excavations deeper than 15 feet, specific recommendations can be made on a case-by-case basis. We do not anticipate the generation of significant quantities of oversize material. Oversize material (greater than 6 inches maximum dimension), if encountered, should be handled in accordance with the General Earthwork and Grading Specifications for Rough Grading presented in Appendix E. 6.1.4 Fill Placement and Compaction The onsite soils are generally suitable for use as compacted fill provided they are free of organic material, debris, and rock fragments larger than 6-inches in maximum dimension. All fill soils should be brought optimum or above-optimum moisture conditions and compacted in uniform lifts to at least 90 percent relative compaction based on laboratory standard ASTM Test Method D1557. The optimum lift thickness required to produce a uniformly compacted fill will depend on the type and size of compaction equipment used. In general, fill should be placed in lifts not exceeding 8 inches in thickness. Placement and compaction of fill should be performed in general accordance with the current city grading ordinances, sound construction practices, and the General Earthwork and Grading Specifications for Rough Grading presented in Appendix E. 6.2 Treatment of Cut/Fill Transition With the recommendations presented above, no cut-fill transitions are anticipated. If they do occur, we recommend that the entire cut portion of transition (cut-fill) building areas be overexcavated to a minimum depth of 3 feet below finished grade and replaced with properly compacted fill of very low to low expansion potential. This depth maybe increased depending on adjacent fill depth. The overexcavation and recompaction should laterally extend at least 5 feet beyond limits of the building footprint. Upon completion of overexcavation, the area to receive fill should be scarified, brought to optimum moisture, and recompacted to at least 90% relative compaction. -15- Leighton 041908-001 6.3 Foundation Design Considerations Based on our investigation of the site and professional experience with similar sites in the general vicinity, we anticipate that the proposed residential structures will be underlain by soil having a very low to low expansion potential (i.e. an expansion index less than 50 per CBC Standard 18-2). Our analysis also indicates that the fill thickness differential on the lot should be less than 4 feet. Therefore, the residential structure on the lot may be constructed with a post-tensioned or conventional foundation assuming very low to low expansive soil. That is, in utilizing these recommendations, foundation deflections should be within tolerable structural limits. The structural engineer/architect should review these recommendations to ensure that the foundation is designed for the acceptable deflection of the structure. 6.3.1 Post-Tensioned Foundation Design We recommend that the post-tensioned slab be designed in general accordance with the following design parameters presented in Table 2 and criteria of the current edition of the California Building Code. Table 2 Post-Tensioned Foundation Design Recommendations Design Criteria Edge Moisture Variation, em Center Lift: 5.5 feet Edge Lift: 2.5 feet Differential Swell, Ym Center Lift: 1.0 inches Edge Lift: 0.4 inches Short Term Differential Settlement 1/2 inch Modulus of Subgrade Reaction: 200 pci The post-tensioned foundation and slab should also be designed in accordance with structural considerations. Continuous footings with a minimum width of 12 inches and a minimum depth of 18 inches below lowest adjacent soil grade may be designed for a maximum allowable bearing pressure of 2,000 pounds per square foot. The allowable bearing capacity may be increased by one-third for -16- Leighton 041908-001 short-term loading. Where the foundation is within 3 feet (horizontally) of adjacent drainage swales, the adjacent footing should be embedded a minimum depth of 12 inches below the swale flow line. The slab should be underlain by a minimum of 2 inches of clean sand (sand equivalent greater than 30), which is in turn underlain by a vapor barrier (i.e. 10- mil plastic sheeting), and an additional 2 inches of clean sand. The sandy onsite soils may be considered for the lower level of sand if approved by the geotechnical consultant during grading. The vapor barrier should be sealed at all penetrations and laps. Moisture vapor transmission through the concrete slabs may be additionally reduced by use of concrete additives. Moisture barriers can retard, but not eliminate moisture vapor movement from the underlying soil up through the slabs. We recommend that the floor covering installer test the moisture vapor flux rate prior to attempting applications of the flooring. "Breathable" floor coverings should be considered if the vapor flux rates are high. A slip-sheet or equivalent should be utilized above the concrete slab if crack-sensitive floor coverings (such as ceramic tiles, etc.) are to be placed directly on the concrete slab. Our* experience indicates that use of reinforcement in slabs and foundations will generally reduce the potential for drying and shrinkage cracking. However, some cracking should be expected as the concrete cures. Minor cracking is considered normal; however, it is often aggravated by a high water/cement ratio, high concrete temperature at the time of placement, small nominal aggregate size, and rapid moisture loss due to hot, dry and/or windy weather conditions during placement and curing. Cracking due to temperature and moisture fluctuations can also be expected. The use of low slump concrete (not exceeding 4 to 5 inches at the time of placement) can reduce the potential for shrinkage cracking and the action of tensioning the tendons can close small shrinkage cracks. In addition, the application of 50 percent of the design post-tensioning loading within three to four days of slab pour is found to be an effective method of reducing the cracking potential. The slab subgrade soil underlying the post-tensioned foundation systems should be presoaked prior to placement of the moisture barrier and slab concrete as indicated in Section 6.3.3. it -17- Leighton 041908-001 6.3.2 Conventionally Reinforced Foundation Design Foundation Design Conventionally reinforced foundations should be designed and constructed in accordance with the recommendations contained in Table 3 based on a very low to low expansion potential. -18- Leighton 041908-001 Table 3 Minimum Foundation And Slab Design Recommendations For Conventionally Reinforced Foundations : - UBC Expansion Index (less than 50) Very Low to Low Expansion 1-Story Footings All footings 12 inches deep. Reinforcement for continuous footings: (See Note 1) two No. 5 bar top and bottom. 2-Story Footings All footings 18 inches deep. Reinforcement for continuous footings: (See Note 1) two No. 5 bar top and bottom. Minimum Footing Width Continuous: 12 inches for 1-story Continuous: 15 inches for 2-story Isolated column: 24 inches (18 inches deep minimum) Garage Door Grade Beam A grade beam 12 inches wide and 18 inches deep (See Note 2) should be provided across the garage entrance. Living Area Floor Slabs Minimum 5 inch thick slab with No. 3 bars @ 18 inches on center, (See Notes 3,4 and 6) each way (at midheight) on 2 inches clean sand over moisture barrier over 2 inches clean sand. Garage Floor Slabs Minimum 5 inch thick concrete slab with No. 3 bars @ 18 inches on (See Notes 4, 5 and 6) center, each way (at midheight) on 2 inches sand base over moisture barrier on pad. Slab should be quarter-sawn. Presoaking of Living Area Optimum moisture content to a depth of 6 inches. and Garage Slabs (see note) Allowable Bearing Capacity 2,000 pounds per square foot (one-third increase for short term loading) Expected Foundation Deflection: 1/2 inch in 50 feet Notes: (I) Depth of interior or exterior footing to be measured from lowest adjacent finish grade or drainage swale flowline elevation. The base of the grade beam should be at the same elevation as that of the adjoining footings. Living area slabs should be tied to the footings as directed by the structural engineer. 10-mil (non-recycled product) plastic sheeting. Equivalents are acceptable. All laps and penetrations should be sealed. Garage slabs should be isolated from stem wall footings with a minimum 3/8-inch expansion joint. Sand base should have a Sand Equivalent of 30 or greater (e.g. washed concrete sand) Presoaking of the basement not required. The recommendations presented above assume that proper maintenance irrigation and drainage are maintained around the structure. The vapor barrier recommended in Table 3 should be sealed at all penetrations and laps. Moisture vapor transmission may be additionally reduced by use of concrete additives. Moisture barriers can retard but not eliminate moisture vapor movement -19- Leighton 041908-001 from the underlying soil up through the slabs. We recommend that the floor covering installer test the moisture vapor flux rate prior to attempting applications of the flooring. "Breathable" floor coverings should be considered if the vapor flux rates are high. A slipsheet or equivalent should be utilized above the concrete slab if crack-sensitive floor coverings (such as ceramic tiles, etc.) are to be placed directly on the concrete slab. Our experience indicates that use of reinforcement in slabs and foundations will generally reduce the potential for drying and shrinkage cracking. However, some cracking should be expected as the concrete cures. Minor cracking is considered normal; however, it is often aggravated by a high water content, high concrete temperature at the time of placement, small nominal aggregate size, and rapid moisture loss due to hot, dry and/or windy weather conditions during placement and curing. Cracking due to temperature and moisture fluctuations can also be expected. The use of low water content concrete can reduce the potential for shrinkage cracking. The slab subgrade soil underlying the conventional foundation systems should be presoaked prior to placement of the moisture barrier and slab concrete as indicated in Section 6.3.3. 6.3.3 Slab Subrade Moisture Conditioning The slab subgrade soil underlying the post-tensioned or conventional foundation system should be presoaked in accordance with the recommendations presented in Table 4 prior to placement of the moisture barrier and slab concrete. The subgrade soil moisture content should be checked by a representative of Leighton and Associates prior to slab construction. Table 4 Presoaking Recommendations Based on Finish Grade Soil Expansion Potential Expansion Potential (CBC 18-i-B) Presoaking Recommendations Very 1.0w to Low Optimum moisture content to a depth of at least 6 inches -20- Leighton 041908-001 6.4 Lateral Earth Pressures and Retaining Wall Design Considerations For design purposes, the following lateral earth pressure values for level or sloping backfill are recommended for walls backfihled with on-site soils or approved granular material of very low to low expansion potential. Table 5 Lateral Earth Pressures Equivalent Fluid Weight (pci) Level Backfill 2:1 Sloping Backfill Active 35 60 At-Rest 55 65 Passive 350 350 Embedded structural walls should be designed for lateral earth pressures exerted on them. The magnitude of these pressures depends on the amount of deformation that the wall can yield under load. If the wall can yield enough to mobilize the full shear strength of the soil, it can be designed for "active" pressure. If the wall cannot yield under the applied load, the shear strength of the soil cannot be mobilized and the earth pressure will be higher. Such walls should be designed for "at-rest" conditions. If a structure moves toward the soil, the resulting resistance developed by the soil is the "passive" resistance. The passive earth pressure values assumes sufficient slope setback. For design purposes, the recommended equivalent fluid pressure for each case for walls founded above the static ground water and backfilled with import soil of very low to low expansion potential or the onsite soil is provided in Table 5. The equivalent fluid pressure values assume free-draining conditions. If conditions other than those assumed above are anticipated, the equivalent fluid pressure values should be provided on an individual-case basis by the geotechnical engineer. Surcharge loading effects from the adjacent structures should be evaluated by the geotechnical and structural engineer. All retaining wall structures should be provided with appropriate drainage and appropriately waterproofed. The outlet pipe should be sloped to drain to a suitable outlet. Typical wall drainage design is illustrated in Appendix E. 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. Wall footings should be designed in accordance with structural considerations. The passive resistance value may be increased by one-third 4 -21- Leighton 041908-001 when considering loads of short duration such as wind or seismic loads. The horizontal distance between foundation elements providing passive resistance should be a minimum of three times the depth of the elements to allow full development of these passive pressures. 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 back-cut excavations should be made in accordance with the applicable OSHA requirements. The backfill soil (having an expansion index less than 50 per CBC 18-I-B) should be compacted to at least 90 percent relative compaction (based on ASTM Test Method D1557) at moisture content of at least 2 percent above optimum. The walls should be constructed and backfihled as soon as possible after back-cut excavation. Prolonged exposure of back-cut slopes may result in some localized slope instability. Foundations for retaining walls in competent formational soil or properly compacted fill should be embedded at least 18 inches below lowest adjacent grade. At this depth, an allowable bearing capacity of 2,000 psf may be assumed. 6.5 Cement TyDe for Construction Concrete in direct contact with soil or water that contains a high concentration of soluble sulfates can be subject to chemical deterioration commonly known as "sulfate attack". Based on the laboratory test results of the representative samples, the onsite soil possesses a negligible potential to attack normal concrete. Accordingly, we recommend that the onsite concrete design mix be designed for a negligible potential of sulfate attack and follow the recommendations presented in Table 19-A-4 of the 2001 edition of the CBC. Laboratory testing of the actual finish grade soil on the lot upon completion of the grading operations should be performed to confirm the sulfate attack potential. 6.6 Concrete Flatwork Concrete sidewalks and other flatwork (including construction joints) should be designed by the project civil engineer or architect and should have a minimum thickness of 4 inches. For all concrete flatwork, the upper 12 inches of subgrade soil should be moisture conditioned to at least 2 percent above optimum moisture content and compacted to at least 90 percent relative compaction based on ASTM Test Method D1557 prior to the concrete placement. -22- Leighton 041908-001 6.7 Control of Ground Water and Surface Water Subsurface water was encountered during our investigation, however we do not anticipate that the onsite groundwater is a constraint to the proposed development given the depth groundwater encountered during site field investigation. Our experience indicates that shallow ground water/perched ground water conditions can develop in areas where no such ground water conditions existed prior to site development, especially in areas where a substantial increase in surface water infiltration results from landscape irrigation. We recommend that an engineering geologist be present during grading operations to explore for future seepage areas and provide field recommendations for mitigation of future potential seepage. Ground water was encountered in all borings during our investigation of the site. The ground water encountered at the site is likely perched on dense relatively impermeable Santiago Formation. Ground water was encountered at of depth 12 feet bgs (i.e., an approximate elevation of 58 feet msl). Ground water is not expected to impact the proposed development. However, seepage conditions may locally be encountered after periods of heavy rainfall or irrigation. These conditions can be treated on an individual basis if they occur. We recommend that measures be taken to properly finish grade the site such that drainage water is directed away from top-of-slopes and away from proposed structures. No ponding of water should be permitted. Drainage design is within the purview of the design civil engineer. 6.8 Preliminary Pavement Design Considerations The appropriate pavement section depends primarily on the type of subgrade soil, shear strength, traffic load, and planned pavement life. Since an evaluation of the characteristics of the actual soils at pavement subgrade cannot be made at this time, we have provided the following pavement sections to be used for planning purposes only. The final subgrade shear strength will be highly dependent on the soils present at finish pavement subgrade. However, for preliminary planning purposes, we have assumed an R-value of 15 for the pavement subgrade soils assuming a blend of the materials on site. The preliminary pavement design sections have been provided on Table 6. Final pavement designs should be completed in accordance with the City of Carlsbad design criteria after R-value tests have been performed on actual subgrade materials. Table 6 Preliminary Pavement Sections -23- Leighton 041908-001 Traffic Index Pavement Sections (20-Year Life) (Assumed R-Value of 15) 4.5 4 inches AC over 5 inches Class 2 base 5.0 4 inches AC over 6 inches Class 2 base For areas subject to unusually heavy truck loading (i.e., trash enclosures, loading docks, etc.), we recommend a full depth of Portland Cement Concrete (PCC) section of 7.5 inches on 6 inches of Class 2 aggregate base with appropriate steel reinforcement and crack-control joints as designed by the project structural or civil engineer. We recommend that sections be as nearly square as possible. A mix that provides a 600 psi modulus of rupture should be utilized. The actual pavement design should also be in accordance with City of Carlsbad and ACI criteria. All pavement section materials should conform to and be placed in accordance with the latest revision of the Greenbook and American Concrete Institute (ACI) codes and guidelines. Prior to placing the AC or PCC pavement section, the upper 12 inches of subgrade soils and all aggregate base should have relative compaction of at least 95 percent (based on ASTM Test Method D1557). If pavement areas are adjacent to heavily watered landscape areas, we recommend some measure of moisture control be taken to prevent the subgrade soils from becoming saturated. It is recommended that the concrete curb separating the landscaping area from the pavement extend below the aggregate base to help seal the ends of the sections where heavy landscape watering may have access to the aggregate base. Concrete swales should be designed in roadway or parking areas subject to concentrated surface runoff. 6.9 Landscaping and Post-Construction Landscaping and post-construction practices exert significant influences on the integrity of structures founded on expansive soil. Improper landscaping and post-construction practices, which are beyond the control of the geotechnical engineer, are frequently the primary cause of distress to these structures. Recommendations for proper landscaping and post- construction practices are provided in the following paragraphs within this section. Adhering to these recommendations will help in minimizing distress due to expansive soil, and in ensuring that such effects are limited to cosmetic damages, without compromising the overall integrity of proposed structures. Initial landscaping should be done on all sides adjacent to the foundation of a structure or associated improvements, and adequate measures should be taken to ensure drainage of water away from the foundation or improvement. If larger, shade providing trees are 4 -24- Leighton 041908-001 desired, such trees should be planted away from structures or improvements (at a minimum distance equal to half the mature height of the tree) in order to prevent penetration of the tree roots beneath the foundation of the structure or improvement. -25- Leighton 041908-001 6.10 Concrete Flatwork Concrete sidewalks and other flatwork (including construction joints) should be designed by the project civil engineer or architect and should have a minimum thickness of 4 inches. For all concrete fiatwork, the upper 18 inches of subgrade soil should be moisture conditioned to at least 3 percent above optimum moisture content and compacted to at least 90 percent relative compaction based on ASTM Test Method D1557 prior to the concrete placement. 6.11 Construction Observation and Plan Review Construction observation of all onsite excavations and field density testing of all compacted fill should be performed by a representative of this office so that construction is in accordance with the recommendations of this report. We recommend that excavations be geologically mapped by the geotechnical consultant during grading for the presence of potentially adverse geologic conditions. Project grading and foundation drawings should be reviewed by Leighton and Associates, Inc. before excavation to see• that the recommendations provided in this report are incorporated in the project plans. .4 -26- Leighton 041908-001 7.0 LIMITATIONS The conclusions and recommendations in this report are based in part upon data that were obtained from a limited number of observations, site visits, excavations, samples, and tests. Such information is by necessity incomplete. The nature of many sites is such that differing geotechnical or geological conditions can occur within small distances and under varying climatic conditions. Changes in subsurface conditions can and do occur over time. Therefore, the findings, conclusions, and recommendations presented in this report can be relied upon only if Leighton has the opportunity to observe the subsurface conditions during grading and construction of the project, in order to confirm that our preliminary findings are representative for the site. -27- Leighton / \ / ,,//\ \ m / NORTH / / 00~ Shed / / / B-I \ GW@12' Qt TD=19.5 'S B-3 'S GW@12 'S TD=16.5' 'S Qt 'S 'S \ \\ 'S 'S 'S \ B-2 'S GW©12' 'S 'S Existin TD=19.5' \ esidence 'S Existing 'S \ Residence \ 'S 'S 'S 'S \ >, / Qt Driveway // LEGEND \ 'S / Qt Quaternary Terrace Deposits 'S / B-I Approximate location of \ // l!l$ GW@12 TD--19.5'geotechnical boring 'S / 2' Project No. 041908-001 GE OTE C H N I CAL MAP Not to scale Geol Barry Collins Drafted By KAM 996 and 998 Pine Avenue Date May 2006 Carlsbad, California Leighton and Associates, Inc. Figure A IEIOHTON GROUP COMPANY 041908-001 APPENDIX A References Abrahamson, N.A., and Silva, W.J., 1997, Empirical Response Spectral Attenuation Relationships for Shallow Crustal Earthquakes, Seismological Research Letters, 1997, Volume 68, Number 1, Seismological Society of America, Pub. pp. 94-127. Blake, 2000, EQFAULT, Ver. 3.00b. California Building Standards Commission (CBSC), 2001, California Building Code, Volumes 1 and 2. California Division of Mines and Geology (CDMG), 1995, Landslide Hazards in the Northern Part of the San Diego Metropolitan Area, San Diego County, California, Open-File Report 95-04. 1996, Probabilistic Seismic Hazard Assessment for the State of California, Open-File Report, 96-08. California Geological Survey (CGS), 2004, California Probabilistic Seismic Hazard Maps, November 2004. Carlsbad, City of, 2004, City of Carlsbad, Engineering Standards, Volumes 1-3, California, dated April 20, 1993, revised December 10, 1996. Hart, E.W., 1997, Fault-Rupture Hazard Zones in California, Aiquist-Priolo Earthquake Fault Zoning with Index to Special Study Zones Maps: Department of Conservation, Division of Mines and Geology, Special Publication 42. International Conference of Building Officials (ICBO), 1997, Uniform Building Code. Jennings, C.W., 1994, Fault Activity Map of California and Adjacent Areas, with Locations and Ages of Recent Volcanic Eruptions: California Division of Mines and Geology, California Geologic Data Map Series, Map No. 6, Scale 1:750,000. Kennedy, M.P., 1975, Geology of the San Diego Metropolitan Area, California: California Division of Mines and Geology Bulletin 200, 38p. Leighton and Associates, Inc., 2007, Foundation and Grading Plan Review, Proposed Condominiums Units 1 through 4, 996-998 Pine Avenue, Carlsbad, California, Project No. 041908-001, dated June 14, 2007. A-i GEOTECHNICAL BORING LOG KEY Date Sheet I of I Project KEY TO BORING LOG GRAPHICS Project No. Drilling Co. Type of Rig Hole Diameter Drive Weight Elevation lop of Elevation - - • - - - - Location E a) Z >10 • DESCRIPTION O , V - .2 0 E 0 CL i & Logged By 81 1 Sampled By _________________________________________ _ _ _ _ _ _ _ — 0 _______ - - - ______________________________ Asphaltic concrete J 4. - Portland cement concrete .. Inorganic clay of low to medium plasticity; gravelly clay; sandy clay Drop .. a) I— MM Inorganic silt; diatomaceous fine sandy or silty soils; elastic Clayey silt to silty clay Poorly graded gravel; gravel-sand little or no fines - - - W Well-graded gravel; gravel-sand mixture, little or no fines SW 1. Well-graded sand; gravelly sand, little or no fines —Sr Poorly graded sand; gravelly sand, little or no fines : - - 5M Silty sand; poorly graded sand-silt mixture Ground water encountered at time of drilling B-I Bulk Sample C-' Core Sample Grab Sample R-1 Modified California Sampler (3" O.D., 2.5 I.D.) SH- 1 Shelby Tube Sampler (3" O.D.) S-I Standard Penetration Test SPT (Sampler (2" O.D., 1.4" LD.) SAMPLE TYPES: TYPE OF TESTS: S SPLIT SPOON G GRAS SAMPLE OS DIRECT SHEAR R RING SAMPLE SH SHELBY TUBE MD MAXIMUM DENSITY B BULK SAMPLE CN CONSOLIDATION I TUBE SAMPLE CR CORROSION LEIGHT SA SIEVEANALYSIS 4 AT ATTERBURG UMITS El EXPANSION INDEX RV R-VAL.UE TES. INC. GEOTECHNICAL BORING LOG B-i Date 3-24-06 Sheet 1 of 1 Project Barry Collins/Pine Avenue Project No. 041908-001 Drilling Co. Scott's Drilling Type of Rig Hollow-Stem Auger Hole Diameter 8" Drive Weight 140 pound hammer Drop 30" Elevation Top of Elevation 70' Location - iU - . WO v z • - 00 o d- CL - 0 ce... >0 102 DESCRIPTION - 0Z a - • - , Logged By MDJ Sampled By MDJ I- 70 0— '.* - SM TOPSOIL @04 @04.5: Silty medium SAND: Dark brown, moist; medium dense - :. .. QUATERNARY TERRACE DEPOSITS (Ot' R-1 ® 1.5': Silty medium SAND: Red-brown, damp, very dense 65 5— @ 5': Silty medium SAND: Red-brown, damp, medium dense to dense R-2 42 109.3 5.0 - . B-2 - . .. ... @8': Silty medium SAND with clay: Red-brown, moist; medium - ..• dense; friable 60 10-7—r., ,. 101: Silty fine SAND: Red-brown, moist, medium dense - .. S-I 13 SP-S? IT: Ground water encountered (boring left opened for 3 hours) - ... tr UQm.9f.bo1ing_____________ c15-7' -,TERTIARY SANTIAGO FORMA11ON (Tsa) R-3 60/6" SM SM @ 15': Silty medium SANDSTONE: Pale brown to off-white, damp, very - S-2 50/5" 50 20— Total Depth= 19.5 Feet - Ground water encountered at 12 feet at time of drilling Backfilled with bentonite on 3/24/06 45 25- 4030— SAMPLE TYPES: TYPE OF TESTS: An S SPLIT SPOON G GRAB SAMPLE OS DIRECT SHEAR SA SIEVE ANALYSIS R RING SAMPLE SH SHELBY TUBE MD MAXIMUM DENSITY AT ATTERBURG LIMITS B BULK SAMPLE CM CONSOLIDATION El EXPANSION INDEX I TUBE SAMPLE CR CORROSION RV R-VALUE LEIGHTON AND ASSOCIATES, INC. GEOTECHNICAL BORING LOG B-2 Date 3-24-06 Sheet 1 of I Project Barry Collins/Pine Avenue Project No. 041908-001 Drilling Co. Scoffs Drilling Type of Rig Hollow-Stem Auger Hole Diameter 8" Drive Weight 140 pound hammer Drop 30" Elevation Top of Elevation 70' Location 0 I 4•I 1a,ui— DESCRIPTION i l.,i I z • I I 1 li..—'ll .o I . I a. .ELL I-i DO- —! 0 Etth>g (Ifl. I13 LoggedBy MDJ 0 Sampled By MDJ i '— Silty SAND with clay: Dark brown, moist, loose NARY TERRACE DEPOSITS (Ofl ltv fine SAND: Light red-brown. darno. dense R-I I 63 1124.11 16.8 (..J Changed at 5.5' M @6': Silty fine to medium SAND: Red-brown, damp to moist, S-I W 12 mediwn dense @9': Silty fine SAND: Light orange-brown, damp, medium dense; R-2 I 22 I I ISP-SMI friable I (Ii 12': Groundwater encountered 8-2 166 12': Silty fine to coarse SAND: Light gray, moist, loose @13-I I hR11AY SANTIAGO FORMATION crsa) R-3 60/6" SM @ 15': Silty medium to coarse SANDSTONE: Light gray, moist, very dense @ 18': Silty medium to coarse SANDSTONE: Light gray, moist, very S-3 89 dense Total Depth = 19.5 Feet Ground water encountered at 12 feet at time of drilling Backfilled with bentonite on 3t24/06 TYPE OF TESTS: G GRAB SAMPLE OS DIRECT SHEAR SA SIEVE ANALYSIS SH SHELBY TUBE MD MAXIMUM DENSITY AT ATTERBURG LIMITS CN CONSOLIDATION El EXPANSION INDEX CR CORROSION RV R-VALUE LEIGHTON AND ASSOCIATES, INC. rk SAMPLE TYPES: S SPLIT SPOON R RING SAMPLE B BULK SAMPLE T TUBE SAMPLE GEOTECHNICAL BORING LOG B-3 Date 3-24-06 Sheet I of I Project Barry Collins/Pine Avenue Project No. 041908-001 Drilling Co. Scoffs Drilling Type of Rig Hollow-Stem Auger Hole Diameter 8" Drive Weight 140 pound hammer Drop 30" Elevation Top of Elevation 69' Location . g CLO ' 0 FA D ru OIL me 'a .2"- . . . i DESCRIPTION Logged By MDJ Sampled By MDJ i I— O- - - -SM TOPSOIL Silty SAND: Dark brown, damp, loose QUATERNARY TERRACE DEPOSITS 65 - : : @3': Silty fine SAND: Red-brown, damp, dense R-I 56 @5': Silty fine SAND: Red-brown, damp, dense Hit looser material, per driller. Silty fine to medium SAND: Red brown, damp, medium dense; % - . R-2 33 friable 10— :-• -• -,-• - ..• ._: SPSK @ II': Silty medium SAND: Light gray, moist medium dense; friable - .. . @ 12': Ground water encountered (perched slowly into hole) - -. .. R-3 40 108.9 16.6 - ' .-11: S-I 87 SM 4hU j' - rTrhorntl 5': Silty fine to medium SANDIDNE: Light gray-brown/oliv; amp. verylDepth=l6Feet und water encountered at 12 feet at time of drilling - Backfilled with bentonite on 3124/06 50 - 20- 45 - 25- 40 - 30— SAMPLE TYPES: TYPE OF TESTS: S SPLIT SPOON G GRAB SAMPLE DS DIRECT SHEAR SA SIEVE ANALYSIS R RING SAMPLE SH SHELBY TUBE MD MAXIMUM DENSITY AT ATTERBURG LIMITS B BULK SAMPLE CN CONSOLIDATION El EXPANSION INDEX T TUBE SAMPLE CR CORROSION RV R-VALUE 4 LEIGHTON AND ASSOCIATES, INC. 041908-001 APPENDIX C Laboratory Testing Procedures and Test Results Chloride Content: Chloride content was tested in accordance with Caitrans Test Method CT422. The results are presented below: Sample Location Chloride Content, ppm Chloride Attack Potential* B-i @ 0'-3' 104 Threshold *per City of San Diego Program Guidelines for Design Consultant, 1992. Hydro-consolidation Tests: Hydro-consolidation tests were performed on selected relatively undisturbed ring samples. Samples were placed in a consolidometer and a load approximately equal to the in-situ overburden pressure was applied. Water was then added to the sample and the percent hydro-consolidation for the load cycle was recorded as the ratio of the amount of vertical compression to the original 1-inch height. The percent hydro-consolidation is presented on the attached figures. Expansion Index Tests: The expansion potential of a selected material was evaluated by the Expansion Index Test, U.B.C. Standard No. 18-2 and/or ASTM Test Method 4829. Specimens are molded under a given compactive energy to approximately the optimum moisture content and approximately 50 percent saturation or approximately 90 percent relative compaction. The prepared 1-inch thick by 4-inch diameter specimens are loaded to an equivalent 144 psf surcharge and are inundated with tap water until volumetric equilibrium is reached. The results of these tests are presented in the table below: Sample Location Sample Description Compacted Dry Expansion Expansion Density (pcf) Index Potential B-i, 0-3 Feet Brown Silty SAND 118.0 0 Very Low Moisture Determination Tests: Moisture content determinations (ASTM Test Method D2216) were performed on disturbed ring samples obtained from the test borings. The results of these tests are presented in the boring logs. Where applicable, only the moisture content was determined from disturbed samples. C-i 041908-001 APPENDIX C (Continued) Minimum Resistivity and pH Tests: Minimum resistivity and pH tests were performed in general accordance with Caltrans Test Method CT643 for Steel or C1532 for concrete and standard geochemical methods. The results are presented in the table below: Sample Sample Description pH Minimum Resistivity Location (ohms-cm) B-i @ 0'-3' Brown Silty Sand 7.44 29,682 Percent Passing No. 200 Sieve (ASTM D1140) Percent Passing No. 200 Sieve analysis was performed according to ASTM D1140. The percent fine particles from these analyses are summarized below. Boring Depth (feet) Percent Passing No. 200 Sieve B-i 12-13 15 Soluble Sulfates: The soluble sulfate contents of a selected sample was determined by standard geochemical methods (Caltrans Test Method CT417). The test results are presented in the table below: Sample Location Sample Description Sulfate Content (%) Potential Degree of Sulfate Attack* B-i @ 0'-3' Brown Silty Sand 0.015 Negligible asea on me iyii eainon or me unironn Building Code, Table No. 19-A-4, prepared by the International Conference of Building Officials (ICBO, 1997). C-2 4' Leighton and Associates, Inc. One-Dimensional Swell or Settlement Potential of Cohesive Soils (ASTM D 4546) Project Name: COLLINS I PINE AVE. Project No.: 041908-001 Boring No.: B-3 Sample No.: R-2 Sample Description: SM, REDDISH BROWN SILTY SAND. Initial Dry Density (pcf): 106.0 Initial Moisture (%): 7.3 Initial Length (in.): 1.0000 Initial Dial Reading: 0.0500 Diameter(in): 2.416 Tested By: JG/BM Date: 4/5/06 Checked By: Date: ;4i7io6..: Sample Type: IN SITU Depth (ft.) 8.0 Final Dry Density (pcf): 108.8 Final Moisture (%): 16.1 Initial Void ratio: 0.5897 Specific Gravity(assumed): 2.70 Initial Saturation (%) 33.4 Pressure (p) Final Reading Apparent Load Swell (+) Settlement Corrected Thickness Compliance % of Sample Void Ratio Deformation ° Thickness o) - 0525 , 00605.r 09895 000 -105 05730 -105 .. fr 1 051 41 . 0 0662 0.9838 0.00 -1.62 0.5639 -1.62 H2O 0.9749 0.00 -2.51 0.5498 -2.51 Percent Swell I Settlement After Inundation =1 -0.90 I Void Ratio - Log Press=Curve 0.6000 - 0.5900 - 0.5800 - 0.5700 - 0 - Q:: 0.5600 - 0.5500 - 0.5400 - 0.5300 - 0.5200 - 0.010 Inundate with water 0.100 1.000 10.000 Log Pressure (ksf) Rev. 0804 cse-sn 8-3. R-2 Leighton and Associates, Inc. One-Dimensional Swell or Settlement Potential of Cohesive Soils (ASTM D 4546) Project Name: COLLINS I PINE AVE. Project No.: 041908-001 Boring No.: B-2 Sample No.: R-2 Sample Description: SM, OLIVE BROWN SILTY SAND Tested By: KD Date: 4/6/06 Checked By: .FtC Date::.. Sample Type: IN SITU Depth (ft.) 9 Initial Dry Density (pcf): 102.4 Initial Moisture (%): 4.5 Initial Length (in.): 1.0000 Initial Dial Reading: 0.0500 Diameter(in): 2.416 Final Dry Density (pcf): 103.8 Final Moisture (%) : 18.4 Initial Void ratio: 0.6464 Specific Gravity(assumed): 2.70 Initial Saturation (%) 1 18.6 . Swell (+) Pressure (p) Final ReadingAppa rent Load Settlement Corrected Thickness Compliance Void Ratio Deformation (S Sample (%) (in) (%) Thickness - . .....j.... 0.9865 0.00 -1.35 0.6242 -1.35 .. . . .• .. . O1oigf. :': 0.9821 0.00 -1.79 0.6170 -1.79 H20 'l-MaJollita40i 0.9860 0.00 -1.40 06234 -1.40 Percent Swell I Settlement After Inundation =1 0.40 I Void Ratio - Log Pressure Curve 0.6300 0.6200 Inundate with water 0.6100 0.6000 4- 0.010 0.100 1.000 10.000 Log Pressure (ksf) Rev. oa.04 CcIse.Se8.Z R-2 ** * * * * * * ** * * * * * E Q F A U L T * * * * Version 3.00 * * * ** *** * * *** DETERMINISTIC ESTIMATION OF PEAK ACCELERATION FROM DIGITIZED FAULTS JOB NUMBER: 041908-001 DATE: 04-04-2006 JOB NAME: Barry Colins I Pine Area CALCULATION NAME: Runi FAULT-DATA-FILE NAME: CGSFLTE.DAT SITE COORDINATES: SITE LATITUDE: 33.1604 SITE LONGITUDE: 117.3422 SEARCH RADIUS: 100 ml ATTENUATION RELATION: 23) Abrahamson & Silva (1995b/1997) Horiz.- Soil UNCERTAINTY (M=Median, S=Sigma): M Number of Sigmas: 0.0 DISTANCE MEASURE: clodis SCOND: 0 Basement Depth: 5.00 km Campbell ssR: Campbell SHR: COMPUTE PEAK HORIZONTAL ACCELERATION FAULT-DATA FILE USED: CGSFLTE.DAT MINIMUM DEPTH VALUE (km): 0.0 --------------- EQFAULT SUMMARY --------------- ----------------------------- DETERMINISTIC SITE PARAMETERS ----------------------------- Page 1 ESTIMATED MAX. EARTHQUAKE EVENT ------------------------- 5.0( 5.3( 21.1( 24.0( 24.2( 33.4( 35.0( 35.6( 44.1( 45.7( 46.5( 47.0( 47.4( 50.91 52.4( 58.3( 59.5 61.1 65.5( 65.5( 65.5 65.5 66.5 67.7( 70.01 70.4 71.51 72.91 74.6 76.6 76.7 77.11 78.51 78.51 78.5i 78.81 79.81 79.81 80.01 81.91 NEWPORT-INGLEWOOD (Offshore) ROSE CANYON CORONADO BANK ELSINORE (TEMECULA) ELSINORE (JULIAN) ELSINORE (GLEN IVY) SAN JOAQUIN HILLS PALOS VERDES EARTHQUAKE VALLEY NEWPORT-INGLEWOOD (L.A. Basin) SAN JACINTO-ANZA SAN JACINTO-SAN JACINTO VALLEY CHINO-CENTRAL AVE. (Elsinore) WHITTIER SAN JACINTO-COYOTE CREEK ELSINORE (COYOTE MOUNTAIN) SAN JACINTO-SAN BERNARDINO PUENTE HILLS BLIND THRUST SAN ANDREAS - San Bernardino M-1 SAN ANDREAS - whole M-la SAN ANDREAS - SB-Coach. M-lb-2 SAN ANDREAS - SB-Coach. M-2b SAN JACINTO - BORREGO SAN JOSE CUCAMONGA SIERRA MADRE PINTO MOUNTAIN SAN ANDREAS - Coachella M-1c-5 NORTH FRONTAL FAULT ZONE (West) UPPER ELYSIAN PARK BLIND THRUST BURNT MTN. CLEGHORN SAN ANDREAS - 1857 Rupture M-2a SAN ANDREAS - cho-Moj M-lb-1 SAN ANDREAS - Mojave M-1c-3 RAYMOND CLAMSHELL-SAWPIT NORTH FRONTAL FAULT ZONE (East) EUREKA PEAK VERDUGO 8.1) 8.6) 34.0) 38.6) 39.0) 53.7) 56.4) 57.3) 70.9) 73.5) 74.9) 75.6) 76.3) 81.9) 84.4) 93.8) 95.8) 98.4) 105.4) 105.4) 105.4) 105.4) 107.0) 108.9) 112.6) 113.3) 115.1) 117.4) 120.1) 123.2) 123.5) 124.1) 126.4) 126.4) 126.4) 126.8) 128.4) 128.5) 128.8) 131.8) MAXIMUM EARTHQUAKE MAG. (MW) 7.1 7.2 7.6 6.8 7.1 6.8 6.6 7;3 6.5 7.1 7.2 6.9 6.7 6.8 6.6 6.8 6.7 7.1 7.5 8.0 7.7 7.7 6.6 6.4 6.9 7.2 7.2 7.2 7.2 6.4 6.5 6.5 7.8 7.8 7.4 6.5 6.5 6.7 6.4 6.9 PEAK SITE ACCEL. g 0.349 0.344 0.151 0.100 0.112 0.075 0.081 0.089 0.050 0.065 0.068 0.058 0.065 0.051 0.045 0.045 0.042 0.063 0.060 0.078 0.067 0.067 0.035 0.039 0.050 0.059 0.047 0.046 0.056 0.034 0.029 0.029 0.061 0.061 0.048 0.035 0.035 0.039 0.026 0.043 EST. SITE INTENSITY MOD.MERC. IX IX VIII VII VII VII VII VII VI VI VI VI VI VI VI VI VI VI VI VII VI VI V V VI VI VI VI VI V V V VI VI VI V V V V VI APPROXIMATE ABBREVIATED DISTANCE FAULT NAME mi (km) ----------------------------- DETERMINISTIC SITE PARAMETERS Page 2 ESTIMATED MAX. EARTHQUAKE EVENT APPROXIMATE ABBREVIATED DISTANCE MAXIMUM I PEAK JEST. SITE FAULT NAME mi (km) J EARTHQUAKE1 SITE JINTENSITY MAG.(Mw) I ACCEL. 9 J MOD.MERC. SUPERSTITION MTN. (San Jacinto) 1 83.0( 133.5)1 6.6 1 0.028 1 V HOLLYWOOD 1 83.8( 134.9)1 6.4 1 0.031 1 V ELMORE RANCH 1 86.6( 139.3)1 6.6 1 0.027 I V LANDERS I 87.1( 140.1)1 7.3 1 0.042 1 VI SUPERSTITION HILLS (San Jacinto)I 87.6( 141.0)1 6.6 1 0.027 1 V HELENDALE - S. LOCKHARDT 1 88.0( 141.6)1 7.3 1 0.041 1 V SANTA MONICA 1 88.0( 141.7)1 6.6 1 0.034 1 V LAGUNA SALADA 1 89.7( 144.3)1 7.0 1 0.034 1 V MALIBU COAST 1 91.4( 147.1)1 6.7 1 0.035 1 V LENWOOD-LOCKHART-OLD WOMAN SPRGS 92.0( 148.1)1 7.5 I 0.045 1 VI JOHNSON VALLEY (Northern) 1 94.6( 152.3)1 6.7 I 0.026 1 V SIERRA MADRE (San Fernando) 1 94.8( 152.6)1 6.7 1 0.033 1 V BRAWLEY SEISMIC ZONE 1 95.5( 153.7)1 6.4 1 0.022 1 IV NORTHRIDGE (E. oak Ridge) 1 95.9( 154.3)1 7.0 1 0.040 1 V EMERSON So. - COPPER MTN. 1 95.9( 154.4)1 7.0 1 0.032 I V SAN GABRIEL 1 96.6( 155.5)1 7.2 1 0.036 I v ANACAPA-DUME 1 96.7( 155.7)1 7.5 1 0.054 1 vi ******************************************************************************* -END OF SEARCH- 57 FAULTS FOUND WITHIN THE SPECIFIED SEARCH RADIUS. THE NEWPORT-INGLEWOOD (Offshore) FAULT IS CLOSEST TO THE SITE. IT IS ABOUT 5.0 MILES (8.1 km) AWAY. LARGEST MAXIMUM-EARTHQUAKE SITE ACCELERATION: 0.3486 g * ** * ** ** * * *** * * * * * * * ** * * * E Q F A U L T * * * version 3.00 * * * DETERMINISTIC ESTIMATION OF PEAK ACCELERATION FROM DIGITIZED FAULTS JOB NUMBER: 041908-001 DATE: 04-04-2006 JOB NAME: Barry ColinS / Pine Area CALCULATION NAME: Run2 FAULT-DATA-FILE NAME: CGSFLTE.DAT SITE COORDINATES: SITE LATITUDE: 33.1604 SITE LONGITUDE: 117.3422 SEARCH RADIUS: 100 ml ATTENUATION RELATION: 23) Abrahamson & Silva (1995b/1997) Horiz.- Soil UNCERTAINTY (M=Median, S=Sigma): S Number of Sigmas: 1.0 DISTANCE MEASURE: clodis SCOND: 0 Basement Depth: 5.00 km Campbell SSR: Campbell SHR: COMPUTE PEAK HORIZONTAL ACCELERATION FAULT-DATA FILE USED: CGSFLTE.DAT MINIMUM DEPTH VALUE (km): 0.0 --------------- EQFAULT SUMMARY --------------- ----------------------------- DETERMINISTIC SITE PARAMETERS ----------------------------- Page 1 ------------------------------------------------------------------------------- ESTIMATED MAX. EARTHQUAKE EVENT APPROXIMATE ABBREVIATED DISTANCE MAXIMUM I PEAK lEST. SITE FAULT NAME mi (km) JEARTHQUAKE1 SITE JINTENSITY MAG.(Mw) I ACCEL. 9 JMOD.MERC. NEWPORT-INGLEWOOD (Offshore) 1 5.0( 8.1)1 7.1 1 0.536 1 x ROSE CANYON I 5.3( 8.6)1 7.2 1 0.529 1 X CORONADO BANK 1 21.1( 34.0)1 7.6 1 0.232 1 Ix ELSINORE (TEMECULA) 1 24.0( 38.6)1 6.8 1 0.158 1 VIII ELSINORE (JULIAN) 1 24.2( 39.0)1 7.1 1 0.172 1 viii ELSINORE (GLEN Ivy) 1 33.4( 53.7)1 6.8 1 0.118 1 vii SAN JOAQUIN HILLS 1 35.0( 56.4)1 6.6 1 0.132 1 VIII PALOS VERDES 1 35.6( 57.3)1 7.3 I 0.136 1 VIII EARTHQUAKE VALLEY 1 44.1( 70.9)1 6.5 I 0.082 1 vii NEWPORT-INGLEWOOD (L.A.Basin) 1 45.7( 73.5)1 7.1 1 0.101 1 VII SAN JACINTO-ANZA 1 46.5( 74.9)1 7.2 1 0.104 1 VII SAN JACINTO-SAN JACINTO VALLEY 1 47.0( 75.6)1 6.9 1 0.090 1 vii CHINO-CENTRAL AVE. (Elsinore) 47.4( 76.3)1 6.7 1 0.103 vii WHITTIER 50.9( 81.9)1 6.8 1 0.080 VII SAN JACINTO-COYOTE CREEK 52.4( 84.4)1 6.6 1 0.072 VII ELSINORE (COYOTE MOUNTAIN) 58.3( 93.8)1 6.8 1 0.071 VI SAN JACINTO-SAN BERNARDINO 59.5( 95.8)1 6.7 1 0.067 VI PUENTE HILLS BLIND THRUST 61.1( 98.4)1 7.1 1 0.097 1 VII SAN ANDREAS - San Bernardino M-11 65.5( 105.4)1 7.5 1 0.092 1 VII SAN ANDREAS - whole M-la 1 65.5( 105.4)1 8.0 1 0.121 1 vii SAN ANDREAS - SB-Coach. M-lb-2 1 65.5( 105.4)1 7.7 1 0.102 1 vii SAN ANDREAS - SB-Coach. M-2b 6S-.5( 105.4)1 7.7 1 0.102 vii SAN JACINTO - BORREGO 66.5( 107.0)1 6.6 1 0.057 VI SAN JOSE 67.7( 108.9)1 6.4 1 0.065 I VI CUCAMONGA 1 70.0( 112.6)1 6.9 I 0.078 I VII SIERRA MADRE I 70.4( 113.3)1 7.2 I 0.091 vii PINTO MOUNTAIN I 71.5( 115.1)1 7.2 1 0.072 VI SAN ANDREAS - Coachella M-1c-5 I 72.9( 117.4)1 7.2 1 0.071 VI NORTH FRONTAL FAULT ZONE (West) I 74.6( 120.1)1 7.2 1 0.087 1 VII UPPER ELYSIAN PARK BLIND THRUST 1 76.6( 123.2)1 6.4 1 0.057 1 vi BURNT MTN. 1 76.7( 123.5)1 6.5 1 0.047 1 VI CLEGHORN 1 77.1( 124.1)1 6.5 1 0.047 1 VI SAN ANDREAS - 1857 Rupture M-2a 1 78.5( 126.4)1 7.8 1 0.094 1 VII SAN ANDREAS - Cho-Moj M-lb-1 1 78.5( 126.4)1 7.8 1 0.094 1 vii SAN ANDREAS - Mojave M-1c-3 1 78.5( 126.4)1 7.4 1 0.074 1 VII RAYMOND 1 78.8( 126.8)1 6.5 1 0.058 1 VI CLAMSHELL-SAWPIT 1 79.8( 128.4)1 6.5 1 0.058 1 VI NORTH FRONTAL FAULT ZONE (East) 1 79.8( 128.5)1 6.7 1 0.063 1 VI EUREKA PEAK 1 80.0( 128.8)1 6.4 1 0.043 1 VI VERDUGO 1 81.9( 131.8)1 6.9 1 0.068 I VI ----------------------------- DETERMINISTIC SITE PARAMETERS Page 2 I J ESTIMATED MAX. EARTHQUAKE EVENT I APPROXIMATE ABBREVIATED I DISTANCE MAXIMUM I PEAK lEST. SITE FAULT NAME I mi (km) J EARTHQUAKE1 SITE IINTENSITY MAG.(Mw) I ACCEL. 9 IMOD.MERC. SUPERSTITION MTN. (San Jacinto) I 83.0( 133.5)1 6.6 1 0.046 I VI HOLLYWOOD I 83.8( 134.9)1 6.4 I 0.052 I VI ELMORE RANCH I 86.6( 139.3)1 6.6 1 0.044 I vi LANDERS I 87.1( 140.1) 7.3• 1 0.064 I VI SUPERSTITION HILLS (San )acinto)I 87.6( 141.0)1 6.6 1 0.044 1 vi HELENDALE - S. LOCKHARDT I 88.0( 141.6)1 7.3 1 0.064 I VI SANTA MONICA I 88.0( 141.7)1 6.6 1 0.055 1 vi LAGUNA SALADA I 89.7( 144.3)1 7.0 1 0.052 1 VI MALIBU COAST I 91.4( 147.1)1 6.7 1 0.055 I VI LENWOOD-LOCKHART-OLD WOMAN SPRGSI 92.0( 148.1)1 7.5 1 0.069 I VI JOHNSON VALLEY (Northern) I 94.6( 152.3)1 6.7 1 0.042 1 VI SIERRA MADRE (San Fernando) I 94.8( 152.6)1 6.7 1 0.053 1 VI BRAWLEY SEISMIC ZONE 1 95.5( 153.7)1 6.4 1 0.036 1 V NORTHRIDGE (E. Oak Ridge) I 95.9( 154.3)1 7.0 1 0.061 1 VI EMERSON So. - COPPER MTN. I 95.9( 154.4)1 7.0 1 0.049 1 VI SAN GABRIEL I 96.6( 155.5)1 7.2 1 0.055 1 VI ANACAPA-DUME I 96.7( 155.7)1 7.5 1 0.083 1 VII -END OF SEARCH- 57 FAULTS FOUND WITHIN THE SPECIFIED SEARCH RADIUS. THE NEWPORT-INGLEWOOD (Offshore) FAULT IS CLOSEST TO THE SITE. IT IS ABOUT 5.0 MILES (8.1 km) AWAY. LARGEST MAXIMUM-EARTHQUAKE SITE ACCELERATION: 0.5359 g CALIFORNIA FAULT MAP Barry Colins / Pine Area ivy iou zuu 250 300 350 400 100 50 0 -50 -100 -150 -200 150 LIQUEFACTION ANALYSIS Barry Colins/Pine Area Hole No. =8-2 Water Depth12 ft Surface Elev. =70 Soil Description Raw Unit Fines Shear Stress Ratio SPTWe,qht% 0 nn - III III fs I fsl 1.30 20 LIZOK TSJ- TSZ - VVaL Shaded Zone has Liquefaction Potential S = 0.971n. 25 I ft 4 Leighton & Associates, Inc. 041908-001 TO I— 10 I— 15 Silty medium SAND, ,c IcI It dense to very dense 12 14 5 7 Tertiary 74 89 Magnitude=7. I Acceleration=0.30g Factor of Safety Settlement 2 01 5 0(in.) 1 D-2 IT Silty medium SAND, red-brown, medium dense to very dense Tertiary Santiago Formation - fs fsl 1.30 —5 —10 H 15 26 13 5 74 100 LIQUEFACTION ANALYSIS Barry Colins/Pine Area Hole No.-B-1 Water Depth12 ft Surface Elev.70 Magnitude=7.1 Acceleration=0.30g Soil Descnption Raw Unit Fines Shear Stress Ratio Factor of Safety Settlement (It) SPT Wesht4.1 0 2 0 1 5 0 (in.) GHM - uit rs— 782 - wet— U 20 Shaded Zone has Liquefaction Potential S = 0.49 in. I— 25 - 30 I 2 lU— 35 Leighton & Associates, Inc. 041908-001 0-1 Leighton and Associates, Inc. GENERAL EARTHWORKAND GRADING SPECIFICATIONS Page lof6 LEIGHTON AND ASSOCIATES, INC. GENERAL EARTHWORK AND GRADING SPECIFICATIONSFOR ROUGH GRADING 1.0 General 1.1 Intent: These General Earthwork and Grading Specifications are for the grading and earthwork shown on the approved grading plan(s) and/or indicated in the geotechnical report(s). These Specifications are a part of the recommendations contained in the geotechnical report(s). In case of conflict, the specific recommendations in the geotechnical report shall supersede these more general Specifications. Observations of the earthwork by the project Geotechnical Consultant during the course of grading may result in new or revised recommendations that could supersede these specifications or the recommendations in the geotechnical report(s). 1.2 The Geotechnical Consultant of Record: Prior to commencement of work, the owner shall employ the Geotechnical Consultant of Record (Geotechnical Consultant). The Geotechnical Consultants shall be responsible for reviewing the approved geotechnical report(s) and accepting the adequacy of the preliminary geotechnical findings, conclusions, and recommendations prior to the commencement of the grading. Prior to commencement of grading, the Geotechnical Consultant shall review the "work plan" prepared by the Earthwork Contractor (Contractor) and schedule sufficient personnel to perform the appropriate level of observation, mapping, and compaction testing. During the grading and earthwork operations, the Geotechnical Consultant shall observe, map, and document the subsurface exposures to verify the geotechnical design assumptions. If the observed conditions are found to be significantly different than the interpreted assumptions during the design phase, the Geotechnical Consultant shall inform the owner, recommend appropriate changes in design to accommodate the observed conditions, and notify the review agency where required. Subsurface areas to be geotechnicallyobserved, mapped, elevations recorded, and/or tested include natural ground after it has been cleared for receiving fill but before fill is placed, bottoms of all "remedial removal" areas, all key bottoms, and benches made on sloping ground to receive fill. The Geotechnical Consultant shall observe the moisture-conditioningand processing of the subgrade and fill materials and perform relative compaction testing of fill to determine the attained level of compaction. The Geotechnical Consultant shall provide the test results to the owner and the Contractor on a routine and frequent basis. 3030.1094 Leighton and Associates, Inc. GENERAL EARTHWORK AND GRADING SPECIFICA11ONS Page 2 of 6 1.3 The Earthwork Contractor: The Earthwork Contractor (Contractor) shall be qualified, experienced, and knowledgeable in earthwork logistics, preparation and processing of ground to receive fill, moisture-conditioning and processing of fill, and compacting fill. The Contractor shall review and accept the plans, geotechnical report(s), and these Specifications prior to commencement of grading. The Contractor shall be solely responsible for performing the grading in accordance with the plans and specifications. The Contractor shall prepare and submit to the owner and the Geotechnical Consultant a work plan that indicates the sequence of earthwork grading, the number of "spreads" of work and the estimated quantities of daily earthwork contemplated for the site prior to commencement of grading. The ContractOr shall inform the owner and the Geotechnical Consultant of changes in work schedules and updates to the work plan at least 24 hours in advance 'of such changes so that appropriate observations and tests can be planned and accomplished. The Contractor shall not assume that the Geotechnical Consultant is aware of all grading operations. The Contractor shall have the sole responsibility to provide adequate equipment and methods to accomplish the earthwork in accordance with the applicable grading codes and agency ordinances, these Specifications, and the recommendations in the approved geotechnical report(s) and grading plan(s). If, in the opinion of the Geotechnical Consultant, unsatisfactory conditions, such as unsuitable soil, improper moisture condition, inadequate compaction, insufficient buttress key size, adverse weather, etc., are resulting in a quality of work less than required in these specifications, the Geotechnical Consultant shall reject the work and may recommend to the owner that construction be stopped until the conditions are rectified. 2.0 Preparation of Areas to be Filled 2.1 Clearing and Grubbing: Vegetation, such as brush, grass, roots, and other deleterious material shall be sufficiently removed and properly disposed of in a method acceptable to the owner, governing agencies, and the Geotechnical Consultant. The Geotechnical Consultant shall evaluate the extent of these removals depending on specific site conditions. Earth fill. material shall not contain more than 1 percent of organic materials (by volume). No fill lift shall contain more than 5 percent of organic matter. Nesting of the organic materials shall not be allowed. If potentially hazardous materials are encountered, the Contractor shall stop work in the affected area, and a hazardous material specialist shall be informed immediately for proper evaluation and handling-of these materials prior to continuing to work in that area. As presently defined by the State of California, most refined petroleum products (gasoline, diesel fuel, motor oil, grease, coolant, etc.) have chemical constituents that are considered to be hazardous waste. As such, the indiscriminate dumping or spillage of these fluids onto the ground may constitute a misdemeanor, punishable by fines and/or imprisonment, and shall not be allowed. 3030.1094 Leighton and Associates, Inc. GENERAL EARTHWORK AND GRADING SPECIFICA11ONS Page 3 of 6 22 Processing: Existing ground that has been declared satisfactory for support of fill by the Geotechnical Consultant shall be scarified to a minimum depth of 6 inches. Existing ground that is not satisfactory shall be overexcavated as specified in the following section. SC* arification shall continue until soils are broken down and free of large clay lumps or clods and the working surface is reasonably uniform, flat, and free of uneven features that would inhibit uniform compaction. 2.3 Overexcavation: In addition to removals and overexcavations recommended in the approved geotechnical report(s) and the grading plan, soft, loose, dry, saturated, spongy, organic-rich, highly fractured or otherwise unsuitable ground shall be overexcavated to competent ground as evaluated by the Geotechnical Consultant during grading. 2.4 Benching: Where fills are to be placed on ground with slopes steeper than 5:1 (horizontal to vertical units), the ground shall be stepped or benched. Please see the Standard Details for a graphic illustration. The lowest bench or key shall be a minimum of 15 feet wide and at least 2 feet deep, into competent material as evaluated by the Geotechnical Consultant. Other benches shall be excavated a minimum height of 4 feet into competent material or as otherwise recommended by the Geotechnical Consultant. Fill placed on ground sloping flatter than 5:1 shall also be benched or otherwise overexcavated to provide a flat subgrade for the fill. 2.5 Evaluation/Acceptance of Fill Areas: All areas to receive fill, including removal and processed areas, key bottoms, and benches, shall be observed, mapped, elevations recorded, and/or tested prior to being accepted by the Geotechnical Consultant as suitable to receive fill. The Contractor shall obtain a written acceptance from the Geotechnical Consultant prior to fill placement. A licensed surveyor shall provide the survey control for determining elevations of processed areas, keys, and benches. 3.0 Fill Material 3.1 General: Material to be used as fill shall be essentially free of organic matter and other deleterious substancesevaluated-and accepted by the Geotechnical Consultant prior to placement. Soils of poor quality, such. as those, with unacceptable gradation, high expansion potential, or low strength shall -be placed in areas acceptable to the Geotechnical Consultant or mixed with other soils to achieve satisfactory fill material.. 32 Oversize: Oversize material defined as rock, or other irreducible material with a maximum dimension greater than 8 inches, shall not be buried or placed in fill unless location, materials, and placement methods' are specifically accepted by the Geotechnical Consultant. Placement operations shall be such that nesting of oversized material does not occur and such that oversize material is completely surrounded by compacted or densified fill. Oversize material shall not be placed within 10 vertical feet of finish grade or within 2 feet of future utilities or underground construction. 3030.1094 Leighton and Associates, nc. GENERAL EARTHWORK AND GRADING SPECIFICATIONS Page 4 of 6 33 Import: If importing of fill material is required for grading, proposed import material shall meet the requirements of Section 3.1. The potential import source shall be given to the Geotechnical Consultant at least 48 hours (2 working days) before importing begins so that its suitability can be determined and appropriate tests performed. 4.0 Fill Placement and Compaction 4.1 Fill Layers: Approved fill material shall be placed in areas prepared to receive fill (per Section 3.0) in near-horizontal layers not exceeding 8 inches in loose thickness. The Geotechnical Consultant may accept thicker layers if testing indicates the grading procedures can adequately compact the thicker layers. Each layer shall be spread evenly and mixed thoroughly to attain relative uniformity of material-and moisture throughout. 42 Fill Moisture Conditioning: Fill soils shall be watered, dried back, blended, and/or mixed, as necessary to attain a relatively uniform moisture content at or slightly over optimum. Maximum density and optimum soil moisture content tests shall be performed in accordance with the American Society of Testing and Materials (ASTM Test Method D1557-91). 4.3 Compaction of Fill: After each layer has been moisture-conditioned, mixed, and evenly spread, it shall be uniformly compacted to not less than 90 percent of maximum dry density (ASTM Test Method D1557-91). Compaction equipment shall be adequately sized and be either specifically designed for soil compaction or of proven reliability to efficiently achieve the specified level of compaction with uniformity. 4.4 Compaction of Fill Slopes: In addition to normal compaction procedures specified above, compaction of slopes shall be accomplished by backrolling of slopes with sheepsfoot rollers. at increments of 3 .to 4 feet in . fill elevation, or by other methods producing satisfactory results acceptable to the Geotechnical Consultant. Upon completion of grading, relative compaction of the fill, out to the slope face, shall be at least 90 percent of maximum density per ASTM Test Method D1557-91. 4.5. Compaction Testing: Field tests for. moisture content and:relative compaction of the fill soils shall be performed by the Geotechnical Consultant. Location and frequency of tests shall be at the Consultant's discretion based on field conditions encountered. Compaction test locations will not necessarily be selected on a random basis. Test locations shall be selected to verify adequacy of compaction levels in areas that are judged. to be prone to inadequate compaction (such as close to slope faces and at the fill/bedrock benches). 3030.1094 Leightonand Associates,lnc. GENERAL EARTHWORK AND GRADING SPECIFICATIONS Page 5 of 6 4.6 Frequency of Compaction Testing: Tests shall betaken at intervals not exceeding 2 feet in vertical rise and/or 1,000 cubic yards of compacted fill soils embankment. In addition, as a guideline, at least one test shall be taken on slope faces for each 5,000 square feet of slope face and/or each 10 feet of vertical height of slope. The Contractor shall assure that fill construction is such that the testing schedule can be accomplished by the Geotechnical Consultant. The Contractor shall stop or slow down the earthwork construction if these minimum standards are not met. 4.7 Compaction Test Locations: The Geotechnical Consultant shall document the approximate elevation and horizontal coordinates of each test location. The Contractor shall coordinate with the project surveyor to assure that sufficient grade stakes are established so that the Geotechnical Consultant can determine the test locations with sufficient accuracy. At a minimum, two grade stakes within a horizontal distance of 100 feet and vertically less than 5 feet apart from potential test locations shall be provided. 5.0 Subdrain Installation Subdrain systems shall -be installed in accordance with the approved geotechnical report(s), the grading plan, and the Standard Details. The Geotechnical Consultant may recommend additional subdrains and/or changes in subdrain extent, location, grade, or material depending on conditions encountered during grading. All subdrains shall be surveyed by a land surveyor/civil engineer for line and grade after installation and prior to burial. Sufficient time should be allowed by the Contractor for these surveys. 6.0 Excavation Excavations, as well as over-excavation for remedial purposes, shall be evaluated by the Geotechnical Consultant during grading. Remedial removal depths shown on geotechnical plans are estimates only. The actual extent of removal shall be determined by the Geotechnical Consultant based on the field evaluation of exposed conditions during grading. Where fill-over-cut slopes are to be graded, the cut portion of the slope shall be made, evaluated, and accepted by t h e Geotechnical Consultant prior to placement of materials for construction of the fill portion of the slope, unless otherwise recommended by the Geotechnical Consultant. 3030.1094 Leighton and Associates, Inc. GENERAL EARTI-IWORKAND GRADINGSPECIFICATIONS Page 6 of 6 7.0 Trench Backfihls 7.1 The Contractor shall follow all OHSA and Cal/OSHA requirements for safety of trench excavations. 72 All bedding and backfill of utility trenches shall be done in accordance with the applicable provisions of Standard Specifications of Public Works Construction. Bedding material shall have a Sand Equivalent greater than 30 (SE>30). The bedding shall be placed to I foot over the top of the conduit and densified by jetting. Backfill shall be placed and densified to a minimum of 90 percent of maximum from 1 foot above the top of the conduit to the surface. 7.3 The jetting of the bedding around the conduits shall be observed by-the Geotechnical Consultant. 7.4 The Geotechnical Consultant shall test the trench backfill for relative compaction. At least one test should be made for every 300 feet of trench and 2 feet of fill. 7.5 Lift thickness of trench backfill shall not exceed those allowed in the Standard Specifications of Public Works Construction unless the Contractor can demonstrate to the Geotechnical Consultant that the fill lift can be compacted to the minimum relative compaction by his alternative equipment and method. 3030.1094 FILL SLOPE PROJECTED PLANE- 1 TO 1 MAXIMUM Fl TOE OF SLOPE TO APPROVED GROUND EXISTING GROUND SURFACE 2' MIN KEY DEPTH FILL-OVER-CUT SLOPE ------------------ ------------------ ------------------ ------------------ ------------------- , 1 A - REMOVE - - UNSUITABLE BENCH MATERIAL BENCH HEIGHT (4' TYPICAL) BENCH (KEY) EXISTING... GROUND SURFACE ----2"TI LOWEST MIN. BENCH DEPTH --- BENCH L-BENCH HEIGHT (4' TYPICAL) REMOVE UNSUITABLE MATERIAL '-CUT FACE SHALL BE CONSTRUCTED PRIOR - TO FILL PLACEMENT TO ASSURE ADEQUATE GEOLOGIC CONDITIONS EXISTING GROUND CUT-OVER-FILL SLOPE SURFACE CUT FACE SHALL BE CONSTRUCTED PRIOR TO FILL PLACEMENT -REMOVE I UNSUITABLE MATERIAL FOR SUBDRAINS SEE LBENCH HEIGHT STANDARD DETAIL C (4' TYPICAL) BENCHING SHALL BE DONE WHEN SLOPE'S ANGLE IS EQUAL TO OR GREATER THAN 5:1. MINIMUM BENCH HEIGHT SHALL BE 4 FEET AND MINIMUM FILL WIDTH SHALL BE 9 FEET. OVERBUILD A TRIM BACK DESIGN SLOPE PROJECTED PLANE 1 TO I MAXIMUM FROM TOE OF SLOPE TO APPROVED GROUND 15 MIN. 2' MIN LOWEST KEY BENCH DEPTH (KEY) GENERAL EARTHWORK AND . KEYING AND BENCHING GRADING SPECIFICATIONS . STANDARD DETAILS A .. I.EICHTON AND ASSOCIATES OVERSIZE ROCK DISPOSAL GENERAL EARTHWORK AND GRADING SPECIFICA11NS STANDARD DETAILS B GRADE --------------------- SLOPE FACE m UMTEOFJLU --- - -: ------------------------ -------------- OVERSIZE WINDROW OVERSIZE ROCK IS LARGER THAN 8 INCHES IN LARGEST DIMENSION. * EXCAVATE A TRENCH IN THE COMPACTED FILL DEEP ENOUGH TO BURY ALL THE ROCK. BACKFILL WITH GRANULAR SOIL JETTED OR FLOODED IN PLACE TO FILL ALL THE VOIDS. DO NOT BURY ROCK WITHIN 10 FEET OF FINISH GRADE. WINDROW OF BURIED ROCK SHALL BE PARALLEL TO THE FINISHED SLOPE. ~1111 , wlp GRANULAR MATERIAL TO BE' DENSIFIED IN PLACE BY DETAIL FLOODING OR JETTING. JETTED OR FLOODED GRANULAR MATERIAL TYPICAL PROFILE ALONG WINDROW LZIGHTON AND ASSOCIATES / / - / EXISTING GROUND SURFACE ---------------------------------------------- / - ""COMP ACTED ------------------------------------ - REMOVE UNSUITABLE BENCHING MATERIAL SUBDRAIN TRENCH SEE DETAIL BELOW 6" MIN. OVERLAP CALTRANS CLASS 2 PERMEABLE-. \ç . OR #2 ROCK (9Fr'3/FT) WRAPPED) .. ..' IN FILTER FABRIC 7,?. . • :- 1/ •• : . lL:•..:c FILTER FABRIC (MIRAFI 140N OR APPROVED EQUIVALENT)* 6 MIN. COVER MIN. BEDDING COLLECTOR PIPE SHALL BE MINIMUM 6" DIAMETER SCHEDULE 40 PVC PERFORATED PIPE. SEE STANDARD DETAIL D FOR PIPE SPECIFICATIONS DESIGN FINISH GRADE MIN. >FIL.TER FABRIC (MIRAFI 140N OR APPROVED / EQUIVALENT) ---- ------------ I"_20' MIN. 5' MIN. NONPERFORATED 6"0 MIN. . • . - ..-CALTRANS CLASS 2 PERMEABLE S. •• ..S.._ • • • • -. OR #2 ROCK (9Fr3/FT) WRAPPED IN FILTER FABRIC -PERFORATED 6" øMIN. PIPE GENERAL EARTHWORK AND CANYON SUBDRAINS GRADING SPECIFICATIONS STANDARD DETAILS C LOGHTON AND ASSOCIATES MIN. F, :_ ~: __ OUTLET PIPES 4" 0 NONPERFORATED PIPE. BACK CUT 1OO MAX. OCHORIZONTALLY 30' MAX O.C. VERTICALLY 1:1 OR FLATTER '- BENCH ------------- SEE SUBDRAIN TRENCH DETAIL LOWEST SUBDRAIN SHOULD BE SITUATED AS LOW AS POSSIBLE TO ALLOW SUITABLE OUTLET ------------------------------- ------------------------------- -------------------------- --------------------------------- ---------------------------------- ----------------------------------- ------------------------------------------- KEY WIDTH -KEY DEPTH AS NOTED ON GRADING PLANS 12 MIN OVERLAP (15- MIN.) FROM THE TOP HOG (2 MIN.) RING TIED EVERY 6 FEET 16" MIN. ICOVER PERFORATED PIPE 57. MIN. 4" / BEDDING PROVIDE POSITIVE SEAL AT THE JOINT FILTER FABRIC ENVELOPE (MIRAFI 140 OR APPROVED EQUIVALENT) SUBDRAIN TRENCH DETAIL SUBDRAIN INSTALLATION - subdroin collector pipe shall be installed with perforation down or, unless otherwise designated by the geotechnicol consultant. Outlet pipes shall be non-perforate d pipe. The subdroin pipe shall have at least 8 perforations uniformly spaced per foot. Perforation shall be 1/4" to 1/2" if drill holes ore used. All subdroin pipes shall have a gradient of at least 2% towards the outlet. SUBDRAIN PIPE - Subdroin pipe shall be ASTM D2751. SDR 23.5 or ASTM D1527. Schedule 40, or ASTM D3034, SDR 23.5. Schedule 40 Polyvinyl Chloride Plastic (PVC) pipe. All outlet pipe shall be placed in a trench no wide than twice the subdroin pipe. Pipe shall be in soil of SE >/=30 jetted or flooded in place except for the outside 5 feet which shall be native soil backfill. BUTTRESS OR GENERAL EARTHWORK AND- REPLACEMENT FILL GRADING SPECIFICATIONS SUBDRAINS STANDARD DETAILS D LEIGHTON AND ASSOCIATES - -------------------- ---------------------- -------------------------- ----------- 4:' CALTRANS CLASS II PERMEABLE OR #2 ROCK (3 FT-3/FT) WRAPPED IN FILTER FABRIC —4" 0 NON-PERFORATED 't OUTLET PIPE ......- - T-CONNECTION FOR COLLECTOR PIPE TO OUTLET PIPE SOIL BACKFILL. COMPACTED TO 90 PERCENT RELATIVE COMPACTION BASED ON ASTM 01557 - ------------------- RETAINING WALL-... ------:---- r-p WALL WATERPROOFING - I OVERLAP 0 0. _(MIRAF1 140N OR APPROVED FILTER FABRIC ENVELOPE PER ARCHITECT'S SPECIFICATIONS 6 MIN. 3/4" TO 1-1/2" CLEAN GRAVEL FINISH GRADE 0 • -:-:-:S 4" (MIN.) DIAMETER PERFORATED PVC PIPE (SCHEDULE 40 OR J 0 . -:-:-::- EQUIVALENT) WITH PERFORATIONS -- 0 0 ORIENTED DOWN AS DEPICTED I JO SUITABLE OUTLET 00 I MINIMUM -1 PERCENT GRADIENT - - --:-:-:-:-:-:-:-:-:-:-:-:-: L _-- ----------------------------- MIN. WALL FOOTING - I COMPETENT BEDROCK OR MATERIAL AS EVALUATED BY THE GEOTECHNICAL CONSULTANT NOTE: UPON REVIEW BY THE GEOTECHNICAL CONSULTANT. COMPOSITE DRAINAGE PRODUCTS SUCH AS MIRADRAIN OR J-DRAIN MAY BE USED AS AN ALTERNATIVE TO GRAVEL OR CLASS 2 PERMEABLE MATERIAL. INSTALLATION SHOULD BE PERFORMED IN ACCORDANCE WITH MANUFACTURERS SPECIFICATIONS. GENERAL EARTHWORK AND RETAINING WALL I GRADING SPECIFICATIONS DRAINAGE DETAIL STANDARD DETAILS .E.. LEIGHTON AND ASSOCIATES RECEIVED AUG 3 0 2001 ENGINEERING DEPARTMENT