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Home My WebLink AboutCDP 07-28; Leucadia Wastewater District; Geotechnical Report; 2004-09-01GEOTECHNICAL INVESTIGATION, LEUCADIA WASTEWATER DISTRICT, PROPOSED HEADQUATERS BUILDING AND FACILITY IMPROVEMENTS, CARLSBAD, CALIFORNIA Prepared For Roesling Nakamura Architects, INC. 363 Fifth Avenue, Suite 202 San Diego, California 92101 Project No. 600203-002 cje>W September 14, 2004 . Y>\0^ Leighton Consulting, Inc. A LEIGHTON GROUP COMPANY Leighton Consulting, Inc. A LEIGHTON GROUP COMPANY September 14, 2004 Project No. 600203-002 To: Roesling Nakamura Architects, Inc. 363 Fifth Avenue, Suite 202 San Diego, Cahfomia 92101 Attention: Mr. Joe Mansfield Subject: Geotechnical Investigation, Leucadia Wastewater District Proposed Headquarters Building and Facility Improvements, Carlsbad, Califomia In accordance with your request and authorization, we have conducted a geotechnical investigation for the proposed headquarters building and improvements located at 1960 La Costa Avenue in Carlsbad, Califomia. Based on the results of our study, it is our opinion that the building and improvements are feasible from a geotechnical standpoint provided the recommendations provided herein are incorporated into the design and construction of the proposed improvements. The accompanying report presents a summary of our investigation and provides geotechnical conclusions and recommendations relative to the proposed improvements. If you have any questions regarding our report, please do not hesitate to contact this offici appreciate this opporttmity to be of service. Respectfully submitted, LEIGHTON CONSULTING /i7M£- William D. Olson, RCE 452 Senior Project Engineer Distribution: (9) Addressee Michael R. Stewart, CEG 1349 Principal GeologistA^ice President 3934 Murphy Canyon Road, Suite B205 • San Diego, CA 92123-4425 858.292.8030 • Fax 858.292.0771 • www.leightonconsulting.com 600203-001 TABLE OF CONTENTS Section Page 1.0 INTRODUCTION 1 1.1 PURPOSE AND SCOPE 1 1.2 SITE LOCATION AND PROPOSED IMPROVEMENTS 2 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 Artificial Fill Undocumented (map unit Afu) 5 3.2.2 Quaternary Alluvium (map unit Qal) 5 3.2.3 Tertiary Santiago Formation (map unit Tsa) 6 3.3 SURFACE AND GROUND WATER 6 3.4 GEOCHEMICAL CONSIDERATIONS/SOIL CORROSIVITY 7 4.0 FAULTING AND SEISMICITY 8 4.1 FAULTING 8 4.2 SEISMICITY 8 4.2.1 Shallow Ground Rupture 10 4.2.2 Liquefaction 10 4.2.3 Earthquake-Induced Settlement 10 4.2.4 Lateral Spread 11 5.0 CONCLUSIONS 12 6.0 RECOMMENDATIONS 14 6.1 EARTHWORK 14 6.1.1 Site Preparation 14 6.1.2 Excavations and Remedial Grading 14 6.1.3 Fill Placement and Compaction 15 6.1.4 Ground Improvements 15 6.2 TEMPORARY EXCAVATIONS AND SHORING 16 6.3 FOUNDATIONS 16 6.4 RETAINING WALL LATERAL EARTH PRESSURES 19 6.5 MSE RETAINING WALLS 20 6.6 PRELIMINARY PAVEMENT RECOMMENDATIONS 21 6.8 CONCRETE FLATWORK 22 6.9 CONSTRUCTION OBSERVATION 23 6.10 PLAN REVIEW 23 7.0 LIMFTATIONS 24 4 Leighton 600203-001 TABLE OF CONTENTS fContinued') TABLES TABLE 1 - SEISMIC PARAMETERS FOR ACTIVE FAULTS - PAGE 9 TABLE 2 - TEMPORARY SLOPES - PAGE 16 TABLE 3 - RETAINING WALL EQUIVALENT FLUID WEIGHT (PCF) - PAGE 19 TABLE 4 - MSE RETAINING WALL DESIGN PARAMETERS - PAGE 20 TABLE 5 - PRELIMINARY PAVEMENT SECHONS - PAGE 22 FIGURES FIGURE 1 - SITE LOCATION MAP - PAGE 3 FIGURE 2 - GEOTECHNICAL MAP - REAR OF TEXT FIGURE 3 - CROSS-SECTION A-A' - REAR OF TEXT APPENDICES APPENDIX A - REFERENCES APPENDIX B - BORING LOGS APPENDIX C - LABORATORY DATA ANALYSIS APPENDIX D - SEISMIC ANALYSIS APPENDIX E - GENERAL EARTHWORK AND GRADING SPECIFICATIONS 4 Leighton 600203-002 1.0 INTRODUCTION 1.1 Purpose and Scope This report presents the results of our geotechnical investigation for proposed Leucadia Wastewater District Headquarters Building, maintenance building and other improvements at the facility located in Carlsbad, Califomia (Figure 1). The purpose of our investigation was to evaluate the existing geotechnical conditions present at the site and to provide preliminary conclusions and geotechnical recommendations relative to the proposed development. Our scope of services for this investigation included: • Review of available pertinent, published and unpublished geotechnical literature and maps (Appendix A). • A geotechnical reconnaissance of the site and geologic mapping of site conditions. • Coordination with Undergroimd Service Alert and Leucadia Wastewater District representatives. • Obtaining a County of San Diego, Department of Health, Boring Permit. • Subsurface exploration consisting of the excavation, logging, and sampling of 4 hollow-stem borings (B-l through B-4). In addition we utilized the information of previous studies including two borings identified as A-12 and A-13 by Amec Earth & Envirormiental, Inc. (Amec, 2001), and two borings identified as LA-1 and LA-2 by Leighton and Associates (Leighton, 2003). The logs of all the borings 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, and are noted on the boring logs (Appendix B). • Compilation and analysis of the geotechnical data obtained from the field investigation and laboratory testing. • Preparation of this report presenting our geotechnical findings, conclusions, and geotechnical recommendations with respect to the proposed design, site grading, and general constmction considerations. 4 -1- Lelghton 600203-002 1.2 Site Location and Proposed Improvements The existing facility is located at 1960 La Costa Avenue in Carlsbad, Califomia. The proposed development will include a two-story commercial building (i.e., a concrete masonry block) over a semi day-lighted parking garage and a lightweight metal maintenance building, as presented on Figure 2, Geotechnical Map. The proposed underground parking garage for the building is assumed to be approximately eight to ten feet below the proposed finish floor elevation of 20.0 mean sea level (msl). Location of the proposed building is in the southeast comer of the facility and is presently occupied by a existing metal storage building, asphalt pavement, and an open areas that is covered with woodchips. Based on drawing reviews and discussions with facility personnel, the southem portion of the proposed building area was also occupied by an above ground digester tank. Topography of the proposed building site at the southem end is relatively flat at an approximate elevation of 20 feet msl and then gently slopes northward to an approximate elevation of 12 feet msl beneath the northem portion of proposed building. At the time of our investigation, site grading plans were not available. However, the proposed surface grades surrounding the building are anticipated to remain relatively the same and earthwork is expected to consist of site preparation, excavation of the underground parking garage beneath the building footprint and wall backfills. In addition, there are two new covered parking stmctures and a retaining wall being proposed (see Figure 2). It is our understanding that the proposed covered parking stmctures, located in the north end of the facility, are to be lightweight metal canopy type stmctures that would requirc permanent footings. The proposed retaining wall is located along the eastem perimeter of the proposed maintenance building and is anticipated to be less than 10 feet tall. 4 Leighton NOT TO SCALE Leucadia Wastewater Treatment Plant Carlsbad, California SITE LOCATION MAP Project No. 600203-002 Date September 2004 Figure No. 1 600203-002 2.0 SUBSURFACE EXPLORATION AND LABORATORY TESTING Our subsurface exploration consisted of the excavation of four (4) small diameter hollow stem augured borings within the vicinity of the proposed improvements, to a depth of approximately 21 to 41 feet below the existing ground surface (bgs). See the Geotechnical Map, Figure 2, for locations of the borings. 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 to be encountered at foundation elevations and the general nature of the soils proposed for use as compacted fills, and provided representative samples for laboratory testing. Prior to boring excavation. Underground Service Alert and representatives of the District were contacted to coordinate location and identification of nearby underground utilities. Indications of hazardous materials were not encountered during drilling. The exploratory excavations were logged by a representative from our firm. Representative bulk and undisturbed samples were obtained at frequent intervals for laboratory testing. The approximate locations of the borings are shown on the Geotechnical Map, Figure 2, and logs of the borings are presented in Appendix B. Subsequent to logging and sampling, the current borings were backfilled with bentonite grout per County of San Diego, Department of Environmental Health requirements. Laboratory testing was performed on representative samples to evaluate the moisture, density, direct shear, maximum density, 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). -4- Lelghton 600203-002 3.0 SUMMARY OF GEOTECHNICAL CONDTFIONS 3.1 Regional Geology The subject site is situated in the coastal section of the Peninsular Range Province, a Califomia geomorphic province with a long and active geologic history. Throughout the last 54 million years, this area known as the San Diego Embayment has undergone several episodes of marine indunation and subsequent, marine regression. This has resulted in a thick sequence of marine and nonmarine sediments deposited on rocks on Southem Califomia batholith during minor episodic tectonic uplift ofthe area. 3,2 Site Geology Based on our subsurface exploration, and review of pertinent geologic literature and maps, the units underlying the site within the proposed subsurface basin area consist of artificial fill and alluvial soils that were underlain by the Santiago Formation. A brief description of the geologic units as encountered on the site is presented below. 3.2.1 Artificial Fill (map unit Af) Artificial fill was encountered in all borings and was on the order of 1 to 9 feet in depth. The fill soil, consisting of loose to medium dense clayey sands and medium stiff to stiff sandy clays, appears to have been placed during the original constmction of existing or previous facility improvements. Any undocumented fill, and/or desiccated documented fills that are encountered during the anticipated future grading operations are considered potentially compressible in their present condition and will require removal and recompaction during site grading. 3.2.2 Quaternary Alluvium (map unit Oa\) Alluvial material was encountered in three borings, B-2, B-3 and B-4, and predominately consists of loose, clayey sand and soft sandy clay. Thickness of the alluvium ranged from 10 to over 40 feet in borings B-2 and B-4, respectively. In general, the alluvium increases in thickness to the north and is considered potenfially compressible in its present condition. These soils, previously tested, have a medium expansion potential (Leighton, 2003). The alluvium beneath the proposed building should be removed and replaced with compacted fill to support foundations or additional stmctural fill. As an ahemative foundation system, Cast In-place Drilled Hole (CIDH) piles extending 4 Leighton 600203-002 through the alluvium and founded in the underlying formational material may be considered given the conditions encountered and potential impacts of higher groundwater elevations. 3.2.3 Tertiary Santiago Formation (map unit Tsa) The Tertiary Santiago Formation is the underlying bedrock unit beneath the site (Tan, et. al., 1996). Our investigation encoimtered the Santiago Formation at depths of approximately 5 to 20 feet bgs within the proposed building area (i.e., borings B-l and B-2) and consists primarily of massively bedded clayey to silty sandstone with interbedded siltstone and claystone. The siltstones and claystones generally are bluish gray to gray, damp to moist, stiff to hard, moderately weathered, fractured and sheared. The sandstone generally consists of grayish green, damp to moist, dense to very dense, fine to medium grained sand. This unit has a very high expansion potential in the clayey portions and a low to very low expansion potential in the sandy portions. Similar to the varying thickness of the alluvium, the contact of the Santiago Formation appears to dip towards the northwest. 3.3 Surface and Ground Water No surface water or evidence of surface ponding was encountered during our field investigations. However, the facility is located adjacent to the San Marcos Creek streambed and may be subject to storm related flooding. In addition, surface water may drain as sheet flow from the higher portions of the site during rainy periods and accumulate in lower elevations. Ground water was encoimtered in borings B-3 and B-4 at a depth of 8 to 9 feet below ground surface (i.e., an approximate elevation of -1.0 feet msl). It should be noted that previous explorations by AMEC in January 2001 at the facility indicated that ground water was encountered at an elevation of +3 to +3.5 feet msl. An investigation in January 1992, also encountered ground water at the surface in lower lying areas of the facility (AMEC, 2001). 4 Leighton 600203-002 3.4 Geochemical Considerations/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 ofthe soils. 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-A-4 of 2001 Califomia Building Code (CBC) provides specific guidelines for the concrete mix-design when the soluble sulfate content of the soil exceeds 0.1 percent by weight or 1,000 ppm. The results of our laboratory tests on representative soils from the site indicated a soluble sulfate content of 0.2 percent (2,000 ppm) and a pH of 8.13 which suggests that the concrete should be designed minimally in accordance with the Severe Category of Table 19A-A-4 ofthe 2001 CBC. A minimum resistivity value less than approximately 5,000 ohm-cm (City of San Diego, 1992) typically indicates a corrosive environment to buried, uncoated metallic conduits. The test results indicate a minimum resistivity of 357 ohm-cm indicating a very high corrosion potential to buried uncoated metal conduits. Chloride testing indicates a severe degree of corrosion potential (3,600 ppm). The test results are provided in Appendix C. For appropriate evaluation and mitigation design for other substances with potential influence from corrosive soils, a corrosion engineer may be consulted. These other substances include (but are not necessarily limited to) buried copper tubing, aluminum elements in close vicinity of soils, or stucco finish that can be potentially influenced. 4 Leighton 600203-002 4.0 FAULTING AND SEISMICITY 4.1 Faulting Our discussion of fauUs on the site is prefaced with a discussion of Califomia legislation and state policies conceming the classification and land-use criteria associated with faults. By definition of the Califomia Mining and Geology Board, an active fauh is a fauft which has had surface displacement within Holocene time (about the last 11,000 years). The State Geologist has defined a potentiallv active fault as any fault considered to have been active during Quatemary time (last 1,600,000 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 Alquist-Priolo Earthquake Fault Zoning Act of 1972 and as most recently revised in 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 any Fault-Rupture Hazard Zone as created by the Alquist-Priolo Act (Hart, 1997). San Diego, like the rest of Southem Califomia, is seismically active as a result of being located near the active margin between the North American and Pacific tectonic plates. The principal source of seismic activity is movement along the northwest-trending regional fault zones such as the San Andreas, San Jacinto and Elsinore Faults Zones, as well as along less active faults such as the Newport-Inglewood (Offshore) and Rose Canyon Fault Zones. Our review of geologic literature pertaining to the site and general vicinity indicates that there are no known major or active faults on or in the immediate vicinity of the site (Jennings, 1994). Evidence for faulting was not encountered during our field investigation. The nearest known active regional fauhs are the Rose Canyon fault located approximately 5 miles west of the site, the Newport Inglewood Fault located offshore 11 miles west of the site the Coronado Bank Fault located 20 miles west of the site (Blake, 2000). 4.2 Seismicity The site can be considered to lie within a seismically active region, as can all of Southem Califomia. Table 1 indicates 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 for the site are included in Table 1 are the distances to the causative faults, earthquake magnitudes, and postulated ground accelerations as generated by the deterministic fault modeling software EQFAULT (Blake, 2000). 4 Leighton 600203-002 Table 1 Seismic Parameters for Active Faults (Blake, 2000) Potential Causative Fault Distance from Fault to Site (Miles) Slip Rate* (mm/yr) Maximum Moment Magnitude Peak Horizontal Ground Acceleration (g) One Standard Deviation (g) Rose Canyon 5.3 1.5 7.2 0.44 0.24 Newport- Inglewood (Offshore) 10.6 1.5 7.1 0.24 0.13 Coronado Bank 20.5 3.0 7.6 0.16 0.09 *CDMG 1996 As indicated in Table 1, the Rose Canyon Fault Zone is the 'active' fault considered having the most significant effect at the site from a design standpoint. A maximum moment magnitude earthquake of moment magnitude 7.2 on the fault could produce an estimated peak horizontal ground acceleration 0.44g at the site. The ground acceleration was modeled using the 1995b/1997 attenuation equation of Abrahamson & Silva for a rock site. The Rose Canyon Fault Zone is considered a Type B seismic source according to Table 16A-U ofthe 2001 CBC. Sunmiary printouts of the detemiinistic analyses are provided in Appendix D of this report. The effect of seismic shaking may be mitigated by adhering to the Califomia Building Code or state-of-the-art seismic design parameters of the Stmctural Engineers Association of Califomia. The seismic parameter setting for the site per 2001 CBC are as follows: • Soil Profile Type (Table 16A-J) = SD • Seismic Zone 4 (Figure 16A-2) Z = 0.4 • Slip Rate, SR, (Table 16A-U) = 1.5mm per year (CDMG, 1996), based on the Rose Canyon fault Zone • Seismic Source Type (Table 16A-U) = B • Na= 1.0 (Table 16A-S) • Nv= 1.1 (Table 16A-T) Secondary effects that can be associated with severe ground shaking following a relatively large earthquake include shallow ground mpture, soil liquefaction, and dynamic setfiement. These secondary effects of seismic shaking are discussed in the following sections. 4 Leighton 600203-002 4.2.1 Shallow Ground Rupture Ground mpture because of active faufting 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. 4.2.2 Liquefaction Liquefaction and dynamic settlement of soils can be caused by strong vibratory motion due to earthquakes. Both research and historical data indicate that loose, saturated, granular soils are susceptible to liquefaction and dynamic settlement. Liquefaction is typified by a total loss of shear strength in the affected soil layer, thereby causing the soil to flow as a liquid. This effect may be manifested by excessive settlements and sand boils at the ground surface. Due to the high clay content in the alluvium deposit and the dense nature of the shallow underlying formational soils above the ground water table, it is our opinion that the potential for liquefaction beneath the proposed building due to the design earthquake is low. However, there is a potential for liquefaction in the vicinity of the proposed covered parking stmctures and retaining wall located to the north. In summary, mitigation measures should be considered beneath the proposed maintenance building and retaining wall stmcture. As for the proposed covered parking stmctures, mitigation measures are not consider appropriate based on the anticipated light foundation loads and our understanding of it use. If the project designers determine that the covered parking stmctures require mitigation for liquefaction, addition subsurface investigation and analysis may be needed to develop site-specific recommendations. 4.2.3 Earthquake-Induced Settlement Granular soils tend to densify when subjected to shear strains induced by ground shaking during earthquakes. Simplified methods were proposed by Tokimatsu and Seed (1987) and Ishihara and Yoshimine (1991) involving SPT N-values used to estimate earthquake induced soil settlement. Due to the low susceptibility of liquefaction beneath the proposed headquarters building, the potential for earthquake-induced settlements is considered to be low during strong ground shaking. Earthquake-induced settlements tend to be most damaging when differential settlements result. Earthquake-induced differential settiements are expected to be VA to Zz of an inch within the headquarters building footprint area. -10- Leighton 600203-002 Dynamic settlement beneath the proposed maintenance building and retaining wall stmcture based on the results of our limited exploration indicates and our experience wdth other project in the vicinity indicate total liquefaction-induced settlement on the order of 2- to 6-inches can be anticipated as a result of the design earthquake event. Differential dynamic settlement is anticipated to be on the order of less than 1 Vz inches provided mitigation measures are implemented. 4.2.4 Lateral Spread Empirical relationships have been derived by Youd and others (Youd, 1993; Bartlett and Youd, 1995; and Youd et. al., 1999) to estimate the magnitude of lateral spread due to liquefaction. These relationships include parameters such as earthquake magnitude, distance of the earthquake from the site, slope height and angle, the thickness of liquefiable soil, and gradation characteristics of the soil. The susceptibility to earthquake-induced lateral spread is considered to be low for the site beneath the proposed headquarters building because of the low susceptibility to liquefaction. 4 -11- Leighton 600203-002 5.0 CONCLUSIONS Based on the results of our geotechnical investigation of the site, it is our opinion that the proposed improvements are feasible from a geotechnical standpoint, provided the following conclusions and recommendations are incorporated into the project plans and specifications. The following is a summary of the geotechnical factors that should be considered. Based on our subsurface exploration and laboratory testing, the upper portions of the existing fill soils and alluvial soils beneath the proposed building are considered potentially compressible and should be removed to competent formational material or to within 2 feet of the ground water and replaced with compacted fill to support additional fill or stmctural loads from conventional foundations (i.e., spread and continuous footings). The depths of these soils are estimated to range from 5 to 20 feet bgs. In addition, drilled piers and the stmctural slab should be considered for the proposed building to mitigate cut/fill transitions and/or alluvial soil left in place. The formational materials and surficial soils present on the site should be generally rippable with conventional heavy-duty earthwork equipment. Based on laboratory testing, the onsite alluvium has a medium expansion potential. It should be noted that clayey portions of the Santiago Formation may have high to very high expansion potential and should not be reused as compacted fill. Laboratory test results indicate the soils present on the site have a high (severe) potential for sulfate attack on concrete. In addition, onsite soils are considered to have a high to very high potential for corrosion on buried uncoated metal conduits firom minimum resistivity testing. The maximum moment magnitude earthquake of moment magnitude 7.2 on the Rose Canyon fault could produce an estimated peak horizontal ground acceleration 0.44g at the site. Considering that there is a potential for liquefaction and differential movements in the vicinity of the proposed maintenance building and retaining wall located in the northeast comer of the facility. Mitigation measure or ground improvement and the use of relatively flexible MSE retaining wall system should be considered. The existing upper fill and alluvium soils appear to be suitable material for reuse as fill provided they are relatively free of organic material, expansive soils, debris, and rock fragments larger than 8 inches in maximum dimension. -12-Leighton 600203-002 Ground water was encountered during our investigation at a depth of 8 to 9 feet below ground surface in the northem boring, B-3 and B-4 (i.e., approximate elevation of -1 ft msl). Previous explorations by AMEC in June 1999 indicated that ground water beneath the facility was encountered at elevations of +3 to +3.5 feet msl. It should also be noted that ground water levels can fluctuate due to runoff, or seasonal flow of San Marcos Creek, and will most likely be higher in elevation in wetter times of the year. The contractor should be prepared to remove ground water from deeper excavations. -13- Leighton 600203-002 6.0 RECOMMENDATIONS 6.1 Earthwork We anticipate that earthwork at the site will consist of site preparation, remedial grading, excavations, fill placement and ground improvement (i.e., mitigation measures beneath the northem retaining wall). We recommend that earthwork on the site be performed in accordance with the following recommendations and the General Earthwork and Grading Specifications for Rough Grading included in Appendix E. In case of conflict, the following recommendations shall supersede those in Appendix E. 6.1.1 Site Preparation Prior to grading, all areas to receive stractural fill or engineered stmctures should be cleared of surface and subsurface obstractions, including any existing debris and undocumented or loose fill soils, and stripped of vegetation. Removed vegetation and debris should be properly disposed off site. All areas to receive fill and/or other surface improvements should be scarified to a minimum depth of 6 inches, brought to near-optimum moisture conditions, and recompacted to at least 90 percent relative compaction (based on ASTM Test Method D1557). 6.1.2 Excavations and Remedial Grading Excavations of the onsite materials may generally be accomplished with conventional heavy-duty earthwork equipment. Artificial fill and alluvial soils present on site may cave during trenching operations. In accordance with OSHA requirements, excavations deeper than 5 feet should be shored or be laid back to 1:1 (horizontal to vertical) if workers are to enter such excavations. See Section 6.2 for additional excavation recommendations. Remedial grading or removals of the undocumented fill and alluvium soils should be performed where possible to competent formational material or to within 2 feet of the ground water. We recommend remedial excavations be started at the proposed finish pad elevation at a point 5 feet from building perimeter and be sloped away from the stmcture at an inclination of 1:1 (horizontal to vertical) to competent material. It should be noted that removals may be limited by the seasonal ground water elevations (i.e., elevations range from -1.0 to +3.5 feet msl) (AMEC, 2001). All removal bottoms should be reviewed by the geotechnical consultant prior to scarification and recompaction. 4 -14- Leighton 600203-002 In order to mitigate the impact of the underlying cut/fill transition condition beneath the headquarters building, we recommend all footings be deepened to extend through the fill soils and founded a minimum of 12 inches into competent formational material. Spread footings may be extended beyond the design bottom of the footing to obtain the minimum recommended embedment with the use of a 2-sack, sand-cement slurry prior to placement of foundation reinforcing steel and concrete. In areas of deeper fill and underlying alluvium (i.e. the northem portion of building) drilled piers and grade beams are recommended. 6.1.3 Fill Placement and Compaction In general, the onsite soils are generally suitable for reuse as compacted fill provided they are free of organic material, debris, and rock fragments larger than 8 inches in maximum dimension. All fill soils should be brought to 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 local grading ordinances, sound conslruction practice, and the General Earthwork and Grading Specifications for Rough Grading presented in Appendix E. All import soils should be granular and tested to have an expansion index of less than 50 (per UBC Standard 18-2). The soils shall be certified (by the soil consultant of the export site) to be free from organic debris and contamination (such as pesticides, hydrocarbons, etc.). The soil engineer shall be notified of the potential borrow source a minimum of 36 hours prior to importing the soils onto the site. The soils engineer shall provide acceptance of these soils prior to tracking of import soils onto the site. Granular soil may also be available on the site. 6.1.4 Ground Improvements Based on the loose characteristics of the onsite alluvium materials beneath the ground water table in the vicinity of the proposed maintenance building and retaining wall, there is potential for liquefaction within sand layer. Therefore, ground improvement mitigation beneath the proposed foundations in this area is recommended. The use of a gravel mitigation blanket (i.e., a 1-foot thick layer of -15- Leighton 600203-002 3/4-inch gravel surrounded with a woven geotextile, Mirafi 500x, or equivalent) and the placement of one geogrid reinforcement layer (Tensar BX-1200, or equivalent) on top of the Mirafi 500x material prior to placement of gravel. The gravel mitigation blanket should extend at least 10 feet beyond the building or retaining wall footprint. Assuming a finish pad elevation of roughly +10 feet msl for the maintenance building and a maximum footing depth of 24-inches, the recommended bottom elevation of the gravel mitigation blanket is +3.0 feet msl. A representative of this office should perform continuous observation during ground improvement. 6.2 Temporar/ Excavations and Shoring Sloped excavations may be utilized when adequate space allows. The cut is most likely to expose fill/alluvium over formational material with a possible seepage condition. Based on our borings and laboratory testing, we provide the following recommendations for sloped excavations in fill/formational materials without seepage conditions: Table 2 Temporary Slopes Excavation Depth (feet) Maximum Slope Ratio in Fill/Alluvium Materials (horizontal to vertical) 0-5' 3/4 : 1 5-20' 1 : 1 greater than 20' 1-1/4 : 1 We do not recommend surcharge loading or equipment lay-down within 5 feet of the top of slope. In addition, cut slopes should not be made within 5 feet (measured horizontally) of adjacent stractures. A "competent person" should observe the slope on a daily basis for signs of instability. If slopes exceeding those indicated are deemed necessary, shoring may be necessary. 6.3 Foundations Foundations should be designed in accordance with stractural considerations and the following recommendations. These recommendations assume that the soils encountered have a low to medium potential for expansion. -16-4 Leighton 600203-002 Conventional Footings for the Building Portions of the headquarters building may be supported by conventional continuous footing depending on depth fill. The footing should extend a minimum of 24 inches beneath the lowest adjacent finish grade and may be designed for a maximum allowable bearing pressure of 3,000 psf if founded on competent formational material. Footings for the maintenance building should extend a minimum of 24 inches beneath the lowest adjacent soil grade. At these depths, footings may be designed for a maximum allowable bearing pressure of 2,000 pounds per square foot (psf) if founded in properly compacted fill soils. Special consideration should be given to the design and installation of foundations in order to maintain integrity of the underlying ground improvement. The minimum recommended width of footings is 18 inches for continuous footings and 24 inches for square or round footings. Footings should be designed in accordance with the stractural engineer's requirements and have a minimum reinforcement of four No. 5 reinforcing bars (two top and two bottom). The allowable pressures may be increased by one-third when considering loads of short duration such as wind or seismic forces. Drilled Piers Drilled piers embedded a minimum of 5 feet into competent formational soils may be designed for an allowable end bearing of 6,000 psf at a maximum diameter of 24 inches. Drilled piers should be spaced at least 3 diameters apart. The capacity may be increased by 500 psf skin friction for each additional foot of embedment. Pier lateral analysis with soil-stracture response and design bending moments accounting for undocumented fill soils and group effects may be performed once the lateral loads are determined. For drilled piers, we recommend that concrete be placed in a manner that prevents segregation of the concrete mix and disturbance to the side of this excavation. Limited shrink concrete is recommended to allow fill mobilization of pier skin friction. We also recommend that concrete be placed as soon as possible after the pier shaft is excavated. Loose or friable sands may be encountered in artificial fill materials and may cave during drilling. Care should be taken to prevent caving of soils into the excavation. Floor Slabs In deeper fill areas we recommend the use of drilled piers and grade beams supporting a stmctural slab. These areas may be transitioned to slab on grade with conventional foundations. The limits of transitioning should be determined in accordance with the stractural engineer's requirements. Where proper removal and recompaction is performed, either a stractural slab or slab on grade may be utilized with drilled piers and grade beams. All floor slabs should have a minimum thickness of 5 inches thick and be reinforced with No. 3 rebars 18 inches on center each way (minimum) placed at mid-height in the slab. Increased thickness or reinforcing may be necessary based on structural requirements and loading conditions. The maintenance building floor slab, which is subjected to equipment 4 -17- Leighton 600203-002 loading, should have a minimum thickness of 7 inches thick and be reinforced with No. 3 rebars 18 inches on center each way (minimum) placed at mid-height in the slab. Stractural slabs should be designed by the stmctural engineer for design loads without support from the underlying subgrade soils. Floor slabs should be underlain by a 2-inch layer of clean sand (SE greater than 50). If reduction of moisture migration up through the slab is desired, the sand or gravel layer should be additionally underlain by a 10-mil (or heavier) moisture barrier plastic sheeting, which is in tum underlain by an additional 2 inches of clean sand. We recommend control joints be provided across the slab at appropriate intervals as designed by the project architect. The potential for slab cracking may be reduced by the use of low water content concrete. The contractor should take appropriate curing precautions during the pouring of concrete in hot weather to minimize cracking of slabs. All slabs should be designed in accordance with stractural considerations. Moisture barriers can retard, but not eliminate, vapor migration from the underlying soils up through the cement slab. We recommend that the floor coverings contractor test the moisture vapor flux rate through the slab prior to attempting the application of moisture- sensitive floor coverings. We recommend that a slipsheet (or equivalent) be utilized as a minimum if grouted tile, marble tile, or other crack-sensitive floor covering is planned directly on concrete slabs. "Breathable" floor coverings or special slab sealants should be considered if crack-sensitive floor coverings are planned on the slab. Settlement For foundations founded on competent formational material, the maximum total and differential settlement are estimated at 1/2 inch and 1/2 inch, respectively. However for most cases, differential settlements are considered unlikely to exceed 1/2 inch and should generally be less than 1/4 inch. Greater settlement may also be experienced if at-grade improvements are founded on deeper fill areas and areas overlying undocumented fill or alluvium. Covered Parking Stracture Foundation Deepened spread footing or reinforced cast-in-place concrete piers are recommended for foundational support of the lightweight canopy type stracture and to resist wind or seismic loads. An allowable bearing capacity of 2,000 pounds per square foot (psf) at a minimum embedment depth of 2 feet below the lowest proposed ground surface is recommended for the footing or pier. The minimum recommended width of footings is 24 inches for square or round footings. The allowable pressure may be increased by one- third when considering loads of short duration such as wind or seismic forces. -18- Leighton 600203-002 For resisting uplift loads, we recommend using the weight of the foundation plus the skin friction resistance of 250 psf for footing/pier in contact with competent soil below a minimum embedment depth of 2 feet. Lateral loads on the face of footing/pier may be resisted by using a lateral bearing pressure of 350 psf/foot in competent fill material. 6.4 Retaining Wall Lateral Earth Pressures For design purposes, the following lateral earth pressure values for level or sloping backfill are recommended for retaining walls backfilled with on-site soils or approved granular material of very low to low expansion potential. Table 3 Retaining Wall Equivalent Fluid Weight (pcf) Conditions Level 2:1 Slope Active 36 55 At-Rest 55 65 Passive 350 (Maximum of 3 ksf) 150 (sloping dowTi) Unrestrained (yielding) cantilever walls up to 10 feet in height should be designed for an active equivalent pressure value provided above. In the design of walls restrained from movement at the top (nonyielding) such as basement walls, the at-rest pressures should be used. If conditions other than those covered herein are anticipated, the equivalent fluid pressure values should be provided on an individual case basis by the geotechnical engineer. A surcharge load for a restrained or unrestrained wall resulting from automobile traffic may be assumed to be equivalent to a uniform pressure of 75 psf which is in addition to the equivalent fluid pressure given above. For other uniform surcharge loads, a uniform pressure equal to 0.35q should be applied to the wall (where q is the surcharge pressure in psf). The wall pressures assume walls are backfilled with free draining materials and water is not allowed to accommodate behind walls. Typical retaining wall drainage design is illustrated in Appendix E. Wall backfill should be compacted by mechanical methods to at least 90 percent relative compaction (based on ASTM D1557). Wall footings should be designed in accordance with the foundation design recommendations and reinforced in accordance with structural considerations. For all retaining walls, we recommend a minimum horizontal distance from the outside base of the footing to daylight of 10 feet. -19-4 Leighton 600203-002 Lateral soil resistance developed against lateral stractural movement can be obtained from the passive pressure value provided above. Further, for sliding resistance, the friction coefficient of 0.35 may be used at the concrete and soil interface. These values may be increased by one-third when considering loads of short duration including wind or seismic loads. The total resistance may be taken as the sum of the frictional and passive resistance provided that the passive portion does not exceed two-thirds of the total resistance. The geotechnical consultant should approve any backfill materials that will be utilized prior to the backfill placement operations. It is the contractors responsibility to provide representative samples of the selected backfill material. 6.5 MSE Retaining Walls Based on laboratory test results of existing on site soils, the proposed ground improvement measures and our experience with similar sites, we have prepared the following soil design parameters for MSE retaining wall design: Table 4 MSE Retaining Wall Design Parameters Soil Property Reinforced Zone Retained Zone Foundation Zone Intemal Friction Angle, (j) (degrees) 28 28 28 Cohesion, c (psf) 0 0 400 Total Unit Weight, y (pcf) 125 125 125 For MSE retaining walls extending a minimum depth of 18 inches beneath the lowest adjacent finish grade, footings may be designed for a maximum allowable bearing pressure of 2,000 pounds per square foot (psf) if founded in properly compacted fill and above the proposed ground improvement. The allowable pressure may be increased by one-third when considering loads of short duration such as wind or seismic forces. We recommend a minimum horizontal setback distance from the face of slopes for all stmctural footings and settlement sensitive structures. This distance is measured from the outside edge of the footing, horizontally to the slope face (or to the face of a retaining wall) and should be a minimum of 7 feet. Please note that the soils within the stractural setback area possess poor lateral stability, and improvements (such as retaining walls, -20-4 Leighton 600203-002 sidewalks, fences, pavements, etc.) constracted within this setback area may be subject to lateral movement and/or differential settlement. Wall drainage should be provided utilizing a clean sand or gravel (sand equivalent greater than 50) at the back of the segmental wall blocks (minimum 1 foot horizontal distance) with filter fabric separating the drainage layer from the backfill soils. Walls should be provided with drainage at the base of the wall consisting of 4-inch diameter, SDR 35 perforated pipe surrounded by 1 cubic foot per lineal foot of 3/4-inch aggregate wrapped in filter fabric. Lined swales should be provided where sloping backfill drains toward the walls. All drains and swales should outlet to suitable locations as determined by the project civil engineer. Appropriate surcharge pressures should be applied for walls influenced within the retained or reinforced zones by improvements or vehicular traffic, if any. The wall design engineer should also select grid design strength based on deflections tolerable to the proposed improvements. This office should review final plans prior to commencement of work. Surface drainage should be controlled at all times. Positive surface drainage should be provided to direct surface water toward suitable drainage facilities. Positive drainage may be accomplished by providing a minimum 2 percent gradient away from proposed improvements. In general, ponding of water should be avoided adjacent to the improvements. 6.6 Preliminary Pavement Recommendations 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 plarming purposes only based on an R-Value of 20. The final subgrade characteristics will be highly dependent on the soils present at fmish pavement subgrade. 4 Leighton 600203-002 Table 5 Preliminary Pavement Sections Pavement Loading Condition Traffic Index (20-Year Life) Anticipated Pavement Sections Parking Areas 4.5 3.0 inches AC over 6.0 inches Class 2 Base Drive Areas 5.0 3.0 inches AC over 8.0 inches Class 2 Base Track Drive Areas 6.0 4.0 inches AC over 9.0 inches Class 2 base For areas subject to unusually heavy track loading, we recommend a full depth of Portland Cement Concrete (P.C.C.) section of 7 inches with appropriate steel reinforcement and crack-control joints as designed by the project architect. We recommend that sections be as nearly square as possible. A 3,500-psi mix that produces a 600-psi modulus of rapture should be utilized. The actual pavement design should also be in accordance with County of San Diego and ACI design criteria. All pavement section materials should conform to and be placed in accordance with the latest revision of the California Department of Transportation Standard Specifications (Caltrans) and American Concrete Institute (ACI) codes. The upper 12 inches of subgrade soil and all aggregate base should be compacted to a relative compaction of at least 95 percent (based on ASTM Test Method Dl 557). 6.8 Concrete Flatwork In order to reduce the potential for differential movement or cracking of sidewalks and other concrete flatwork, wire mesh reinforcement (i.e. 6X6-WW6) is recommended along with keeping pad grade soils al elevated moisture content. Additional control can be obtained by providing thickened edges and 4 to 6 inches of base below the flatwork. Reinforcement should be placed in the middle of concrete section. Even though the slabs are reinforced, some cracking may occur. Proper design and constraction control joints is recommended to mitigate cracking. -22-4 Leighton 600203-002 6.9 Construction Observation The recommendations provided in this report are based on preliminary design information and subsurface conditions disclosed by widely spaced excavations. The interpolated subsurface conditions should be checked in the field during constraction. Constraction observation of all onsite excavations and field density testing of all compacted fill should be performed by a representative of this office. In addition, all footing excavations observed prior to placing steel or concrete. 6.10 Plan Review Final project drawings should be checked by Leighton before grading to see that the recommendations in this report are incorporated in project plans. 4 -23- Leighton 600203-002 7.0 LIMFFATIONS 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 constraction of the project, in order to confirm that our preliminary findings are representative for the site. 4 -24- Leighton . , Proposed-^, /^—retaining walk; Approximate loc,atibr proposed maintenance building Sp-V LEGEND Af Artificial fill Tsa Tertiary Santiago Formation (circled wfiere buried) Qal Quaternary Alluvium (circled where buried) ™ Approximate location of geologic contact (dashed where approximate, • • • dotted where buried, queried where uncertain) TD=4?"^ ^5 Approximate location of Leighton and Associates borings (2004) A-13 A TD=36 5' W Approximate location of AMEC borings (AMEC, 2001) LA-2 (j) Approximate location of L&A borings (Leighton, 2003) NORTH Approximate cross-section location 40 80 Scale in Feet GEOTECHNICAL MAP Leucadia Wastewater Treatment Plant Carlsbad, California 600203-002 1"=40' Project No. Scale Engr./Geol. WDO/MRS Drafted By KAM Date September 2004 Leighton Consulting, Inc. ^. LEIGHTON GROUP CON-'PAN Figure No. 2 ra » > 40- Approximate limits of proposed building ra « 1-40 20- •a o Existing ground surface 0-" -9 Qal •20- -a 0) 9 : 77?T 9 ? ? ?- Qal EXISTING BUILDING Af EXISTING TREATMENT STRUCTURE ca Qal -9 -9^ - .9- -9- _9- - -9- - -_9- - - TD=36.5' Tsa TD=41.5' -40- h20 Af Qal Tsa TO •20 TD=35.5' 40-J Approximate limits of . proposed building Existing ground surface MSE wall 20H m • Qal ^ ^ -r Tsa Af^_ - Af Af / __?__ ?-Tsa TD=21.5' -20- -40. -40 A' -40 -20 So ra a? > For Legend, see Figure No. 2 -0 --20 -40 CROSS-SECTION A-A' Leucadia Wastewater Treatment Plant Carlsbad, California 600203-002 Project No. Scale 1"=20' Engr./Geol. WDO/MRS Drafted By KAM Date September 2004 Leighton Consulting, Inc. Figure NO. 3 A L F I G H r C N GROUP C O r.i P A N 600203-002 APPENDIX A REFERENCES AMEC, 2001, Geotechnical Report Gafner Water Reclamation Facility Expansion, Leucadia County Water District, January 15, 2001. Blake, 2000, EQFAULT, Version 3.0. Califomia Building Standards Commission (CBSC), 2001, Califomia Building Code, Volume I - Administrative, Fire- and Life-Safety, and Field Inspection Provisions, Volume II - Stractural Engineering Design Provisions, and Volume III - Material, Testing and Installation Standards. CDMG, 1996, Probabilistic Seismic Hazard Assessment for the State of Califomia, Open-File Report 96-08. City of San Diego, 1992, Program Guidelines for Design Consultants, dated February, 1992. Eisenberg, L., 1983, Pleistocene and Eocene Geology of the Encinitas and Rancho Santa Fe Quadrangles, San Diego, California. Dudek , 2003, Revised Site Plan, Leucadia Pump Station, Leucadia County Water District, Figure 3-1, undated. Hart, 1994, Fault-Rupture Hazard Zones in Califomia, Alquist-Priolo Special Study Zones Act of 1972 with Index to Special Study Zones Maps: Department of Conservation, Division, Division of Mines and Geology, Special Publication 42. Intemationai Conference of Building Officials, 1997, Uniform Building Code. Ishihara, K., 1985, "Stability of Natural Deposhs during Earthquakes", Proceeding of the Eleventh Intemationai Conference of Soil Mechanics and Foundation Engineering, A.A. Belkema Publishers, Rotterdam, Netherlands. Ishihara, K., and Yoshimine, M., 1992, "Evaluation of Settlements in Sand Deposits Following Liquefaction of Sand Under Cyclic Stresses", Soils and Foundations, Vol. 32, No. 1, pp. 173-188. Leighton and Associates, Inc. 2003, Geotechnical Investigation, Pump Station Improvements, Leucadia Wastewater District's Leucadia Pump Station, Carlsbad, California, Project No. 600203-001, dated December 19, 2003 A-1 600203-002 APPENDIX A (continued) Marcuson, W.F., IE and Bieganousky, W.A., 1977, "SPT and Relative Density in Coarse Sands", Joumal of the Geotechnical Engineering Division, ASCE 103 (GTll): 1295 - 1309. National Research Council, 1985, "Liquefaction of Soils during Earthquakes" Report No.: CETS-EE-001, National Academy Press, Washington, D.C. NCEER, 1997, Proceedings of the NCEER Workshop on Evaluation of Liquefaction Resistance of Soils, edited by Youd and Idriss, Technical Report NCEER-97-0022, December 31, 1997. Schnabel, P.B., and Seed, H.B., 1973, Accelerations in Rock for Earthquakes in the Westem United States, Seismological Society of America Bulletin, Vol. 63, No. 2, pp. 501-575. Seed, H.B., and Idriss, I.M., 1971, "Simplified Procedure for Evaluating Soil Liquefaction Potential", Joumal of the Soil Mechanics and Foundation Division, ASCE 97 (SM9): 1249-1273. , 1982, "Ground Motion and Soil Liquefaction During Earthquake", Monograph, Series, Earthquake Engineering Research Institute, Berkeley, Califomia , 1976, Relationships of Maximum Accelerations, Maximum Velocity, Distance from Source and Local Site Conditions for Moderately Strong Earthquakes, Bull Seism, Soc. Amer., 66:4, dated August. Seed, H.B., Murarkla, R., Lysmer, J., and Idriss, 1., 1975, "Relationships Between Maximum Acceleration, Maximum Velocity, Distance from Source and Local Site Conditions for Moderately Strong Earthquake", Report No. EERC 75-17, University of Califomia, Berkeley. Tan, Saing, S, Kennedy, M.P., 1996, Geology of the Northwestern Part of San Diego County, California Divisions of Mines and Geology, Special Bulletin 200. A-2 GEOTECHNICAL BORING LOG KEY Date Project Drilling Co. Hole Diameter Elevation Top of Hole KEY TO BORING LOG GRAPHICS Sheet 1 of _± Project No. Type of Rig Drive Weight Location Drop I m CD •D < o z a. E m CO v> o ou- CQ o a. >» C4- d) o oa. oc so O DESCRIPTION Logged By Sampled By (A (U I- H-o « Q. 10 ^-77. TT W7^_ •Q •.. 15 ^7 20 25-- 30- SAMPLE TYPES: S SPLIT SPOON R RING SAMPLE B BULK SAMPLE T TUBE SAMPLE B-l C-l G-1 R-l SH-1 S-1 G GRAB SAMPLE C CORE SAMPLE Asphaltic concrete Portland cement concrete CL CH Inorganic clay of low to medium plasticity; gravelly clay; sandy clay; silly clay; lean clay OL ML Inorganic silt; clayey silt with low plasticity MH Inorganic silt; diatomaceous fine sandy or silty soils; elastic silt ML-CL Clayey silt to silty clay GW Well-graded gravel; gravel-sand mixture, little or no fines GP Poorly graded gravel; gravel-sand mixture, little or no fines GM GC Clayey gravel; gravel-sand-clay mixture SW Well-graded sand; gravelly sand, little or no fines SP Poorly graded sand; gravelly sand, little or no fines SM Silty sand; poorly graded sand-silt mixture SC Bedrock Ground water encountered at time of drilling Bulk Sample Core Sample Grab Sample Modified Califomia Sampler (3" O.D., 2.5 I.D.) Shelby Tube Sampler (3" O.D.) Standard Penetration Test SPT (Sampler (2" O.D., 1.4" I.D.) TYPE OF TESTS: DS DIRECT SHEAR MD MAXIMUM DENSITY CN CONSOLIDATION CR CORROSION SA SIEVE ANALYSIS SE SAND EQUIVALENT El EXPANSION INDEX RV R VALUE LEIGHTON CONSULTING, INC. GEOTECHNICAL BORING LOG B-1 Date Project 7-8-04 Leucadia Wastewater District Sheet 1 of 1 Project No. 600203-002 Drilling Co. Tri-County Type of Rig Hollow-Stem Auger Hole Diameter 8;' Drive Weight 140 pound hammer Drop 30" Elevation Top of Hole 20' Location See Map LU (3 (A •a 3 < o z a. E ra (0 (/) o 5 o ou- CQ a> o. w QD- >< Q 5c S° O Logged By Sampled By DESCRIPTION GJM GJM in o « Q. >» I- 20 0- 15 -5 5 15— 25- -lOJ 30 SAMPLE TYPES: S SPLIT SPOON R RING SAMPLE B BULK SAMPLE T TUBE SAMPLE R-I B-l (3,5'-! SC 4" Asphalt Concrete _£LAggregate Base ARtMCTAL FILL (Af) @ I': Fine to medium clayey SAND: Light gray-green to light green, damp to moist, medium dense to dense I 29 lOI.O 21.5 CL WEATHERED TERTIARY SANTIAGO FORMATION (Tsa) @ 5': Fine to medium sandy CLAY: Light gray-green to light green, damp to moist, hard R-2 I 47 106.1 19.8 SC @ 10': Grades to clayey fine to medium SAND: Light green, damp to moist, dense R-3 I 73 R-4 I 73/11' 117.2 119.4 13.5 CL 12.9 SM @ 16': CLAYSTONE: Olive-green, damp to moist, hard; oxidzation staining @ 20': Fine to medium silty SANDSTONE: Light green to light gray-green, damp, very dense Total Depth = 21.5 Feet No ground water encountered at time of drilling Backfilled with bentonite on 7/8/04 G GRAB SAMPLE C CORE SAMPLE TYPE OF TESTS: DS DIRECT SHEAR MD MAXIMUM DENSITY CN CONSOLIDATION CR CORROSION SA SIEVE ANALYSIS -200 200 WASH El EXPANSION INDEX PI ATTERBERG LIMIT 4 LEIGHTON CONSULTING, INC. GEOTECHNICAL BORING LOG B-2 7-8-04 Leucadia Wastewater District Sheet 1 of Project No. 600203-002 Date Project Drilling Co. Tri-County Type of Rig Hollow-Stem Auger Hole Diameter 8;; Drive Weight 140 pound hammer Drop 30" Elevation Top of Hole 12' Location See Map SAMPLE TYPES; S SPLIT SPOON R RING SAMPLE B BULK SAMPLE T TUBE SAMPLE CL/SC Logged By Sampled By DESCRIPTION GJM GJM 6^Woodchips/mu]tch ARTIFICIAL FILL (Af) @ .5': Clayey fine to medium SAND: Brown, orange-brown, damp to moist, medium dense ) 5': Clayey fine to medium SAND: Brown, orange-brown, damp to moist, medium dense QUATERNARY ALLLWIUM (Oal) @ 10': CLAY to fine to medium sandy CLAY: Brown to dark red-brown, moisl, stiff @ 15': Clayey fine to medium SAND: Orange-brown to brown, moist, loose WEATHERED TERTIARY SANTIAGO FORMATON (Tsa) @ 20': CLAY: Light greenish gray to light olive-green, damp to moist, hard tf) 0) o 0) Q. G GRAB SAMPLE C CORE SAMPLE TYPE OF TESTS: DS DIRECT SHEAR MD MAXIMUM DENSITY CN CONSOLIDATION CR CORROSION SA SIEVE ANALYSIS -200 200 WASH El EXPANSION INDEX PI ATTERBERG LIMIT LEIGHTON CONSULTING, INC. GEOTECHNICAL BORING LOG B-2 Date 7-8-04 Project Drilling Co. Hole Diameter Elevation Top of Hole Leucadia Wastewater District Tri-County Sheet 2 of Project No. Type of Rig 600203-002 8" 12' Drive Weight Location 140 pound hammer Hollow-Stem Auger Drop 30" See Map h I"- LU -20 -25 a.* 30 35- 40- -30 -35 -40 •SO" 9-° o 45 50 55- o TS *3 < Q. E ra w tf) o oil. CQ g» Q. R-6 172/11' R-7 I 50/5 -45 60 SAMPLE TYPES: S SPLIT SPOON R RING SAMPLE B BULK SAMPLE T TUBE SAMPLE tf) CM- 0) o DO. >< 116.5 tf)« Oc SO O 13.8 Z.V) SM Logged By Sampled By DESCRIPTION GJM GJM ! 31': Silty fine to medium SANDSTONE: Light green to light gray-green, damp, very dense @_35': Silty fine to medium SANDSTONE: Green to dark olive-green. \ damp, very dense; little recovery Total Depth = 35.5 Feet Ground water seepage at 30 feet Backfilled with bentonite on 7/8/04 o o (O a. GRAB SAMPLE CORE SAMPLE TYPE OF TESTS: DS DIRECT SHEAR MD MAXIMUM DENSITY CN CONSOLIDATION CR CORROSION SA SIEVE ANALYSIS -200 200 WASH El EXPANSION INDEX PI ATTERBERG LIMIT 4 LEIGHTON CONSULTING, INC. GEOTECHNICAL BORING LOG B-3 Date 7-8-04 Project Drilling Co. Hole Diameter Elevation Top of Hole Leucadia Wastewater District Tri-County Sheet 1 of Project No. Type of Rig 600203-002 8" Drive Weight Location 140 pound hammer Hollow-Stem Auger Drop 30" See Map lU tf) 13 5 2 < o z OJ Q. E ra w tf) o on- CQ a> Q. tf) 0) o aa. Oc so O tf)-r DESCRIPTION Logged By Sampled By GJM GJM tf) 0) a. -15 10 20- SC 4" Asphalt Concrete JL!-Aggregate Base ARTIFICTAL FILL (Af) @ I': Clayey fine to medium SAND: Brovvn to red-brown, damp to moist, loose to medium dense R-l R-2 I QUATERNARY ALLUVIUM (Oal) @ 3': Fine to medium sandy CLAY: Mottled green to brown, moist to wet, stiff 10 push 102.5 18.5 SC @ 10': Poor recovery I S-1 S-2 push 17 @ 15': No recovery CH @ 20': CLAY: Dark gray to black, wet, very soft; slight organic odor SM ] 25': Silty fme SAND: Ohve-gray, wet, medium dense SAMPLE TYPES: S SPLIT SPOON R RING SAMPLE B BULK SAMPLE T TUBE SAMPLE G GRAB SAMPLE C CORE SAMPLE TYPE OF TESTS: DS DIRECT SHEAR MD MAXIMUM DENSITY CN CONSOLIDATION CR CORROSION SA SIEVE ANALYSIS •200 200 WASH El EXPANSION INDEX PI ATTERBERG LIMIT LEIGHTON CONSULTING, INC. GEOTECHNICAL BORING LOG B-3 7-8-04 Date Project Drilling Co. Hole Diameter Elevation Top of Hole Leucadia Wastewater District Tri-County Sheet 2 Project No. Type of Rig of 8" 8' Drive Weight Location 140 pound hammer 600203-002 Hollow-Stem Auger Drop 30" See Map -25 -30 -35 30 35- 40- -40 -45 45- 50 55- -50 60- SAMPLE TYPES: S SPLIT SPOON R RING SAMPLE B BULK SAMPLE T TUBE SAMPLE S-3 S-4 tf) o 5 o o"^ CD b Q. 17 20 tf) c^- 0) U QQ. tf)« OC so o 09 OIJ to-' SC DESCRIPTION Logged By Sampled By GJM GJM ! 30': Clayey fine to medium SAND: Mottled orange-brown and green, damp to moist, medium dense WEATHERED SANTIAGO FORMATION (Tsa) @ 35': Clayey fine to medium SANDSTONE: Mottled orange-brown Io olive-green, damp to moist, dense Total Depth = 36.5 Feet Ground water encountered at 9 feet at time of drilling Backfilled vvith bentonite on 7/8/04 tf) 0) o a> a. >. I- G GRAB SAMPLE C CORE SAMPLE TYPE OF TESTS: DS DIRECT SHEAR MD MAXIMUM DENSITY CN CONSOLIDATION CR CORROSION SA SIEVE ANALYSIS -200 200 WASH El EXPANSION INDEX PI ATTERBERG LIMIT LEIGHTON CONSULTING, INC. GEOTECHNICAL BORING LOG B-4 7-8-04 Date Project Drilling Co. Hole Diameter Elevation Top of Hole Leucadia Wastewater District Tri-County Sheet 1 of Jl Project No. 600203-002 Type of Rig Hollow-Stem 8" Drive Weight Location 140 pound hammer Drop 30" See Map -10 -15 -20 20- 25- U) <S) TJ 3 •*3 < R-4 B-l ®5'-10' OJ Q. E « OT tf) O CQ V Q. I I R-2 I push R-3 I 12 R-4 I 13 R-5 I push 4 tf) ev-il) u QQ. 78.8 68.6 86.6 107.1 56.6 (flOJ o c SO o 37.9 58.7 34.8 21.6 75.2 tf)T 09 _OT ozi CL CH SM SM CH Logged By Sampled By DESCRIPTION GJM GJM 4" Asphalt Concrete -61Aggregate Base ARllFldAL HLL (Af) @ 1': CLAY: Brown to gray-brown, moist to wet, stiff @ 5': CLAY: Brown to gray-brown, moist to wet, stiff QUATERNARY ALLUVIUM (Oal) @ 10': CLAY: Dark gray to dark gray-brown, wet to saturated, very soft thinlv laminated beds @ 15': Grades to silty fine to medium SAND: Gray to medium gray, wet to saturated, loose, shell fragments (ill 20': Fine to medium SAND: Gray to medium gray, wet to saturated, loose; shell fragments @25': CLAY: Dark gray, wet, stoft o a> a SAMPLE TYPES: S SPLIT SPOON R RING SAMPLE B BULK SAMPLE T TUBE SAMPLE G GRAB SAMPLE C CORE SAMPLE TYPE OF TESTS: DS DIRECT SHEAR MD MAXIMUM DENSITY CN CONSOLIDATION CR CORROSION SA SIEVE ANALYSIS -200 200 WASH El EXPANSION INDEX PI ATTERBERG LIMIT LEIGHTON CONSULTING, INC. GEOTECHNICAL BORING LOG B-4 7-8-04 Date Project Drilling Co. Hole Diameter Elevation Top of Hole Leucadia Wastewater District Tri-County Sheet 2 Project No. Type of Rig of 600203-002 8" Drive Weight Location 140 pound hammer Hollow-Stem Drop 30" See Map I* 5<i) Ui 1^ 30- N_ •So* S-o «_i CD tf) 0) T3 3 *3 < Q) Q. ra OT tf) O 5 o o"^ CQ a> U) Ci.-0) u DO. 4-t c WO) oc SO O tf)-r 09 _OT od OT— Logged By Sampled By DESCRIPTION GJM GJM »> 0) o a> a. -25 35- -30 SP @ 30': No recovery S-I S-2 -35 -40 -45 -50 45- 50- 55- 60 SAMPLE TYPES: S SPLIT SPOON R RING SAMPLE B BULK SAMPLE T TUBE SAMPLE @ 35': Fine to coarse SAND: Gray, wet to saturated, loose 15 SC @ 40': Clayey fine to medium SAND: Olive-green, moist, loose Tolal Depth-41.5 Feet Ground water encountered at 8 feet at time of drilling Backfilled with bentonite on 7/8/04 G GRAB SAMPLE C CORE SAMPLE TYPE OF TESTS: DS DIRECT SHEAR MD MAXIMUM DENSITY CN CONSOLIDATION CR CORROSION SA SIEVE ANALYSIS -200 200 WASH El EXPANSION INDEX PI ATTERBERG LIMIT 4 LEIGHTON CONSULTING, INC. 600203-001 APPENDIX C Laboratory Testing Procedures and Test Results Chloride Content: Chloride content was tested in accordance with DOT Test Method No. 422. The results are presented below: Sample Location Chloride Content, ppm Degree of Corrosivity** B-4, 5-10 Feet 3,600 Severe ** Based on City of San Diego, Program Guidelines for Design Consultants, CWP, Febmary 1992. Consolidation Tests: Consolidation tests were performed on selected, relatively undisturbed ring samples. Samples were placed in a consolidometer and loads were applied in geometric progression. The percent consolidation for each load cycle was recorded as the ratio of the amount of vertical compression to the original 1-inch height. The consolidation pressure curves are presented in the test data. Direct Shear Tests: Direct shear tests were performed on selected undisturbed samples which were soaked for a minimum of 24 hours under a surcharge equal to the applied normal force during testing. After transfer of the sample to the shear box, and reloading the sample, pore pressures set up in the sample due to the transfer were allowed to dissipate for a period of approximately 1 hour prior to application of shearing force. The samples were tested under various normal loads, a motor-driven, strain-controlled, direct-shear testing apparatus at a strain rate of less than 0.001 to 0.5 inches per minute (depending upon the soil type). The test results are presented in the test data. Sample Location Sample Description Friction Angle Apparent Cohesion B-2, 10 Feet Sandy CLAY 28 700 Minimum Resistivity and pH Tests: Minimum resistivity and pH tests were performed in general accordance with Califomia Test Method 643. The results are presented in the table below: Sample Location pH Minimum Resistivity (ohms-cm) Corrosion Potential** B-4, 5-10 Feet 8.13 357 Very High ** Based on City of San Diego, Program Guidelines for Design Consultants, CWP, Febmary 1992. C-l 600203-001 APPENDIX C (Continued) Moisture and Density Determination Tests: Moisture content and dry density determinations were performed on relatively undisturbed samples obtained from the test borings. The results of these tests are presented in the boring logs. Where applicable, only moisture content was determined from "imdisturbed" or disturbed samples. Soluble Sulfates: The soluble sulfate contents of selected samples were determined by standard geochemical methods. The test results are presented in the table below: Sample Location Sulfate Content (ppm) Potential Degree of Sulfate Attack* B-4, 5-10 Feet 2,000 Severe * Based on the 1997 edition of the Uniform Building Code, Table No. 19-A-4, prepared by the Intemationai Conference of Building Officials (ICBO, 1997). C-2 4000 3000 tf) a in in 2 2000 OT k_ ra V .c OT 1000 1000 2000 3000 Vertical Stress (psf) 4000 Boring Location Sample Depth (feet) Sample Description B-2 10ft CL, BROWN SANDY CLAY Average Strength Parameters Friction Angle, <t)'peak (deg) 28 Cohesion, c'peak (Psf) 700 Friction Angle, (^'^,^^ (deg) Cohesion, c'^,i, (psf) 28 400 DIRECT SHEAR SUMMARY Project No. Project Name Figure No. 600203-002 LWD C-l n E £ o Q 0.1500 0.1600 0.1700 0.1800 0.1900 0.2000 Time Readings ( 0 ksf 0.1 1.0 10.0 100.0 1000.0 10000.0 Log of Time (min.) 0.1500 1 0.1600 c 0.1700 o 0.1800 0.1900 0.2000 0.0 10.0 20.0 30.0 40.0 Square Root of Time (min."^) 50.0 0.00 10.00 0.10 1.00 10.00 Pressure, p (ksf) 100.00 Boring Number Sample Number: Depth (ft.) Moisture Content (%) Initial Final Dry Density (pcf) Initial Final Void Ratio Initial Final Degree of Saturation (%) Initial Final B-2 R-3 15 21.4 18.6 109.6 109.9 0.513 0.443 107 94 Sample DescriDtion: SM: PALE YELLOWISH-BROWN LEAN SILT Leighton Consulting, Inc. Project Name: LEUCADIA WASTEWATER Dl Leighton Consulting, Inc. Project Number: 600203-002 ONE-DIMENSIONAL CONSOLIDATION PROPERTIES OF SOIL ASTM D 2435 0.1500 0.1600 c 0.1700 f-o 0.1800 0.1900 0.2000 Time Readings @ 0 ksf 0.1 1.0 10.0 100.0 1000.0 10000.0 Log of Time (min.) 0.1500 0.1600 c 0.1700 o 0.1800 0.1900 0.2000 0.0 10.0 20.0 30.0 40.0 50.0 Square Root of Time (min. ) 0.00 10.00 0.10 1.00 10.00 Pressure, p (ksf) 100.00 Boring Number Sample Number: Depth (ft.) Moisture Content (%) Dry Density (pcf) Void Ratio Degree of Saturation (%) Boring Number Sample Number: Depth (ft.) Initial Final Initial Final Initial Final Initial Final B-4 R-2 10 58.7 54.1 68.6 72.4 1.338 1.327 109 110 Sample DescriDtion: CH: PALE BROWN HEAVY CLAY Leighton Consulting, Inc. Project Name: LEUCADIA WASTEWATER Dl Project Number: 600203-002 CH: PALE BROWN HEAVY CLAY ONE-DIMENSIONAL CONSOLIDATION PROPERTIES OF SOIL ASTM D 2435 Project Name: Project Number: Boring Number: Sample Number: Sample Description: CT 532, CT 417, CT 422 LEUC/\DIA WASTEWATER DISTRiC T 600203-002 B-4 B1 Date; Tested By: Checked By: Depth (ft.): CL: PALE BROWN LEAN CLAY Initial Moisture Content Initial Sample Weight (g) 1300 Wet Weight of Soil+Container (g) 100.0 Box Constant 6.87 Dry Weight of Soil+Container (g) 87.5 Soil pH 8.13 Weight of Container (g) 0.0 Sulfate Content (ppm) 2000 Moisture Content (%) 14.3 Chloride Content (ppm) 3600 Water Added (ml) 100 200 300 4bp '., Moisture Content (%) 23.08 31.87 40.66 49.45 Spec. Cond.(uhm/cm) 80 53 52 53 Resistivity (ohms-cm) 550 364 357 364 Resistivity of Soil 600 E o 0) E > ]> '••3 (0 o CO 500 — 400 300 200 100 0.00 10.00 20.00 30.00 40.00 Moisture Content (%) 60.00 Rev 10-01 *********************** * * * EQFAULT * * * * Version 3.00 * * * *********************** DETERMINISTIC ESTIMATION OF PEAK ACCELERATION FROM DIGITIZED FAULTS JOB NUMBER: 600203-002 DATE: 09-01-2004 JOB NAME: RNP CALCULATION NAME: Test Run Analysis FAULT-DATA-FILE NAME: C:\Program Files\EQFAULTl\cdmgenew(HMR).dat SITE COORDINATES: SITE LATITUDE: 33.0863 SITE LONGITUDE: 117.2671 SEARCH RADIUS: 100 mi ATTENUATION RELATION: 22) Abrahamson & Silva (1995b/l997) Horiz.- Rock 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: C:\Program Files\EQFAULTl\cdmgenew(HMR).dat MINIMUM DEPTH VALUE (km): 0.0 EQFAULT SUMMARY DETERMINISTIC SITE PARAMETERS Page 1 ABBREVIATED FAULT NAME APPROXIMATE DISTANCE mi (km) ESTIMATED MAX. EARTHQUAKE EVENT MAXIMUM EARTHQUAKE MAG.(Mw) PEAK SITE ACCEL, g EST. SITE INTENSITY MOD.MERC. ROSE CANYON AB Modified trace 6-| 5 3 ( 8 .5) 1 7 2 1 0 442 X NEWPORT-INGLEWOOD (Offshore) AB j 10 6 ( 17 . 0) I 7 1 1 0 242 IX CORONADO BANK (Mmx Mod. 8-15-03) j 20 5 ( 33 . 0) I 7 6 1 0 159 VIII ELSINORE-TEMECULA | 24 9 ( 40 .1)1 6 8 i 0 090 VII ELSINORE-JULIAN j 24 9 ( 40 . 1) 7 1 1 0 105 VII SAN JOAQUIN HILLS AB Added 2-9-j 36 0 ( 57 • 9) 1 6 8 1 0 079 VII ELSINORE-GLEN IVY j 38 8 ( 62 .4) 1 6 8 1 0 056 VI EARTHQUAKE VALLEY j 40 2 ( 64 • 7) 1 6 5 1 0 046 VI PALOS VERDES j 41 2 ( 66 .3) I 7 1 1 0 063 VI SAN JACINTO-ANZA | 47 7 ( 76 .8)1 7 2 1 0 057 VI SAN JACINTO-SAN JACINTO VALLEY j 49 5 ( 79 .7)1 6 9 1 0 046 VI SAN JACINTO-COYOTE CREEK ' j 50 9 ( 81 • 9) 1 6 8 1 0 042 VI NEWPORT-INGLEWOOD (L.A.Basin) j 52 3 ( 84 .2) 1 6 9 1 ° 044 VI ELSINORE-COYOTE MOUNTAIN j 53 1 ( 85 .4) 1 6 8 1 0 040 V CHINO-CENTRAL AVE. (Elsinore) | 53 7 ( 86 .4) I 6 7 1 0 049 VI WHITTIER 1 57 2 ( 92 .1) j 6 8 1 0 037 V COMPTON THRUST j 62 1 ( 99 . 9 ) 1 6 8 1 ° 044 VI SAN JACINTO - BORREGO j 62 6 ( 100 .8)1 6 6 1 0 030 V SAN JACINTO-SAN BERNARDINO j 64 3 ( 103 . 5) I 6 7 1 0 031 V ELYSIAN PARK THRUST | 64 9 ( 104 .5) 1 6 7 1 0 040 V SAN ANDREAS - San Bernardino | 67 5 ( 108 • 7) 1 7 3 1 0 043 VI SAN ANDREAS - Southern j 67 5 ( 108 • 7) 1 7 4 1 0 046 VI SAN ANDREAS - Coachella | 73 9 ( 119 . 0) 1 7 1 1 0 035 V SAN JOSE 1 74 0 ( 119 .1) I 6 5 1 0 030 V PINTO MOUNTAIN | 74 2 ( 119 .4) I 7 0 1 0 032 V CUCAMONGA j 76 4 ( 123 . 0) 1 7 0 1 0 040 V SIERRA MADRE | 76 7 ( 123 .4) 1 7 0 1 0 040 V SUPERSTITION MTN. (San Jacinto) j 78 1 ( 125 .7) 6 6 1 0 023 IV BURNT MTN. j 78 6 ( 126 .5)1 6 4 1 0 020 IV NORTH FRONTAL FAULT ZONE (West) | 80 1 ( 128 .9) 7 0 0 039 V EUREKA PEAK | 81 3 ( 130 .9) 6 4 1 0 019 IV ELMORE RANCH 81 9 ( 131 .8) 1 6 6 1 0 022 IV CLEGHORN | 82 K 132 1) 1 6 5 1 0 021 1 IV SUPERSTITION HILLS (San Jacinto) j 82 9( 133 4) 1 6 6 I 0 022 1 IV NORTH FRONTAL FAULT ZONE (East) j 83 3 ( 134 0) 1 6 7 I 0 030 1 V LAGtlNA SALADA j 84 0( 135 2) 1 7 0 1 0 028 1 V SAN ANDREAS - Mojave j 85 9( 138 3) 1 7 1 1 0 030 I V SAN ANDREAS - 18 57 Rupture j 85 9 ( 138 3) 1 7 8 1 0 048 I VI RAYMOND I 86 0 ( 138 4) 6 5 1 0 025 I V CLAMSHELL-SAWPIT j 86 2 ( 138 7) 6 5 1 0 025 I V DETERMINISTIC SITE PARAMETERS Page 2 1 ESTIMATED MAX. EARTHQUAKE EVENT 1 APPROXIMATE ABBREVIATED j DISTANCE MAXIMUM 1 PEAK |EST. SITE FAULT NAME j mi (km) EARTHQUAKE I SITE I INTENSITY MAG (Mw) I ACCEL, g I MOD.MERC. VERDUGO 1 88 . 6 ( 142 . 6) 6 7 1 0 . 028 I V LANDERS I 89 . 2 ( 143 . 6) 7 3 I 0 . 033 I V HOLLYWOOD j 90 . 5 ( 145 . 7) 6 4 I 0 . 022 I IV HELENDALE - S. LOCKHARDT j 91. 7 ( 147 . 5) 7 1 I 0 . 028 i V BRAWLEY SEISMIC ZONE j 92 . 1 ( 148 . 2) 6 4 1 0 . 017 1 I'^ LENWOOD-LOCKHART-OLD WOMAN SPRGS j 94 . 9 ( 152 . 7) 7 3 I 0 . 031 I V SANTA MONICA j 95 . 4 ( 153 . 5) 6 6 I 0 . 024 I V EMERSON So. - COPPER MTN. j 96 . 9 { 155 . 9) 6 9 1 0 . 023 I IV JOHNSON VALLEY (Northern) j 97 . 4 ( 156 . 8) 6 7 I 0 . 020 I IV MALIBU COAST j 98 . 1 ( 157 . 9) 6 7 1 0 . 025 i V IMPERIAL I 99 . 1 ( 159. 5) 7 0 1 0 . 024 1 IV ********************************************************** * * ******************* -END OF SEARCH- 51 FAULTS FOUND WITHIN THE SPECIFIED SEARCH RADIUS. THE ROSE CANYON AB Modified trace 6- FAULT IS CLOSEST TO THE SITE. IT IS ABOUT 5.3 MILES (8.5 km) AWAY. LARGEST MAXIMUM-EARTHQUAKE SITE ACCELERATION: 0.4420 g *********************** * * * EQFAULT * * * * Version 3.00 * * * *********************** DETERMINISTIC ESTIMATION OF PEAK ACCELERATION FROM DIGITIZED FAULTS JOB NUMBER: 600203-002 DATE: 09-01-2004 JOB NAME: RNP CALCULATION NAME: Test Run Analysis FAULT-DATA-FILE NAME: C:\Program Files\EQFAULTl\cdmgenew(HMR).dat SITE COORDINATES: SITE LATITUDE: 33.0863 SITE LONGITUDE: 117.2671 SEARCH RADIUS: 100 mi ATTENUATION RELATION: 22) Abrahamson & Silva (1995b/l997) Horiz.- Rock UNCER'^'AINTY (M=Median, S=Sigma) : S Number of Sigmas: 1.0 DISTANCE MEASURE: clodis SCOND: 0 Basement Depth: 5.0 0 km Campbell SSR: Campbell SHR: COMPUTE PEAK HORIZONTAL ACCELERATION FAULT-DATA FILE USED: C:\Program Files\EQFAULTl\cdmgenew(HMR).dat MINIMUM DEPTH VALUE (km): 0.0 EQFAULT SUMMARY DETERMINISTIC SITE PARAMETERS Page 1 ABBREVIATED FAULT NAME APPROXIMATE DISTANCE mi (km) ESTIMATED MAX. EARTHQUAKE EVENT MAXIMUM EARTHQUAKE MAG.(Mw) PEAK SITE ACCEL, g EST. SITE INTENSITY MOD.MERC. ROSE CANYON AB Modified trace 6-| 5 . 3 ( 8 .5) j 7 . 2 j 0 . 679 XI NEWPORT-INGLEWOOD (Offshore) AB | 10 . 6 ( 17 .0) 1 7 . 1 1 0 .371 IX CORONADO BANK (Mmx Mod. 8-15-03) j 20 - 5 ( 33 .0) 1 7 . 6 1 0 . 245 IX ELSINORE-TEMECULA j 24 . 9 ( 40 . 1) I 6 . 8 j 0 . 143 VIII ELSINORE-JULIAN j 24 . 9 ( 40 . 1) I 7 . 1 1 0 .161 VIII SAN JOAQUIN HILLS AB Added 2-9-j 36 . 0 ( 57 .9) 1 6 . 8 1 0 . 125 VII ELSINORE-GLEN IVY j 38 . 8 ( 62 .4) I 6 . 8 1 0 . 089 VII EARTHQUAKE VALLEY j 40 .2 ( 64 .7)1 6 . 5 1 0 . 075 VII PALOS VERDES j 41 2 { 66 .3) 1 7 . 1 1 0 . 097 VII SAN JACINTO-ANZA j 47 7 ( 76 . 8) 1 7 .2 1 0 088 VII SAN JACINTO-SAN JACINTO VALLEY j 49 5 ( 79 • 7) 1 6 . 9 1 0 072 VI SAN JACINTO-COYOTE CREEK j 50 9 ( 81 .9) I 6 8 1 0 067 VI NEWPORT-INGLEWOOD (L.A.Basin) j 52 3 ( 84 .2) I 6 9 1 0 068 VI ELSINORE-COYOTE MOUNTAIN | 53 1 ( 85 .4) 1 6 8 1 0 064 VI CHINO-CENTRAL AVE. (Elsinore) | 53 7 { 86 .4) 1 6 7 1 0 078 VII WHITTIER 1 57 2 ( 92 .1) 6 8 1 0 059 VI COMPTON THRUST j 62 1 ( 99 . 9 ) 1 6 8 1 0 070 VI SAN JACINTO - BORREGO | 62 6 ( 100 .8)1 6 6 1 0 048 VI SAN JACINTO-SAN BERNARDINO j 64 3 ( 103 .5) I 6 7 1 0 049 VI ELYSIAN PARK THRUST j 64 9 ( 104 .5) I 6 7 1 0 063 VI SAN ANDREAS - San Bernardino | 67 5 ( 108 7) 1 7 3 j 0 066 VI SAN ANDREAS - Southern j 67 5 ( 108 7) I 7 4 1 0 071 • VI SAN ANDREAS - Coachella j 73 9 ( 119 0) I 7 1 1 0 053 VI SAN JOSE I 74 0 ( 119 1) 1 6 5 1 0 049 VI PINTO MOUNTAIN 74 2 ( 119 4) I 7 0 1 0 050 1 VI CUCAMONGA | 76 4 ( 123 0) 1 7 0 1 0. 062 1 VI SIERRA MADRE j 76 7 ( 123 4) 1 7 0 1 0 • 062 1 VI SUPERSTITION MTN. (San Jacinto) j 78 . 1 ( 125 7) 1 6 . 6 1 0 • 038 1 V BURNT MTN. | 78 . 6 ( 126 5) I 6 . 4 1 0. 034 I V NORTH FRONTAL FAULT ZONE (West) | 80 . 1 ( 128 9) I 7 . 0 1 0-059 1 VI EUREKA PEAK j 81. 3 ( 130 9) 1 6 . 4 1 0 . 032 I V ELMORE RANCH | 81. 9 ( 131 8) I 6 . 6 1 0. 036 1 V CLEGHORN | 82 K 132 1) 1 6 5 1 0 034 1 V SUPERSTITION HILLS (San Jacinto) j 82 9( 133 4) 6 6 I 0 035 I V NORTH FRONTAL FAULT ZONE (East) j 83 3 ( 134 0) 6 7 I 0 048 1 VI LAGUNA SALADA j 84 0 ( 135 2) 7 0 I 0 043 I VI SAN ANDREAS - Mojave j 85 9{ 138 3) 1 7 1 I 0 046 I VI SAN ANDREAS - 1857 Rupture j 85 9{ 138 3) 1 7 8 I 0 074 1 VII RAYMOND 86 0( 138 4) 1 6 5 1 0 042 1 VI CLAMSHELL-SAWPIT | 86 2( 138 7) 6 5 I 0 042 I V DETERMINISTIC SITE PARAMETERS Page 2 1 ESTIMATED MAX. EARTHQUAKE EVENT APPROXIMATE ABBREVIATED j DISTANCE j MAXIMUM 1 PEAK |EST. SITE FAULT NAME j mi (km) EARTHQUAKE 1 SITE I INTENSITY MAG (Mw) I ACCEL, g I MOD.MERC. VERDUGO I 88 . 6 ( 142 . 6) 6 7 i 0 . 045 j VI LANDERS I 89 . 2( 143 . 6) 7 3 I 0 . 050 VI HOLLYWOOD | 90 . 5( 145 . 7) 6 4 I 0 . 037 1 V HELENDALE - S. LOCKHARDT j 91. 7( 147 . 5) 7 1 1 0 . 043 1 VI BRAWLEY SEISMIC ZONE j 92 . K 148 . 2) 6 4 1 0 . 028 1 V LENWOOD-LOCKHART-OLD WOMAN SPRGSj 94 . 9( 152 . 7) 7 3 1 0 . 047 1 VI SANTA MONICA j 95 . 4( 153 . 5) 6 6 1 0 . 039 1 V EMERSON So. - COPPER MTN. j 96 . 9{ 155 . 9) 6 9 1 0 . 035 1 V JOHNSON VALLEY (Northern) j 97 . 4 ( 156 . 8) 6 7 1 0 . 031 V MALIBU COAST j 98 . K 157 . 9) 6 7 1 0 . 040 1 V IMPERIAL I 99 . K 159. 5) 7 0 1 0 .03 7 1 V ******************************************************************************* -END OF SEARCH- 51 FAULTS FOUND WITHIN THE SPECIFIED SEARCH RADIUS. THE ROSE CANYON AB Modified trace 6- IT IS ABOUT 5.3 MILES (8.5 km) AWAY. FAULT IS CLOSEST TO THE SITE. LARGEST MAXIMUM-EARTHQUAKE SITE ACCELERATION: 0.6795 g Leighton and Associates, Inc. GENERAL EARTHWORK AND GRADING SPECIFICATIONS Page 1 of 6 LEIGHTON AND ASSOCIATES, INC. GENERAL EARTHWORK AND GRADING SPECIFICATIONS FOR 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 infonn the owner, recommend appropriate changes in design to accommodate the observed conditions, and notify the review agency where required. Subsurface areas to be geotechnically observed, 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 SPECIFICATIONS 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-conditioningand 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 ov/ner 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 tiie Geoteclmical 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, goveming 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 Leightonand Associates, Inc. GENERAL EARTHWORK AND GRADING SPECIFICATIONS Page 3 of 6 2.2 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. Scarification 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 determiningelevationsof 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 substances evaluated 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. 3.2 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 LeTghton and Associates, Inc. GENERAL EARTHWORK AND GRADING SPECIFICATIONS Page 4 of 6 3.3 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 Lavers: 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 tlu"oughout, 4.2 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 soii 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 Dl 557-91. 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). Leightonand Associates,Inc. GENERAL EARTHWORK AND GRADINGSPECIFICATIONS Page 5 of 6 4.6 Frequency of Compaction Testing: Tests shall be taken 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 sun-eys. 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 the Geotechnical Consultant prior to placement of materials for construction of the fill portion of the slope, unless otherwise recommended by the Geotechnical Consultant. Leightonand Associates,Inc. GENERAL EARTHWORK AND GRADING SPECIFICATIONS Page 6 of 6 7.0 Trench Backfills 7.1 The Contractor shall follow all OHSA and Cal/OSHA requirements for safety of trench excavations. 7.2 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 1 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 shaii 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 altemative equipment and method. 3030.1094 FILL SLOPE PROJECTED PLANE 1 TO 1 MAXIMUM FROM TOE OF SLOPE TO APPROVED GROUND GROUND BENCH HEIGHT (4' TYPICAL) REMOVE UNSUITABLE MATERIAL 2 MIN.' KEY DEPTH LOWEST BENCH (KEY) FILL-OVER-CUT SLOPE EXISTING GROUND SURFACE OMPAGTED:-:-:-» "yiLL;:^^:^^ BENCH HEIGHT (4" TYPICAL) REMOVE UNSUITABLE MATERIAL CUT-OVER-FILL SLOPE OVERBUILD AND TRIM BACK -CUT FACE SHALL BE CONSTRUCTED PRIOR TO FILL PLACEMENT TO ASSURE ADEQUATE GEOLOGIC CONDITIONS EXISTING- GROUND SURFACE /T' ' A.-. PROJECTED PLANE 1 TO 1 MAXIMUM FROM TOE OF SLOPE TO APPROVED GROUND 2' MIN KEY DEPTH CUT FACE SHALL BE CONSTRUCTED PRIOR TO FILL PLACEMENT REMOVE UNSUITABLE MATERIAL BENCH HEIGHT (4' TYPICAL) FOR SUBDRAINS SEE STANDARD DETAIL C LOWEST BENCH (KEY) 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. KEYING AND BENCHING GENERAL EARTHWORK AND GRADING SPECIFICATIONS STANDARD DETAILS A LEIGHTON AND ASSOCIATES FINISH GRADE SLOPE FACE 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. GRANULAR MATERIAL TO BE' DENSIFIED IN PLACE BY FLOODING OR JETTING. DETAIL -JETTED OR FLOODED GRANULAR MATERIAL TYPICAL PROFILE ALONG WINDROW OVERSIZE ROCK DISPOSAL GENERAL EARTHWORK AND GRADING SPECIFICATIONS STANDARD DETAILS B LEIGHTON AND ASSOCIATES 'EXISTING GROUND SURFACE BENCHING REMOVE UNSUITABLE MATERIAL CALTRANS CLASS 2 PERMEABLE OR #2 ROCK (9FT''3/FT) WRAPPED IN FILTER FABRIC SUBDRAIN TRENCH SEE DETAIL BELOW FILTER FABRIC (MIRAFI HON OR APPROVED EQUIVALENT)* MIN. 4" MIN. BEDDING COLLECTOR PIPE SHALL BE MINIMUM 6" DIAMETER SCHEDULE 40 PVC PERFORATED PIPE. SEE STANDARD DETAIL D FOR PIPE SPECIFICATIONS SUBDRAIN DETAIL DESIGN FINISH GRADE FILTER FABRIC (MIRAFI MON OR APPROVED EQUIVALENT) CALTRANS CLASS 2 PERMEABLE OR #2 ROCK (9FT"3/FT) WRAPPED IN FILTER FABRIC NONPERFORATED 6 0 MIN 6" 0 MIN. PIPE DETAIL OF CANYON SUBDRAIN OUTLET CANYON SUBDRAINS GENERAL EARTHWORK AND GRADING SPECIFICATIONS STANDARD DETAILS C LEIGHTON AND ASSOCIATES OUTLET PIPES 4" 0 NONPERFORATED PIPE, 100' MAX. O.C. HORIZONTALLY. 30' MAX O.C. VERTICALLY BACK CUT 1:1 OR FLATTER -BENCH •SEE SUBDRAIN TRENCH DETAIL LOWEST SUBDRAIN SHOULD BE SITUATED AS LOW AS POSSIBLE TO ALLOW SUITABLE OUTLET ""^mnr; '%7777T77777^'^''^-7^ -KEY DEPTH (2' MIN.) KEY WIDTH AS NOTED ON GRADING PLANS (15" MIN.) 12 MIN. OVERLAP — FROM THE TOP HOG RING TIED EVERY 6 FEET CALTRANS CLASS II PERMEABLE OR #2 ROCK (3 FTZ/n) WRAPPED IN FILTER FABRIC V4" 0 NON-PERFORATED OUTLET PIPE PROVIDE POSITIVE SEAL AT THE JOINT T-CONNECTION FOR COLLECTOR PIPE TO OUTLET PIPE 6 MIN. COVER ^TmT~~[_ FILTER FABRIC ENVELOPE (MIRAFI 140 OR APPROVED EQUIVALENT) 4" 0 PERFORATED PIPE -4" MIN. BEDDING SUBDRAIN TRENCH DETAIL SUBDRAIN INSTALLATION - subdroin collector pipe shall be instolled with perforotion down or, unless otherwise designated by the geotechnicol consultont. Outlet pipes sholl be non-perforoted pipe. The subdrain pipe shall hove at least 8 perforations uniformly spaced per foot. Perforation shall be 1/4" to 1/2" if drill holes ore used. All subdrain pipes shall have o gradient of at least 2% towards the outlet. SUBDRAIN PIPE - Subdroin pipe sholl be ASTM D2751, SDR 23.5 or ASTM D1527, Schedule 40, or ASTM D3034, SDR 23.5, Schedule 40 Polyvinyl Chloride Plostic (PVC) pipe. All outlet pipe shall be placed in o trench no wide than twice the subdroin pipe. Pipe sholl 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 REPLACEMENT FILL SUBDRAINS GENERAL EARTHWORK AND GRADING SPECIFICATIONS STANDARD DETAILS D LEIGHTON AND ASSOCIATES -SOIL BACKFILL, COMPACTED TO 90 PERCENT RELATIVE COMPACTION BASED ON ASTM D1557 RETAINING WALL WALL WATERPROOFING PER ARCHITECT'S SPECIFICATIONS WALL FOOTING FILTER FABRIC ENVELOPE (MIRAFI HON OR APPROVED EQUIVALENT)** 3/4" TO 1-1/2" CLEAN GRAVEL 4" (MIN.) DIAMETER PERFORATED PVC PIPE (SCHEDULE 40 OR EQUIVALENT) WITH PERFORATIONS ORIENTED DOWN AS DEPICTED MINIMUM 1 PERCENT GRADIENT TO SUITABLE OUTLET 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 MANUFACTURER'S SPECIFICATIONS. RETAINING WALL DRAINAGE DETAIL GENERAL EARTHWORK AND GRADING SPECIFICATIONS STANDARD DETAILS E LEIGHTON AND ASSOCIATES