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Home My WebLink About; Fire Station No. 6 Geotechnical Investigation; Fire Station No. 6 Geotechnical Investigation; 2004-12-104 Leighton Consulting, Inc. A LEIGHTON GROUP COMPANY December 10, 2004 Project No. 600680-001 To: WLC Architects 10470 Foothill Boulevard Rancho Cucamonga, Califomia 91730 Attention: Mr. Kelley Needham Subject: Geotechnical Investigation, Proposed Carlsbad Fire Station No. 6, Carlsbad, Califomia In accordance with your request and authorization, we have conducted a geotechnical investigation for the proposed Carlsbad Fire Station No. 6 to be located in Carlsbad, Califomia (Figure 1). Based on the results of our study, it is our professional opinion that the development of the site is geotechnically feasible provided the conclusions and recommendations provided herein are incorporated into the design and constmction of the proposed improvements. The accompanying report presents a summary of our current investigation and provides geotechnical conclusions and recommendations relative to the proposed development of the site. If you have any questions regarding our report, please do not hesitate to contact this office. We appreciate this opportunity to be of service. Respectftilly submitted, LEIGHTON CONSULTING, P^^^i^ll^vVj William D. Olson, RCE 45 Senior Project Engineer Distribution: (8) Addressee Michael R. Stewart, CEG 1349 ieologist 3934 IVIutphy Canyon Road, Suite 8205 • San Diego, CA 9212^4425 858.292.8030 • Fax 858.292.0771 • www.leightonconsulting.com 600680-001 TABLE OF CONTENTS Section Page 1.0 INTRODUCnON 1 1.1 PURPOSE AND SCOPE 1 1.2 SITE LOCATION AND DESCRIPTION i 1.3 PROPOSED DEVELOPMENT 2 2.0 SUBSURFACE EXPLORATION AND LABORATORY TESTING 4 3.0 SUMMARY OF GEOTECHNICAL CONDITIONS 5 3.1 GEOLOGIC SETTING 5 3.2 SrrE-SPEaFic GEOLOGY 5 3.2.1 Undocumented Artificial Fill (Map Symbol - Afu) ...5 3.2.2 Santiago Peak Volcanics (Map Symbol - Jsp) 6 3.3 GEOLOGIC STRUCTURE. 6 3.4 SURFACE AND GROUND WATER 6 3.5 ENGINEERING CHARACTERisncs OF ON-SFTE SOILS 6 3.5.1 Expansion Potential 7 3.5.2 Soil Corroslvity 7 3.5.3 Excavation Characteristics 7 4.0 FAULTING AND SEISMICFPi' ..8 4.1 FAULTING 8 4.2 SEISMICTTY 8 4.2.1 Shallow Ground Rupture 10 4.2.2 Liquefaction 10 4.2.3 Earthquake-Induced Settlement u 4.2.4 Lateral Spread 11 4.2.5 Tsunamis and Seiches 11 5.0 CONCLUSIONS 12 6.0 RECOMMENDATIONS 14 6.1 EARTHWORK 14 * 6.1.1 Site Preparation 14 6.1.2 Excavations 14 6.1.3 Fill Placement and Compaction 15 •» 6.1.4 Import Soils 15 6.2 SURFACE DRAINAGE AND EROSION 15 6.3 FOUNDATION AND SLAB DESIGN CONSIDERATIONS 16 • 6.3.1 Foundations 16 6.3.2 Floor Slabs. ig 6.3.3 Settlement 17 Iff ff 11 4 Leighton 600680-001 m m m m m m m m m m TABLE OF CONTENTS rContinued) Section Page 6.3.4 Foundation Setback • 6.4 UTERAL EARTH PRESSURES 6.5 CONCRETE FLATWORK 6.6 PREUMINARY PAVEMENT DESIGN 18 6.6.1 Flexible Pavement Design 19 6.6.2 Driveway Pavement Design 20 6.7 CONSTRUCTION OBSERVATION AND PLAN REVIEW 21 7.0 LIMITATIONS 22 TABLES TABLE 1 - SEISMIC PARAMETERS FOR ACHVE FAULTS - PAGE 9 TABLE 2 - STATIC EQUIVALENT FLUID WEIGHT (PCF) - PAGE 18 TABLE 3 - PREUMINARY PAVEMENT SECHONS - PAGE 19 FIGURES FIGURE 1 - STTE LOCATION MAP - PAGE 3 PLATE 1 - GEOTECHNICAL MAP - REAR OF TEXT APPENDICES APPENDIX A - REFERENCES APPENDIX B - BORING LOGS APPENDIX C - LABORATORY TEST RESULTS AND TEST PROCEDURES APPENDIX D - SEISMIC ANALYSIS APPENDIX E - GENERAL EARTHWORK AND GRADING SPECIFICATIONS FOR ROUGH GRADING 4 Leighton 600680-001 1.0 INTRODUCTION ^ 1.1 Purpose and Scope ^ This report presents the results of our geotechnical investigation for the proposed Carlsbad Fire Station No. 6 to be located in Carlsbad, Califomia (Figure 1). The purpose of our investigation was to evaluate the existing geotechnical conditions at the site and provide a. preliminary conclusions and geotechnical recommendations relative to the proposed development. Our scope of services included the following: m • Review of pertinent documents regarding the geotechnical conditions at the site ^ (Appendix A). ^ • Geotechnical reconnaissance of the site. • Notification and coordination of underground utility locators. m m • Excavation, logging and representative sampling of nine exploratory trenches. The trench logs are presented in Appendix B. m • • Laboratory testmg of representative soil samples obtained from the subsurface exploration. Resuhs of these tests are presented in Appendix C. m m m m Compilation and analysis of the geotechnical data obtained from our review, field investigation and laboratory testing (including seismic analysis presented in Appendix D). Preparation of this report presenting our findings, conclusions, and geotechnical recommendations with respect to the proposed design, site grading and general constmcfion considerafions. General Earthwork and Grading Specificafions are provided as Appendix E. 1.2 Site Location and Description The proposed project site is located north of the Cadencia Street and approximately 260 m feet west of the new Rancho Santa Fe Road (i.e., immediately east of the old Rancho ^ Santa Fe Road alignment, as shown on Figure 1) in Carlsbad, Califomia. The site is bounded by the old Rancho Santa Fe Road alignment to the west, a new proposed road •» alignment/easement to the north, and sparsely vegetated open areas to the south and east, li The site gently sloping or descends the southwest with elevafions ranging from • approximately 535 feet above mean sea level (msl) at the northeast end to approximately m m ^ Leighton 600680-001 m m m m 529 feet msl at the southwestem boundary of the site. Evidence of previous grading was observed throughout the site, and an approximately 2 to 3 feet high earthen berm exists along the westem portion of the site extending fi-om the south through a majority of the site to the northem boundary. 1.3 Proposed Development Based on our review of preliminary development plans prepared for the site by WLC Architects (WLC, 2004), we understand the proposed development will include the constmcfion of a two-story, approximately 6000 square foot (sf) fire stafion building on an approximately 0.5-acre site. In addition, underground ufilities, subsurface oil water separator and storm water treatment units, tmck and automobile drive and parking areas, and associated concrete flatwork adjacent to the proposed stmctures are anticipated. Preliminary grading plans and foundation designs or stmctural loads were not available prior to the preparation of this report. Based on verbal discussions with MSL Engineering, the project civil engineer, it is our understanding that the proposed site grades may generally increase slighfiy with a finish pad elevafion of approximately 534.0 feet msl. In addition, we have assumed that the proposed single and dual axle weights of the proposed fire tmck equipment will be up to 24,000 and 40,000 pounds, respectively, in the design of concrete pavement area, and traffic indices (TI) of 4.5 and 5 for the design of asphah parking and drive areas. Excavation for subsurface oil water separator and storm water treatment units are anticipated to extend 8 to 10 feet below the proposed final surface grades. 4 -2- Leighton TN .5 1 MIIE 1030 fttT 0 500 \m METERS Map created with TOPO!© ©2003 National Geographic (www.nationalgeographic.conn/topo) Base Map: San Diego. Califomia 7.5-Minute Quadrangle SITE LOCATION MAP Carlsbad Fire Stafion No. 6 Carlsbad, California Project No. 600680-001 Scale (approx) As Shown Engr./Gcoi. WDO/MRS Drafted By BQT Date December, 2004 4 Leighton Consulting, inc. A LEIGHTON CROUP COMPANY Figure No. I 600680-001 •? n Q |Rc;i IRFACE EXPLORATTQN AND LABORATORY TESTING As part of our investigafion, nine exploratory trenches (T-1 through T-9) were excavated, representative soil samples were collected, and logged by a geologist from our office. The trenches were excavated to depths ranging from approximately 2 to 5 feet below the existmg ground surface (bgs). All trenches were excavated ufilizing a John Deere 310 Backhoe equipped with a 24-inch bucket. The purpose of these excavations was to evaluate the physical characterisfics of the onsite soils in die vicinity of the proposed improvements. The trenches also allowed evaluation of the soils to be encountered at the proposed foundation elevations, the general nature of the soils proposed for use as compacted fills, the approximate location of bedrock and provided representative samples for laboratory testing. Prior to our subsurface invesfigation. Underground Service Alert (USA) was contacted to coordinate the location and idenfificafion of nearby underground ufilifies (USA Ticket No. A3170495). The exploratory trenches were logged by a geologist from our firm. Representafive bulk samples were collected for laboratory testing. The approximate locations of the trenches are shown on die Geotechnical Map (Plate 1). After logging and sampling, the excavafions were backfilled with native soil. Laboratory testing was performed on representative samples to evaluate the expansion index (EI), R-Value, and chemical 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. 4 -4- Leighton 600680-001 m ^ n NUMMARY OF GEOTECHNICAL CONDITIGNS 3.1 Geologic Setting The site is located in the coastal section of the Peninsular Range Province, a geomorphic province with a long and acfive geologic history throughout Southem Califomia. Throughout the last 54 million years, the area known as "San Diego Embayment" has undergone several episodes of marine inundafion and subsequent marine regression, resulting in the deposition of a thick sequence of marine and nonmarine sedimentary rocks on the basement rock of the Southem Califomia batholith. Gradual emergence of the region from the sea occurred in Pleistocene fime, and numerous wave-cut platforms, most of which were covered by relatively thin marine and nonmarine terrace deposits, formed as the sea receded from the land. Accelerated fluvial erosion during periods of heavy rainfall, coupled with the lowering of the base sea level during Quaternary times, resulted in the rolling hills, mesas, and deeply incised canyons which characterize the landforms we see in the general site area today. 3.2 Site-Specific Geology Based on our subsurface explorafion, and review of pertinent geologic literature and maps, the geologic units underiying the site consist of undocumented artificial fill soils and the Jurassic-aged Sanfiago Peak Volcanics. A brief description of the geologic units encountered on the site is presented below. 3.2.1 Undocumented Artificial Fill (Map Svmbol - Afu) Undocumented artificial fill was encountered in all of the trenches to depths ranging from approximately 1 to 4 feet below the existing ground surface (bgs). An as- graded report documenting the placement of the fill was not available for our review. As encountered during our subsurface exploration, the fill soils generally consisted of moist to wet, soft to firm, sandy clay with angular metavolcanic cobbles to 8 inches in diameter. In general, the composition, origin, stability, and method of placement of undocumented fill soils is unknown. Therefore, these soils are considered potentially compressible in their current state and will require complete removal and recompacfion within the limits of site grading. ^ Leighton 600680-001 tm m 3.2.2 Santiago Peak Volcanics (Map Symbol - 3sD^ The Jurassic-aged Santiago Peak Volcanics were encountered beneath undocumented fill soils in all of the trenches. The primary volcanic rock type encountered during excavafion was diacite. The volcanic rock is typically blue gray in color on fresh unweathered surfaces. The weathered portion of the rock is red gray in color. Weathering of fiiis unit is generally concentrated to the joints and fractures present throughout the site. The jointing was primarily encountered on the eastem half to the site with a general northeast to southwest trend with many randomly oriented fractures throughout the site. The depth of highly weathered material varies from approximately IV2 feet to 4V2 feet bgs. Due to the dense nature of the rock, heavy ripping, breaking and/or blasfing is anficipated in excavations or cut areas extending into the competent metavolcanic rock. 3.3 Geologic Structure Based on the resuhs of our current invesfigafion, literature review, and our professional experience on nearby sites, the Sanfiago Peak Volcanics are massive, with numerous fractures and jointing throughout. Joint trends at the site ranged from N30E to N55E and vertical, fractures were randomly oriented throughout the site. 3.4 Surface and Ground Water Surface water and ponding resulting from a relatively recent rainstorm was observed in a topographic low-lying area during our field invesfigafion. This low-lying area was generally located in the south central portion of the site. In addifion, seepage of perched ground water was encountered within four of the nine exploratory trenches (T-1, T-3, T-4, and T-9) from the surface to 2V2 feet bgs. It should be noted that a subdrain may be required to remove the perched ground water trapped on or within depressions the impermeable underlying bedrock. Recommendafions for subdrain should be developed based on a review of the grading plans and should be refined during site grading. 3.5 Engineering Characteristics of On-site Soils Based on the results of our current geotechnical invesfigation, laboratory tesfing of representative on-site soils, and our professional experience on adjacent sites with similar soils, the engineering characteristics of the on-site soils are discussed below. 4 ^ Leighton 600680-001 m m 3.5.1 Expansion Potential The onsite materials are anticipated to be in the low to medium expansion range. Geotechnical observations and/or laboratory testing upon complefion of the graded pad is recommended to determine the actual expansion potential of finish grade soils on the site. 3.5.2 Soil Corroslvity The National Associafion of Corrosion Engineers (NACE) defines corrosion as ^'a deterioration of a surface or its properties because of a reaction with its environment." The "environment" is the surrounding soil and ground water, and the "substances" are reinforced concrete foundations or various types of steel substmctures such as piles, pipes, etc., that are in contact with the soil. In general, soil environments that are detrimental to concrete have high concentrations of soluble sulfates and/or pH values of less than 5.5. Table 19A-A- 4 of the Califomia Building Code (CBSC, 2001) provides specific guidelines for the concrete mix-design when the soluble sulfate content of the soil exceeds 0.1 percent by weight. Soluble sulfate test resuhs performed on a sample collected indicate soluble sulfate contents of less than 0.015 percent and a pH level of 8.02. Refer to Table 19 A-A-4 of CBC, 2001 for mix design placement requirements. Chloride content in excess of 300 ppm may present a corrosion risk to buried improvements. Testing indicates chloride contents is 44 ppm. Electrical resistivifies of less than 10,000 ohm-cm are generally considered corrosive to buried uncoated metal conduits. Tesfing indicates a resistivity value of 3,710 ohm-cm. A discussion on laboratory tesfing procedures and die geochemical laboratory test results are provided in Appendix C of this report. For appropriate evaluafion and mifigafion design a corrosion engineer should be consulted. 3.5.3 Excavation Characteristics It is anficipated the onsite soils can be excavated wifii conventional heavy-duty constmction equipment. However, excavations and cuts (e.g., subsurface oil water separator and storm water treatment unit excavations) into the very dense underiying bedrock may require heavy ripping, breaking or even blasting. In addition, oversize material (typically over 8 inches in maximum dimension) will be generated and its reuse as a fill material is unlikely. In general, the oversize material should be placed in non-stmctural areas (as approved by the geotechnical consultant), or hauled off-site. 4 ^ Leighton 600680-001 lit m m m 4 n FAIIITTNG AND SEISMICITY 4.1 Faulting tm Our discussion of faults on the site is prefaced with a discussion of Califomia legislation and policies conceming die classificafion and land-use criteria associated with faults. By definition of the Califomia Mining and Geology Board, an active fault is a fauU which has had surface displacement within Holocene time (about the last 11,000 years). The state geologist has defined a potentially active fault as any fault considered to have been active during Quaternary time (last 1,600,000 years). This definition is used in delineating Earthquake Fault Zones as mandated by the Alquist-Priolo Geologic Hazards Zones Act of 1972 and most recently revised in 1997 (Hart, 1997). The intent of tiiis act is to assure that unwise urban development and certain habitable stmctures do not occur across the traces of active faults. The subject site is not included witiiin any Earthquake Fault Zones as created by the Alquist-Priolo Act. Our review of available geologic literature (Appendix A) indicates that there are no known major or active faults on or in the immediate vicinity of the site. The nearest active regional fault is the Rose Canyon Fauh Zone located approximately 8 miles west of the site. 4.2 Seism icitv The site can be considered to lie within a seismically active region, as can all of Southem Califomia. Table 1 (below) identifies potenfial seismic events that could be produced by tiie maximum moment magnitude eartiiquake. A maximum moment magnitude earthquake is the maximum expectable earthquake given the known tectonic framework. Site-specific seismic parameters for the site included in Table 1 are tiie distances to the causative faults, earthquake magnitudes, and expected ground accelerations as generated by the deterministic fauh modeling software EQFAULT (Blake, 2000). 4 Leighton 600680-001 m m Table 1 Seismic Parameters for Active Faults (Blake, 2000) Potential Causative FauU Distance from Fauh to Site (Miles/km) Maximum Moment Magnitude (Mw) Peak Ground Motion at Mean Attenuation Relationship (g) One Standard Deviation (g) Rose Canyon (Offshore) 7.2/12.5 7.2 0.33 0.18 Newport- Inglewood (Offshore) 12.7/20.5 7.1 0.20 0.11 Coronado Bank 22.7/36.6 7.6 0.14 0.08 Elsinore-Julian 22.9/36.9 7.1 0.11 0.06 As indicated in Table 1, the Rose Canyon fault is the 'active' fauh considered having tiie most significant effect at the site from a design standpoint. A maximum moment magnitude earthquake of moment magnitude 7.2 on the fauh could produce an esfimated peak horizontal ground accelerafion of 0.33g at the site, with a one standard deviation of O.lg. The bedrock ground acceleration was modeled using tiie rock site attenuation equation of Abrahamson & Silva (1997). The Rose Canyon fauh is considered a Type B seismic source according to Table 16-U of the 2001 Califomia Building Code (CBC, 2001) and the Califomia Geological Survey (CGS, 2003). Summary printouts of the deterministic analyses are provided in Appendix D of this report. From a probabilistic standpoint, tiie design ground motion is defined as the ground mofion having a 10 percent probability of exceedance in 50 years. This ground motion is referred to as the maximum probable ground mofion (CBSC, 2001). Based on review of statewide mapping at the Califomia Geological Survey website Cwww.consrv.ca.gov/cgs/rghm/pshamap/pshamain.html), the maximum probable bedrock ground motion at the site is postulated to be 0.25g. Site effect would need to be considered if this value is utilized in structural design. Wifii respect to seismic slope stability, the bedrock ground motion is a consideration. 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. -9-4 Leighton 600680-001 The seismic design parameters considered applicable based on the site conditions and seismic setting are as follows per the 2001 CBC: Soil Profile Type (Table 16A-J) = SB Seismic Zone (Figure 16A-2) = 4 Seismic Source Type (Table 16A-U) = B Slip Rate, SR, (Table 16A-U) - 1.5mm per year (CDMG, 1996), based on tiie Rose Canyon Fault Na=1.0 (Table 16A-S) Nv= 1.0 (Table 16A-T) Secondary effects associated with severe ground shaking following a relatively large earthquake can include shallow ground mpture, soil liquefaction and dynamic settlement, lateral spreading, seiches and tsunamis. These secondary effects of seismic shaking are discussed in the following sections. 4.2.1 Shallow Ground Rupture No active fauhs are mapped crossing the site, and tiie site is not located within a mapped Alquist-Priolo Earthquake Fauh Zone (Hart, 1997). Shallow ground mpture 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 mofion due to earthquakes. Research and historical data indicate tiiat loose granular soils underlain by a near surface ground water table are most susceptible to liquefaction, while the stability of most clayey material are not adversely affected by vibratory motion. Liquefacfion is characterized by a loss of shear strength in the affected soil layer, tiiereby causing the soil to behave as a viscous liquid. This effect may be manifested at the ground surface by settiement and, possibly, sand boils where insufficient confining overburden is present over liquefied layers. Where sloping ground condhions are present, liquefacfion- induced instability can result. The Sanfiago Peak Formation tiiat underiies tiie site is not considered liquefiable due to hs very dense physical characteristics. Surficial materials including undocumented fill are recommended for removal and replacement with compacted engineered fill material. Properiy compacted engineered fill is not considered to be liquefiable. 4 -10- Leighton 600680-001 PI m m m 4.2.3 Earthquake-Inrliired Seti:lement 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. Considering that tiie site has no liquefaction potential, the potenfial for earthquake-induced settiement is expected to be negligible, if any. 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. Considering that tiie site has no liquefaction potential, the susceptibility to earthquake-induced lateral spread is not applicable. * 4.2.5 Tsunamis and Seiches il pi Based on the distance between tiie site and large, open bodies of water, and the elevation of the site with respect to sea level, tiie possibility of seiches and/or tsunamis is not applicable. il n 4 -11- Leighton 600680-001 li pi fti m m m m m m m m w PI m m M il S n CONCLUSIONS Based on the results of our geotechnical investigation of the site, it is our professional opinion that the proposed development is feasible from a geotechnical standpoint, provided the following conclusions and recommendations are incorporated into the project plans and specifications and are implemented during design and constmction. The following is a summary of the significant geotechnical factors that may affect development of the site. " Potentially compressible undocumented artificial fill should be removed and replaced compacted fill or reprocessed prior to placement of engineered stmctures, addifional fills or settlement-sensitive surface improvements. The depth of removals of potentially compressible material is anficipated to range from approximately 1 to 4 feet below the exisfing ground surface. • Surface water was observed in a low-lying area during our field invesfigafion. Based on our observations and explorations, the underlying bedrock formation is relatively impermeable material or barrier. A subdrain may be required to remove the perched ground water trapped • on or within depressions the impermeable underlying bedrock. Recommendations for a subdrain should be developed based on a review of the grading plans and should be refined during site grading. • Based on laboratory testing and visual classificafion, the onsite fill soils possess a low to medium expansion potenfial. • Geochemical laboratory test results indicate the near-surface soils present on the site have a negligible potenfial for sulfate attack on concrete and are considered to have a moderate potenfial for corrosion to buried uncoated metal conduits. These tests should be confirmed upon completion of the grading activifies. • The exisfing onsite soils appear to be suitable material for reuse as compacted fill provided they are relafively free of organic material, debris, and rock fragments larger than 8 inches in maximum dimension. • Excavations (i.e., subsurface oil water separator and storm water treatment units, etc.) into the very dense underlying bedrock may require heavy ripping, breaking or even blasting. In addition, oversize material (typically over 8 inches in maximum dimension) will be generated and its reuse as a fill material is unlikely. " Active or potenfially active faults are not known to exist on or in the immediate vicinity of the site. 4 Leighton 600680-001 According to 2001 CBC, tiie site is within Zone 4, tiie soil profile type is Sc, and near source factors, Na and Nv of 1.0 and 1.0 are appropriate for seismicity. The Santiago Peak Volcanics tiiat underiie tiie site are not considered liquefiable due to hs very dense physical characteristics. Earthquake-induced total and differential settlements in the area of the proposed constmction are expected to be negligible, if any. The susceptibility to earthquake-induced lateral spreading is not applicable. m m m m 4 -13- Leighton 600680-001 fi n RECOMMENDATIONS tm 6.1 Earthwork We anticipate that earthwork at tiie site will consist of site preparation, excavations, and site grading to create a uniform building pad, approximate 3-feet thick. We recommend that earthwork on the site be performed in accordance with tiie 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 of areas to receive stmctural fill or engineered stmctures, tiie areas should be cleared of surface obstmctions, potentially compressible material (such as undocumented fill and disturbed bedrock materials) and stripped of vegetation. The removal deptiis of potentially compressible material are anticipated to range from approximately 1 to 4 feet bgs. Vegetation and debris should be removed and properiy disposed of off site. All removal bottoms should be reviewed by tiie geotechnical consultant prior to scarification and recompaction. In general, areas to receive fill and/or other surface improvements should be scarified to a minimum depth 12 inches (under tiie observation of the geotechnical consultant), brought to a minimum 2-percent over optimum moisture content, and recompacted to at least 90 percent relative compaction (based on American Standard of Testing and Materials [ASTM] Test Metiiod D1557). A subdrain may be required to remove the perched ground water trapped on or within depressions the impermeable underiying bedrock. Recommendations for subdrain should be developed based on a review of the grading plans and should be refined during site grading. Pi ^ 6.1.2 Excavations pi Shallow excavafions of the onsite materials may generally be accomplished with conventional heavy-duty earthwork equipment. However, heavy ripping, breaking, or blasting may be required where excavations extend below the very dense metavolcanic rock. In addifion, oversized rock (i.e. rock with a maximum dimension greater than 8 inches) should be hauled off site or placed in nonstructural or landscaped areas, as approved by the geotechnical consuhant. All excavafions should be made in accordance with current OSHA requirements. 4 -14- Leighton PI ii 600680-001 6.1.3 Fill Placement and Comoaction From a geotechnical standpoint, the onsite soils are generally suitable for use 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 at least 2 percent above the optimum moisture content and compacted in uniform lifts to at least 90 percent relative compaction based on the laboratory maximum dry density (ASTM Test Metiiod D1557). The optimum lift thickness required to produce a uniformly compacted fill will depend on the type and size of compacfion equipment used. In general, fill should be placed in lifts not exceeding 8 inches in thickness. In areas subjected to vehicular traffic, we recommend that the upper 12 inches of tiie subgrade soils be compacted to at least 95 percent (based on ASTM Test Method Dl 557). The onsite soils may require moisture conditioning or drying prior to use as compacted fill. Placement and compaction of fill should be performed in general accordance with tiie current City of Carlsbad grading ordinances, sound constmction practice, and the General Earthwork and Grading Specifications for Rough Grading presented in Appendix E. 6.1.4 Import Soils If import soils are necessary to bring the site up to the proposed grades, tiiese soils should be granular and have an expansion index less than 50 (per ASTM Test Method D4829). Import soils and/or the borrow site should be evaluated by the geotechnical consultant prior to importafion. 6.2 Surface Drainage and Erosion Surface drainage should be controlled at all fimes. The proposed stmctures should have appropriate drainage systems to collect roof mnoff. Positive surface drainage should be provided to direct surface water away from the stmctures toward tiie street or suitable drainage facilifies. Posifive drainage may be accomplished by providing a minimum 2 percent gradient away from the stmctures for a distance of at least 5 feet. Below grade planters should not be situated adjacent to stmctures or pavements unless provisions for drainage such as catch basins and drains are made. In general, ponding of water should be avoided adjacent to the stmctures or pavements. Over-watering of the site should be avoided. Protecfive measures to mitigate excessive site erosion during constmction should also be implemented in accordance with the latest City of Carisbad grading ordinances. 4 Leighton 600680-001 ipi ii m m m m m 6.3 Foundation and Slab Design Considerations Foundations and slabs should be designed in accordance with stmctural considerations and the following recommendations. The foundation recommendations outlined below assume that the uniform building pad will be constmcted to an elevation of at least 534 feet msl, and tiiat approximately 12 inches of compacted fill will underiie the proposed foofing elevation and extend at least 5 feet beyond building footprint. These recommendations also assume tiiat tiie soils encountered within 3 feet of pad grade have a low to medium expansion potential. If more expansive soils are encountered or imported to constmct the uniform building pad, additional foundation design may be necessary. 6.3.1 Foundations The proposed stmctures may be supported by conventional continuous or isolated spread footings. Footings should extend a minimum of 18 inches beneatii the lowest adjacent soil grade. At tiiese depths, footings may be designed for a maximum allowable bearing pressure of 3,000 pounds per square foot (psf) if founded on compacted fill. The allowable pressure may be increased by one-tiiird when considering loads of short duration such as wind or seismic forces. The minimum recommended width of footings is 18 inches for continuous footings and 24 inches for square or round footings. Continuous footings should be designed in accordance with the stmctural engineer requirements and have a minimum reinforcement of four No. 5 reinforcing bars (two top and two bottom). Reinforcement of isolated footings should be per the stmctural engineer's design. 6.3.2 Floor Slabs For living and office areas, the slab-on-grade floor slab should be at least 5 inches thick and be reinforced with No. 3 rebars 18 inches on center, each way (minimum), placed at mid-height in the slab. In addition, a 4-inch layer of clean sand should underiie tiie living and office areas floor slab. For the interior floor slab supporting fire tmcks, the slab-on-grade should be at least 8 inches thick and be reinforced with No. 4 rebars 18 inches on center, each way (minimum), placed at mid-height in the slab. This slab should also be underiain by a 4-inch layer of clean sand and a minimum of 8 inches of Caltrans Class 2 Aggregate Base. To reduce moisture migrafion up through all floor slabs, we recommend installing a 10-mil plastic sheeting moisture barrier between the upper and lower 2-inches of sand. We emphasize that this is tiie responsibility of the contractor to ensure that tiie slab reinforcement is placed at slab midheight. We 4 -16- Leighton 600680-001 recommend control joints be provided across tiie slab at appropriate intervals as designed by the project architect. The potential for slab cracking may be reduced by utilizing a mix design witii low water content. The contractor should take appropriate curing precautions during the pouring of concrete in hot weather to minimize cracking of slabs. We recommend that a slipsheet (or equivalent) be utilized if grouted tile, marble tile, or other crack-sensitive floor covering is planned directiy on concrete slabs. 6.3.3 Settlement The recommended allowable-bearing capacity is based on a maximum total and differential settlement of 3/4 inch and 1/2 inch, respectively. Since settlements m are a ftmction of footing size and contact bearing pressures, some differential settlement can be expected between adjacent columns or walls where a large • differential loading condition exists. However for most cases, differential •i settlements are considered unlikely to exceed 1/4 inch. With increased footing depth/width ratios, differential settlement should be less. m m 6.3.4 Foundation Setback PI • We recommend a minimum horizontal setback of 10 feet be maintained from tiie face of slopes to the bottom outside edge of all stmctural footings and * settiement-sensitive stmctures. Utility trenches that parallel or nearly parallel stmcture footings should not encroach witiiin an imaginary 1:1 plane extending downward from the outside edge of the footing. il 6.4 Lateral Earth Pressures For design purposes, the following lateral earth pressure values for level or sloping backfill are recommended for walls backfilled with onsite and/or import soils of low expansion potenfial (expansion potenfial less than 50 per ASTM Test Method D4829) as indicated on Table 2. pi m 4 -17- Leighton 600680-001 IP m m Table 2 Static Equivalent Fluid Weight (pcf) Conditions Level 2:1 Slope Active 35 55 At-Rest 55 65 Passive 350 (Maximum of 3 ksf) 150 (Sloping Down) The wall pressures assume walls are backfilled with free draining materials and water is not allowed to accumulate behind walls. A typical wall drainage design is presented in Appendix E. Wall backfill should be brought to at least 2 percent above the optimum moisture content and compacted by mechanical methods to at least 90 percent relative compaction (based on ASTM D1557). Wall foofings should be designed in accordance with the foundation design recommendations and reinforced in accordance with stmctural considerafions. For all retaining walls, we recommend a minimum horizontal distance from the outside base of the footing to daylight of 10 feet. Lateral soil resistance developed against lateral structural 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 durafion including wind or seismic loads. The total resistance may be taken as tiie sum of the frictional and passive resistance provided tiiat the passive portion does not exceed two-thirds of the total resistance. il 6.5 Concrete Flatwork On-site concrete sidewalks and other flatwork (including constmction joints) should be designed by the project civil engineer and should have a minimum thickness of 4 inches. For ail concrete flatwork, the upper 12 inches of subgrade soils should be moisture condifioned to at least optimum moisture content and compacted to at least 90 percent relative compaction based on ASTM Test Method D1557 prior to the concrete placement. 6.6 Preliminary Pavement Design The appropriate pavement secfion depends primarily on the type of subgrade soil, shear strength, traffic load, and planned pavement life. Since an evaluafion of the characteristics -18-4 Leighton 600680-001 of tiie actual soils at pavement subgrade cannot be made at tiiis time, we have provided the following pavement sections to be used for planning purposes only. The final subgrade shear strengtii will be highly dependent on the soils present at finish pavement subgrade. However, based on preliminary testing (Appendix C), we have assumed an R-value of 5 for the pavement subgrade soils. m m m m 6.6.1 Flexible Pavement Design The preliminary pavement design sections (i.e., on-site pavements) have been provided on Table 3. Final pavement design should be evaluated based on R-value tests performed on representafive subgrade soils upon completion of grading. Altemative pavement design secfions may be provided once tiie appropriate traffic index is selected by the project architect or civil engineer. It should be noted that the City of Carlsbad pavement requirement presented on the Stmctural Section of Streets and Alleys, GS-17, will govem for all off-site street pavement (Carlsbad, 1996). Table 3 Preliminary Pavement Sections Pavement Loading Condition Traffic Index (20-Year Life) R-Value of 5 Pavement Secfions Auto Parking Areas 4.5 3 inches AC over 8 inches Class 2 base Auto Driveways 5.0 3 inches AC over 10 inches Class 2 base All pavement secfion materials should conform to and be placed in accordance with the latest revision of the Greenbook and Caltrans guidelines and standard specificafions. Prior to placing the AC pavement secfion, the upper 12 inches of subgrade soils and all aggregate base should have relafive compacfion of at least 95 percent (based on ASTM Test Method D1557). If pavement areas are adjacent to heavily watered landscape areas, we recommend some measure of moisture control be taken to prevent the subgrade soils from becoming saturated. It is recommended that the concrete curb separafing the landscaping area from the pavement extend below the aggregate base to help seal the ends of the sections where heavy landscape watering may have access to the aggregate base. Concrete swales should be designed in roadway or parking areas subject to concentrated surface mnoff. -19-4 Leighton m m m m 600680-001 6.6.2 Drivewav Pavement Design For areas subjected to heavy vehicle traffic (i.e., fire trucks), we recommend Portland Cement Concrete (PCC) sections be designed in accordance with the design presented below. Based on our experience witii similar projects in the she vicinity and for preliminary design purposes, we have assumed that tiie proposed single and dual axle weights of the proposed fire tmck equipment will be up to 24,000 and 40,000 pounds, respectively. For the maximum axle loads described above, we recommend pavement be a minimum of 8 inches thick utilizing a concrete mix that provides a flexural modulus of mpture of at least 600 psi. The PCC should be underlain by a minimum of 12 inches of Caltrans Class 2 Aggregate Base. The PCC Pavement should be reinforced at mid height with No. 4 rebars at 18 inches on center (each way) at a minimum. Actual reinforcement may be heavier based on tiie recommendations of the stmcture engineer for other loading conditions. For otiier loading conditions, tiie concrete flatwork may be designed with a modulus of subgrade reaction of 120 psi per inch. The actual pavement design should also be in accordance with City of Carlsbad and ACI criteria. If any concrete flatwork are located adjacent to landscape areas, the concrete should be thickened with a perimeter beam to a total of 12 inches deep by 12 inches wide and reinforced witii two No. 5 rebars near the bottom. The concrete flatwork should be cut within two days of placement with suitable constmction joints at a minimum of 8 foot spacing to one third the depth of the concrete. The rebars should not be cut. All pavement section materials should conform to and be placed in accordance with the latest revision of the Greenbook and American Concrete Institute (ACI) Codes and Guidelines. Prior to placement of the concrete, the upper 12 inches of subgrade soils should be scarified, moisture condifioned and compacted to a minimum of 95 percent relative compacfion based on ASTM Test Method D1557. A minimum of 12 inches of Caltrans Class 2 Aggregate Base should then be placed. The aggregate Base Material should also be compacted to a minimum of 95 percent relative compaction (based on ASTM Method D1557). 4 -20- Leighton 600680-001 6.7 Construction Observation and Plan Review Constmction observation of all onsite excavations and field density tesfing of all compacted fill should be performed by a representative of tiiis office so tiiat constmction is in accordance with the recommendations of this report. Final plans and the contract specifications should be checked by Leighton prior to site grading to see that the recommendafions in this report are incorporated in project plans and specificafions. m 4 -21- Leighton 600680-001 7.0 LIMITATIONS The conclusions and recommendations in tiiis report are based in part upon data that were obtained from a limited number of observations, site vishs, 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 constmction of the project, in order to confirm that our preliminary findings are representafive for the site. 4 -22- Leighton 600680-001 APPENDIX A REFERENCES Abrahamson, N.A., and Silva, W.J., 1997, Empirical Response Spectral Attenuafion Relationships for Shallow Cmstal Earthquakes, Seismological Research Letters, 1997, Volume 68, Number 1, Seismological Society of America, Pub. pp. 94-127. Bartlett, S.F., and Youd, T.L., 1995, Empirical Prediction of Liquefaction-Induced Lateral Spread, ^ Journal of Geotechnical Engineering, Vol. 121, No. 4, April 1995. Blake, 2000, EQFAULT, Ver. 3.00b. Califomia Building Standards Commission (CBSC), 2001, Califomia Building Code, Volumes 1 and 2. am ^ California Department of Conversation (CDC), 1996, Division of Mines and Geology, Probabihstic Seismic Hazard Assessment for the Stale of Califomia, Open File Report 96-08. PI m Carlsbad, City of, 1996, Standards for Design and Constmction of Public Works hnprovements in tiie City of Carlsbad, Califomia, Project No. 05332-12-01, dated April 20, 1993, • revised December 10,1996. Hart, E.W., 1997, Fault-Rupture Hazard Zones in Califomia, Alquist-Priolo Earthquake Fauh " Zoning with Index to Special Study Zones Maps: Department of Conservation, » Division of Mines and Geology, Special Publication 42. * Intemational Conference of Building Officials (ICBO), 1997, Uniform Building Code, it Ishihara, K., and Yoshimine, M., 1991, Evaluation of Settlements in Sand Deposits Following Liquefacfion during Earthquakes, Soils and Foundafions, Vol. 32, No. 1, pp: 173- • 188. Jennings, C.W., 1994, Fault Activity Map of Califomia and Adjacent Areas, with Locations and Ages of Recent Volcanic Emptions: Califomia Division of Mines and Geology, Califomia Geologic Data Map Series, Map No. 6, Scale 1:750,000. Southem Califomia Chapter, American Public Works Association and Southem Califomia Districts, Associated General Contractors, 1997, "Green Book" Standard Specificafions for Public Works Constmction with 1999 Supplement. il PI IPI A-l 600680-001 m m m APPENDIX A(Continued) Tan, S.S., and Kennedy, M.P. 1996, Geologic Maps of tiie Northwestem Part of San Diego County, Califomia, Califomia Division of Mines and Geology, Open File Report 96-02, Plate 1 of 2, Scale 1:24,000. Tokimatsu, K., and Seed, H.B., 1987, Evaluation of Settlements in Sands Due to Eartiiquake Shaking, ASCE Joumal of Geotechnical Engineering, Vol. 113, No. 8, dated August 1987. WLC Architects, 2002, Preliminary Site Plan, Proposed San Marcos Fire Station #2, San Marcos, Califomia, received December, 2002. Youd, T. L., 1993, Liquefaction-Induced Lateral Spread Displacement, NCEL Tech. Note 1862, Naval Civil Engineering Laboratory, Port Hueneme, Califomia. Youd, T. L., Hanson C. M., and Bartlett, S. F., 1999, Revised MLR Equations for Predicting Lateral Spread Displacement, Proceedings of the 7*^ U.S.-Japan Workshop on Earthquake Resistant Design of Lifeline Facilities and Countermeasures Against Soil Liquefaction, November 19, 1999, pp. 99-114. A-2 li fl »i fi ii fi il fl II ii ii ft* If f I if i 1 LOG OF TRENCH: T-1 i I i i Project Name:. WT.r/Fire Sration No. 6 Project Number: Equipment: Logged by: Elevation:— Am. S^S fee-t m^l Location/Grid; r.pnTprHnifal Map GEOLOGIC ATTITUDES Joint: N30E Vertical DATE: 11/18/04 DESCRIPTION: ARTIFICIAL FILL (UNDOCUMENTED') A @ 0': Sandy lean CLAY: Brown, moist to wet, soft, fine to coarse sand, few angular cobbles to 6 inches in diameter, few rootlets present in top 1 foot @ 2.5': Moderate to heavy seepage along the base of the fill SANTLVGO PEAK VOLCANICS B @ 2.5': Red-gray, moist to saturated, very dense; moderately to well indurated, moderately to highly weathered, oxidization along fractures (0)4': Refusal GEOLOGIC UNIT Afii Jsp ENGINEERING PROPERTIES uses CL Sample No. B-l@ 0-2.5' Moisture (%) Density GRAPHICAL REPRESENTATION: NE Wall SCALE: r=5' SURFACE SLOPE: level TREND: N25W Total Depth = 4 Feet No Ground Water Encountered Backfilled: 11/! 8/04 i €i fti ft fi fl il fl il it il i* i I i f f 1 I f LOG OF TRENCH: r i T-7 f f f I Project Name:. WT.r/Fire Station No. 6 Project Number: Equipment: Logged by: Elevation:— AJB. 533 msl Location/Grid: See Geotechnical Map GEOLOGIC ATTITUDES DATE: 11/18/04 DESCRIPTION: GEOLOGIC UNIT ENGINEERING PROPERTIES uses Sample No. Moisture (%) Density (pcf) Joint: N50E Vertical ARTIFICIAL FILL (UNDOCUMENTED) A @ 0': Sandy lean CLAY: Brown, moist to very moist, sott, fme to coarse sand, few angular cobbles to 6 inches in diameter, few rootlets present in top 6 inches SANTIAGO PEAK VOLCANICS B @ 1': Red-gray, moist, very dense; moderately to well indurated, moderately to highly weathered, oxidization along fractures (a). 2': Refusal Afu CL Jsp GRAPHICAL REPRESENTATION: E Wall SCALE: I'-5' SURFACE SLOPE: level TREND: N5W B Total Depth = 2 Feet No Ground Water Encountered Backfilled: 11/18/04 ri «i fi fi fl If fl ii ii li ii ^i ii it fi ii «i 'i LOG OF TRENCH: T-^ Project Name:. WTC/Fire Station No. 6 Project Number: ^00680-001 Equipment: Rarkhoe ID 10 Logged by: Elevation:— Am. T feet msl Location/Grid: Sipp Opntpnhnir.al M?ip GEOLOGIC ATTITUDES DATE: 11/18/04 DESCRIPTION: GEOLOGIC UNIT ENGINEERING PROPERTIES uses Sample No. Moisture Density (pcf) Joint: N45E Vertical ARTIFICIAL FILL (UNDOCUMENTED) A @ 0': Sandy lean CLAY: Brown, moist to wet, soft; fine to coarse sand, few angular cobbles to 6 inches in diameter, few rootlets present in top 6 inches SANTIAGO PEAK VOLCANICS B @ 1 '• Red-gray, moist to saturated, very dense; moderately to well indurated, moderately to highly weathered, oxidization along fractures @ T: Seepage (2) 4': Refusal Afii CL Jsp GRAPHICAL REPRESENTATION: NE Wall SCALE: r=5' SURFACE SLOPE: level TREND: N65W Total Depth - 4 Feet No Ground Water Encountered Backfilled: 11/18/04 I fl ft fi ffr fi il fi ii ii li Ci ii I I I I I 1 LOG OF TRENCH: i I T-4 i I f I Project Name:. WT,r/Fire Station Nn. 6 Project Number: Equipment: Logged by: Elevation:_ Am. Location/Grid: See Geotechnical Map GEOLOGIC ATTITUDES Joint: N55E Vertical DATE: 11/18/04 DESCRIPTION: ARTIFICIAL FILL (UNDOCUMENTED) A @ 0': Sandy lean CLAY: Brown, moist to wet, soft; fme to coarse sand, few cobbles to 6 inches in diameter, few rootlets present in top 1 foot @2': Seepage SANTIAGO PEAK VOLCANICS B @ 2': Red-gray, moist to saturated, very dense; moderately to well indurated, moderately to highly weathered, oxidation along fractures (S3': Refusal GEOLOGIC UNIT Afu Jsp ENGINEERING PROPERTIES uses CL Sample No. B-2 a),0-2' Moisture (%) Density (pcf) GRAPHICAL REPRESENTATION: SW Wall SCALE: 1"=5' SURFACE SLOPE: Level TREND: N30E —•- —• - ^£y —•- —• - Total Depth - 3 Feet No Ground Water Encountered Backfilled: 11/18/04 ii il fi il f» fi fl ii ii ii il il It II II il ii *i LOG OF TRENCH: 1^5 Project Name:. WT.G/Fire Station No. 6 Project Number: f^OOt^SO-OOl Equipment: Backhoe JD 310 Logged by: Elevation:— _AJB. m^l Location/Grid: *^ep r.pntpn.hniral Map GEOLOGIC ATTITUDES DATE: 11/18/04 DESCRIPTION: GEOLOGIC UNIT ENGINEERING PROPERTIES uses Sample No. Moisture (%) Density (pcf) ARTIFICIAL FILL (UNDOCUMENTED) A @ 0'; Sandy lean CLAY: Brown, moist to very moist, soft; fme to coarse sand, few cobbles to 8 inches in diameter, few rootlets present in top 6 inches SANTIAGO PEAK VOLCANICS B @ L: Red-gray, moist to very moist, very dense; moderately to well indurated, moderately to highly weathered, oxidization along fractures (aW: Refusal Afu CL B-2 5)0-2' Jsp GRAPHICAL REPRESENTATION: NW Wall SCALE: l"-5' SURFACE SLOPE: Level TREND: N25E 3 D V ^^4 Total Depth = 3 Feet No Ground Water Encountered Backfilled; 11/18/04 II il il fl fl fl it fl ii ii ii ii ii ii ti ii ii ii i* LOG OF TRENCH: 1=6 Project Name:. Wi r/Fire Station No. 6 Project Number: f^006R0-001 Equipment: Backhoe ID31.Q.. Logged by: Elevation:— A.TR 'ill fm msl Location/Grid: See Geotechnical Map GEOLOGIC ATTITUDES DATE: 11/18/04 DESCRIPTION: GEOLOGIC UNIT ENGINEERING PROPERTIES uses Sample No. Moisture (%) Density (pcf) ARTIFICIAL FILL (UNDOCUMENTED) A @ 0': Sandy lean CLAY: Brown, moist, soft to firm; fme to coarse, few angular cobbles to 4 inches in diameter, few rootlets present in top 6 inches SANTIAGO PEAK VOLCANICS B @ 1': Red-gray, moist, ver*' dense; moderately to well indurated, moderately to highly weathered, oxidization along fractures (2) 3.5': Refusal Afu CL Jsp GRAPHICAL REPRESENTATION: NE Wall SCALE: 5' SURFACE SLOPE: Level TREND: N65W r I il fi ii fifiii if ii il II iiii il it il iiiifi LOG OF TRENCH: T-7 Project Name:. WFC/Fire Station No. 6 Project Number: f^00680-001 Equipment: Backhoe JO .ilO Logged by: Elevation:— Am. S'^ 1 Feet msl Location/Grid: See Geotechnical,Map. GEOLOGIC ATTITUDES DATE: 11/18/04 DESCRIPTION: GEOLOGIC UNIT ENGINEERING PROPERTIES uses Sample No. Moisture (%) Density (pcf) ARTIFICIAL FILL (UNDOCUMENTED) A @ 0': Sandy CLAY: Brown, moist to wet, soft; fine to coarse sand, few cobbles to 8 inches in diameter, few rootlets present in top 6 inches SANTIAGO PEAK VOLCANICS B @ 2': Red-gray, moist, very dense; moderately to well indurated, moderately to highly weathered, oxidation along fractures (a), 3': Refusal Afii CL B-3 5)0-2' Jsp GRAPHICAL REPRESENTATION: SE Wall SCALE: 1"=5' SURFACE SLOPE: Level TREND: N80E II il fl ffl fi fl fl fi il il il il II II II II II ii il LOG OF TRENCH: T-8 Project Name:. WLC/Fire Station No. 6 Project Number: f^no^SO-OOl Equipment: Backhoe.JD 3.10.. Logged by: Elevation:— -Aia feet msl Location/Grid: Sep Gpnterhpin^j Map GEOLOGIC ATTITUDES DATE: 11/18/04 DESCRIPTION: GEOLOGIC UNIT ENGINEERING PROPERTIES uses Sample No. Moisture (%) Density (pcf) ARTIFICIAL FILL (UNDOCUMENTED) A @ 0': Sandy CLAY: Brown, moist, soft; fme to coarse, few angular cobbles to 4 inches in diameter, asphalt debris, few rootlets present in top 1 foot SANTIAGO PEAK VOLCANICS B @ 2': Blue-gray, slightly moist, ver\' dense; moderately to well indurated, moderately weathered, oxidization along fractures (o), 2.5': Reftisal Afu CL Jsp GRAPHICAL REPRESENTATION: NW Wall SCALE: l"=5' SURFACE SLOPE: Level TREND: N30E Total Depth = 2.5 Feet No Ground Water Encountered Backfilled: 11/18/04 ii ii mm ci li ti ii ii ii ii li ti ii it ii ii i^ii ii LOG OF TRENCH: T-Q Project Name:. W'l.C/Fire Station No. 6 Project Number: 600680-001 Equipment: Backhoe JD 310 Logged by: Elevation:— S30 fppf msl Location/Grid: See Gpntprhnjr^l M;^p GEOLOGIC ATTITUDES DATE: 11/18/04 DESCRIPTION: GEOLOGIC UNIT ENGINEERING PROPERTIES uses Sample No. Moisture (%) Density (P^f) ARTIFICIAL FILL (UNDOCUMENTED) A @ 0': Sandy lean CLAY: Brown, moist, soft; fme to coarse, few angular cobbles to 4 inches in diameter, saturated (seepage throughout), few rootlets in top 1-1/2 feet SANTL\GO PEAK VOLCANICS B @ 4': Blue-gray, moist to saturated, very dense; moderately to very well indurated, moderately weathered, oxidization along fractures iS) 5': Refusal Afii CL B-4 @0-4' Jsp GRAPHICAL REPRESENTATION: NW Wall SCALE: r'=5' SURFACE SLOPE: Level TREND: N55E 600680-001 APPENDIX C Laboratory Testing Procedures and Test Results Chloride Content: Chloride content was tested in accordance with Caltrans Test Method CT422. The results are presented below: Sample Location Chloride Content, ppm T-7, 0-2 Feet 44 m m Expansion Index Tests: The expansion potential of selected materials was evaluated by the Expansion Index Test, ASTM Test Method 4829. Specimens are molded under a given compactive energy to approximately the optimum moisture content and approximately 50 percent saturation or approximately 90 percent relative compaction. The prepared 1-inch thick by 4-inch diameter specimens are loaded to an equivalent 144 psf surcharge and are inundated with tap water until volumetric equilibrium is reached. The results of these tests are presented in the table below: Sample Location Sample Description Compacted Dry Density (pcf) Expansion Index Expansion Potential T-7, 0-2 Feet Silty to Clayey SAND 102.0 19 Low Minimum Resistivity and pH Tests: Minimum resistivity and pH tests were performed in general accordance with Caltrans Test Method CT643 for Steel or CT532 for concrete and standard geochemical methods. The results are presented in the table below: Sample Location Sample Description pH Minimum Resistivity (ohms-cm) T-7,0-2 Feet Silty to Clayey SAND 8.02 3,710 C-1 600680-001 APPENDIX C (Continued) "R"-Value: The resistance "R"-value was determined by the Califomia Materials Method CT301 for base, subbase, and basement soils. The samples were prepared and exudation pressure and "R"- value determined. The graphically determined "R"-value at exudation pressure of 300 psi is reported. Sample Location Sample Description R-Value T-4, 0-2 Feet Brown Sandy CLAY 5 Soluble Sulfates: The soluble sulfate contents of selected samples were determined by standard geochemical methods (Caltrans Test Method CT417). The test results are presented in the table below: Sample Location Sample Description Sulfate Content (%) Potential Degree of Sulfate Attack* T-7, 0-2 Feet Silty to Clayey SAND Less than 0.015 Negligible Based on the 2001 edition of the Califomia Building Code, Table No. I9A-A-4, prepared by the Califomia Building Standards Commission (CBSC, 2001). C-2 CALIFORNIA FAULT MAP WLC Carlsbad FS 6 m m m 200 250 300 350 400 *********************** * * * EQFAULT * * * * Version 3.00 * * * *********************** DETERMINISTIC ESTIMATION OF PEAK ACCELERATION FROM DIGITIZED FAULTS JOB NUMBER: 600680-001 DATE: 12-07-2004 ^ JOB NAME: WLC Carlsbad FS 6 ^ CALCULATION NAME: Test Run Analysis FAULT-DATA-FILE NAME: CGSFLTE.DAT SITE COORDINATES: SITE LATITUDE: 33.0930 SITE LONGITUDE: 117.2220 ^ SEARCH RADIUS: 100 mi m ATTENUATION RELATION: 22) Abrahamson & Silva (1995b/l997) Horiz.- Rock «i 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 ii m m FAl^jT-DATA FILE USED: CGSFLTE.DAT MINIMUM DEPTH VALUE (km): 0.0 EQFAULT SUMMARY DETERMINISTIC SITE PARAMETERS Page 1 « CM ABBREVIATED FAULT NAME APPROXIMATE DISTANCE mi (km) ROSE CANYON [ 7 .8 { 12 5) 1 7 2 1 0 328 IX m NEWPORT-INGLEWOOD (Offshore) j 12 .7 { 20 5) 1 7 1 1 0 203 VIII CORONADO BANK | 22 .7 ( 36 6) 1 7 6 1 0 145 VIII ELSINORE (JULIAN) | 22 . 9 ( 36 9) ! 7 1 1 ° 114 VII ELSINORE (TEMECULA) | 23 .1 ( 37 1) i 6 8 1 0 098 VII EARTHQUAKE VALLEY | 37 .6 ( 60 5) i 6 5 I 0 049 VI ELSINORE (GLEN IVY) | 38 . 7 ( 62 3) 1 6 8 I 0 057 VI m SAN JOAQUIN HILLS | 43 .2 ( 69 5) 1 6 6 1 0 058 VI m PALOS VERDES | 43 .6 ( 70 1) 7 3 j 0 067 VI m SAN JACINTO-ANZA | 45 . 7 ( 73 6) 1 7 2 1 0 060 VI SAN JACINTO-SAN JACINTO VALLEY | 48 . 1 ( 77 4) 1 6 9 0 048 VI m SAN JACINTO-COYOTE CREEK | 48 .4 ( 77 9) 1 6 6 j 0 040 V m ELSINORE (COYOTE MOUNTAIN) | 50 . 6 ( 81 4) 1 6 8 1 0 042 VI NEWPORT-INGLEWOOD (L.A.Basin) | 53 .9 ( 86 8) 1 7 1 i 0 048 VI m CHINO-CENTRAL AVE. (Elsinore) | 54 .2 { 87 3) 1 6 7 1 0 048 VI WHITTIER 1 57 . 8 ( 93 0) 1 6 8 1 ° 037 V m SAN JACINTO - BORREGO j 60 . 0 { 96 5) 1 6 6 1 0 031 V SAN JACINTO-SAN BERNARDINO | 63 .9( 102 8) 1 6 7 1 0 031 V m SAN ANDREAS - Whole M-la j 67 .0 { 107 9) 1 8 0 1 0 069 VI m SAN ANDREAS - San Bernardino M-lj 67 .0 ( 107 9) 1 7 5 1 ^ 050 VI SAN ANDREAS - SB-Coach. M-lb-2 j 67 . 0 ( 107 9) 1 7 7 1 0 056 VI SAN ANDREAS - SB-Coach. M-2b j 67 .0 ( 107 9) 1 7 7 1 0 056 VI PUENTE HILLS BLIND THRUST | 68 .7 ( 110 6) 1 7 1 1 0 048 VI m SAN ANDREAS - Coachella M-lc-5 j 72 .0 ( 115 8) 1 7 2 1 0 038 V PINTO MOUNTAIN | 72 .5 ( 116 7) 1 7 2 1 0 038 V m SAN JOSE 1 74 .6 ( 120 0) 1 6 4 j 0 028 V m BURNT MTN. 1 75 . 5 ( 121 5) 1 6 5 1 0 023 IV m SUPERSTITION MTN. (San Jacinto) { 75 . 6 ( 121 6) 6 6 i 0 024 V CUCAMONGA | 75 .7 ( 121 8) 1 6 9 1 0 038 V •IP SIERRA MADRE | 77 . 2 ( 124 3) 1 7 2 0 046 VI Mi NORTH FRONTAL FAULT ZONE (West) | 78 . 7 ( 126 6) 1 7 2 1 0 045 VI EUREKA PEAK | 78 . 7 ( 126 6) 1 6 4 1 0 020 IV m ELMORE RANCH | 79 .3 ( 127 6) 6 6 1 0 023 IV m SUPERSTITION HILLS (San Jacinto)| 80 .3 ( 129 2) 1 6 6 1 0 023 IV m CLEGHORN | 81 . 6 ( 131 4) 6 5 1 0 021 IV LAGUNA SALADA | 81 .6 ( 131 4) 1 7 0 1 0 029 V NORTH FRONTAL FAULT ZONE (East) j 81 . 8 ( 131 7) 6 7 1 ° 031 V m SAN ANDREAS - 18 5 7 Rupture M-2a | 84 . 2 ( 135 5) 7 8 1 0 049 VI SAN ANDREAS - Cho-Moj M-lb-1 | 84 .2 ( 135 5) 1 7 8 1 0 049 VI SAN ANDREAS - Mojave M-lC-3 | 84 .2 ( 135 5) 1 7 4 1 0 037 V ESTIMATED MAX. EARTHQUAKE EVENT MAXIMUM EARTHQUAKE MAG.(Mw) PEAK SITE ACCEL, g EST. SITE INTENSITY MOD.MERC. DETERMINISTIC SITE PARAMETERS m m m Page 2 1 ESTIMATED MAX. EARTHQUAKE EVENT 1 APPROXIMATE ABBREVIATED | DISTANCE MAXIMUM 1 PEAK |EST. SITE FAULT NAME j mi (km) EARTHQUAKE 1 SITE 1 INTENSITY MAG . (Mw) I ACCEL, g 1 MOD.MERC. UPPER ELYSIAN PARK BLIND THRUST j 84 .4 ( 135 . 9) 6 .4 1 0 .024 1 V RAYMOND 1 86.2 ( 138 . 8) \ 6 . 5 i 0 .025 1 V LANDERS 1 86 . 9 ( 139. 9) i 7 . 3 1 0 .034 j V CLAMSHELL-SAWPIT | 86 . 9 ( 139. 9) 1 6 .5 1 0 .025 I V BRAWLEY SEISMIC ZONE | 89. 5 ( 144 . 0) 1 6 .4 1 0 .017 I IV VERDUGO 1 89. 7 ( 144 . 4) 1 ^ .9 1 0 .032 1 V HELENDALE - S. LOCKHARDT | 90 . 6 ( 145. 8) 1 "7 .3 1 0 .032 1 V HOLLYWOOD | 91. 8 ( 147 . 8) 1 6 .4 1 0 .022 i LENWOOD-LOCKHART-OLD WOMAN SPRGSj 93 . 5 ( 150 . 5) 1 . 5 1 0 . 036 1 V EMERSON So. - COPPER MTN. j 94 . 9 ( 152 . 8) 1 7 . 0 1 0 . 025 1 V JOHNSON VALLEY (Northern) j 95 . 2 ( 153 . 2) 1 6 . 7 1 0 .020 1 SANTA MONICA j 96 . 3 ( 155 . 0) 1 S .6 1 0 . 024 1 ^ IMPERIAL 1 96 . 6 ( 155 . 5) 7 . 0 1 0 . 024 1 V MALIBU COAST | 99. 7 ( 160 . 5) 6 . 7 1 0 . 025 1 ^ ********************************************************************************* -END OF SEARCH- 54 FAULTS FOUND WITHIN THE SPECIFIED SEARCH RADIUS. THE ROSE CANYON FAULT IS CLOSEST TO THE SITE. IT IS ABOUT 7.8 MILES (12.5 km) AWAY. LARGEST MAXIMUM-EARTHQUAKE SITE ACCELERATION: 0.3276 g m m m *********************** * * * EQFAULT * * * * Version 3.00 * * * *********************** DETERMINISTIC ESTIMATION OF PEAK ACCELERATION FROM DIGITIZED FAULTS JOB NUMBER: 600680-001 DATE: 12-07-2004 JOB NAME: WLC Carlsbad FS 6 CALCULATION NAME: Test Run Analysis FAULT-DATA-FILE NAME: CGSFLTE.DAT SITE COORDINATES: SITE LATITUDE: 33.0930 SITE LONGITUDE: 117.2220 SEARCH RADIUS: 100 mi ATTENUATION RELATION: 22) Abrahamson & Silva (1995b/l997) Horiz.- Rock UNCERTAINTY (M=Median, S=Sigma): S Number of Sigmas; 1.0 DISTANCE MEASURE: clodis SCOND: 0 Basement Depth: 5.00 km Campbell SSR: Campbell SHR: COMPUTE PEAK HORIZONTAL ACCELERATION FAinjT-DATA FILE USED: CGSFLTE.DAT MINIMUM DEPTH VALUE (km): 0.0 EQFAULT SUMMARY DETERMINISTIC SITE PARAMETERS Page 1 ABBREVIATED FAULT NAME APPROXIMATE DISTANCE mi (km) ROSE CANYON 1 7 . 8 ( 12 5) 1 7 2 1 0 .504 X 90 NEWPORT-INGLEWOOD (Offshore) | 12 . 7 ( 20 5) 1 7 1 1 0 .311 IX CORONADO BANK | 22 . 7 { 36 6) 1 7 6 1 0 .223 IX ELSINORE (JULIAN) | 22 . 9 ( 36 9) 7 1 1 0 . 175 VIII ELSINORE (TEMECULA) | 23 . 1 ( 37 1) 6 8 1 0 . 155 VIII m EARTHQUAKE VALLEY | 37. 6 ( 60 5) 1 6 5 1 0 . 081 VII ELSINORE (GLEN IVY) | 38. 7 ( 62 3) 1 6 8 1 0 . 089 VII m SAN JOAQUIN HILLS | 43 2 ( 69 5) j 6 6 1 0 . 094 VII PALOS VERDES | 43 6 ( 70 1) i 7 3 1 0 . 102 VII SAN JACINTO-ANZA | 45 7 ( 73 6) i 7 2 1 0 . 092 VII SAN JACINTO-SAN JACINTO VALLEY } 48 1 ( 77 4) 6 9 1 0 . 074 VII IM SAN JACINTO-COYOTE CREEK j 48 4 ( 77 9) 1 6 6 1 0 . 064 VI H ELSINORE (COYOTE MOUNTAIN) | 50 6 ( 81 4) 1 6 8 1 0 . 067 VI NEWPORT-INGLEWOOD (L.A.Basin) j 53 9 ( 86 8) 1 7 1 1 0 . 073 VII m CHINO-CENTRAL AVE. (Elsinore) j 54 2 ( 87 3) 6 7 1 0 . 077 VII WHITTIER 1 57 8 ( 93 0) 1 6 8 1 0 .058 VI m SAN JACINTO - BORREGO ] 60 0 { 96 5) 1 6 6 1 0 .051 VI SAN JACINTO-SAN BERNARDINO | 63 9 { 102 8) 1 6 7 1 0 .050 VI m SAN ANDREAS - Whole M-la j 67 0 ( 107 9) 1 8 0 1 0 .106 VII in SAN ANDREAS - San Bernardino M-l| 67 0 { 107 9) 1 7 5 i 0 .076 VII SAN ANDREAS - SB-Coach. M-lb-2 | 67 0 ( 107 9) 1 7 7 1 0 .087 VII SAN ANDREAS - SB-Coach. M-2b j 67 0 ( 107 9) 1 7 7 i Q . 087 VII PUENTE HILLS BLIND THRUST j 68 7 ( 110 6) 1 7 1 1 0 . 074 VII m SAN ANDREAS - Coachella M-lc-5 1 72 0 ( 115 8) 1 7 2 I 0 . 058 VI PINTO MOUNTAIN | 72 5 { 116 7) 1 7 2 i 0 .058 VI m SAN JOSE 1 74 6 { 120 0) 1 6 4 ! 0 . 046 VI BURNT MTN. | 75 5 { 121 5) 6 5 1 0 . 037 V W SUPERSTITION MTN. (San Jacinto) | 75 6 { 121 6) 6 6 I 0 . 039 V CUCAMONGA | 75 7 { 121 8) 1 6 9 1 0 . 060 VI SIERRA MADRE | 77 2 { 124 3) 1 7 2 1 0 . 070 VI m NORTH FRONTAL FAULT ZONE (West) | 78 7 { 126 s) 1 7 2 1 0 . 069 VI EUREKA PEAK | 78 7 ( 126 6) 1 6 4 1 0 .034 V m ELMORE RANCH | 79 3 ( 127 6) 1 6 6 1 0 . 037 V liHi SUPERSTITION HILLS (San Jacinto)| 80 3 ( 129 2) 1 6 6 1 0 .037 V • CLEGHORN | 81 6 ( 131 4) 1 6 5 j 0 . 034 V LAGUNA SALADA | 81 6 ( 131 4) 1 7 0 1 0 . 045 VI wm NORTH FRONTAL FAULT ZONE (East) | 81 8 ( 131 7) 6 7 1 0 .049 VI m SAN ANDREAS - 1857 Rupture M-2a | 84 2 ( 135 5) 7 8 1 . 075 VII SAN ANDREAS - Cho-Moj M-lb-1 j 84 2 ( 135 5) 1 7 8 1 0 . 075 VII SAN ANDREAS - Mojave M-lc-3 | 84 2 ( 135 5) 1 7 4 I 0 . 057 VI ESTIMATED MAX. EARTHQUAKE EVENT MAXIMUM EARTHQUAKE MAG.(Mw) PEAK SITE ACCEL, g EST. SITE INTENSITY MOD.MERC. m DETERMINISTIC SITE PARAMETERS Page 2 1 ESTIMATED MAX. EARTHQUAKE EVENT 1 APPROXIMATE MM ABBREVIATED | DISTANCE MAXIMtJM 1 PEAK |EST. SITE FAULT NAME | mi (km) EARTHQUAKE 1 SITE 1 INTENSITY KM MAG (Mw) 1 ACCEL, g I MOD.MERC. m UPPER ELYSIAN PARK BLIND THRUST | 84 . 4( 135. 9) 6 4 1 0.040 1 ^ RAYMOND 1 86 . 2( 138 . 8) 6 5 1 0.041 1 ^ MR LANDERS i 86 . 9( 139. 9) 7 3 1 0.052 1 "^I mm CLAMSHELL-SAWPIT j 86 . 9{ 139. 9) 6 5 1 0.041 I V ^M BRAWLEY SEISMIC ZONE j 89. 5{ 144 . 0) 6 4 I 0.029 1 ^ VERDUGO i 89. 7{ 144 . 4) 6 9 1 0.050 1 HELENDALE ~ S. LOCKHARDT ] 90. 6( 145. 8) 7 3 1 0.050 1 VI a« HOLLYWOOD | 91. 8( 147. 8) 6 4 1 0.037 1 V LENWOOD-LOCKHART-OLD WOMAN SPRGSj 93 . 5( 150 . 5) 7 5 1 0.055 1 EMERSON So. - COPPER MTN. | 94 . 9( 152 . 8) 7 0 I 0.038 1 ^ JOHNSON VALLEY (Northern) j 95. 2( 153 . 2) 6 7 1 0.032 1 V SANTA MONICA | 96 . 3( 155. 0) 6 6 I 0.039 1 ^ IMPERIAL 1 96. 6( 155 . 5) 7 0 I 0.038 1 V MALIBU COAST | 99.7 ( 160 . 5) 6 7 I 0.040 I V ******************************************************************************* -END OF SEARCH- 54 FAULTS FOUND WITHIN THE SPECIFIED SEARCH RADIUS. THE ROSE CANYON FAULT IS CLOSEST TO THE SITE. IT IS ABOUT 7.8 MILES (12.5 km) AWAY. LARGEST MAXIMUM-EARTHQUAKE SITE ACCELERATION: 0.5036 g Leighton Consulting, Inc. GENERAL EARTHWORK AND GRADING SPECIFICATIONS Page 1 of 6 LEIGHTON CONSULTING, INC. GENERAL EARTHWORK AND GRADING SPECIFICATIONS FOR ROUGH GRADING i.O 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 Geoteclmical 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 rcconmienflalions prior to the coimuencement 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 persomiel 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 geoteclmical design assumptions. If the observed conditions are found to be significantly different than the interpreted assumptions during the design phase, the Geotechnical Consultant shall inform the owner, recommend appropriate changes in design to accommodate the observed conditions, and notify the review agency where required. Subsurface areas to be • 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. m The Geotechnical Consultant shall observe the moisture-conditioning and processing of the ^ subgrade and fill materials and perform relative compaction testing of fill to determine the IK attained level of compaction. The Geoteclmical Consultant shall provide the test results to the owner and the Contractor on a routine and frequent basis, m m m 3030.109-1 Leighton Consulting, 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-conditioning and processing of fill, and compacting fill. The Contractor shall review and accept the plans, geotechnical report(s), and these Specifications prior to commencement of grading. The Contractor shall be solely responsible for performing the grading in accordance with the plans and specifications. The Contractor shall prepare and submit to the owner and the Geotechnical Consultant a work plan that indicates the sequence of earthwork grading, the number of "spreads" of work and the estimated quantities of daily earthwork contemplated for the site prior to commencement of grading. The Contractor shall inform the owner and the Geotechnical Consultant of changes in work schedules and updates to the work plan at least 24 hours in advance of such changes so that appropriate observations and tests can be planned and accomplished. The Contractor shall not assume that the Geotechnical Consultant is aware of all grading operations. The Contractor shall have the sole responsibility to provide adequate equipment and methods to accomplish the earthwork in accordance with the applicable grading codes and agency ordinances, these Specifications, and the recommendations in the approved geotechnical report(s) and grading plan(s). If, in the opinion of the Geotechnical Consultant, unsatisfactory conditions, such as unsuitable soil, improper moisture condition, inadequate compaction, insufficient buttress key size, adverse weather, etc., are resuUing in a quality of work less than required in these spccificalions. the (Icotcchnical 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 properiy disposed of in a method acceptable to the owner, governing agencies, and the Geotechnical Consultant. The Geotechnical Consultant shall evaluate the extent of these removals depending on specific site conditions. Earth fill material shall not contain more than 1 percent of organic materials (by volume). No fill lift shall contain more than 5 percent of organic matter. Nesting of the organic materials shall not be allowed. If potentially hazardous materials are encountered, the Contractor shall stop work in the affected area, and a hazardous material specialist shall be infonned 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 fiiel, 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 lines and/or iniprisomnent, and shall not be allowed. 3030.1094 Leighton Consulting, 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 scanfied 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, fiat, and free of uneven features that would inhibit uniform compaction. 2.3 Overexcavation: In addition to removals and overexcavafions recommended in the approved geotechnical report(s) and the grading plan, soft, loose, dry, saturated, spongy, organic-nch, 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 reconmiended by the Geoteclmical Consultant. Fill placed on ground sloping fiatter than 5:1 shall also be benched or otherwise overexcavated to provide a flat subgrade for the fill. 2.5 EvalualIOll.•^^cceplance.oLFiiL^^^^-'i: •'-^1 ^reas to receive fill, includmg removal and processed areas, key bottoms, and benches, shall be obser\'cd, mapped, elevations recorded, and/or tested prior to being accepted by the Geotechnical Consultant as suitable to receive fill. The Contractor shall obtain a wntten acceptance from the Geotechnical Consultant prior to fill placement. A licensed surveyor shall provide the survey control tor detemiining elevations of processed areas, keys, and benches. 3.0 Fill Material ^ 3.1 General: Matenal to be used as fill shall be essentially free of organic matter and other <• deleterious substances evaluated and accepted by the Geoteclmical 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 Geoteclmical IH Consultant or mixed with other soils to achieve satisfactory fill material. 3.2 Oversize: Oversize matenal defined as rock, or other irreducible material with a maxunum 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 materia! is completely surroundctl by compacted or densified fill. Oversize matenal shall not be placed within 10 vertical feet of finish grade or within 2 feet of future utilities or underground construction. m m m 3030.1094 m m m m Leighton Consulting, 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 Secfion 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 appropnate tests performed. 4.0 Fill Placement and Compaction 4.1 Fill Layers: Approved fill matenal shall be placed in areas prepared to receive fill (per Section 3.0) m 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 tliroughout. 4.2 Fill Moisture Conditioning: Fill soils shall be watered, dried back, blended, and/or mixed, as necessary to attain a relatively unifonn moismre 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 Matenals (ASTM Test Method D1557-9I). 4.3 Compaction of Fill: After each layer has been moisture-conditioned, mixed, and evenly .spread, it shall be unifoimly compacted to not less than 90 percent of maximum dry density (ASTM Test Method Dl 557-91). Compaction equipment shall be adequately sized and be either specifically designed for soil compaction or of proven reliability to efficiently achieve the specified level of compaction with uniformity. 4.4 Compaction of Fill Slopes: In addition to normal compaction procedures specified above, compaction of slopes shall be accomplished by backrolling of slopes with sheepsfoot rollers at increments of 3 to 4 feet in fill elevation, or by other methods producing satisfactory results acceptable to the Geotechnical Consultant. Upon completion of grading, relative compaction of the fill, out to the slope face, shall be at least 90 percent of maximum density per ASTM Test Method 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). 4.6 Frequency of Compaction Testmg: Tests shall be taken at intervals not exceeding 2 feet in vertical nse and/or 1,000 cubic yards of compacted fill soils embankment, hi 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 constmction is such that the testing schedule can be accomplished by the Geoteclmical Consultant. The Contractor shall stop or slow down the earthwork construction if these minimum standards are not met. 3030.1094 *>0 Leighton Consulting, Inc. GENERAL EARTHWORK AND GRADING SPECIFICATIONS Page 5 of 6 4,7 Compaction Test Locations: The Geotechnical Consultant shall document the approximate elevation and horizontal coordinates of each test location. The Contractor shall coordinate with the project surveyor to assure that sufficient grade stakes are established so that the Geotechnical Consultant can determine the test locations with sufficient accuracy. At a minimum, two grade stakes within a horizontal distance of 100 feet and vertically less than 5 feet apart from potential test locations shall be provided. 5.0 Subdrain Installation Subdrain systems shall be installed in accordance with the approved geotechnical report(s), the grading plan, and the Standard Details. The Geotechnical Consultant may recommend additional subdrains and/or changes in subdrain extent, location, grade, or material depending on conditions encountered during grading. All subdrains shall be surveyed by a land surveyor/civil engineer for line and grade after installation and prior to burial. Sufficient time should be allowed by the Contractor for these surveys. 6,0 Bxcavaiion r.'"xcavations, as well as over-exca\ation lor remedial purposes, shall be evaluated by the Geotechnical Consultant dunng grading. Remedial removal depths shown on geotechnical plans are estimates only. The actual extent of removal shall be determined by the Geoteclmical 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 Geoteclmical Consultant prior to placement of materials for construction of the fill portion of the slope, unless otherwise recommended by the Geotechnical Consultant. m m m m 3030,1094 Leighton Consulting, 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 shall be observed by the Geotechnical Consultant. 7.4 The Geotechnical Consultant shall test the trench backfill for relative compaction. At least one test should be made for every 300 feet of trench and 2 feet ot fill, 7.5 Lift thickness of trench backt^ill shall not exceed those allowed m the Standard Specifications of Public Works Construction unless the Contractor can demonstrate to the Geoteclmical Consultant that the fill lift can be compacted to the minimum relative compaction by his altemative equipment and mclhod. 3030 1094 FILL SLOPE PROJECTED PLANE 1 TO 1 MAXIMUM FROM TOE OF SLOPE TO APPROVED GROUND EXISTING GROUND SURFACE REMOVE UNSUITABLE MATERIAL BENCH HEIGHT 4' TYPICAL) 2' MIN KEY DEPTH LOWEST BENCH (KEY) RLL-OVER-CUT SLOPE EXISTING GROUND SURFACE OMPACTED:-: :^"tLL"-:ic^ '-BENCH HEIGHT (4' TYPICAL) REMOVE UNSUITABLE MATERIAL CUT-OVER-FILL SLOPE -CUT FACE SHALL BE CONSTRUCTED PRIOR TO FILL PLACEMENT TO ASSURE ADEQUATE GEOLOGIC CONDITIONS EXISTING GROUND SURFACE m PROJECTED PLANE 1 TO 1 MAXIMUM FROM TOE OF SLOPE TO APPROVED GROUND BENCH CUT FACE SHALL BE CONSTRUCTED PRIOR TO FILL PLACEMENT OVERBUILD AND TRIM BACK DESIGN SlOPl~~~~~.:0^mP6Cim'\ 1 REMOVE UNSUITABLE MATERIAL T BENCH HEIGHT (4' TYPICAL) FOR SUBDRAINS SEE STANDARD DETAIL C 2' MIN,—' KEY DEPTH 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 FINISH GRADE SLOPE FACE jrM-:-:-:-:-i$;-x-;-:-:-:-:-x-:<<-:-x^^^^ MIN.-:-3*.'^.V.----.-:-?C • 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 BENCHING REMOVE UNSUITABLE MATERIAL SUBDRAIN TRENCH SEE DETAIL BELOW CALTRANS CLASS 2 PERMEABLE OR #2 ROCK C9FT''3/FT) WRAPPED IN FILTER FABRIC // m m m m FILTER FABRIC (MIRAFI 140N OR APPROVED EQUIVALENT)' 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 m NONPERFORATED 6"0 MIN 6" 0MIN, PIPE FILTER FABRIC (MIRAFI 140N OR APPROVED EQUIVALENT) CALTRANS CLASS 2 PERMEABLE OR #2 ROCK (9FT'^3/FT) WRAPPED IN FILTER FABRIC DETAIL OF CANYON SUBDRAIN OUTLET il CANYON SUBDRAINS GENERAL EARTHWORK AND GRADING SPECIFICATIONS STANDARD DETAILS C 5' MIN. OUTLET PIPES 4" 0 NONPERFORATED PIPE. 100' MAX. O.C. HORIZONTALLY, 30' MAX O.C. VERTICALLY BACK CUT 1:1 OR FLATTER SEE SUBDRAIN TRENCH DETAIL m LOWEST SUBDRAIN SHOULD BE SITUATED AS LOW AS POSSIBLE TO ALLOW SUITABLE OUTLET •KEY DEP (2' MIN.) KEY WIDTH AS NOTED ON GRADING PLANS TH (15' MIN.) MIN. OVERLAP — FROM THE TOP HOG RING TIED EVERY 6 FEET CALTRANS CLASS PERMEABLE OR #2 ROCK (3 FT'"3/FT) WRAPPED IN FILTER FABRIC 4" 0 NON-PERFORATED OUTLET PIPE PROVIDE POSITIVE SEAL AT THE JOINT T-CONNECTION FOR COLLECTOR PIPE TO OUTLET PIPE 6 MIN, COVER 4" 0 PERFORATED PIPE FILTER FABRIC ENVELOPE (MIRAFI 140 OR APPROVED EQUIVALENT) 4" MIN, BEDDING m m m m SUBDRAIN TRENCH DETAIL SUBDRAIN INSTALLATION - subdroin collector pipe sholl be instolled with perforotion down or, unless otherwise designated by the geotechnical consultant. Outlet pipes sholl be non-perforated pipe. The subdroin pipe shall have ot leosl 8 perforotions unifornnly spoced per foot. Perforation shall be 1/4" to 1/2" if drill holes ore used. All subdroin pipes sholl hove o gradient of at leost 2% towords the outlet, SUBDRAIN PIPE - Subdrain pipe shall be ASTM D2751, SDR 23.5 or ASTM D1527, Schedule 40, or ASTM D3034. SDR 23 5. Schedule 40 Polyvinyl Chloride Plastic (PVC) pipe All outlet pipe shall be placed in o trench no wide then twice the subdrom pipe. Pipe shall be in soil of SE >/=30 jetted or flooded in ploce except for the outside 5 feel which sholl be native soil backfill. BUTTRESS OR REPLACEMENT FILL SUBDRAINS GENERAL EARTHWORK AND GRADING SPECIFICATIONS STANDARD DETAILS D m SOIL BACKFILL, COMPACTED TO 90 PERCENT RELATIVE COMPACTION BASED ON ASTM D1557 RETAINING WALL WALL WATERPROOFING PER ARCHITECT'S SPECIFICATIONS m WALL FOOTING •32 TYP.: 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 MIN. COMPETENT BEDROCK OR MATERIAL AS EVALUATED BY THE GEOTECHNICAL CONSULTANT m m m m 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. 11 RETAINING WALL DRAINAGE DETAIL GENERAL EARTHWORK AND GRADING SPECIFICATIONS STANDARD DETAILS E