Loading...
HomeMy WebLinkAboutPD 08-07; CHS at Cannon and College; High School at Cannon and College; 2009-06-05roFY Initu*. UPDATED GEOTECHNICAL INVESTIGATION AND 50-SCALE GRADING PLAN REVIEW, CARLSBAD UNIFIED SCHOOL DISTRICT HIGH SCHOOL AT COLLEGE AND CANNON, CARLSBAD, CALIFORNIA 03-01 45 Prepared For: Carlsbad Unified School District 6225 El Camino Real Carlsbad, California 91351 Project No. 601579-005 JUNE 5, 2009 Leighton Consulting, Inc. A LEIGHTON GROUP COMPANY RECORD COPY Initial |)ate rasJ Leighton Consulting, Inc. A LEIGHTON GROUP COMPANY To: June 5, 2009 Project No. 601579-005 Carlsbad Unified School District 6225 El Camino Real Carlsbad, California 92009 Attention: Mr. Robert Todd Subject: Updated Geotechnical Investigation and 50-Scale Grading Plan Review, Carlsbad Unified School District High School at College and Cannon, Carlsbad, California As requested, Leighton Consulting, Inc. has conducted a geotechnical investigation for the Carlsbad Unified School District (CUSD) High School at College and Cannon in the northeast portion of Carlsbad, California. The purpose of the investigation was to develop geotechnical recommendations for design and construction of the proposed school campus. This update report presents our geotechnical findings, conclusions, and recommendations regarding this site and incorporates the most current rough grading plan, additional analysis for buttress construction, subdrainage measures, additional geologic cross-sections, updated seismic design parameters and updated slope stability analyses. We appreciate the opportunity to work with you on this project. If you have any questions, or if we can be of further service, please call us at your convenience. Respectfully submitted, LEIGHTON CONSULTING, INC. Se Princip Distribution A Michael R. Stewart, CEG 1349 Principal Geologist/Vice Presiden (2) Addressee (4) Gafcon, Attention: Mr. Aaron Golde (1) Roesling Nakamura Terada Architects, Attention: Mr. Rommel Olaes (1) Stedman and Dyson Structural Engineers, Attention: Ms. LeeAnn Rogalski (1) Flores Lund Consultants, Attention: Ms. Erin Sweeney NO. 1349 CERTIFIED ENGINEERING GEOLOGIST 3934 Murphy Canyon Road, Suite B205 » San Diego, CA 92123-4425 858.292.8030 » Fax 858.292.0771 601579-005 TABLE OF CONTENTS Section Page 1.0 INTRODUCTION 1 1.1 PURPOSE AND SCOPE 1 1.2 SUE LOCATION AND DESCRIPTION 2 1.3 PREVIOUS INVESTIGATIONS 2 1.4 PROPOSED DEVELOPMENT 3 2.0 SUBSURFACE EXPLORATION AND LABORATORY TESTING 4 2.1 GEOTECHNICAL BORINGS 4 2.2 TRENCHES 4 2.3 LABORATORY TESTING 5 3.0 SUMMARY OF GEOTECHNICAL CONDITIONS 6 3.1 GEOLOGIC AND TECTONIC SETTING 6 3.2 EXISTING SITE CONDITIONS 6 3.3 SITE-SPECIFIC GEOLOGY 7 3.3.1 Artificial Fill Soils (Map Symbols - Afu and Afo) 7 3.3.2 Topsoil (Unmapped) and Colluvium (Map Symbol - Qcol) 7 3.3.3 Alluvium (Map Symbol - Qal) 8 3.3.4 Landslide Deposits (Map Symbol - Qls) 8 3.3.5 Santiago Formation (Map Symbol - Tsa) 9 3.3.6 Lusardi Formation (Map Symbol - Kl) 9 3.3.6 Lusardi Formation (Map Symbol - Kl) 9 3.3.7 Granitic Rock (Map Symbol - Kgr) 9 3.3.8 Santiago Peak Volcanics (Map Symbol - Jsp) 10 3.4 GEOLOGIC STRUCTURE 10 3.5 GROUND WATER 10 3.6 SOIL SURVEY MAPPING 11 3.7 DAM FAILURE INUNDATION AND FLOOD HAZARD 12 3.8 ABOVE GROUND WATER STORAGE TANK HAZARD 12 3.9 EXCEPTIONAL GEOLOGIC CONDITIONS 12 3.9.1 Environmental Site Assessment and Hazardous Materials 13 3.9.2 Environmental Impact Report 13 3.9.3 Ground Water Quality 13 3.9.4 On-Site Septic Systems 13 3.9.5 Regional Subsidence 13 3.9.6 Non-Tectonic Faulting 14 3.9.7 Volcanic Eruption 14 3.9.8 Asbestos 14 4 Leighton 601579-005 TABLE OF CONTENTS Section Page 3.9.9 Radon-222 Gas 14 4.0 FAULTING AND SEISMICITY 15 4.1 FAULTING 15 4.1.1 Historical Seismicity 17 4.2 SEISMICITY 17 4.2.1 Building Code Seismic Parameters 20 4.2.2 Site Specific Analysis Seismic Design Parameters 20 4.3 SECONDARY SEISMIC HAZARDS 21 4.3.1 Shallow Ground Rupture 21 4.3.2 Liquefaction Potential 21 4.3.3 Seismically Induced Landslides 22 4.3.4 Seiches and Tsunamis 22 5.0 GEOTECHNICAL DESIGN CONSIDERATIONS 23 5.1 SLOPE STABILITY 23 5.1.1 Cross-Section A-A' 24 5.1.2 Cross-Section B-B' 24 5.1.3 Cross-Section C-C 24 5.1.4 Cross-Section D-D' 24 5.1.5 Cross-Section E-E' 25 5.1.6 Surficial Slope Stability 25 5.1.7 Natural Slopes 26 5.2 EXPANSION POTENTIAL 26 5.3 SOIL CORROSMTY 27 6.0 CONCLUSIONS 28 7.0 RECOMMENDATIONS 30 7.1 EARTHWORK 30 7.1.1 Site Preparation 30 7.1.2 Removal and Recompaction of Potentially Compressible Soils 30 7.1.3 Excavations and Oversize Material 32 7.1.4 Fill Placement and Compaction 32 7.1.5 Expansive Soils and Selective Grading 33 7.2 CUT/FILL TRANSITION CONDITIONS 33 7.3 SLOPE STABILITY 34 7.3.1 Fill Slopes 34 7.3.2 Cut Slopes 35 7.3.3 Recommended Baseball Reid Cut Slope Buttress 35 7.4 CONTROL OF GROUND WATER AND SURFACE WATER 36 4 Leighton 601579-005 TABLE OF CONTENTS Section Page 7.5 FOUNDATION AND SLAB CONSIDERATIONS 37 7.5.1 Conventional Foundation Design 37 7.5.2 Settlement 38 7.5.3 Post-Tensioned Foundation Design 39 7.5.4 Mat Foundation Design 40 7.5.5 Ribbed-Mat Foundation Design 40 7.5.6 Moisture Conditioning 40 7.6 EARTH AND HYDROSTATIC WALL PRESSURES 41 7.7 SEGMENTAL BLOCK RETAINING WALLS 42 7.8 GEOCHEMICAL CONSIDERATIONS 43 7.9 PRELIMINARY PAVEMENT DESIGN CONSIDERATIONS 43 7.10 CONCRETE FLATWORK 44 7.10.1 Basketball and Tennis Courts 44 7.11 ALL WEATHER TRACK AND FIELD DRAINAGE 45 7.12 CONSTRUCTION OBSERVATION AND PLAN REVIEW 45 8.0 LIMITATIONS 46 Tables Table 1 - Soil K Factor - Page 11 Table 2 - Seismic Parameters for Nearby Active Faults (CGS, 2003) - Page 16 Table 3 - Seismic Parameters for Nearby Active Faults (CGS, 2008) - Page 18 Table 4 - Ground Motion Parameters - Page 19 Table 5 - 2007 CBC Seismic Design Parameters - Page 20 Table 6 - Site-Specific Seismic Design Parameters - Page 21 Table 7 - Soil Strength Parameters - Page 23 Table 8 - Allowable Soil Bearing Values for Spread Footings - Page 38 Table 9 - Post-Tensioned Foundation Design Recommendations for Expansive Soils - Page 39 Table 10 - Static Equivalent Fluid Weight (pcf) - Page 41 Table 11 - Preliminary Pavement Sections - Page 43 Leighton 601579-005 TABLE OF CONTENTS (Continued^ Figures And Plates Figure 1 - Site Location Map - Rear Of Text Figure 2 - Site Reconnaissance Map - Rear Of Text Figure 3 - Regional Topographic Map - Rear Of Text Figure 4 - Regional Geologic Map - Rear Of Text Figure 5 - Regional Fault Map - Rear Of Text Figure 6 - Soil Survey Map - Rear Of Text Figure 7 - Dam Failure Inundation Hazard Zone Map - Rear Of Text Figure 8 - Flood Hazard Zone Map - Rear Of Text Figure 9 - Lateral Earth and Hydrostatic Pressures - Rear of Text Plate 1 - Geotechnical Map - In Pocket Plate 2 - Geologic Cross-Sections A-A' Through D-D' - In Pocket Plate 3 - 50-Scale Geotechnical Map (Sheet C3.01R) - In Pocket Plate 4 - 50-Scale Geotechnical Map (Sheet C3.02R) - In Pocket Plate 5 - 50-Scale Geotechnical Map (Sheets C3.03R) - In Pocket Appendices Appendix A Appendix B Appendix C Appendix D Appendix E Appendix F Appendix G - References - Boring And Trench Logs (This Investigation) - Trench Logs (Prior Leighton Investigations) - Laboratory Testing Procedures And Test Results - Seismic Hazard Analysis - Slope Stability Analyses - General Earthwork and Grading Specification -iv-Leighton 601579-005 1.0 INTRODUCTION 1.1 Purpose and Scope This report has been prepared to update our geotechnical investigation for the proposed Carlsbad Unified School District (CUSD) High School site located northeast of the intersection of Cannon Road and College Boulevard in Carlsbad, California (Figure 1). As part of the effort to update our investigation report, we have incorporated 50-scale rough grading plans (FLC, 2009). The purpose of our investigation was to identify and evaluate the geologic hazards and significant geotechnical conditions present at the site in order to provide geotechnical recommendations for site development. Our scope of services included: • Review of available pertinent, published and unpublished geotechnical literature and maps. References cited are listed in Appendix A. • Field reconnaissance of the existing onsite geotechnical conditions. • Subsurface exploration consisting of the excavation, logging, and sampling of 10 exploratory small-diameter hollow-stem borings, 5 large-diameter bucket auger borings, and 26 trenches across the site. The boring and trench logs are presented in Appendix B and locations are shown on the Geotechnical Map - Plate 1. • Review of available subsurface geotechnical studies previously performed. Selected boring and trenches are plotted on the Geotechnical Map (Plate 1). Available logs from prior investigations (Leighton and Associates, 2001 and 2005) are presented in Appendix C. • Laboratory testing of representative soil samples obtained from the subsurface exploration program. Results of these tests are presented on the subsurface logs and in Appendix D. • Preparation of updated geotechnical cross-sections to illustrate the existing topographic and geologic profiles relative to the proposed site design (Plate 2). • Preparation of 50-scale Geotechnical Maps (Plates 3, 4, and 5) illustrating buttress and recommended site subdrains. The most current 50-Scale Grading Plans were used as a base (FLC, 2009). • Assessment of geologic hazards. Leighton 601579-005 • Development of updated seismic design parameters based on the 2007 California Building Code (Appendix E), including site-specific seismic hazard evaluation. • Compilation and analysis of the geotechnical data obtained from the field investigation and laboratory testing. • Slope stability analyses of the proposed slopes and the hillside on the site (Appendix F). • Preparation of this report presenting our findings, conclusions, and geotechnical recommendations with respect to the proposed geotechnical design, site grading and general construction considerations. 1.2 Site Location and Description The subject property is located northeast of the intersection of Cannon Road and College Boulevard in Carlsbad, California (Figure 1). The County of San Diego Assessor's office designates the subject site as Assessor Parcel Number (APN) 168-050-019 (42.64 acres) and APN 168-050-046 (15 acres). There are no street addresses assigned to the site. A Site Reconnaissance Map (Figure 2) illustrates the approximate site boundaries on an aerial photograph base. Portions of the site has been used for agriculture since prior to 1974 and the property is surrounded primarily by undeveloped land. It is also bordered on the west by an intermittent stream and a dirt road. The pre-development topography of the site area is presented on Figure 3. 1.3 Previous Investigations Various geotechnical investigations have been performed in areas adjacent to the proposed school site property; and we have incorporated the applicable data for areas which border the site. Leighton and Associates performed a geotechnical investigation relative to the proposed extension of Cannon Road (L&A, 2001). Boring B-2, and Trenches T-10 through T-15 of that investigation are presented on our Geotechnical Map in the southern portion of the proposed school site. We also performed a limited subsurface investigation for the Rancho Carlsbad Mobile Home Park (L&A, 2005) which included Boring B-l. Logs of the boring and trenches are included in Appendix C and associated laboratory test results have been incorporated into Appendix D. We have also reviewed geotechnical investigations performed by GeoSoils for properties to the west of the CUSD site (GeoSoils, 2001 and 2002). Boring locations adjacent to the site, along the alignment of College Boulevard west of the site, are approximately located Leighton 601579-005 on the Geotechnical Map (Plate 1). Data from these borings is summarized on the map; however, logs of the borings were not available for inclusion in this report. We have conducted several phases of environmental assessment studies and reporting (Leighton Consulting, 2006, 2007, 2008b, 2009a, 2009b). Assessment and mitigation of hazardous materials are addressed in those reports. 1.4 Proposed Development Based on the site plan provided by Roesling Nakamura Terada Architects (RNT, 2009), the proposed school is designed to be centrally located on the site. The site plan illustrates a centralized campus of eight buildings, including: an adjoining food service/science classroom building, an adjoining library classroom building, an adjoining administration classroom building, a gymnasium, a fine arts building, a press box, an electric building, and a concessions building. A ninth building is also shown as a future classroom that is not included as part of the present site development. The development also includes a track and field stadium with bleachers; a baseball field, a softball field, tennis courts, basketball courts, and parking lots and driveways. Site improvements are also anticipated to include placement of underground utility lines, construction of a bio-swale and desilting/retention facility along the western property boundary, access roads, concrete flatwork, and landscaping. The rough grading plan, prepared by Flores Lund Consultants and received May 28, 2009 (FLC, 2009) has been used as the base map for the Geotechnical Map (Plate 1). From discussions with the Civil Engineer, we understand the planned finish grades will be within 1 foot of the grades shown on the rough grading plan elevations. Compared to the existing topography, the deepest cut (up to 43 feet) is proposed in the area of the northern baseball field. However, cuts and fills in the vicinity of the proposed buildings are on the order of approximately 15 feet of cut and 15 feet of fill. Outside of the building complex, cuts on the east side of the site, and fills on the west and south are anticipated. The cut slope on the northeast side of the baseball field has a maximum height of approximately 87 feet. The maximum fill slope is approximately 26 feet in height and is located on the south side of the softball field. Cut and fill slopes are all proposed at gradients of 2 to 1 (horizontal to vertical) or flatter. The maximum retaining wall height is 26 feet at the northwest corner of the baseball field area. -3- € Leighton 601579-005 2.0 SUBSURFACE EXPLORATION AND LABORATORY TESTING The subsurface exploration performed for our geotechnical investigation included the excavation of 10 small diameter (hollow-stem auger) borings and 5 large diameter (bucket auger) borings throughout the site. We also excavated a series of 26 backhoe test pits to evaluate the near- surface soils. The approximate locations of the exploration borings and trenches are shown on the Geotechnical Map - Plate 1, and logs are presented in Appendix B. The purpose of the borings and trenches was to investigate the stratigraphy, physical characteristics, and specific engineering properties of the soils that underlie the site. During the exploration operations, engineering geologists from our firm prepared geologic logs and collected bulk and relatively undisturbed samples for laboratory testing and evaluation. 2.1 Geotechnical Borings Our subsurface investigation was performed between December 26, 2007 and January 21, 2008, and included the excavation, logging, and sampling of a total of 15 borings, ranging in depth of 9 to 58 below the existing ground surface. Ten small-diameter borings (Borings H-l through H-10) were performed using a truck-mounted hollow-stem auger. These borings enabled the collection of Modified California Ring and Standard Penetration Split Spoon (SPT) samples for visual observation and laboratory testing. A total of 5 large-diameter borings, (Borings B-l through B-5) were excavated utilizing a truck-mounted bucket auger, outfitted for downhole logging. These borings were performed in bedrock cut areas to characterize the stratigraphy and excavation characteristics of the geologic bedrock units. The large-diameter borings were sampled and downhole logged by a Certified Engineering Geologist from Leighton. Boring B-3 was not downhole logged, as it encountered hard bedrock and "practical refusal" to drilling at a relatively shallow depth (9 feet). Borings were backfilled in accordance with County of San Diego Department of Environmental Health requirements upon completion (Leighton Consulting, 2008). 2.2 Trenches A total of 26 exploration trenches (Trenches T-l through T-26) were excavated, sampled, and logged by a geologist from our office. The trenches were excavated to depths of up to approximately 11 feet below the existing ground surface. The trenches were excavated utilizing a rubber track John Deere JD-410G excavator equipped with a 3-foot wide bucket. The purpose of these excavations was to evaluate the physical characteristics of the surficial soils and assess the depth to competent material within limits of the proposed development. The trenches also allowed evaluation of the soils to be encountered at the proposed design elevations, the general nature of the soils proposed for use as compacted -4-Leighton 601579-005 fills, the approximate depth to formational material, and provided representative samples for laboratory testing. After logging and sampling, the excavations were backfilled and compacted with effort using the bucket of the excavator. No compaction testing was performed. 2.3 Laboratory Testing Laboratory testing performed during this investigation included moisture content, unit weight, grain-size distribution, chloride content, maximum density, pH, minimum resistivity, sulfate content, consolidation, expansion potential, plasticity (Atterberg Limits), R-value, and shear strength of the subsurface soils. A brief discussion of the laboratory tests performed and a summary of the laboratory test results are presented in Appendix D. -5- <c Leighton 601579-005 3.0 SUMMARY OF GEOLOGIC CONDITIONS 3.1 Geologic and Tectonic Setting The site is located within the coastal subprovince of the Peninsular Ranges Geomorphic Province, near the western edge of the southern California batholith. Throughout the last 54 million years, the area known as the "San Diego Embayment" has gone through several episodes of marine inundation and subsequent marine regression, resulting in the deposition of a thick sequence of marine and nonmarine sedimentary rocks on the basement rock of the Southern California batholithic. 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. A regional geology map of the site is attached as Figure 4. The Peninsular Ranges are traversed by several major active faults. The Whittier-Elsinore, San Jacinto, and the San Andreas faults are major active fault systems located northeast of the site and the Rose Canyon, Newport-Inglewood (offshore), Coronado Bank, and San Diego Trough are active faults located to the west-southwest. A regional fault map relative to the site is attached as Figure 5. Major tectonic activity associated with these and other faults within this regional tectonic framework is right-lateral strike-slip movement. These faults, as well as other faults in the region, have the potential for generating strong ground motions at the project site. Further discussion of faulting relative to the site is provided in the Faulting and Seismicity section of this report. 3.2 Existing Site Conditions Topographically, the site generally consists of a west- to southwest-facing hillside with a north-south trending main drainage along the west boundary of the site and a southwest- trending drainage along the southern property boundary. A southwest trending tributary canyon is also present in the central portion of the site. Elevations range from a high of approximately ±240 feet mean sea level (msl) in the northeast corner of the site to a low of ±70 feet msl along southwest side of the site (Figure 3). Vegetation on the site ranges from planted vegetable crops in the southern portion of the site, native grasses and weeds on the steeper hillsides in the eastern portion of the site, and moderate chaparral and trees along the drainages of the site. Man-made features that were present during our site investigation included several buildings associated with the farming activities; numerous dirt roads which cross the property; and undocumented fills associated with the dirt roads and farming activities (Figure 2). -6-Leighton 601579-005 3.3 Site-Specific Geology Jurassic-aged Santiago Peak Volcanics, Cretaceous-aged Granitics and Lusardi Formation, the Tertiary-aged Santiago Formation, and surficial units consisting of undocumented and older documented fill soils, topsoil/colluvium, alluvium, and landslide deposits were observed during our evaluation of the site. The approximate distribution of these geologic units are shown on the Geologic Map (Plate 1) and discussed below youngest to oldest. 3.3.1 Artificial Fill Soils (Map Symbols - Afu and Afo) Undocumented fill soils (Afu) were observed in a number of places on the site. As observed, the undocumented fill soils were generally associated with the grading of the onsite dirt roads and prior farming activities. These undocumented fill soils are anticipated to be relatively thin and limited in extent. The thickest undocumented fill was mapped in the central drainage and consisted of an earthen embankment (dam) evidently constructed to retain or pond surface water. Another significant area of undocumented fill was associated with the existing farming buildings located in the southwest portion of the site. The remaining areas of surficial undocumented fill were not mapped. All existing undocumented fills located on the site are considered potentially compressible and unsuitable in their present state for structural support and will require removal and recompaction. Artificial fills (Afo) controlled and compacted by others are mapped in the vicinity of the existing College Boulevard and Cannon Road intersection. These soils have been placed relatively recently during construction of the roadways and associated utility installation and backfill. These artificial fills are expected to be suitable to support the proposed site entry road, although minor conditioning and/or removal of loose desiccated surficial soils may be necessary. 3.3.2 Topsoil (Unmapped) and Colluvium (Map Symbol - QcoO Topsoil and Colluvium (Qcol) was observed during our site investigation and mantles the majority of the site. These soils predominantly consist of light to dark brown, moist, soft, sandy to silty clay and some clayey to silty sands. These soils are usually massive, porous, and contain scattered roots and organics. The topsoil, generally less then 2 feet in thickness, was located on the upper hillsides and was not mapped. The potentially compressible colluvium averages approximately 2 to 4 feet in thickness; commonly thickening up to 5 or 6 feet in the lower lying areas near the alluvial drainages. The thickest colluvium interfingers with alluvium to a depth of approximately 10 feet in the northwest corner of the site, as encountered -7-Leighton 601579-005 in Trench T-15 and Boring H-6. Localized areas of thicker accumulations of colluvium may be encountered during grading. All colluvium and topsoil materials are considered unsuitable for support of additional fill or site improvements and will need to be removed and recompacted during grading. 3.3.3 Alluvium (Map Symbol - Pah Alluvium is present in the main canyon along the western property boundary, in the tributary east-west drainage in the central portion of the site, and in the tributary drainages along the south property boundary. The alluvial soils are usually thickest in the center of drainages and often interfmger with colluvial soils on the drainage margins forming wedges of alluvial and colluvial soils that thin away from the drainages. These soils typically consisted of brown, damp to wet, loose to medium dense/stiff, silty sands, sandy clays and silty clays. The upper portion of alluvium in the main drainages and generally all of the alluvium in the tributary drainages typically is moderately porous and often contains localized zones of moderate to abundant roots and other organic matter. The alluvium is considered potentially compressible and is recommended to be removed to competent material in areas of proposed development. Complete removal to competent bedrock material is expected to be necessary within the central drainage which underlies the proposed gym/locker and kitchen/commons buildings. To the west, removal depths of alluvium on the order of 5 to 10 or more feet should be expected in the lower main drainage, underlying the western parking areas and athletic facilities. The alluvium may be recompacted and used as structural fill provided detrimental organic materials are removed. 3.3.4 Landslide Deposits (Map Symbol - Ols) A landslide was noted in the northern portion of the site (as indicated on Plate 1 and Cross-Sections A-A' and D-D') and extends beyond the property boundary to the north. As encountered in Boring B-4, the landslide basal rupture surface is a clayseam or a weak zone in the formational claystone at an approximate elevation of 165 feet. Due to potential instability concerns and the compressible nature of the landslide materials, the complete removal of the landslide within the CUSD property along with the buttressing of the proposed cut slope in the northern portion of the site is anticipated. It should be noted, however, that the proposed grading is expected to remove the majority of this landslide. -8-Leighton 601579-005 3.3.5 Santiago Formation (Map Symbol - Tsa) The Tertiary-aged Santiago Formation is anticipated across most of the site. The Santiago Formation is composed of yellow-brown to off-white, dense to very dense, silty, fine sandstone and olive-brown to dark olive-green, moderately stiff to stiff, silty claystones and clayey siltstones. In general, the upper portion of the Santiago Formation consists of finer grained, weathered silty claystones, while our deeper explorations encountered harder siltstones and very fine grained sandstones. The sandy soils typically have a very low to low expansion potential and favorable engineering characteristics, while the claystones and siltstones typically have a medium to very high expansion potential. The siltstones and claystones have relatively low soil strengths resulting in potential instability problems when exposed in slopes or on steeper hillsides. Sandstone beds within the unit can be well cemented, requiring heavy ripping during grading, particularly in the deeper cuts. 3.3.6 Lusardi Formation (Map Symbol - Kl) The Cretaceous-aged Lusardi Formation is mapped along the eastern property boundary. It was also encountered in our borings and trenches excavated along the upper portion of the central drainage which bisects the site. As encountered, the Lusardi Formation is composed of a light yellow-brown and gray, dense, gravel to cobble conglomerate with a medium to coarse sandstone matrix to green-gray, stiff, sandy claystone. This unit mantles the underlying granitic bedrock and includes subangular clasts of gravel to boulder sized volcanic rock. In addition, it may contain localized scattered large to very large (up to 10 to 20 feet in diameter) granitic boulders. Typically these large to very large granitic boulders are very weathered (i.e. they generally consist of decomposed granite). The soils comprising the Lusardi Formation generally have a very low to medium potential for expansion and are suitable for use as structural fill provided oversize materials are properly incorporated or removed. 3.3.7 Granitic Rock (Map Symbol - Kgr) Cretaceous-aged granitic rock outcrops and weathered granitic material were observed to the east of the site. This hard rock unit underlies the water storage tank up hill to the east of the site, and some medium to large sized boulders can be seen at the surface, potentially transported downhill onto the site. Although not expected, relatively unweathered granitic bedrock could potentially be encountered in deep cuts, beneath the overlying Lusardi Formation. Although not -9-Leighton 601579-005 proposed, deep cuts (generally greater than approximately 15 to 25 feet) in these areas may require heavy ripping or local blasting. 3.3.8 Santiago Peak Volcanics (Map Symbol - Jsp) Jurassic-aged Santiago Peak Volcanics, while not encountered during our subsurface investigation, are located west of the site and were encountered beneath the alluvium along the western side of the property by others (GeoSoils, 2001 and 2002). The Santiago Peak Volcanics is usually a dacite or andesite hard rock. We do not anticipate that the Santiago Peak Volcanics will be encountered during the grading of the site. 3.4 Geologic Structure Based on our professional experience in the Carlsbad area and our subsurface investigation, the Tertiary-aged Santiago Formation overlies the Cretaceous-aged Lusardi Formation and granitic basement rocks, as illustrated on the Cross-Sections (Plate 2). Bedding observed on-site appears to be slightly dipping (10 degrees or less). As encountered in the borings and trenches in the southern half of the site, bedding strikes northeast/southwest and dips 2 to 4 degrees to the southeast. In the northern portion of the site, bedding appears to be striking northeast/southwest and dipping 5 to 10 degrees to the northwest. Our professional experience indicates that the Lusardi Formation is typically massively bedded. Jointing within the units was found to be randomly oriented but generally was subparallel to the hillside and relatively steep. Jointing within the granitic rock is usually very minimal, while jointing in the Santiago Peak Volcanics is abundant with joint spacing generally less than 12 to 18 inches. No faults have been mapped on the site nor were any observed during our site investigation although minor inactive faults were encountered during our prior investigation for the College Boulevard extension south of the site (Leighton and Associates, 2001). These inactive faults were found to be discontinuous and generally trend in a north-south direction dipping moderately steeply to the west and east. 3.5 Ground Water Perched ground water conditions are present in the alluvium/colluvial soils on the site (especially along the western property boundary). Perched ground water is not expected to significantly impact the proposed development. Based on our review of geotechnical documents from nearby sites and our experience with similar conditions, the depth of the perched ground water condition is estimated to be approximately 10 to 15 feet below the -10-Leighton 601579-005 ground surface in the main north-south trending drainage along the western property boundary. Minor ground water conditions (i.e. perched water in the alluvium/colluvium in the central drainages) and seepage (along permeable units within the formational materials) may be encountered in the other portions of the site but should not be a significant constraint to development. 3.6 Soil Survey Mapping Based on our review of historic maps published by the United States Department of Agriculture (USDA, 1973) the majority of the site is overlain by Huerhuero loam (HrD) characterized by gentle to moderate (9 to 15 percent) slopes, very low to moderately low permeability and moderate erodibility (Figure 6). The remainder of the site area to be developed is overlain by Altamont clay (AtD and AtE) on gentle to moderate (9 to 30 percent) slopes. These materials possess moderately low permeability are moderately erodible. The natural slopes above the site to the east are mapped to consist of Las Flores loamy fine sand to south, and Cineba-Fallbrook rocky sandy loams through the central portion and Altamant clay (AtE)on the north. These materials range from slightly to moderately erodible. The following table presents USDA K factor ratings which represent a measure of the soil erodibility by water. Table 1 Soil K Factor Map Unit AtD AtE CnE2 HrD LeE Rating 0.20 0.20 0.28 0.37 0.37 The possible range of K Factors is between 0.02 to 0.69, with higher values reflecting more susceptibility to sheet and rill erosion. In terms of permeability, it is noted that all of the mapped soils are underlain by shallow bedrock or bedrock derived landslide deposits that restrict and limit infiltration. -11-Leighton 601579-005 3.7 Dam Failure Inundation and Flood Hazard Based on our review of the data on the FEMA web site (FEMA, 2008) and the City of Carlsbad Geotechnical Hazards Study (L&A, 1992), it appears that the southwestern portion of the site is mapped within a "100-year" flood zone and dam failure inundation zone (Lake Calavara is located roughly 4,000 feet to the north). The approximate location of the mapped dam failure inundation and flood zone hazards maps are presented as Figures 7 and 8. It should be noted that construction of the intersection of Cannon Road and College Boulevard may have changed the limits of these dam failure inundation and flood zones. Based on the preliminary grading plans, the western and southwestern portions of the property will be raised approximately 10 to 20 feet by the addition of compacted fill which will likely reduce the dam failure inundation and flood zone impacts to the school site. 3.8 Above Ground Water Storage Tank Hazard The site is situated downslope of an existing 1.5-million gallon water storage tank that is approximately 1000 feet east of the site and over 200 feet higher in elevation. Based on review of geologic mapping, the tank is founded over granitic bedrock materials. These materials are generally not considered to be susceptible to instability and provide strong bearing support. According to the City of Carlsbad Geotechnical Hazards Analysis and Mapping Study (Leighton and Associates, 1992), the bedrock unit is classified as "generally stable". Assessment of the hazard due to tank failure is discussed in Appendix M of the EIR for the New High School (The Planning Center, 2008). That report concludes that the water tank poses a very low risk of catastrophic failure when subject to a Maximum Considered Earthquake Ground Motion of 0.49g. If further structural analysis is deemed appropriate, site response spectra, including long period motions, can be developed utilizing AWWA methodologies for design of steel water tanks (AWWA, 2005). 3.9 Exceptional Geologic Conditions Exceptional geologic items are items that are present across the State of California, and occur on a site by site basis. We have addressed the presence or non-presence of these items in the sections below. -12-Leighton 601579-005 3.9.1 Environmental Site Assessment and Hazardous Materials A Final Preliminary Environmental Assessment (PEA) report was prepared by Leighton Consulting, Inc. (Leighton Consulting, 2007) on behalf of the CUSD in accordance with the guidance of the California Environmental Protection Agency (Cal/EPA) Department of Toxic Substances Control (DISC. Due to the current and historical usage of the site for agricultural purposes, various hazardous and regulated substances, including containers of herbicides, insecticides, fungicides, oil and unknown liquids and solids, were observed in the southwestern area of the subject site. Based upon the findings presented, further assessment of the site was performed and reviewed by DISC (Leighton Consulting, 2008b and 2009a). Just recently, the Draft Remedial Action Workplan was prepared for the site (Leighton Consulting, 2009b). 3.9.2 Environmental Impact Report Review of an Environmental Impact Report was not part of the services to be provided in our scope of work. 3.9.3 Ground Water Quality Assessment of ground water quality was not part of the services to be provided in our scope of work. The proposed development is not expected to impact, or be dependent on, the regional ground water table, and will utilize municipally provided water. 3.9.4 Qn-Site Septic Systems The proposed project will use existing City of Carlsbad sewer systems; therefore, on-site septic systems are not applicable to the site. 3.9.5 Regional Subsidence Due to the depth of the regional groundwater elevation and the dense nature of the bedrock materials underlying the majority of the site, regional subsidence is considered to be unlikely. -13-Leighton 601579-005 3.9.6 Non-Tectonic Faulting Surface expressions of differential settlement, such as ground fissures, can develop in areas affected by ground water withdrawal or banking activities, including geothermal production. The site location is not within an area affected by differential settlement caused by non-tectonic sources. 3.9.7 Volcanic Eruption The proposed site is not located within or near a mapped area of potential volcanic hazards (Miller, C.D., 1989). 3.9.8 Asbestos Due to the lack of proximal sources of serpentinic or ultramafic rock bodies, naturally-occurring asbestos is not considered a hazard at the site. 3.9.9 Radon-222 Gas Historically, Radon-222 gas has not typically been recognized as an environmental consideration in San Diego County. The predominant geologic units at the site (i.e. the Lusardi Formation, granitic rock, Santiago Peak Volcanics and the Santiago Formation) are not considered to be likely sources (Churchill, 2003); therefore, this investigation did not include testing for the presence of Radon gas. -14-Leighton 601579-005 4.0 FAULTING AND SEISMICiTY 4.1 Faulting Our discussion of faults on the site is prefaced with a discussion of California legislation and policies concerning the classification and land-use criteria associated with faults. By definition of the California Geologic Survey, an active fault is a fault which has had surface displacement within Holocene time (about the last 11,000 years). The state geologist has defined a potentially active fault as any fault considered to have been active during Quaternary time (last 1,600,000 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 2007 (Bryant and Hart, 2007). The intent of this act is to assure that unwise urban development and certain habitable structures do not occur across the traces of active faults. The subject site is not located within any State mapped Earthquake Fault Zones. 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 Rose Canyon Fault Zone. 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 (Hannan, 1975; Weber, 1982; Leighton, 1992; Jennings, 1994; CGS, 1998; and COS, 2000). Evidence for minor inactive faulting was encountered south of the site (Leighton and Associates, 2001) but should not be a constraint to development. The nearest known active fault is the Rose Canyon Fault Zone, which is located approximately 7.4 miles (11.9 kilometers) west of the site. Because of the lack of known active faults on the site, the potential for surface rupture at the site is considered low. A Regional Fault Map (Figure 5) is attached to illustrate the proximity of the site to major regional faults. Regional faults that are considered capable of producing significant seismic shaking at the site are summarized in Table 2. The slip rates and maximum magnitude events are based on the statewide probabilistic seismic hazard assessment and the subsequent update report (CGS, 2003), which forms the basis for the statewide seismic hazard maps contained in the 2008 California Building Code. -15-Leighton 601579-005 Table 2 Seismic Parameters for Nearby Active Faults (CGS, 2003) Fault Rose Canyon Newport- Inglewood (offshore) Elsinore (Temecula) Elsinore (Julian) Coronado Bank Elsinore (Glen Ivy) San Joaquin Hills Palos Verdes Earthquake Valley San Jacinto- Anza San Jacinto- San Jacinto Valley San Jacino- Coyote Creek Newport- Inglewood (L.A. Basin) Chino-Central Avenue (Elsinore) Geometry Right Lateral Strike Slip Right Lateral Strike Slip Right Lateral Strike Slip Right Lateral, Strike Slip Right Lateral, Strike Slip Right Lateral Strike Slip Reverse, Blind Thrust Right Lateral, Strike Slip Right Lateral, Strike Slip Right Lateral, Strike Slip Right Lateral, Strike Slip Right Lateral Strike Slip Right Lateral Strike Slip Right Lateral Reverse, 65SW Closest Distance from Fault to Site Miles 7.4 8.4 20.3 20.3 23.3 32.3 37.4 38.9 40.4 44.9 44.9 47.8 48.2 48.2 Kilometers 11.9 13.5 32.7 32.7 37.5 52.0 60.2 62.6 65.0 72.3 72.3 77.0 77.6 77.6 Maximum Moment Magnitude 7.2 7.1 6.8 7.1 7.6 6.8 6.6 7.3 6.5 7.2 6.9 6.8 7.1 6.7 Average Slip Rate (mm/yr) 1.5 1.5 5.0 5.0 3.0 5.0 0.5 3.0 2.0 12.0 12.0 4.0 1.0 1.0 Fault Class (CGS, 2003) B B A A B A B B B A A A B B -16- 4 Leighton 601579-005 4.1.1 Historical Seismicity Historically, the San Diego region has been spared major destructive earthquakes. The most recent earthquake on the Rose Canyon Fault Zone in San Diego occurred after A.D. 1523 but before Spanish arrived in 1769. Studies by Rockwell and Murbach (1999) indicate that the earthquake occurred A.D. 1650 + 125. Two additional earthquakes, the 1800 M6.5 and 1862 M5.9, may have also occurred on the Rose Canyon Fault Zone. However, no direct evidence of ground rupture within the Rose Canyon Fault Zone for those events was recorded. The site location with respect to significant past earthquakes (greater than or equal to M5.0) is shown on the Historical Seismicity Map in Appendix D. The historic seismicity for the site presented in Appendix D, indicates that the maximum historical site acceleration from 1800 to present is estimated to be 0.35g to 0.40g. 4.2 Seism icitv The site can be considered to lie within a seismically active region, as can all of Southern California. In 2008, the California Geological Survey published a fault model update for the State of California (WGCEP, 2008). The model was part of the USGS effort to update the United States National Seismic Hazard Maps. We regard that fault model update to reflect the best available science for modeling of the seismic hazard at the site. The following Table 3 summarizes the revised fault magnitudes and interconnected fault segments that were added to the model. -17-Leighton 601579-005 Table 3 Seismic Parameters for Nearby Active Faults (CGS, 2008) Fault Newport- Inglewood Connected Rose Canyon Newport- Inglewood (offshore) Elsinore Connected Elsinore (Temecula) Elsinore (Julian) Palos Verdes Connected Coronado Bank Elsinore (Glen Ivy) San Joaquin Hills Earthquake Valley San Jacinto Connected San Jacinto- Anza San Jacinto- San Jacinto Valley San Jacino- Coyote Creek Newport- Inglewood (L.A. Basin) Chino-Central Avenue (Elsinore) Geometry (CGS, 2003) Right Lateral Strike Slip Right Lateral Strike Slip Right Lateral Strike Slip Right Lateral Strike Slip Right Lateral Strike Slip Right Lateral, Strike Slip Right Lateral, Strike Slip Right Lateral, Strike Slip Right Lateral Strike Slip Reverse, Blind Thrust Right Lateral, Strike Slip Right Lateral, Strike Skip Right Lateral, Strike Slip Right Lateral, Strike Slip Right Lateral Strike Slip Right Lateral Strike Slip Right Lateral Reverse, 65SW Closest Distance from Fault to Site Miles 7.4 7.4 8.4 20.3 20.3 20.3 23.3 23.3 32.3 37.4 40.4 44.9 44.9 44.9 47.8 48.2 48.2 Kilometers 11.9 11.9 13.5 32.7 32.7 32.7 37.5 37.5 52.0 60.2 65.0 72.3 72.3 72.3 77.0 77.5 77.6 Maximum Magnitude by Ellsworth-B 7.5 6.9 7.0 7.78 7.07 7.35 7.7 7.4 6.89 7.1 6.8 7.80 7.28 7.04 7.03 7.2 6.7 by Hans & Bakun, 2002 7.5 6.7 6.8 7.85 6.89 7.28 7.7 7.3 6.67 6.9 6.6 7.88 7.17 6.85 6.85 1.0 1.0 Fault Class CGS, 2008 B B B A A A B B A B B A A A A B B -18-Leighton 601579-005 We have performed a site-specific evaluation of the peak ground acceleration associated with the Design Earthquake Ground Motion utilizing the earthquake ground motion estimation software developed by RISK Engineering (EZ-FRISK 7.32a). Next Generation Attenuation (NGA) relationships of Boore-Atkinson (2008), Campbell-Bozorgnia (2008), and Chiou-Youngs (2008) were considered in the analysis along with a Vs30 of 400 m/s and a Z2.5 of 0.2 km (depth to rock with a shear wave velocity of 2,500 m/s). Based on our site-specific deterministic seismic hazard analysis (DSHA), a ground motion of 0.56g corresponding to the 84th percentile deterministic ground motion was calculated for the site. Based on our probabilistic seismic hazard analysis (PSHA), ground motions of 0.30g and 0.45g corresponding to two-thirds of the 2,475-year event and the 2,475-year event were calculated. For a rock site, such as for the location of the water tank east of the site, ground motions of 0.26 and 0.39g were calculated for the two-thirds of the 2,475 year and the 2,475 year event. The site-specific MCE response spectrum was compared to the USGS 2008 Seismic Hazard Maps. Comparison to the USGS PSHA is similar in that they both utilize the 2008 California fault model and the same NGA relationships. The current web-based software is preset to a Z2.5 of 2.5km, compared to 0.2km for the site-specific analysis. To account for near-fault effects, both spectra have been corrected to represent the maximum rotated component, including average directivity effects. The following table presents parameters for the Maximum Considered Earthquake and the Design Earthquake ground motions based on the 2008 USGS Seismic Hazard Maps and site specific hazard analysis based on the 2008 update of the US National Seismic Hazard Maps. For comparison, the parameters from the 2002 mapped values are also included. Table 4 Ground Motion Parameters Seismic Event DE MCE 2002 USGS Site Class C PGA = 0.30g Mw = 6.93 PGA = 0.30g Mw = 6.93 2008 USGS Vs3o = 400m/s PGA = 0.30g MW = 6.64 PGA = 0.45g MW = 6.64 Site Specific Vs30 = 400 m/s PGA = 0.30g Mw = 6.65 PGA = 0.45g Mw = 6.65 ASCE 7-05 states that the site-specific SMS and SMI are determined from the lesser of the deterministic and probabilistic analysis. The Maximum Considered Earthquake (MCE) and the Design Earthquake (DE) ground motions are governed by probabilistic seismic hazard analysis as those events are considered the lesser of the probabilistic and deterministic seismic hazard analyses. -19-Leighton 601579-005 4.2.1 Building Code Seismic Parameters The effect of seismic shaking may also be mitigated by adhering to the California Building Code or state-of-the-art seismic design parameters of the Structural Engineers Association of California. The following geotechnical design parameters have been determined in accordance with the 2007 California Building Code (CBSC, 2008) and the USGS Ground Motion Parameter Calculator (Version 5.0.9): Table 5 2007 CBC Seismic Design Parameters Site Class Site Coefficients Mapped Spectral Accelerations Site Modified Spectral Accelerations Design Spectral Accelerations C Fa Fv Ss Si SMS SMI SDS SDI 1.0 = 1.369 = 1.135g = 0.43 Ig - 1.135g = 0.591g = 0.757g = 0.394g Since the mapped spectral response at 1-second period is less than 0.75g than all structures subject to the criteria in Section 1613A of the 2007 CBC are considered to be in Seismic Design Category D. 4.2.2 Site Specific Analysis Seismic Design Parameters To evaluate the affects on the seismic hazard based on the 2008 updated fault model, site-specific determination of the Maximum Considered Earthquake and the Design Earthquake seismic design parameters. For the analysis, the NGA Attenuation relationships were employed along with the methodology prescribed by DSA Bulletin 09-01 that became effective March 1, 2009. Corrections to consider the maximum rotated component and near fault effects were considered using the findings of Huang, Y., Whittaker, A.S., Luco, N., (2008). For the deterministic analysis, 84th percentile was considered in place of 150 percent of the mean deterministic event. -20-Leighton 601579-005 The following seismic design parameters have been determined from site-specific analysis. Table 6 Site-Specific Seismic Design Parameters Design Spectral Accelerations Site Modified MCE Spectral Acceleration SDS - SDI = SMS = SMI = 0.734g 0.428g UOlg 0.642g The spectra for the USGS and the site-specific evaluation parameters are judged to be similar, and confirm that the 2002 mapped values are appropriate for building design. It is noted that development of site-specific design parameters is not required since the site is beyond 10 km from the closest active fault. However, in light of the revised fault model for the State, the parameters are provided for the consideration of the structural engineer. 4.3 Secondary Seismic Hazards In general, secondary seismic hazards for sites in the region could include soil liquefaction, earthquake-induced settlement, lateral displacement, surface manifestations of liquefaction, landsliding, and seiches and tsunamis. These potential secondary seismic hazards are discussed below. 4.3.1 Shallow Ground Rupture Ground rupture because of active faulting is not likely to occur on site due to the absence of known active faults. Cracking due to shaking from distant seismic events is not considered a significant hazard, although it is a possibility at any site in California. 4.3.2 Liquefaction Potential According to the City of Carlsbad Geotechnical Hazards Analyses and Mapping Study (Leighton and Associates, 1992), the alluvium mapped along the west side of the CUSD property can be generally considered to be susceptible to liquefaction. Additional site-specific investigations have been performed in this report, and the results presented herein. -21-Leighton 601579-005 Liquefaction and dynamic settlement of soils can be caused by strong vibratory motion due to earthquakes. Research and historical data indicate that loose granular soils underlain by a near-surface ground water table are most susceptible to liquefaction, while the stability of most silty clays and clays is not adversely affected by vibratory motion. Because of the dense nature of the underlying formational material, the anticipated removal and recompaction of the surficial soils, the relatively fine grained nature (i.e. silts and clays) of the on-site soils, and lack of a shallow permanent groundwater table, it is our opinion that the potential for liquefaction or seismically induced dynamic settlement across the majority of the site due to the design earthquake is low. 4.3.3 Seismically Induced Landslides According to the City of Carlsbad Geotechnical Hazards Analysis and Mapping Study (Leighton and Associates, 1992), formational slopes on the site may be susceptible to seismic instability. Based our professional experience and slope stability analyses, seismic slope instability is not expected to be a constraining issue at this site for the currently planned campus layout. If the layout of the campus changes, additional seismic induced landslide analysis should be performed. The landslide mapped in the north portion of the property fields is recommended to be completely removed during the proposed site grading within the limits of the property. In addition, a buttress is proposed along the planned cutslope east of the baseball field. Our slope stability analysis performed for the site included seismic conditions and is further discussed in Section 5.1. 4.3.4 Seiches and Tsunamis Seiches are large waves generated in enclosed bodies of water in response to ground shaking. Tsunamis are waves generated in large bodies of water by fault displacement or major ground movement. Based on the inland location of the site and its distance from lakes or ponds, seiches and tsunamis are not a hazard to the site. -22-Leighton 601579-005 5.0 GEOTECHNICAL DESIGN CONSIDERATIONS Based on the geologic conditions outlined herein, our professional knowledge of the Carlsbad area, and our experience with projects having similar conditions, the pertinent geotechnical conditions impacting site development are presented below. Evaluation of the geotechnical design considerations and measures recommended to mitigate these adverse impacts are included in the following sections. 5.1 Slope Stability Geologic cross-sections through the proposed main campus (Cross-Section B-B'), the parking area (Cross-Section C-C'), and the landslide/proposed cut for the baseball field (Cross-Sections A-A' and D-D') were analyzed for deep-seated stability. Slope stability analyses were performed using the PC software program SlopeW. Idealized models were constructed using the geologic sections and soil strengths derived from laboratory test results, our observations, and professional judgments. The values used in the analysis are provided on Table 7. The slope stability calculations are presented in Appendix F. Table 7 Soil Strength Parameters Soil Type Artificial Fill Alluvium/Colluvium Santiago Formation (fine-grained soil) Santiago Formation- Anisotropic (mixed) Sheared Clay Bed Lusardi Formation/ Granitic Rock/Volcanics Friction Angle (degrees) 32 28 32 38 11 11 40 Cohesion (psf) 300 200 300 400 150 150 400 A seismic slope stability analysis was performed using displacement methods of Bray and Rathje (1998). For the displacement analysis, a peak acceleration of 0.26g from site-specific seismic hazard analysis was considered along with the calculated yield acceleration. The modal magnitude event of M6.65 along the Rose Canyon Fault Zone at a calculated modal -23- 4 Leighton 601579-005 distance of 12.5 kilometers was considered in the displacement analysis. The 2008 USGS deaggregation for rock PGA at the site is contained in Appendix F. Our deep-seated stability search routines considered circular and wedge-type failure surfaces analyzed using Bishop's modified method and Spencer's Method of limit equilibrium analysis. Surficial stability analysis was performed using the infinite slope model, the fill soil strengths in Table 2 and considering saturated depths of 3 feet. The results along Cross- Sections A-A' through E-E' are presented below. The slope stability calculations are presented in Appendix F. 5.1.1 Cross-Section A-A' Our analysis of the proposed cut slope along Cross-Section A-A' indicated a static factor of safety of less than 1.5. Accordingly, a buttress was designed to improve the stability of the slope along Cross-Section A-A'. Based on the construction of a buttress with an 100-foot wide keyway (135 feet along skew of section) and a 1.5:1 (horizontal to vertical) buttress backcut inclination, the static factor of safety along the cross-section was found to be at least 1.5. Seismic stability analysis of the buttressed configuration indicated a yield acceleration of 0.12g and a displacement of 8.3 cm. Recommendations concerning the buttress are presented in Section 7.3. 5.1.2 Cross-Section B-B' Our stability analysis considering static properties and loading conditions indicated a factor-of-safety of at least 1.5 to resist deep-seated instability along the cross- section. Our seismic slope stability analysis indicated a yield acceleration of 0.20g and a corresponding displacement of less than 1 centimeter (cm). 5.1.3 Cross-Section C-C' Our stability analysis along Cross-Section C-C', considering static properties and loading conditions, indicated a factor-of-safety of at least 1.5 to resist static deep- seated instability. Seismic slope stability analysis indicated a yield acceleration of 0.12g and a corresponding displacement at 9 cm. 5.1.4 Cross-Section D-D' Our analysis of the proposed cut slope along Cross-Section D-D' indicated a static factor of safety of less than 1.5. Accordingly, a buttress was designed to improve the stability of the slope along Cross-Section D-D'. Based on the construction of a "24~ Leighton 601579-005 buttress with an 80-foot wide keyway and a 1.5:1 (horizontal to vertical) buttress backcut inclination, the static factor of safety along the cross-section was found to be at least 1.5. Seismic stability analysis of the buttressed configuration indicated a yield acceleration of 0.12g and a displacement of 8 cm. Recommendations concerning the buttress are presented in Section 7.3. 5.1.5 Cross-Section E-E' Cross-Section E-E' was performed to evaluate the overall stability of the highest retaining wall. Based on that analysis we calculate a static overall factor of safety of 1.5, and a global seismic displacement of less than 1 cm. 5.1.6 Surficial Slope Stability The strength parameters presented on Table 2 were used for our surflcial stability analysis. Based on our analysis and professional experience, we anticipate that the planned slopes will generally perform adequately. Erosion and/or surficial failure potential of slopes may be reduced if the following measures are implemented during design and construction of the subject slopes. We recommend against the exclusive use of either highly expansive clayey soils or poorly-graded sands of the Santiago Formation. Highly expansive soils are generally known to be subject to surficial failures when exposed in slope faces. Clayey soils of the Santiago Formation weather, thereby generally losing integrity when exposed on slope faces. Poorly-graded sands utilized in slope faces may be subject to excessive erosion and rilling. A mixture of clayey soils and sandy soils is recommended to reduce overall expansion potential and slope erosion and increase surficial slope stability. We recommend that a mixture of soils be approved by the project geotechnical engineer prior to placement in fill slopes. Cut and fill slopes should be provided with appropriate surface drainage features and landscaped with drought tolerant, slope stabilizing vegetation as soon as possible after grading to minimize potential for erosion. Berms should be provided at the top of all slopes and drainage directed such that surface runoff on slope faces is minimized. -25-Leighton 601579-005 5.1.7 Natural Slopes Based on review of the mapped geology (Figure 4) and soil maps (Figure 6), the materials are generally comprised of Santiago Formation Materials overlain by developed soil. Overall, the slopes above the school site are at gradients of 4:1 (H:V) or flatter above the south and central portions of the site. The slopes above the north portion of the site are slightly steeper at 4:1 to 3-1/2:1. We have analyzed the surficial stability of the materials upslope using a slope gradient of 3-1/2:1 (horizontal:vertical) and soil strength parameters for colluvium. Based on our analysis, the natural slopes above the site possess a factor of safety of 1.5 for saturation depths of 3 feet. 5.2 Expansion Potential The anticipated expansion potential of the soils encountered on the site is described as follows: • Topsoil/Colluvium and Alluvium: Medium to very high expansion potential. The surficial soils overlying much of the site consist of sandy to silty clays with medium to very high expansion potential depending on the parent material and degree of weathering. Alluvial materials derived from the granitic rocks uphill to the east are expected to have a lower expansion potential relative to the topsoils and colluvial soils overlying the Santiago Formation. These alluvial soils having a lower expansion potential are located at the mouth of the tributary east-west drainage in the central portion of the site. • Santiago Formation: Low expansion potential for the silty sandstones, medium to high expansion potential for the sandy to clayey siltstones, and high to very high expansion potential for the claystones. These soils underlie the majority of the site and the highest expansion results are noted in the upper portion of the unit (i.e. generally above an elevation of approximately 100 to 120 feet within the central and western portions of the site). • Lusardi Formation/Granitic Rock: Very low expansion potential, however, siltstone beds in this unit may have a medium expansion potential. This is the predominant soil type in the elevated hillside areas on the east side of the property. Our subsurface exploration also encountered this rocky unit underlying the drainage area through the central portion of the site (beneath the proposed Gym/Lockers buildings). -26-Leighton 601579-005 5.3 Soil Corrosivity The soil corrosivity test results from this investigation indicate the onsite soils possess a negligible to severe soluble sulfate content; a less than threshold chloride content; and a moderate to severely corrosive level based on soil pH and resistivity test results. Laboratory testing of finish grade soils at-grade or in contact with concrete and/or buried metal conduits should be performed once site-specific plans are developed. A corrosion engineer should be contacted for design of measures to mitigate corrosion. -27- 4 Leighton 601579-005 6.0 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 during design and construction. • Based on our subsurface exploration and review of pertinent geotechnical reports, the site is underlain by surficial soils including undocumented and documented fills, topsoil, colluvium, alluvium, and landslide deposits. The bedrock units underlying the site include the Tertiary- aged Santiago Formation, Cretaceous-aged Lusardi Formation and Granitic rock basement, and the Jurassic-aged Santiago Peak Volcanics. • The undocumented fill, topsoil, colluvium, alluvium, landslide deposits, and weathered formational materials are considered unsuitable in their present state and will require removal and recompaction in areas of proposed development or future fill. • The claystone soils and topsoil/alluvial soils derived from the Santiago Formation were found to be moderately to very highly expansive. These expansive soils should either be removed where present within 5 feet of proposed foundations and/or finish pad grades and replaced with soil having a lower expansion potential or a post-tensioned or mat-type foundation design should be provided. Similar treatment (i.e. removal of the expansive soils and replacement with soils having a very low to low expansion potential) to a depth of 3 feet should be performed if expansive soils are present below other stress-sensitive improvements (e.g. concrete flatwork, etc). • Where present behind planned retaining walls, expansive soils should be removed within a distance equal to 1/2 the wall height and replaced with granular materials having a very low to low expansion potential. • The existing on-site soils appear to be suitable material for use as fill provided they are relatively free of rocks (larger than 8 inches in maximum dimension), organic material and debris. • Evidence for faulting was not encountered during our field investigation. Our review of the geologic literature (Appendix A) indicates there are no known major or active faults on or in the immediate vicinity of the site. Because of the lack of known active faults on the site, the potential for surface rupture at the site is considered low. • The main seismic hazard that may affect the site is ground shaking from one of the active regional faults. The nearest known active fault is the Rose Canyon Fault Zone, which is located approximately 7.4 miles (11.9 kilometers) west of the site. 28 Leighton 601579-005 Due to the lack of a permanent shallow ground water elevation, the age and relatively dense and fine-grained nature of the on-site soils, the potential for liquefaction and dynamic settlement of the site is considered very low. Minor seepage was encountered in several of our subsurface borings. In general, these seeps were noted where relatively permeable material, such as alluvium or weathered bedrock, was underlain by relatively dense, unweathered formational material. Ground water seepage conditions should be expected during site development where excavations extend through the alluvial materials to the formational contract. Recommendations to mitigate their conditions can be made on a case-by-case basis. Our slope stability analysis indicates the proposed cut slope on the east side of the basketball field will not have an adequate factor-of-safety. As a result, we recommend the slope be replaced with a buttress. -29-Leighton 601579-005 7.0 RECOMMENDATIONS 7.1 Earthwork We anticipate that earthwork at the site will consist of site preparation, removals of potentially compressible soil, excavation of cut material, fill placement, and trench excavation and backfill. We recommend that earthwork on site be performed in accordance with the following recommendations, California State Guidelines, and the General Earthwork and Grading Specifications for Rough-Grading (GEGS) included in Appendix G. In case of conflict, the following recommendations shall supersede those included as part of Appendix G. 7.1.1 Site Preparation Prior to the grading of areas to receive structural fill or engineered structures, the areas should be stripped of vegetation and cleared of surface obstructions, any existing debris, and potentially compressible material (such as undocumented fill soils, topsoil, colluvium, alluvium, landslide deposits, and weathered formational materials) as discussed in Section 7.1.2. Vegetation and debris should be removed and properly disposed of offsite. Holes resulting from the removal of buried obstructions which extend below finished site grades should be replaced with suitable compacted fill material. Areas to receive fill and/or other surface improvements should be scarified to a minimum depth of 12 inches, brought to at least 2 percent above the optimum moisture condition, and recompacted to at least 90 percent relative compaction (based on ASTM Test Method D1557). 7.1.2 Removal and Recompaction of Potentially Compressible Soils As previously discussed, portions of the site are underlain by potentially compressible soils that may settle under the surcharge of fill and/or foundation loads. These materials include undocumented fill soils, topsoil, colluvium, alluvium, landslide deposits, alluvium, and weathered formational material. Compressible materials not removed by the planned grading should be excavated to competent material, moisture conditioned or dried back (as needed) to at least a 2 percent above optimum moisture content, and then recompacted prior to additional fill placement or construction. The actual depth and extent of the required removals should be determined during the grading operations by the geotechnical consultant. However, estimated removal depths are summarized below. ~30~ Leighton 601579-005 Undocumented Fill Minor amounts of undocumented fill soil is anticipated on the site in various locations and is expected to consist of minor fills placed to create unimproved farm roads, end-dumped piles, and utility trench backfill. The thickest undocumented fill is mapped within the central drainage, where an earthen dam has been constructed. Undocumented fill soils, where encountered, should be completely removed to expose competent material. Colluvium/Topsoil Areas to receive fill which are on slopes flatter than 5:1 (horizontal to vertical) and where normal benching would not completely remove the topsoil should be excavated to competent formational material prior to fill placement. Topsoil is expected to be generally 2 to 4 feet thick on the site. Localized deeper accumulations may be encountered. Removal of colluvium will generally require overexcavation depths on the order of 4 to 6 feet, with some deeper deposits up to approximately 10 feet in depth in the lower areas of the site. Alluvium Alluvial materials are mapped within the main drainage on the west of the site, as well as through the east-west trending central drainage and minor tributary drainages on the south side of the site. All alluvial materials (estimated to be approximately 5 to 20 feet in thickness) should be removed from the central drainage underlying the proposed buildings and site structures and to a 1:1 projection outside the building or site structure limits. Elsewhere, including the main drainage area to the west of the stadium, athletic fields, and the western parking area, removals should be performed to competent material, to be determined by the geotechnical consultant during grading. These removals are expected to be on the order of 5 to 10+ feet, although deeper removals of highly weathered, soft, or loose material may be necessary. Landslide Debris The proposed grading is expected to remove a majority of the landslide mapped in the area of the proposed baseball field. Due to the inherent instability and compressible nature, the landslide material is not considered suitable for the support of improvements. Landslide deposits encountered within the grading limits should be completely removed, and any offsite portions left-in-place should be adequately supported by buttress-fill construction. -31-Leighton 601579-005 Weathered Formational Material Based on our professional experience, the amount of weathering of the upper portion of the formational materials on the site is dependent on a number of factors. However, we anticipate that the weathered portion that needs to be removed is on the order of less than 1 to 2 feet in thickness. 7.1.3 Excavations and Oversize Material Excavations of the weathered granite and on-site sedimentary and surficial materials may generally be accomplished with conventional heavy-duty earthwork equipment. Cuts in the granitics and localized cemented zones in the sedimentary units may be encountered that may require heavy ripping. Due to the relatively shallow excavations proposed in the areas of possible granitic exposure, the need for blasting is not anticipated. Relatively unweathered cobbles and boulders that may be present in the Lusardi Formation and produced during excavation of the granitics may also pose some handling problems, if encountered. These oversized rocks (i.e. rocks greater than 8 inches in maximum dimension) that are encountered should be placed as fill in accordance with the recommendations presented in Appendix G. 7.1.4 Fill Placement and Compaction The onsite soils are generally suitable for use as compacted fill provided they are free of organic material, debris, and rock fragments larger than 8-inches in maximum dimension. All fill soils should be brought to at least 2 percent above optimum moisture conditions and compacted in uniform lifts to at least 90 percent relative compaction based on laboratory standard ASTM Test Method D1557. Where material has a very low to low expansion potential, moisture conditioning may be performed to at least the optimum moisture content. The optimal 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 State of California guidelines, sound construction practices, and the General Earthwork and Grading Specifications for Rough Grading presented in Appendix G. -32-Leighton 601579-005 7.1.5 Expansive Soils and Selective Grading It anticipated that highly expansive soils will be encountered during site grading. We anticipate that the cuts for the proposed school buildings will be excavated into the surficial topsoils/colluvium and weathered Santiago formational material that generally has a medium to high potential for expansion. In order to reduce the impacts of these expansive soils on the proposed site improvements, selective grading and lot capping may be performed. If selective grading is proposed, the fill materials within 5 feet of building and wall foundations and within 3 feet of stress-sensitive improvements (concrete flatwork, etc.) should possess an expansion index less than 70. In addition, granular soils are recommended behind retaining walls, within a minimum distance equal to !/2 the wall height. Also, our expansion potential testing resulted in materials with ranging expansion index values between 0 to 105. If more highly expansive material is encountered beneath the proposed improvements, revised recommendations should be evaluated during grading. Based on our subsurface investigation of the site, soils having an expansion potential less than 70 are limited on the site. We anticipate that these soils are present as: 1) as alluvial soils derived from the granitic bedrock in the mouth of the east-west tributary canyon in the central portion of the site; 2) sandy soils derived from cuts into the Lusardi Formation on the flanks of the same east-west drainage; and 3) cuts into the lower portion of the Santiago Formation (generally below an approximate elevation of 100 to 120 feet msl) along the west side of the site. Selective grading of "lower" expansive soils would involve timing the grading operations so that lower expansion soils can be cut and then placed in the overexcavated building pads and/or stockpiling soil with lower expansion potential for later use near the surface of the graded improvement areas. 7.2 Cut/Fill Transition Conditions In order to reduce the potential for differential settlement in areas of cut/fill transitions, we recommend the entire cut portion of the transition building pads be overexcavated and replaced with properly compacted fill to mitigate the transition condition beneath the proposed structures. The overexcavation of the cut portion of the building pad should be a minimum of 3 feet below the bottom of the proposed building foundations. All overexcavations should extend at least 10 feet beyond the building perimeter. Deeper overexcavation may be necessary for buildings having split-levels. ~33~ Leighton 601579-005 7.3 Slope Stability Based on the current site development plan, fill slopes up to approximately 20 feet and cut slopes up to approximately 90 feet in height are planned at slope inclinations of 2:1 (horizontal to vertical) or flatter. Retaining walls up to 26 feet in height are anticipated. The following is provided based on our knowledge of site geotechnical conditions and the current development plans. These recommendations should be updated once final plans are developed. For evaluation of slopes, a factor of safety of 1.5 was utilized in the static design of the proposed slopes. For evaluation of the stability under seismic conditions, yield analysis was performed and mean displacement values were estimated utilizing the methodology of Bray J.D. and Rathje, E.M. (1998). For evaluation of the calculated displacements, the discussion presented by the Southern California Earthquake Center and the Los Angles Chapter of the American Society of Civil Engineers (SCEC/ASCE, 2002) was analyzed. The majority recommendation presented in that document was for a 5 cm median threshold displacement for critical slip surfaces from slope stability analyses that daylight within an occupied structure. The minority recommendation from that document was for a 15 cm threshold displacement for surfaces through occupied structures. The document also points out that the calculated displacement provide only an index of slope performance. Treated as an index, no additional loading is considered necessary in the structural design to accommodated the calculated displacement. In our analysis we have utilized the 5 cm displacement threshold for design and evaluation of slip surfaces that daylight into the proposed building pads and a 15 cm displacement threshold for sufaces that do not daylight in building pads. 7.3.1 Fill Slopes The materials anticipated for use in fill slope grading will predominantly consist of on-site soils derived from the surficial units and formational soils. Our analysis, assuming homogeneous slope conditions, indicates the anticipated fill slopes up to the maximum proposed height of 25 feet will have a calculated factor of safety of 1.5 or greater with respect to potential, deep-seated failure under static conditions. The proposed slopes should be constructed in accordance with the recommendations of this report, the attached General Earthwork and Grading Specifications for Rough-grading (Appendix G), and State of California guidelines. -34-Leighton 601579-005 The analyzed sections have calculated static factor of safety values at least 1.5. Calculated seismic displacements are below the threshold values of 5 cm and 15 cm for occupied structure intersecting slip surfaces and for surfaces daylighting beyond occupied structures. 7.3.2 Cut Slopes Engineering analysis of the proposed 2:1 cut slopes within the formational materials up to a maximum height of approximately 90 feet indicates the deep- seated stability of the slopes, in general, possess a static factor of safety in excess of 1.5 assuming the mitigation measures discussed in Section 5.1 and herein are implemented during grading. The analyzed sections have calculated static factor of safety values at least 1.5. Calculated seismic displacements are below the threshold values of 5 cm and 15 cm for occupied structure intersecting slip surfaces and for surfaces daylighting beyond occupied structures. Along Cross-Section C-C', revised slope stability analysis should be performed in future phases modify the grading to create a building pad to accommodate future phases of construction. If deformations are found to exceed the target value of 5 cm, stabilization in measures (e.g. tie-back anchors) may need to be incorporated in the site design for the building pad area. During grading, we recommend that the geotechnical consultant observe and geologically map all excavations including cut slopes during grading. The purpose of this mapping is to substantiate the geologic conditions anticipated in our analyses. Additional investigation and stability analysis may be required if unanticipated or adverse conditions are encountered during site grading. 7.3.3 Recommended Baseball Field Cut Slope Buttress Based on our slope stability analysis, the proposed cut slope on the east side of the baseball field will not possess an adequate factor-of-safety as designed. In order to provide a minimum factor-of-safety of at least 1.5, we recommend that the cut slope be replaced with a buttress. The buttress should have a key width of approximately 135 feet along Cross-Section A-A' and 90 along Cross-Section D-D'. The proposed key bottoms are shown along keyway on Plate 1 and Plate 3. The key bottom should be angled a minimum of 2-percent into the slope. The westerly facing backcut for the buttress should have a maximum slope inclination of 1.5:1 (horizontal to -35-Leighton 601579-005 vertical). Along the north side, the backcut will need to be steepened to stay within the property limits. To mitigate the presence of anticipated weak clay beds behind and below proposed site retaining walls, stabilization fills are recommended at the retaining walls in the baseball field and the upper tennis court area. Those keyways are also shown on Plates 1 and 3. To evaluate temporary stability during backcut construction, we performed stability analysis on the backcut configuration along Cross-Sections A-A' and D-D' (Appendix F). In an unsupported condition, we calculated factor of safety values of 1.05 and 1.16. Due to the potential for instability, we recommend the main buttress be constructed in segments or anchorage be installed to provide additional lateral support. For segmented construction, we recommend that the existing overburden be left in-place and that the keyway be constructed in 100-foot sections starting at the northwest end of the main keyway. Excavation from the next section should be placed as fill in the section where the keyway has been prepared and the buttress constructed as the excavation progresses along the keyway. As an alternative to the segmented grading of the keyway and where conditions allow, temporary slope tie- back anchors can be installed across the upper portion of the backcut to improve temporary stability, With this approach, an anchored grade beam would be installed on the backcut at an elevation approximately 30 feet below the existing ground surface. To attain a factor of safety of 1.3, a line load of 71 kips per lineal foot was calculated along Section A-A'. To accomplish this loading using post-tensioned tie- back anchors inclined at 15 degrees, we calculate a minimum unbounded length of 100 feet. Additional analysis is needed if this option is elected. Where constrained by property limits, anchorage may not be feasible. Prior to the placement of the fill, a subdrain system should be placed along the back of the buttress key and outletted on the northwest and of the key. Additional subdrains should be installed at 30-foot vertical intervals along the buttress backcut. Detail D of the General Earthwork and Grading Specifications presented in Appendix G provides recommendations concerning the buttress subdrains. 7.4 Control of Ground Water and Surface Water Ground water and/or seepage conditions were encountered during our current site investigation. The ground water is believed to be perched on the contact between the overlying alluvium and underlying bedrock units. As a result, to mitigate the potential for accumulation of a shallow perched groundwater condition, we recommend subdrains be installed after the removal of alluvial materials in the central east-west trending canyon, and for all retaining walls and buttress/replacement fill keys. The locations of the proposed -36- . . , .Leighton 601579-005 subdrains should be determined after additional plan review and/or during the site grading operations. Details C, D, and E of Appendix G provide recommendations concerning the subdrains. The control of ground water in a hillside development is essential to reduce the potential for undesirable surface flow, hydrostatic pressure and the adverse effects of ground water on slope stability. We recommend that measures be taken to properly finish grade the site such that drainage water is directed away from top-of-slopes and away from proposed structures. No ponding of water should be permitted. Drainage design is within the purview of the design civil engineer. Even with these provisions, our experience indicates that shallow ground water/perched ground water conditions can develop in areas where no such ground water conditions existed prior to site development, especially in areas where a substantial increase in surface water infiltration results from landscape irrigation. We recommend that an engineering geologist be present during grading operations to explore for future seepage areas and provide field recommendations for mitigation of future potential seepage. Because of the potential for instability, the clayey nature of the soils, and the terraced nature of the buildings and the site, much of the site is not considered appropriate for onsite storm water infiltration. While the lower alluvial drainage area along Cannon Road may be most appropriate geographically, we expect the soils to possess relatively low permeability. 7.5 Foundation and Slab Considerations Foundations and slabs should be designed in accordance with structural considerations and the following recommendations. 7.5.1 Conventional Foundation Design We anticipate that the proposed structure can be supported on compacted fill soils or formational material by isolated spread and/or continuous footings designed in accordance with the following criteria. The following recommendations assume that the soils encountered within 5 feet of the foundation/footing elevation have an expansion potential of less than 70. -37- 4 Leighton 601579-005 Table 8 Allowable Soil Bearing Values for Spread Footings Depth Below Lowest Adjacent Soil Grade (feet) 2* Allowable Soil Bearing Value for Isolated Continuous Footings (Minimum Width = Spread or = 1.5 feet) 3,500 psf * Minimum Depth of Embedment The above values are for dead plus live loads and may be increased by one-third for short-term wind or seismic loads. We recommend a minimum horizontal setback distance from the face of slopes for all structural 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 H/2, where H is the slope height (in feet). Please note that the soils within the structural setback area possess poor lateral stability, and improvements (such as retaining walls, sidewalks, fences, pavements, etc.) constructed within this setback area may be subject to lateral movement and/or differential settlement. Slabs on grade should be reinforced with reinforcing bars placed at slab mid- height. Slabs should have crack joints spacing's designed by the structural engineer. Columns should be structurally isolated from slabs. Slabs should be a minimum of 5 inches thick and reinforced with No. 4 rebars at 18 inches on center on center (each way). Underslab moisture proofing should be designed by the project architect considering the building finishes and uses. Additional guidance may be found in ACI 302.1R-04 (ACI, 2004) and ACI 302.2R-06 (ACI, 2006). All waterproofing measures should be designed by the project architect. 7.5.2 Settlement The recommended allowable bearing capacities are based on a maximum total and differential settlement of 1 inch and 3/4 inch, respectively, with all footings founded in competent formational material or all footings founded in compacted fill materials. Since settlements are a function 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. -38-Leighton 601579-005 7.5.3 Post-Tensioned Foundation Design For the proposed building pad areas which are underlain by expansive soils (i.e. an expansion index greater than 70 per ASTM D4829) or where otherwise elected, post-tensioned foundations should be designed in accordance with the preliminary design parameters presented in the following table and criteria of the 2007 California Building Code. These preliminary parameters should be verified at the completion of grading by testing of the building pad materials during grading. Table 9 Post-Tensioned Foundation Design Recommendations for Expansive Soils Design Criteria Center Lift Edge Lift ^m center Ym center ^m edge Ym^edge Differential Settlement: Expansion Index Very Low/Low (0-50) 9.0ft 0.46 in 4.8ft 0.78 in 3/4 inch Medium (51-90) 8.3ft 0.75 in 4.2ft 1.32 in 3/4 inch High (91-130) 7.0ft 1.09 in 3.7ft 1.99 in 3/4 inch The post-tensioned foundations and slabs should be designed in accordance with structural considerations. Continuous footings ribs or thickened edges with a minimum width of 18 inches and a depth of 24 inches below adjacent soil grade may be designed for a maximum allowable bearing pressure of 2,500 pounds per square foot. The allowable pressures may be increased by one-third when considering loads of short duration such as wind or seismic forces. The slab should also be designed for the anticipated loading using a subgrade modulus (K) value of 100 pounds per cubic inch. The slab subgrade soils underlying the post-tensioned foundation systems should be presoaked as indicated in Section 7.5.6 prior to placement of the moisture barrier and slab concrete. -39-Leighton 601579-005 7.5.4 Mat Foundation Design A soil modulus of 100 pounds per cubic inch is recommended for design of mat foundations. The mat foundation should be designed by the project structural engineer utilizing parameters outlined for post-tensioned slabs and an allowable bearing pressure of 1,000 psf. 7.5.5 Ribbed-Mat Foundation Design The proposed buildings may be supported by a conventionally-reinforced ribbed mat foundation that incorporates continuous or isolated spread footings. Design should conform to 2007 California Building Code Section 1805A.8. Spread footings should extend a minimum of 24 inches beneath the lowest adjacent finish grade. At these depths, footings may be designed for a maximum allowable bearing pressure 2,500 pounds per square foot (psf) if founded in properly compacted fill soils. The allowable pressures may be increased by one-third when considering loads of short duration such as wind, but not for seismic forces. The minimum recommended width is 18 inches for continuous footings and 24 inches for square or round footings. Additional design and construction information for the conventionally-reinforced ribbed mat foundation can be obtained in US Army Corps of Engineer, Technical Instructions (TI) 809-28 (USACOE, 1999). A soil modulus of 100 psi/inch is recommended for static design of mat foundation angular distortions. To accommodate differential settlement that could result from a major seismic event, mat or grade beam foundations should be designed by the project structural engineer for total and differential settlement. Total and differential settlements for footings designed in accordance with the above recommendations should be less than 1 and 3/4 inch, respectively. All floor slabs should have a minimum thickness of 5 inches and reinforced in accordance with the 2007 California Building Code using a plasticity index of 60. Slabs subjected to heavy loading may require greater thickness and increased reinforcement. We emphasize that it is the responsibility of the contractor to ensure that the slab reinforcement is placed at proper height. 7.5.6 Moisture Conditioning The slab subgrade soils underlying the post-tensioned and mat slabs should be moisture conditioned prior to placement of the moisture barrier and slab concrete. The subgrade soil moisture content should be checked by a representative of I • L.1Leighton 601579-005 Leighton Consulting prior to slab construction. The upper 12 inches of pad should be at least 2 percent above the optimum moisture content. 7.6 Earth and Hydrostatic Wall Pressures For design purposes, the following lateral earth pressure values for level or sloping backfill are recommended for walls backfilled with soils having a very low to the low expansion potential (i.e. an expansion potential less than 50 per ASTM Test Method D4829). The placement of soils having an expansion index less than 50 will likely require selective grading, the use of import material, or lime-treatment of the medium to highly expansive on-site soils. Table 10 Static Equivalent Fluid Weight (pcf) Conditions Active At-Rest Passive Level 35 55 300 (Maximum of 3 ksf) 2:1 Slope 60 80 150 (Sloping Down) Unrestrained (yielding) cantilever walls up to 15 feet in height should be designed for an active equivalent pressure value provided in Table 4 above. For the design of walls restrained from movement at the top (nonyielding) such as basement walls, the at-rest pressures should be used. Retaining walls may be considered as active if the top of the wall is free to move at least 0.002 times the wall height, where the wall height is measured from the top of the footing. 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 horizontal pressure of 75 psf which is in addition to the equivalent fluid pressure given above. For other uniform surcharge loads, a uniform horizontal 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 accumulate behind walls. A typical wall drainage design is provided in Appendix G. Wall backfill should be brought to optimum or above moisture content and 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 -41-Leighton 601579-005 with structural considerations. For all retaining walls, we recommend the previously discuss setback distance from the outside base of the footing to daylight. 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 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. To account for potential redistribution of forces during a seismic event, retaining walls that fall under requirements of 2007 CBC Sections 1802A.2.7, 1806A.1 and/or ASCE 7-05 Section 15.6.1 should also be analyzed for seismic loading. For that analysis, an additional uniform seismic pressure distribution as indicated in Figure 8 should be utilized. For walls greater than 15 feet in height designed to the values in Table 4, we recommend that the wall be backfilled with granular structural backfill material within distance equal to 1/2 the wall height. These materials should possess a minimum frictional strength of 36 degrees. In cases where the retaining wall above is founded over the wall backfill, vertical wall joints, should be added to allow flexibility where the wall spans the underlying wall backfill. 7.7 Segmental Block Retaining Walls If segmental retaining walls are constructed on the site, we recommend that these walls be designed utilizing NCMA (NCMA, 1998; NCMA, 2002; and NCMA, 2003) and FHWA Methologies (FHWA, 200la; FHWA, 200Ib). Final designs should be reviewed by this office. Because of the generally expansive nature of onsite soils, we anticipate that the walls will be backfilled with sandy import soils. Import soils should conform to NCMA material guidelines and possess a minimum internal friction angle (phi) of 32 degrees. Design should comply with the requirements of DSA Interpretation of Regulation IR-16- 3 (DSA, 2007). Should wall segments have an overall height of 20 feet, or greater, survey points are recommended on the wall at 50-foot intervals. Survey points should be established at the toe, mid-height, and top after wall construction is completed to monitor wall movement during the period over which the geogrid becomes active. -42-Leighton 601579-005 7.8 Geochemical Considerations Concrete in direct contact with soil or water that contains a high concentration of soluble sulfates can be subject to chemical deterioration commonly known as "sulfate attack." Soluble sulfate results (Appendix D) indicated a negligible to severe soluble sulfate content. We recommend that concrete in contact with earth materials be designed in accordance with Section 4 of ACI 318-08 (ACI, 2008). Minimum resistivity and pH tests were performed on representative samples of subgrade soils (Appendix D). Based on our results, the site soils have a moderate to very corrosive potential to buried uncoated metal conduits and concrete. We recommend measures to mitigate corrosion be implemented during design and construction. 7.9 Preliminary Pavement Design Considerations The appropriate pavement section depends primarily on the type of subgrade soil, shear strength, traffic load, and planned pavement life. Since an evaluation of the characteristics of the actual soils at pavement subgrade cannot be made at this time, we have provided the following pavement sections to be used for planning purposes only. The final subgrade shear strength will be highly dependent on the soils present at finish pavement subgrade. However, for preliminary planning purposes, we have assumed an R-value of 5 for the pavement subgrade soils, based on laboratory testing of representative soils (Appendix D). The preliminary pavement design sections have been provided on Table 5. Final pavement design should be evaluated based on R-value tests performed on representative subgrade soils upon completion of grading. Table 11 Preliminary Pavement Sections Pavement Loading Condition Auto Parking Areas Auto Driveways Main Driveways and Fire Access Lanes Traffic Index 4.5 5.0 6.0 R- Value = 5 Pavement Sections 3 inches AC over 8 inches Class 2 base 3 inches AC over 10 inches Class 2 base 3.5 inches AC over 1 3 inches Class 2 base For areas subject to truck loading (i.e., trash enclosures), we recommend a full depth of Portland Cement Concrete (PCC) section of 7.5 inches on 6 inches of Class 2 aggregate base with appropriate steel reinforcement and crack-control joints as designed by the project structural or civil engineer. We recommend that sections be as nearly square as possible. A mix that provides a 600 psi modulus of rupture should be utilized. The actual -43-Leighton 601579-005 pavement design should also be in accordance with City of Carlsbad and ACI criteria. All pavement section materials should conform to and be placed in accordance with the latest revision of the Greenbook and American Concrete Institute (ACI) codes and guidelines. Prior to placing the AC or PCC pavement section, the upper 12 inches of subgrade soils and all aggregate base should have relative compaction of at least 95 percent (based on ASTM Test Method D1557). Where expansive soils are present beneath PCC pavements, the subgrade compaction may be reduced to 90 percent. If pavement areas are adjacent to heavily watered landscape areas, we recommend some measure of moisture control be taken to prevent the subgrade soils from becoming saturated. It is recommended that the concrete curb separating the landscaping area from the pavement extend below the aggregate base to help seal the ends of the sections where heavy landscape watering may have access to the aggregate base. Concrete swales should be designed in roadway or parking areas subject to concentrated surface runoff. 7.10 Concrete Flatwork Concrete sidewalks and other flatwork (including construction joints) should be designed by the project civil engineer and should have a minimum thickness of 4 inches. For all concrete flatwork, the upper 6 inches of subgrade soils should be moisture conditioned to at least 4 percent above optimum moisture content and compacted to at least 90 percent relative compaction based on ASTM Test Method D1557 prior to the concrete placement. Due to the presence of medium to highly expansive soil on the site, the tennis and basketball courts should be designed with special considerations. These include a thicker concrete slab, placement of low expansive subgrade soils and/or moisture conditioning of the subgrade soils. 7.10.1 Basketball and Tennis Courts If the proposed basketball and tennis courts are planned to be asphalt concrete (AC) surfaces, we recommend that the AC section consist of 3 inches of asphalt concrete over 6 inches of aggregate base. Aggregate base materials and the upper 6 inches of the subgrade below the base should be compacted to at least 90 percent relative compaction based on ASTM D1557, at or above the optimum moisture content. The architect should also refer to the guidance of the American Sports Builders Association for additional considerations in the design of the proposed court surfaces. If concrete slabs courts are planned, we recommend that the slabs be post- tensioned. For post-tensioned slabs, we recommend that the slabs be designed -44-Leighton 601579-005 and constructed in accordance with the guidance of the Post-Tensioning Institute (PTI, 2006). Post-tensioned court slabs should be at least 4-1/2 inches thick. For post-tensioned slabs, we recommend 2 inches of moist sand be placed under the slab to reduce subgrade drag friction and aid in curing. If a moisture sensitive surface treatment is to be applied to the slab surface, the architect should consider placement of a plastic sheet between the slab and sand layer to mitigate moisture migration from the subgrade. 7.11 All Weather Track and Field Drainage Based on our experience on similar projects, the landscape architect typically provides details for surface drainage, subdrainage, and drain liners beneath the proposed improvements. The American Sports Builders Association provides additional guidance related to surface and subsurface drainage provisions. 7.12 Construction Observation and Plan Review Construction observation and testing during the site grading and excavation operations including field density testing of all compacted fill should be performed by a representative of this office so that construction is in accordance with the recommendations of this report. We recommend that the excavations be geologically mapped by the geotechnical consultant during grading for the presence of potentially adverse geologic conditions. Final development plans should also be reviewed and an additional geotechnical evaluation/grading plan review should be performed once the proposed development is finalized. Project grading and foundation drawings should be reviewed by Leighton Consulting, Inc. before excavation to see that the recommendations provided in this report are incorporated in the project plans. -45- 4 Leighton 601579-005 8.0 LIMITATIONS m 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 and test the subsurface conditions during grading and construction of the project, in order to confirm that our preliminary findings are representative for the site. -46-Leighton Figures 1 through 9 Base Map: AerialsExpress, GDT-Teleatlas Street Data, Spring 2008 Key Map: AerialsExpress, GDT-Teleatlas Street Data Spring 2005 Site Boundary APN 168-050-46 & 168-050-19 Project No. 601579-005Carlsbad Unified School District High School at College and Cannon Carlsbad. California SITE LOCATION MAP \\GIS\Drafting\B01579\005\GIS\of_09-06-02\Figure1-SiteLocatinMap.mxd Base Map: AerialsExpress, GDT-Teleatlas Street Data, Approximate Site Boundary APN 168-050-46 & 168-050-19 Parcel Boundaries (white) Carlsbad Unified School District High School at College and Cannon Carlsbad, California SITE RECONAISSANCE MAP Project No. 601579-005 Date June 2009 Figure 2 \\GIS\Draning\601579\005\GIS\of_09-06-02\Figure2-SiteReconMap.rnxd 1.000 2,000 ALE FEET Base Map: USGS Topographic Map, San Luis Rey Quadrangle, California 7.5' series, San Diego County, 1979 '<*>. ?>n 'A*^ f.<«•A- .''*, V, 'tr:••»«.--• \«'«> f^ .f^.'/ \ -..»''' X -'^v V. u / iter, Hank M,0 V ,7 U 1 - / ^:j J^*& J^f"! ~~ / Site Boundary APN 168-050-46 & 168-050-19 ,- CM"*° •* ^ «y^ 'Sintorosa f Country CI Lr. — :**, ; ->: \ ..*\ « ¥ • V < vff /•*."./•/ Carlsbad Unified School District High School at College and Cannon Carlsbad, California REGIONAL TOPOGRAPHY MAP Project No. 601579-005 Date June 2009 Figure 3 ftGIS\Drafting«01579\005\GIS\of_09-06-02\Figure3-RegTopoMap.mxd Qoa Old Alluvial Flood Plain Deposits Tsa Santiago Formation Kp Point Loma Formation Lusardi Formation Kg Granite, undivided SCALE FEET Base Map: USGS Topographic Map, San Luis Rey Quadrangle, California 7.5' series, San Diego County, 1979 MzU Metasedimentary and Metavolcanic Rocks Source:USGS, 2006, Geologic map of the Oceanside 30' x 60' quadrangle, California, Version 1.0, Open File Report 2006-1217 M.> #- Offsite Water Tank Site Boundary APN 168-050-46 & 168-050-19 r-s "^-^^ --fo- V-'- --: 'T{CDkf*' \ Carlsbad Unified School District High School at College and Cannon Carlsbad, California REGIONAL GEOLOGY MAP Project No. 601579-005 Date June 2009 Figure 4 \\GIS\Drafting\601579\005\GIS\of_09-06-02\Figure4-GeologyMap.mxd Base Map: AerialsExpress, GDT-Teleatlas Street Data, Spring 2005, COS Digital Fault Database, 2000 Approximate Location Carlsbad Unified School District High School at College and Cannon Carlsbad, California REGIONAL FAULT MAP \\GIS\Drafting\601579\005\GIStof_09-06-02\Figure5-RegFaultMapmxd Base Map: AerialsExpress, GDT-Teleatlas Street Data Spring 2008 USDA Soil Voer Data :http://websoilsurvey.nrcs.esda gov/app/ Topography: SANGIS Topographic Data, 1999 Legend AID I Altamont clay, 9 to 15 percent slopes AtE Altamont clay, 15 to 30 percent slopes CnE2 Cieneba-Fallbrook rocky sandy loams Huerhuero loam Las Flores loamy fine sand SbA Salinas clay loam Carlsbad Unified School District High School at College and Cannon Carlsbad, California Project No. 601579-005SOIL SURVEY MAP Date June 2009 \\GIS\Drafting\601579\005\GIS\of_09-06-02\Rgure6-SoilMap.mxcl Base Map:AerialsExpress, Spring 2008 Site Boundary APN 168-050-46 & 168-050-19 Carlsbad Unified School District High School at College and Cannon Carlsbad, California DAM INUNDATION HAZARD ZONE MAP Project No. 601579-005 Date June 2009 Figure 7 «3IS\Drafting\601579\005\GIS\of_09-06-02\Figure7-DamlnundationMap.mxd I ll I 100-Year Flood Hazard Zone 500-Year Flood Hazard Zone Base Map:AerialsExpress, Spring 2005 Site Boundary APN 168-050-46 & 168-050-19 Carlsbad Unified School District High School at College and Cannon Carlsbad, California FLOOD HAZARD ZONE MAP Project No. 601579-005 Date June 2009 Figure 8 \\GIS\Drafting\601579\005\GIS\of_09-06-02\FJgure8-FloodHazardMap.mxd uoiiipuoo oiLusies aAjpe do|3A3p oj IIBM am puiLjeq psjejodjooui aq Aem (LUBOjos6) suoisnpu] siqissajdiuoQ pejeauiBug :a)0jsj o S CO LU CO LU Oa:<io CO LU O LU O £ COO 1 1 ' 1 •1 1 ii ,V) 1 '1 '1 1 LJU LU> a; CO O O UL QC.z z>z> to \\ X & *> & LU O< If o ** c- (A 10 (0 (O w w ^ 0-3 TJ""_ c ww Icow CT11 i «SL W ^,_ Q) Q) u *• *~" X10 CO 3 Wo 3*= 5 X X\\ o 0) TJOO5= Cg> 'S50)•o o•o0)to(0 £a> o> o <u c IO ^ QJ UUt^l.S 8 ? 2 raQ. W UJ Q Q o Z3 COc: o o S cu COLUa: 13 CO COLU -a .c c sis I- wtt £ < .9> UJ X Lt LU 5 A Appendix A References 601579-005 APPENDIX A References American Concrete Institute (ACI), 2004, Guide for Concrete Floor and Slab Construction. , 2006, Guide for Concrete Slabs that Receive Moisture-Sensitive Flooring Materials. , 2008, Building Code Requirements for Structural Concrete (ACI 318-08) and Commentary, January 2008. American Water Works Association, 2005, AWWA D-100 Welded Carbon Steel Tanks for Water Storage. ASCE, 2005, ASCE/SEI 7-05, Minimum Design Loads for Buildings and Other Structures. Boore, D.M. and Atkinson, G.M., 2007, Boore-Atkinson NGA Ground Motion Relations for the Geometric Mean Horizontal Component of Peak and Spectral Ground Motion Parameters, Pacific Earthquake Engineering Research Center, PEER Report 2007/01. , 2008, Ground-Motion Prediction Equations for the Average Horizontal Component of PGA, PGV, and 5% Damped PSA at Spectral Periods between 0.015 and 10.05. Bray, J.D. and Rathje, E.M., 1998, Earthquake-Induced Displacements of Solid Waste Landfills in Journal of Geotechnical and Geoenvironmental Engineering, dated March 1998. Bryant, W.A., and Hart E.W., 2007, Special Publication 42, Fault Rupture Hazard Zones in California, Alquist-Priolo Earthquake Fault Zoning Act with Index to Earthquake Fault Zone Maps, Interim Revision 2007. California Code of Regulations, Title 5, Division 1, Chapter 13, Subchapter 1, Section 14010. California Building Standards Commission (CBSC), 2007 California Building Code, Based on 2006 International Building Code. California Department of Transportation (Caltrans), 2003, Corrosion Guidelines Version 1.0, California Department of Transportation Division of Engineering Services Materials and Testing Services Corrosion Technology, September 2003. California Education Code, Section 17213. A-l 601579-005 APPENDIX A (Continued) California Geological Survey (COS) formally California Division of Mines and Geology (CDMG), 1996a, Probabilistic Seismic Hazard Assessment for the State of California, OFR 96-08. , 1996b, Geologic Maps of the Northwestern Part of San Diego County, California, CDMG Open-File Report 96-02, Plate 1, Geologic Map of the Oceanside, San Luis Rey, and San Marcos 7.5' Quadrangles, San Diego County, California, Scale 1:24,000. , 1998, Maps of Known Active Fault Near-Source Zones in California and Adjacent Portions of Nevada, to be used with the 1997 Uniform Building Code, International Conference of Building Officials, dated February 1998. , 1999, Seismic Shaking Hazard Maps of California: Map Sheet 48. , 2000, CD-ROM containing digital images of Official Maps of Alquist-Priolo Earthquake Fault Zones that affect the Southern Region, CDMG CD 2000-003 2000. , 2003, Seismic Shaking Hazards in California, Based on the USGS/CGS Probabilistic Seismic Hazards Assessment (PSHA) Model, 2002 (revised April 2003), CGS website, http://www.consrv.ca.gov/cgs/rghm/pshamap/ pshamain.html. , 2007, Checklist for the Review of Engineering Geology and Seismology Reports for California Public Schools, Hospitals, and Essential Services Buildings - Note 48, dated October, 2007. , 2008, Guidelines for Evaluating and Mitigating Seismic Hazards in California, Special Publication 117a. Campbell, K.W. and Bozorgnia, Y., 2007, Campbell-Bozorgnia NGA Ground Motion Relations for the Geometric Mean Horizontal Component of Peak and Spectral Ground Motion Parameters, Pacific Earthquake Engineering Research Center, PEER Report 2007/02, dated May 2007. , 2008, NGA Ground Motion Model for the Geometric Mean Horizontal Component of PGA, PGV, PGD and 5% Damped Liner Elastic Response Spectra for Periods Ranging from 0.01 to 105. Chiou, B.S.J. and Youngs, R.R., 2007, Chiou and Youngs PEER-NGA Empirical Ground Motion Model for the Average Horizontal Component of Peak Acceleration and Pseudo- Spectral Acceleration for Spectral Periods of 0.01 to 10 Seconds, Interim Report for USGS Review, dated June 14, 2006 (Revised Editorially July 10, 2006). A-2 601579-005 APPENDIX A (Continued) , 2008, An NGA Model for the Average Horizontal Component of Peak Ground Motion and Response Spectra. Churchill, Ronald, 2003, Geologic Controls on the Distribution of Radon in California, dated January 25, 1992, revised December, 2003. Division of State Architect (DSA), 2007, IR 16-3 Earth Retaining Systems, revised September 18,2007. , 2008, DSA Bulletin 09-01, Use of Next Generation Altenuation (NGA) Relations, effective March 1,2009. Eisenberg, L.I., 1985, Pleistocene Faults and Marine Terraces, Northern San Diego County in Abbott, P.L., Editor, On the Manner of Deposition of the Eocene Strata in Northern San Diego County, San Diego Association of Geologists, Field Trip Guidebook, pp. 86-91. Eisenberg, L.I. and Abbott, P.L., 1985, Eocene Lithofacies and Geologic History, Northern San Diego County in Abbott, P.L., ed., On the Manner of Deposition of the Eocene Strata in Northern San Diego County: San Diego Association of Geologists, Field Trip Guidebook, pp. 19-35. Federal Highway Administration (FHWA), 200la, Mechanically Stabilized Earth Walls and Reinforced Soil Slopes - Design and Construction Guidelines, Publication No. FHWA NHI-00-043, dated March 2001. , 200 Ib, Corrosion/Degradation of Soil Reinforcements for Mechanically Stabilized Earth Walls and Reinforced Soil Slopes, Publication No. FHWA NHI-00-44, dated March 2001. FEMA, 2008, web site (https://hazards.fema.gov/femaportal/wps/portal/). Flores Lund Consultants, Inc., (FLC), 2009 Preliminary Grading Plan, digital file received March 28, 2009. GeoSoils, 2001, Preliminary Geotechnical Evaluation, Calavera Hills II, College Boulevard and Cannon Road Bridge and Thoroughfare District No. 4 B&TD City of Carlsbad, California, WO# 2863-A-SC, dated January 24,2001. — , 2002, Geotechnical Evaluation of the Robertson Ranch Property, Carlsbad, San Diego County, California, W.O. #3098-A1-SC, dated January 29,2002. A-3 601579-005 APPENDIX A (Continued) Hannan, D., 1975, Faulting in the Oceanside, Carlsbad and Vista Areas, Northern San Diego County, California in Ross, A. and Dowlens, R.J., eds., Studies on the Geology of Camp Pendleton and Western San Diego County, California: San Diego Association of Geologists, pp. 56-59. Huang, Y., Whittaker, A.S., and Luco, N., 2008, Maximum Spectral Demands in the Near-Fault Region. Jennings, C.W., 1994, Fault Activity Map of California and Adjacent Areas; California Division of Mines and Geology, Geologic Data Map 6, Scale 1:750,000. Kennedy, M.P., and Tan, S.S., 2005, Geologic Map of the Oceanside Quadrangle, California, California Geologic Survey, 1:100,000 scale. Leighton and Associates, Inc. (L&A), 1992, City of Carlsbad, Geotechnical Hazards Analysis and Mapping Study, 84 Sheets, dated November, 1992. , 2000, Preliminary Geotechnical Investigation, Cantarini Property, Carlsbad, California, Project No. 4980160-001, dated February 3, 2000. , 2001, Geotechnical Investigation for the Proposed College Boulevard Reach A and Cannon Road Reach 4 Extensions, Carlsbad, California, Project No. 990101-002, dated March 20,2001. , 2005, Geotechnical Investigation for the Proposed Maintenance Area, Rancho Carlsbad Mobile Home Park, Carlsbad, California, Project No. 040910-001, dated January 4,2005. , Undated, Unpublished In-House Geotechnical Data. Leighton Consulting, 2006, Environmental Hazard Survey Report for the Carlsbad Unified School District Proposed High School, Northeast of the Intersection of Cannon Road and College Boulevard, Carlsbad, California, Project No. 601579-001, dated November 8, 2006. , 2007, Final Preliminary Environmental Assessment (PEA) Report, Carlsbad Unified School District, Proposed High School at College and Cannon, College Boulevard and Cannon Road, Carlsbad, California, Project No. 601579-002, dated November 20, 2007, revised December 26,2007. A-4 601579-005 APPENDIX A (Continued) , 2008a, 60-Day Report/Boring Completion Letter, Project No. 601579-003, dated January 4, 2008. , 2008b, Revised Technical Memorandum Work Plan, Proposed High School at College and Cannon, Carlsbad, California, Project No. 601579-004, dated November 12, 2008. , 2009a, Final Supplemental Site Investigation Report, Carlsbad Unified School District, Proposed Additional High School, Cannon Road and College Boulevard, Carlsbad, California, Project No. 601579-004, dated May 15, 2009. , 2009b, Draft Removal Action Workplan, Carlsbad Unified School District, Proposed Additional High School, Cannon Road and College Boulevard, Carlsbad, California, Project No. 601579-004, dated May 2009. Lindvall, S.C., and Rockwell, T.K., 1995, Holocene Activity of the Rose Canyon Fault Zone in San Diego, California: Journal of Geophysical Research, V. 100, No. B12, p. 24, 124-24, 132. Miller, C.D., 1989, Potential Hazards from Future Volcanic Eruptions in California: U.S. Geological Survey Bulletin 1847, Plate I, Scale 1:500,000, http://vulcan.wr.usgs.gov. National Concrete Masonry Association (NCMA), 1998, Segmental Retaining Walls-Seismic Design Manual, First Edition, NCMA Publication No. TR160. , 2002, Design Manual for Segmental Retaining Walls, Second Edition, Third Printing NCMA Publication No. TR127A. , 2003, Segmental Retaining Wall Drainage Manual, NCMA Publication No. TR204. Post Tensioning Institute, 2004, Design of Post Tension Slabs-on-Ground, Third Edition , 2006, Design and Construction of Post-Tensioned Sport Courts, First Edition, , 2007, Addendum No. 1 to the 3rd Edition of the Design of Post-Tensioned Slabs-On- Ground, May 2007. , 2008a, Standard Requirements for Analysis of Shallow Concrete Foundations on Expansive Soils, May 2008. —, 2008b, Standard Requirements for Design of Shallow Concrete Foundations on Expansive Soils, May 2008. A-5 601579-005 APPENDIX A (Continued) iM ,.|W , 2008c, Addendum No. 2 to the 3rd Edition of the Design of Post Tensioned Slabs-on- Ground, May 2008. •»m u RISK Engineering, Inc., 2009, EZ-FRISK Version 7.32a. "* Rockwell, T.K., and Lindvall, S.C., 1990, Holocene Activity of the Rose Canyon Fault in San «* Diego, California, Based on Trench Exposures and Tectonic Geomorphology; Geological Society of America, Abstracts with Programs. m , 1991, Minimum Holocene Slip Rate for the Rose Canyon Fault in San Diego, ^ California in Environmental Perils, San Diego Region: San Diego Association of Geologists, p. 37-46. „, Rockwell, T.K., and Murbach M., 1999, Holocene Earthquake History of the Rose Canyon Fault Zone: Final Technical Report Submitted for USGS Grant No. 1434-95-G-2613, 37pp. <•« Roesling Nakamura Terada Architects (RNT), 2008, Preliminary Site Plan, digital file, undated, received January 21, 2008. — San Diego, City, 2004, Corrosion Control, Chapter 6 of the City of San Diego Sewer Design Guide, ^ dated October 2004. SCEC/ASCE, 2002, Recommended Procedures for Implementation of DMG Special Publication „. 117 Guidelines for Analyzing and Mitigating Landslide Hazards in California, dated June 2002. ** Tan, S.S., and Kennedy, M.P., 1996, Geologic Maps of the Northwestern Part of San Diego County, California: California Division of Mines and Geology, DMG Open-File Report 96- "" 02, 2 Plates. m Tan, S.S., and Giffen, D.G., 1995, Landslide Hazards in the Northern Port of the San Diego Metropolitan Area, San Diego County, California, Landslide Hazard Identification Map No. ** 35, Division of Mines and Geology, Open-File Report No. 95-04. «w The Planning Center, 2008, Water Tank Risk Assessment for Carlsbad High School #2, dated April ** 2008. •IK Treiman, J.A., 1984, The Rose Canyon Fault Zone: A Review and Analysis, California Division of Mines and Geology, Funded by Federal Management Agency Cooperative Agreement - EMF-83-K-0148. A-6 601579-005 APPENDIX A (Continued) , 1993, The Rose Canyon Fault Zone, Southern California: California Division of Mines and Geology, Open-File Report 93-2, 45p. United States Army Corps of Engineer (USACOE), 1999, Technical Instructions TI 809-28: "Design and Construction of Conventionally Ribbed Mat Slabs", dated September 15, 1999. United States Department of Agriculture, 1953, Aerial Photographs, Flight AXN-8M, Numbers 69 and 70, scale approximately 1:20,000, dated April 11, 1953. United States Geological Survey Topographic Map, 1997, San Luis Rey, 7.5-Minute Quadrangle USGS 1997. Weber, F.H., 1982, Recent Slope Failures, Ancient Landslides and Related Geology of the Northern-Central Coastal Area, San Diego County, California: California Division of Mines and Geology, Open File Report 82-12LA, 77 p. Wilson, K.L., 1972, Eocene and Related Geology of a Portion of the San Luis Rey and Encinitas Quadrangles, San Diego County, California: Master Thesis, University of California at Riverside, 123 p. Working Group of California Earthquake Probabilities, (WGCEP), 2008, The Uniform California Earthquake Rupture Forecast, Version 2 (UCERF2). Ziony, J.I., and Yerkes, R.F., 1985, Evaluating Earthquake and Surface-Faulting Potential in Ziony, ed., 1985, Evaluating Earthquake Hazards in the Los Angeles Region - An Earth - Science Perspective: U.S. Geological Survey, Professional Paper 1360, pp. 43-91. A-7 B Appendix B Small Diameter Boring Logs (Borings HB-1 to HB-10) Large Diameter Boring Logs (Borings B-l to B-5) Test Pits (Trenches T-l through T-26) from Current Investigation GEOTECHNICAL BORING LOG KEY Date Project Drilling Co. Hole Diameter Elevation Top of Elevation KEY TO BORING LOG GRAPHICS Sheet 1 of 1 Project No. Type of Rig Drive Weight Location Drop ElevationFeet\ SAMI S S R R B B T T 5*-Is o — 7 20— 25 — O Q-O* O ffli* ~ _~~ 1 //'Aw t » y''/ffl "•fY ' 0 [|\J-%' '•Q*'.'. '. . >/Jf/ '•;. *ss' §*§§AttitudesJU >LE TYPES: PUT SPOON ING SAMPLE ULK SAMPLE UBE SAMPLE ozo> Q. mV) B-l C-l G-l R-l SH-1S-l <nO Ol£ CD CD Q. '55Cv-0)0DO. 1_ Q MoistureContent, %w"'! CO Q™"J CO"*^ CL CH OL ML MH ML-CL GW GP GM GC sw SP SM SC DESCRIPTION Logged By Sampled By Asphaltic concrete Portland cement concrete Inorganic clay of low to medium plasticity; gravelly clay; sandy clay; siltv dav: lean clav Inorganic silt; clayey silt with low plasticity Inorganic silt; diatomaceous fine sandy or silty soils; elastic silt Clayey silt to silty clay Well-graded gravel; gravel-sand mixture, little or no fines Poorly graded gravel; gravel-sand mixture, little or no fines Clayey gravel; gravel-sand-clay mixture Well-graded sand; gravelly sand, little or no fines Poorly graded sand; gravelly sand, little or no fines Silty sand; poorly graded sand-silt mixture Bedrock Ground water encountered at time of drilling Bulk Sample Core Sample Grab Sample Modified California 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 TestsTYPE OF TESTS: ^j^ G GRAB SAMPLE DS DIRECT SHEAR SA SIEVE ANALYSIS ^fcS^ SH SHELBY TUBE MD MAXIMUM DENSITY AT ATTERBURG LIMITS '3BE' CN CONSOLIDATION El EXPANSION INDEX ^&&f CR CORROSION RV R-VALUE ^T LEIGHTON GEOTECHNICAL BORING LOG H-1 12-27-07Date Project Drilling Co. Hole Diameter Elevation Top of Hole CUSD/Cannon Road and College Boulevard Pacific Drilling Sheet _J of 1 Project No. Type of Rig 601579-003 MARL M5 7" 102' Drive Weight Location 140 pound hammer Drop 30" Northeast Stadium o '•g*«0>«"- UJ 100 95 90 85- 80- 75- S - : c - - in 1 ^ - - - 25— ->/\ o 9-0°2-io N S _• . '• '•'. • ".' *.' * . • • • • • •'• /. *• * '• •• .' •• •; ,*. . Ill #//y? <$i I /*y/ '% % W. • /v." • inCD•a 31 SAMPLE TYPES: S SPLIT SPOON R RING SAMPLE B BULK SAMPLE oz CD a. COOT S-l R-l S-2 S-3 WO 0^OQa>Q. 24 12 25 50/5" 4-1'35 QQ. I_ ~s£t-3c</>« '5cs°o WOT 59•=OT. aj2- SM sc SC/CL sw DESCRIPTION Logged By DB Sampled By DB UNDOCUMENTED ARTIFICIAL FILL (Afu) @ 0'-8': Silty medium SAND: Brown, damp to moist, roots @ 5': Silty medium SAND: Brown, damp, medium dense; poor recovery QUATERNARY ALLUVIUM (Gal) @ 10': Clayey SAND: Brown, moist to wet, loose; no recovery; medium grained @ 15': Clayey SAND to sandy CLAY: Brown, moist to wet; cobble in shoe; sand is fine to medium grained @ 17': Drilling slowed; tighter material @ 20': Medium- to coarse-grained SAND: Light yellow-brown, damp, "\ very dense; oxidation stains; possible bedrock?; no ground water r \ noted; includes gravel clast / Total Depth = 20.75 Feet No ground water encountered at time of drilling Backfilled with bentonite on 12/27/07 «in0)I—i^0 0)S TYPE OF TESTS: ^fe G GRAB SAMPLE DS DIRECT SHEAR SA SIEVE ANALYSIS ,^^3/r SH SHELBY TUBE MD MAXIMUM DENSITY AT ATTERBURG LIMITS ^9K CN CONSOLIDATION El EXPANSION INDEX ^^&l T TUBE SAMPLE CR CORROSION RV R-VALUE "^F LEIGHTON CONSULTING, INC. GEOTECHNICAL BORING LOG H-2 12-26-07Date Project Drilling Co. Hole Diameter Elevation Top of Hole CUSD/Cannon Road and College Boulevard Pacific Drilling Sheet 1 of 1 Project No. Type of Rig 601579-003 MARL M5 131' Drive Weight Location 140 pound hammer Drop 30" Administration Building 6 1*gfl)gu- UJ 130- 125 120 115 110 105 IS Q _o Q.O <5 si S ino>•o 3 g< -wCmI 5 — kTyyyyyy/i 10— 15— vvyy/yyy/II \/ p • •/: •/• I *.* ••' ! JU SAMPLE TYPES: S SPLIT SPOON oz "5. (0OT B-l 2.5'-5' S-l R-l S-2 R-2 S-3 $ 00 o> Q. 16 59 47 56 46 '55CM-0)UQO. ^ 85.6 144.4 108.8 0,5^ R*<no> 'ocSOu 17.4 11.9 19.3 WOT TO • =£ CH CL SM CL SM/MI DESCRIPTION Logged By DB Sampled By DB TOPSOH, @ 0'-2.5': Light brown, moist to wet @ 2.5'-5': Change in color: Pale light brown to light gray ItKllAKV SAiNllAOU rUKMAIiUN lisa) @ 5': Silty CLAYSTONE: Pale greenish-gray, moist, stiff, moderately weathered, oxidation staining @ 10': Silty fine SANDSTONE: Light brown to light gray, damp, dense; moderate to strong, lensedquartz, oxidation stains @ 15': Silty medium SANDSTONE: Light brown, damp, dense; moderate, oxidation stains @ 20': Silty CLAYSTONE: Greenish-gray, damp, hard; moderately weathered; oxidation stains @ 25': Silty fine to medium SANDSTONE: Lightgray, damp, dense; oxidation stains; lower sample is: sandy SILTSTONE: light ^ greenish-gray, damp, hard; moderately weathered; oxidation stains ^_ Total Depth = 26.5 Feet No ground water encountered at time of drilling Backfilled with bentonite on 12/26/07 £V)0) »«-o 0)Q.>, EI,CR TYPE OF TESTS: ^fe G GRAB SAMPLE DS DIRECT SHEAR SA SIEVE ANALYSIS ^S9r R RING SAMPLE SH SHELBY TUBE MD MAXIMUM DENSITY AT ATTERBURG LIMITS ^^B> B BULK SAMPLE CN CONSOLIDATION El EXPANSION INDEX ^^5 T TUBE SAMPLE CR CORROSION RV R-VALUE ^T LEIGHTON CONSULTING, INC. GEOTECHNICAL BORING LOG H-3 12-26-07Date Project Drilling Co. Hole Diameter Elevation Top of Hole CUSD/Cannon Road and College Boulevard Pacific Drilling Sheet 1 of 1 Project No. Type of Rig 601579-003 MARL M5 7" 115' Drive Weight Location 140 pound hammer Drop 30" Fine Arts/Performing Arts Building 9 ElevationFeet1 * c 1 1rt- 105 100 95 90 Of S n u"i.™ O N s AttitudesII - 10— - 15 — _ - 20— - - 25— tn tScn 't'o'1"'U s •: ;':••*, ^ify5 » ^, C^ *• **" *•• i ••^••.^ :"• . rfc? • * * * dz 0> 0. reCO 2B-i , : +•» d£ CD aiD. 1pR-l 1 S-l ) . 56 \ 29 . R-2 1 50/6" H S-2 >? 50/4" %c*.0>UQQ. Q 110.6 MoistureContent, %15.7 9.0 5& CH ML sw-srv DESCRIPTION Logged By DB Sampled By DB COLLUVIUM/TOPSOIL @2.5'-5': CLAY: Brown, moist TERTIARY SANTIAGO FORMATION (Tsa)@ 5': Clayey sandy SILFSIONE: Pale light brown, damp; dense;moderately weathered with oxidation stains @ 10': Grades to medium to very coarse SANDSTONE, change indensity; medium dense; otherwise similar to above @12'-15': Difficult drilling @ 15': SANDSTONE with SILT: Pale orange-brown, damp, very dense; friable; interbed cobble, poor recovery @ 16'-20': Difficult drilling -\<fi) 20': Similar to above; less weathered; poor sample recovery /- Total Depth = 20.3 Feet No ground water encountered at time of drilling Backfilled with bentonite on 12/26/07 ype of Tests*~ SAMPLE TYPES: TYPE OF TESTS: ^jfc S SPLIT SPOON G GRAB SAMPLE DS DIRECT SHEAR SA SIEVE ANALYSIS ^^9r R RING SAMPLE SH SHELBY TUBE MD MAXIMUM DENSITY AT ATTERBURG LIMITS ^9£ B BULK SAMPLE CN CONSOLIDATION El EXPANSION INDEX ^^S T TUBE SAMPLE CR CORROSION RV R-VALUE ^T LEIGHTON CONSULTING, INC. GEOTECHNICAL BORING LOG H-4 Date 12-26-07 Project Drilling Co. Hole Diameter Elevation Top of Hole CUSD/Cannon Road and College Boulevard Pacific Drilling Sheet 1 of 1 Project No. Type of Rig 601579-003 MARL M5 7" 123' Drive Weight Location 140 pound hammer Drop 30" Performing Arts Building 9 * LU •=0)D-0 31 oz _0> a. 08 OT 0"-Tjru.CQo>a a.'5c5°O (0(0 DESCRIPTION Logged By Sampled By DB DB O 0> S: 120 . 5- 115 10— 110 15- 105 20- 100 25— 95 30- COLLlJyilJM/TqPSOIL @ 0'-4': Sandy CLAY: Brown, moist R-l 20 90.5 22.3 :L/CH TERTIARY SANTIAGO FORMATION (Tsa) @ 5': CLAYSTONE: Ci-eenish-gray, moist, very stiff; moderate to strong induration; oxidation stains fa>. 10': Similar to above S-l 20 R-2 78 108.4 15.0 SM ! 15': Silty fine SANDSTONE: Light gray and light brown, damp to moist, very dense; somewhat micaceous S-2 38 ML @ 20': SILTSTONE: Light gray and greenish gray, damp, hard; moderate cementation Total Depth = 21.5 Feet No ground water encountered at time of drilling Backfilled with bentonite on 12/26/07 SAMPLE TYPES: S SPLIT SPOON R RING SAMPLE B BULK SAMPLE T TUBE SAMPLE G GRAB SAMPLE SH SHELBY TUBE TYPE OF TESTS: DS DIRECT SHEAR MD MAXIMUM DENSITY CN CONSOLIDATION CR CORROSION SA SIEVE ANALYSIS AT ATTERBURG LIMITS El EXPANSION INDEX RV R-VALUE LEIGHTON CONSULTING, INC. tut GEOTECHNICAL BORING LOG H-5 Date 12-26-07 Project Drilling Co. Hole Diameter Elevation Top of Hole CUSD/Cannon Road and College Boulevard Pacific Drilling Sheet 1 of 1 Project No. Type of Rig 601579-003 MARL M5 7" 1 38' Drive Weight Location 140 pound hammer Drop 30" Library Building 5 ElevationFeeto Attitudesz 0)a m<n 0"-TTU.CDo)a. vi Cs-0)UQ a.MoistureContent, %WOT DESCRIPTION Logged By Sampled By DB DB Type of Tests135 5— 130 10- 125 120 115 25— 110 30- SAMPLE TYPES: S SPLIT SPOON R RING SAMPLE B BULK SAMPLE T TUBE SAMPLE S-l (JL COLLUynJM/TOPSOlL @ 0'-5': Sandy CLAY: Brown, moist TERTIARY SANTIAGO FORMATION (Tsa) @ 3': CLAYS I ONE: Greenish-gray, damp to moist, stiff; weathered with oxidation stains 15 94.6 17.1 SM 10': Silty SANDSTONE: Brown, light brown, damp, very stiff, very fine grained with trace coarse sand and gravel AT,DS,SA S-2 CL 15': CLAYSTONE: Greenish-gray, damp to moist, very stiff; moderate, oxidation stains 107.1 14.5 SM @ 20': Silty fine SANDSTONE: Light brown, damp, dense; oxidation stains Total Depth = 21.5 Feet No ground water encountered at time of drilling Backfilled with bentonite on 12/26/07 G GRAB SAMPLE SH SHELBY TUBE TYPE OF TESTS: DS DIRECT SHEAR MD MAXIMUM DENSITY CN CONSOLIDATION CR CORROSION SA SIEVE ANALYSIS AT ATTERBURG LIMITS El EXPANSION INDEX RV R-VALUE LEIGHTON CONSULTING, INC. GEOTECHNICAL BORING LOG H-6 Date 12-27-07 Sheet 1 of 1 Project CUSD/Cannon Road and College Boulevard Project No. Drilling Co. Hole Diameter 7" Elevation Top of Hole 84' Pacific Drilling Drive Weight Location Type of Rig 140 pound hammer Athletic Fields 601579-003 MARL M5 Drop 30"ElevationFeet80 75- 70 65 60 55- » n u J=o> Q-O O N S AttitudesM - : 15— 'aid'////////>*.' r 1 1 i •^;^^H- - - 20— - 25 — SAMPLE TYPES: oz 0) D. wCO B-l 0-4' S-l R-l S-2 MO 3° 0^CD Q) Q. 8 16 12 '55 (DODO. 1_ 93.2 MoistureContent, %26.1 COT55 $ CH CH/CL CL CH DESCRIPTION Logged By DB Sampled By DB QUATERNARY ALLUVIUM/COLLUVIUM@ 0'-4': CLAY: Dark brown, moist to wet @ 5': CLAY: Brown, moist, medium , 4" sandy clay TERTIARY SANTIAGO FORMATION fTsa) @ 10': CLAYSTONE: Light greenish-gray, moist, very stiff, moderately weathered; rusty stained veins throughout @ 15': Similar to above; still weathered, stiff Total Depth = 16.5 Feet No ground water encountered at time of drilling Backfilled with bentonite on 12/27/07 M ype of Testi- CN TYPE OF TESTS: ,-^te S SPLIT SPOON G GRAB SAMPLE DS DIRECT SHEAR SA SIEVE ANALYSIS ^^9P R RING SAMPLE SH SHELBY TUBE MD MAXIMUM DENSITY AT ATTERBURG LIMITS ^9ft- B BULK SAMPLE CN CONSOLIDATION El EXPANSION INDEX ^"^3 T TUBE SAMPLE CR CORROSION RV R-VALUE ^T LEIGHTON CONSULTING, INC. GEOTECHNICAL BORING LOG H-7 12-27-07Date Project Drilling Co. Hole Diameter Elevation Top of Hole CUSD/Cannon Road and College Boulevard Pacific Drilling Sheet 1 of 1 Project No. Type of Rig 601579-003 MARL M5 7" 122' Drive Weight Location 140 pound hammer Drop 30" Gym/Lockers Building 7 ElevationFeet120- 115 110 105 100 95- Q"- 0. - - 5 — — 1ftlu — - "~ - - - 20— - 25 — - -»A _o H13 N S " * *• * • •'.''• .; \ :'; '.• •* •* *••P '• .'•:•.'•:£ '•'p''.V. , • :'<£•: :v:# • • • •Attitudesjv o a> Q. (0CO B-l 2.5'-5' R-4 S-l R-2 S-2 <*-* 0"- CQoj Q. 76 50/6" 50/6" 50/4" i vuQO. ^Q 101.2 106.5 Moisture 1Content, % I11.4 10.4 id 'OJD. SM SW SP SW DESCRIPTION Logged By DB Sampled By DB TOPSOIL/COLLUVIUM @ 0'-2.5': Silty medium to coarse SAND: Red-brown, damp CRETACEOUS LUSARDI FORMATION (Kl) @ 2.5'-5': Coarse-grained SAND: Light brown, damp @ 5': Medium SANDSTONE: Light brown and light gray, damp, very dense; weak to moderate, oxidation stains @ 10': Similar to above; more weathered; change in color: light brown, include subangular mafic gravel clast @11': Difficult drilling @ 15': Similar to above; less weathered moderate; include largeangular mafic clasts, disturbed sample, poor recovery ^@ 18': No recovery, practical refiisal during drilling /- Total Depth = 18.3 FeetNo ground water encountered at time of drilling Backfilled with bentonite on 12/27/07 ype of Testsi- MD,EI,CR, DS SAMPLE TYPES: TYPE OF TESTS: .Jjjfc S SPLIT SPOON G GRAB SAMPLE DS DIRECT SHEAR SA SIEVE ANALYSIS ^St* R RING SAMPLE SH SHELBY TUBE MD MAXIMUM DENSITY AT ATTERBURG LIMITS ^9K B BULK SAMPLE CN CONSOLIDATION El EXPANSION INDEX ^^S T TUBE SAMPLE CR CORROSION RV R-VALUE ^^ LEIGHTON CONSULTING, INC. GEOTECHNICAL BORING LOG H-8 Date 12-26-07 Sheet 1 of 1 Project CUSD/Cannon Road and College Boulevard Project No. Drilling Co. Hole Diameter 7" Elevation Top of Hole 1 56' Pacific Drilling Drive Weight Location Type of Rig 140 pound hammer Classroom Building 2 601579-003 MARL M5 Drop 30"ElevationFeet155 150 145 140 135 130 11 ff\ u '-=0)Q-O (5 1 ,*•>Attitudesin ' ~~" / -; ic •yn - — 25— wm§.§ • ' JU SAMPLE TYPES: S SPLIT SPOON R RING SAMPLE B BULK SAMPLE T TUBE SAMPLE ^'///'%1 0z 0) a. re00 R-l B-l T-91 S-I R-2 S-2 CQo>0. 38 44 42 59 '5Cs-0>U00. Ui 98.6 90.5 96.6 MoistureContent, %21.1 16.3 22.6 '02. CH CL MH SM DESCRIPTION Logged By DB Sampled By DB COLLUVIUM/TOPSOIL @ 0': CLAY: Brown, moist TERTIARY SANTIAGO FORMATION (Tsa) @ 4': CLAYS 1 ONE: Brown, damp, hard; moderate to strong, yellow stains @ T-9': CLAY: Light brown and brown, moist @ 10': Silty CLAYSTONE: Greenish-gray, damp, hard; moderate oxidation stains @ 15': Clayey SILTSTONE, generally similar to above; change in color: from light gray to light brown @ 20': Silty fine-grained SANDSTONE: Light gray, damp, very dense; moderate to strong, oxidation stains Total Depth = 21.5 Feet No ground water encountered at time of drilling Backfilled with bentonite on 12/26/07 ype of TestsH EI,AT DS,AT,SA TYPE OF TESTS: .^fe G GRAB SAMPLE DS DIRECT SHEAR SA SIEVE ANALYSIS ^S^F SH SHELBY TUBE MD MAXIMUM DENSITY AT ATTERBURG LIMITS ^9E CN CONSOLIDATION El EXPANSION INDEX ^^9 CR CORROSION RV R-VALUE ^F LEIGHTON CONSULTING, INC. GEOTECHNICAL BORING LOG H-9 12-27-07Date Project Drilling Co. Hole Diameter Elevation Top of Hole CUSD/Cannon Road and College Boulevard Pacific Drilling Sheet 1 of Project No. Type of Rig _ 601579-003 MARL M5 7" 76' Drive Weight Location 140 pound hammer Drop 30" West of Stadium ElevationFeet75- 70- TO- 60 55 50 £*- & - O Q-O (5 *iiV ^AttitudesII - - - - - — _ -»n %4%% • "•'_•• 1 /y % v ;•/ 'l > *.' SAMPLE TYPES: S SPLIT SPOON R RING SAMPLE B BULK SAMPLE T TUBE SAMPLE \V •i • •. • •• 0z Q) Q. mCO R-l S-l R-2 S-2 R-3 Sj Q o"iC0o>Q. 11 17 59 40 37 'w Cl4-0)OQQ. ^ 107.1 107.6 99.1 Moistureon tent, %u 20.6 18.4 13.0 18^ CL CH CL SM CL ML/SM DESCRIPTION Logged By DB Sampled By DB QUATERNARY ALLUVIUM @ 0'-3.5': Sandy CLAY: Dark brown, moist to wet @ 3.5': CLAY: Brown, moist to wet @ 5': CLAY: Light brown, moist to wet, stiff @ 10': 12" Clayey SILT: Brown, moist, very stiff; includes 6" thick silt layer: light gray, damp, very stiff; yellow stains throughout @ 11': Highly weathered formational material TERTIARY SANTIAGO FORMATION (Tsa) @ 15': Silty fine-grained SAND: Light gray, damp to moist, dense; oxidation stains @ 20': CLAYSTONE: Greenish-gray, hard @ 25': Sandy SILTSTONE to silty SANDSTONE: Light greenish-gray, damp, hard M pe of Test>, DS,SA TYPE OF TESTS: ^fc G GRAB SAMPLE DS DIRECT SHEAR SA SIEVE ANALYSIS ^^90 SH SHELBY TUBE MD MAXIMUM DENSITY AT ATTERBURG LIMITS ^9F CN CONSOLIDATION El EXPANSION INDEX ^^5 CR CORROSION RV R-VALUE ^T LEIGHTON CONSULTING, INC. GEOTECHNICAL BORING LOG H-9 12-27-07Date Project Drilling Co. Hole Diameter Elevation Top of Hole CUSD/Cannon Road and College Boulevard Pacific Drilling Sheet 2 of Project No. Type of Rig _ 601579-003 MARL M5 7" 76' Drive Weight Location 140 pound hammer Drop 30" West of Stadium Elevation 1Feet 145 40 35 30 25- 20^ SAMF || -in 35— - 40— - 45— - *~. 55— _O Q-Oz° CD N S Attitudesou »LE TYPES: dz 0) a (0U) \ **•(00JO OlJL OQo)a. / 41 iCM-<DOa a. k.a MoistureContent, %wco— (> °5. ML DESCRIPTION Logged By DB Sampled By DB @ 30': Clayey SILTSTONE: Light greenish-gray, damp, hard, weak to moderate Total Depth = 31. 5 Feet No ground water encountered at time of drilling Backfilled with bentonite on 12/27/07 Type of TestsTYPE OF TESTS: ^ft& S SPLIT SPOON G GRAB SAMPLE DS DIRECT SHEAR SA SIEVE ANALYSIS J^&F R RING SAMPLE SH SHELBY TUBE MD MAXIMUM DENSITY AT ATTERBURG LIMITS ^9E B BULK SAMPLE CN CONSOLIDATION El EXPANSION INDEX ^^& T TUBE SAMPLE CR CORROSION RV R-VALUE ^^ LEIGHTON CONSULTING, INC. GEOTECHNICAL BORING LOG H-10 12-27-07Date Project Drilling Co. Hole Diameter Elevation Top of Hole CUSD/Cannon Road and College Boulevard Pacific Drilling Sheet 1 of 1 Project No. Type of Rig 601579-003 MARL M5 74' Drive Weight Location 140 pound hammer Drop 30" Parking Lot A 1*g$£"- IU 70- 65 60 55- 50 45- £%g-S Q"- - - c u JE a (5 N S W0)•Dai 13 - - - - 20— - 25— - in 9, JU SAMPLE TYPES: S SPLIT SPOON R RING SAMPLE B BULK SAMPLE T TUBE SAMPLE 6z "5. EreCO B-l 2.5'-5' S-l R-l S-2 *-•wo5° CQflj Q. 12 40 46 •a QQ. i_ Q 113.6 «5S 5="wa> '5c S°O 15.7 WOT _OT ML CH CL DESCRIPTION Logged By DB Sampled By DB QUATERNARY ALLUVIUM (Oal) @ 2.5'-5': Clayey SILT: Brown, light greenish-gray, moist TERTIARY SANTIAGO FORMATION (Tsa) @ 5': CLAYS IONL: Light greenish-gray, moist, stiff, moderate, oxidation stains @ 10': Similar to above; less weathered, hard @ 15': CLAYSTONE: Light greenish-gray, damp, hard, weak to moderate Total Depth = 16.5 Feet No ground water encountered at time of drilling Backfilled with bentonite on 12/27/07 £inV M-0 0) g;i- TYPE OF TESTS: ^jjfc G GRAB SAMPLE DS DIRECT SHEAR SA SIEVE ANALYSIS ^^9^ SH SHELBY TUBE MD MAXIMUM DENSITY AT ATTERBURG LIMITS ^9^ CN CONSOLIDATION El EXPANSION INDEX ^^S CR CORROSION RV R-VALUE ^^ LEIGHTON CONSULTING, INC. GEOTECHNICAL BORING LOG B-1 Date Project Drilling Co. 1-15-08 CUSD/Cannon Road and College Boulevard Pacific/Larive Drilling Sheet 1 of 1 Project No. Type of Rig 601579-003 im Hole Diameter 30" Elevation Top of Hole 152' Drive Weight Location #3500@0-25' #2400@ 25-55' #1300@55-85' Earthdrill 45L _ Drop 30" See Map ElevationFeet150 145 140 135 130 125- II - 5— 10— : 15— - ~ 20 - 25— o •So)9-°2-Jo N E x -. / ^ - >- ^f-" . ' - ' ,' • ~ ' .' , ' - , ^_ -~ " r~AttitudesC:N30-50\N 7SW ji» SAMPLE TYPES: S SPLIT SPOON R RING SAMPLE B BULK SAMPLE 6z "5.| to R-l R-2 *••WO CQaj Q. 7 6 '55 UitjQQ. ^Q MoistureContent, % |<ri~^3 DESCRIPTION Logged By BJO Sampled By BJO TOPSODL/COLLUVIUM @ 0-4.5': Brown silty CLAY, very moist; very soft; homogeneous color @2': Bottom of casing @ 4.5': Planar contact, looks to mimic bedding; sharp; southwest dip; , \ weathered 1-2" below j SANTIAGO FORMATION @ 5': Light gray sandy~5ILTS 1ONE with clay; damp to moist, stiff; abundant orange staining, along cross-bedded bands, common through 6' @ 6'-24': Light gray clayey to very fine sandy SILTSTONE; moist, very stiff; some dark orange-brown staining in pockets, tend to be silty fine-grained SAND; otherwise homeogenous throughout @ 7-9': Irregular zones of weak to moderate cementation, appear near-horizontal and possibly reflective of bedding @ 10': Sample is: Light bluish gray, clayey sandy SILTSTONE, to silty very fine SANDSTONE with clay; moist, very stiff/dense @ 15'-20': Orange staining less common @ 18': Rare gypsum-filled vein, short, subhorizontal @ 20': Sample is: Generally similar to above; orange-stained pockets no longer visible, unweathered Total Depth = 24 Feet Downhole Logged to 22 FeetNo Ground Water Encountered at Time of Drilling No CavingBackfilled with Native (Bentonite Plug at 23 to 25 Feet) Tamped to Total Depth ype of Testsf- TYPE OF TESTS: ^jjjfc G GRAB SAMPLE OS DIRECT SHEAR SA SIEVE ANALYSIS ^^9^ SH SHELBY TUBE MD MAXIMUM DENSITY AT ATTERBURG LIMITS ^9E CN CONSOLIDATION El EXPANSION INDEX ^i^5 T TUBE SAMPLE CR CORROSION RV R-VALUE ^F LEIGHTON CONSULTING, INC. GEOTECHNICAL BORING LOG B-2 Date 1-15-08 Project Drilling Co. CUSD/Cannon Road and College Boulevard Pacific/Larive Drilling Sheet 1 of Project No. Type of Rig _ 601579-003 Hole Diameter 30" Elevation Top of Hole 158' Drive Weight Location #3500@0-25' #2400® 25-55' #1300@55-85' Earthdrill 45L _ Drop 30" See Map o 2$Sx UJ 155 150 145-1**J 140 135 nn-LJ\f £•" 1- - - _ 10— - - 15 — — 20— — — 25— tfi •C O)0.0 5 W E ^ f \ r _-- / \(\ S,V • V / /" — -"s^^—/ \ ^f >,; .^y V / ^~ X* 1 "FA ,. , 4 .r •- (A •031 B:N45E 0-5SE J:N56E 55NW B:20-30E 2-4E O-XKn 7HPD.1N JVJ* /UC, 2-3SE J:N20E 70-75NW GB:N60- 80W"55SWJV SAMPLE TYPES: Oz 0)"5. raCO B-l R-l R-2 >Q mo> 0. 3 4 •iCK-0)O QQ. k. 0,3? -3"= '5cS°O (0- — o'it CH DESCRIPTION Logged By BJO Sampled By BJO TOPSOIL/COLLUYIUM @ 0-5': Light brown CLAY: very moist, soft @3.5': Bottom of casing SANTIAGO FORMATION@ 5': Weathered, near horizontal contact @ 6-9: Bulk sample of gray to slightly bluish gray clayeySILTSTONE, moist, stiff; some minor orange staining, generallyhomogeneous color @ 10': Local near horizontal to southeast dipping zone of partingsurfaces, possible generalized bedding @ 10': Sample is: Green-gray silty CLAYSTONE, moist, mediumstiff; sligntly weathered/fractured but generally tight; some rustystaining veins throughout sampler tip @ 13'-15': Some gypsum veins, short, irregular, tight; materialcontinues to be weathered and broken by short, unpolished fractures @ 15'-17': Bed of red-brown silty CLAYSTONE to clavey SILTSTONE layer; southeast dipping; abundant pockets/veins ofyellow-gray, clayey SILT (limonite?) @ 18 and 19': Some pinkish brown to light red-brown stained zones @ 20': Sample is: Green-gray silty CLAYSTONE, moist, mediumstiff; appears generally similar to 10' sample; some orange andbone-white-fifled veins are generally tight; otherwise unweathered @ 20'-23': Generally becomes less weathered fractured, with larger blocky CLAYSTONE, medium stiff and indurated @ 26.3'-26.5': Thin (3/4") wide band/bed of purple-brown silty fine SANDSTONE, dips very slightly; planar surface, continuous aroundhole @ 28': Rusty, wavy, but relatively long joint (1.5') @ 29-30': Short bedding, truncated by cemented zone to west,abundant manranese nxide/limonite stamina anH ovnsnm infill Tn I— "o V H AT,DS,SA TYPE OF TESTS: ^jfc S SPLIT SPOON G GRAB SAMPLE DS DIRECT SHEAR SA SIEVE ANALYSIS .^^S? R RING SAMPLE SH SHELBY TUBE MD MAXIMUM DENSITY AT ATTERBURG LIMITS ^9E B BULK SAMPLE CN CONSOLIDATION El EXPANSION INDEX ^^9 T TUBE SAMPLE CR CORROSION RV R-VALUE ^^ LEIGHTON CONSULTING, INC. GEOTECHNICAL BORING LOG B-2 Date 1-15-08 Project Drilling Co. Hole Diameter Elevation Top of Hole CUSD/Cannon Road and College Boulevard Pacific/Larive Drilling Sheet 2 of Project No. Type of Rig _ 601579-003 30" 158' Drive Weight Location #3500@0-25' #2400@ 25-55' #1300@55-85' See Map Earthdrill 45L _ Drop 30" 1*gggu. UJ 125- 120 115 110 105 100- *X $ ~tf\ - 35— — Af\4U — - - 45— - 50— - 55 — o Ho \N E \ \ / N ^^"r^ s*=& *sf*""', "-"^ •- '_ -' v>0)•oS1 S:N80E 10-15SE S/C:N59E 14SE GN75E 2-4SE Wf SAMPLE TYPES: S SPLIT SPOON 6z <o"a. mCO R-3 WO3 O 00 o>Q. 6 8(6") 'v>Cv-0)OQQ. W Q S55 cWO) '5cS°O »^ it DESCRIPTION Logged By BJO Sampled By BJO @ 30': Gray CLAYSTONE with silt; moist, medium stiff; tight but slightly broken by thin veins of orange to bone-white silty material; slightly pinkish coloration but generally similar to above; sampler tip is medium brown in color §32': Top of bedding plane shear zone 32.5'-34': Dark red-brown CLAYSTONE, very moist to wet, stiff but fractured; abundant polished surfaces dip gently to moderately southeast; predominant yellow-brown (limonite) infillings; seepage @ 34. T-34.6': Basal shear/contact with light yellow-brown silty to clayey fine SANDS; sharp, planar surface; continuous around hole; parallel to shear fabric above @ 34.5'-36.5': Yellow-gray to light yellow-brown fine sandy SILTSTONE with some clay; moist, stiff; sand is abundant but fine grained; lower contact is southeast dipping and unsheared @ 38'-39': Color transitions to light gray, still very fine sandy SILTSTONE, no clay; local cementation @ 40': Sample is: Blue-gray sandy SILTSTONE with clay, damp, \ hard; cemented; homogeneous color / Total Depth = 40 Feet Downhofe Logged to 37 Feet No Ground Water Encountered at Time of Drilling Seepage at 33 to 35 Feet No Caving Backfilled with Native Bentonite Plug at 20 to 25 Feet, 30 Feet, and 3 to 40 Feet Tamped to Total Depth 2 4-o 1- , TYPE OF TESTS: ^fe G GRAB SAMPLE DS DIRECT SHEAR SA SIEVE ANALYSIS J^S& R RING SAMPLE SH SHELBY TUBE MD MAXIMUM DENSITY AT ATTERBURG LIMITS ^^K- B BULK SAMPLE CN CONSOLIDATION El EXPANSION INDEX ^^9 T TUBE SAMPLE CR CORROSION RV R-VALUE ^T LEIGHTON CONSULTING, INC. GEOTECHNICAL BORING LOG B-3 1-16-08Date Project Drilling Co. Hole Diameter Elevation Top of Hole CUSD/Cannon Road and College Boulevard Pacific/Larive Drilling Sheet 1 of 1 Project No. Type of Rig 601579-003 30" 127' Drive Weight Location #3500@0-25' #2400® 25-55' #1300@55-85' Earthdrill 45L _ Drop 30" See Map IsfS UJ 125 120 110 105 100 f* — - « —*J — 10— _ - 15— - 20— 25 — tn O H(3 W E ^' A V • — • : — .' '. • "7^- "~S v " X _• -^/V-?^ I/)0)•O S1 JV SAMPLE TYPES: S SPLIT SPOON R RING SAMPLE B BULK SAMPLE 6z Q)a <o00 B-i r WO ^*- CQa> Q. J R-l 1 6 n B-2 . £"thCM-GOQQ. >. Q' 0,^ 3c'w« 'ocS°O Idit sw DESCRIPTION Logged By BJO Sampled By BJO TOPSOIL/COLLyVIUM @ 0-2.5': Brown silty to sandy CLAY, moist, soft; very plastic; few roots LUSARDI FORMATION @ 3'-5': Bag Sample: Light yellow-brown silty SANDSTONE; moist, dense; sand is generally fine with scattered medium to coarse grains @ 5': Sample is: Weathered Granitic Rock; oxidized quartz and feldspar, with some zones of mafic minerals; damp, stiff to hard @ 7-9': Bag Sample: Light yellow-brown silty SAND, damp; somewhat decomposed, but includes unweathered, subangular clasts of gravel to cobble-size material @ 9': Difficult digging, excavates slowly/practical refusal; possible \ granitic basement / Total Depth = 9 *eet Not Down hole Logged No Ground Water Encountered at Time of Drilling No Caving Backfilled with Native Soil Tamped to Total Depth 42«> ftM-o Vg TYPE OF TESTS: ^fc; G GRAB SAMPLE DS DIRECT SHEAR SA SIEVE ANALYSIS .^^9^ SH SHELBY TUBE MD MAXIMUM DENSITY AT ATTERBURG LIMITS ^9^ CN CONSOLIDATION El EXPANSION INDEX ^1^9 T TUBE SAMPLE CR CORROSION RV R-VALUE "^F" LEIGHTON CONSULTING, INC. GEOTECHNICAL BORING LOG B-4 •m Date 1-17-08 Project Drilling Co. Hole Diameter Elevation Top of Hole CUSD/Cannon Road and College Boulevard Pacific/Larive Drilling Sheet 1 of Project No. Type of Rig _ 601579-003 30" 161' Drive Weight Location #3500@0-25' #2400@ 25-55' #1300@55-85' Earthdrill 45L _ Drop 30" See Map 1*g$«"• HI 160- 155 150 145 140 135 §•»a"- - - 5 - - 10 — 15 — - - 20 — - 25 — — in _O w"° <5 W E ~- / ^ / " r ^y- f / V / / _ S>5^ - - ^ " ' *^.c (* "~"~ (A0)•a 3 1 J:N33E 65NW GB:N50- 60E 10SE S:N85W 35N jv SAMPLE TYPES: 6z Q>"a. reOT B-l B-2 WOSO^J~ CQva. •RC*.Q)OQ Q. ^ 0,35 3^ W^JOC5°O WOT O~^ |= DESCRIPTION Logged By BJO Sampled By BJO LANDSLIDE MATERIAL @0-1': Minor topsoil with scattered roots @ l'-3 1': Generally greenish gray silry CLAYSTONE to clayey SILTSTONE; damp to moist, medium stiff; easily excavated @3.9': Bottom of casing @ 8'-10': Irregular zone/bed of reddish brown siltv CLAYSTONE, moist, soft and broken; fractures sometimes filled with orange-stained fine sand pockets; some root hairs @ 10'- 15': Bag Sample: Greenish gray clayey SILTSTONE with some orange sandy SILT, damp, medium stiff @ 10': Generalized bedding attitude of undulatory, south to southeast dipping brown CLAYSTONE laminated with some fine sand, some gypsum crystals along surface @ 16'-17': Grades to greenish gray clayey SILTSTONE to silty CLAYSTONE, moist, stiff; some orange-staining along fracture surfaces @ 20'-25': Bag Sample: Greenish gray clayey SILTSTONE, moist, medium stiff; still block/indurated clasts throughout spoils; generally representative of material below @ 24.7': Rusty clay shear enters hole; lined with thin (1/8-1/4") of yellow-brown clay; polished, very weathered surface @ 27': Shear exits holes to north @ 28': Spoils include some gypsum veins through clayey SILTSTONE with orange-brown staining throughout; moist to very moist £(A 0) n- O <0J; EI,CR TYPE OF TESTS: ^fe S SPLIT SPOON G GRAB SAMPLE DS DIRECT SHEAR SA SIEVE ANALYSIS ^^HF R RING SAMPLE SH SHELBY TUBE MD MAXIMUM DENSITY AT ATTERBURG LIMITS ^9K B BULK SAMPLE CN CONSOLIDATION El EXPANSION INDEX ^i^S T TUBE SAMPLE CR CORROSION RV R-VALUE ^T LEIGHTON CONSULTING, INC. GEOTECHNICAL BORING LOG B-4 •m Date _ Project 1-17-08 set CUSD/Cannon Road and College Boulevard ng Co. Diameter 30" rtion Top of Hole 161' Pacific/Larive Drilling Drive Weight #3500@0-25' #2400® Location Sheet 2 of Project No. Type of Rig 25-55' #1300@55-85' See Map 3 601579-003 Earthdrill 45L Drop 30" 1*«s«"- UJ 130 125 120 115 110 105 ^ fli & ->A - ~ 35 — - 40— 45— - — 50— 55— ~_ £(\ 0 •C OQ-Os° O l/tf E .. _. • r~Jit '•-i f i*~~^~ ; . • - • . - • — - ~ • ~ - 0 "Y • 0) I S RS:N23W 6-8SW B/C:N74E 5-7SE uu SAMPLE TYPES: dz "5. mCO R-l R-2 R-3 D AK.-4 WOs O 0"- DQo>0. 4 6 7 Bounce % CH-0)O00. U. 2s: '5c O <o--r ^d CO*" CH DESCRIPTION Logged By BJO Sampled By BJO @ 30': Sample is: Dark greenish gray silty CLAYSTONE, moist, stiff; some threads of light yellow-brown (limonite) silt and orange-brown fine sand towards sample tip 1 @ 31.8': 2-3" of olive sticky clay, no ground water, dips to SSW; Very / \ jjlanar Rupture Surfacejjwlisned j SANTIAGO FORMATION @ 32'-34': Light brown to pinkish brown silty CLAYSTONE, moist, stiff; few fractures and gypsum infilling, generally tight @ 34': Bedding/contact with light gray, very fine SANDSTONE bed, moist, dense but friable, gentle southward dip @ 35'-45': Light gray clayey to very fine sandy SILTSTONE, moist, very stiff, some minor @ 40': Sample is: Gray SILTSTONE, moist, very stiff; some minor fine sand, orange-brown color, in pocket (sample tip) @ 40'-45': Coarsens downward, with increased sand, still very fine grained, moist, and very stiff; massive @ 47': Grades stiffer, generally bluish gray sandy SILTSTONE with clay, moist, very stiff/well indurated; gradational transition from above @ 50': Grayish green sandy SILTSTONE, damp, very stiff; some rusty grains; scattered volcanic cobbles at 53'-58' @ 53': Rock encountered, bluish gray; well developed silica cementation; very hard, no decomposition @ 54'-57': Very stiff, difficult drilling, rock auger required; excavates to dark greenish gray SILT with some fine sand and clay, moist, well indurated ^@ 58.5': Sample bounce, no recovery; possible Lusardi Formation? ^ o> "o 0)& AT,DS,SA TYPE OF TESTS: <tk S SPLIT SPOON G GRAB SAMPLE DS DIRECT SHEAR SA SIEVE ANALYSIS <^^9F R RING SAMPLE SH SHELBY TUBE MD MAXIMUM DENSITY AT ATTERBURG LIMITS ^9» B BULK SAMPLE CN CONSOLIDATION El EXPANSION INDEX ^^9 T TUBE SAMPLE CR CORROSION RV R-VALUE ^T LEIGHTON CONSULTING, INC. GEOTECHNICAL BORING LOG B-4 _ Date*rPI 1-17-08 Project Drilling Co. Hole Diameter Elevation Top of Hole CUSD/Cannon Road and College Boulevard Pacific/Larive Drilling Sheet 3 of Project No. Type of Rig 601579-003 30" 161' Drive Weight Location #3500@0-25' #2400@ 25-55' #1300@55-85' Earthdrill 45L _ Drop 30" See Map ElevationFeet100 95- 90 85 80 75- SAMF II f(\ - 65 — - 70— - 75— - 80 — - 85— on 0 2=0)O.Q <5 W E AttitudesVU~ >LE TYPES: dz "E. (0 CV- C0o> D. '5CM-VO00. k.Q Moisture 1Content, % 1WOT 0^•="? DESCRIPTION Logged By BJO Sampled By BJO Total Depth = 59 Feet Downhofe Logged to 57 Feet No Ground Water Encountered at Time of Drilling No Caving Backfilled with Native Bentonite Plugs at 30-35 Feet, 42 Feet, and 56 to 58 Feet Tamped to Total Depth Type of TestsTYPE OF TESTS: ^te S SPLIT SPOON G GRAB SAMPLE DS DIRECT SHEAR SA SIEVE ANALYSIS ^^3F R RING SAMPLE SH SHELBY TUBE MD MAXIMUM DENSITY AT ATTERBURG LIMITS ^9£ B BULK SAMPLE CN CONSOLIDATION El EXPANSION INDEX ^^9 T TUBE SAMPLE CR CORROSION RV R-VALUE ^^ LEIGHTON CONSULTING, INC. GEOTECHNICAL BORING LOG B-5 1-21-08Date Project Drilling Co. Hole Diameter Elevation Top of Hole CUSD/Cannon Road and College Boulevard Pacific Prilling/Larive Sheet 1 of Project No. Type of Rig _ 601579-003 30" 190' Drive Weight Location Drop 30" See Map S*5«a>u- 01 190 185- 180 175- 17O-l i\j 165 160 SAMf t|a"- _ s - 10— 15 — - _ _ 70£*\J ~~ - 25 — O 1L0' 5 W E V \ _ - ^-.' _ — „ _ ~l~.--. y.~\ *\ '/ .> — ^— ~ v // ^ • ^ XJ- ;'f N - • A! 1 V Y '' \ - " __ ' — - — - '- •?^r- _ V)0)•o3'S< J:N30E 80-85NW GB:N60- 70E 5NW J:N40E 75-85NW •S:NS 06W J(B?) N35E 8NW S:N26E 64SE B:Horizonte >LE TYPES: Oz 0) a EnsCO B-l R-l R-2 B-2 1 §1 Jt CQfl) Q. 1 5 iS4-u QdL 1_ a,ss 5*J Sj OcSO K«s DESCRIPTION Logged By BJO Sampled By BJO SANTIAGO FORMATION ($ U-l1: Minor lopsoil: Brown, silty CLAY, moist, soft, few roots @ 1 '- 1 5' : Light gray to greenish gray clayey SILTSTONE to silty CLAYSTONE, moist, soft to medium stiff; very weathered with abundant fractures through 15 to 20 feet; fractures are randomly oriented @2.5': Bottom of casing @ 5'-7: Bag Sample is: Light greenish gray SILTSTONE with clay, moist, medium stiff; generally representative of upper 20 feet §9.5': Sand bed below weathered zone, generalized, wavy, irregular 10': Sample is: Light bluish gray silty CLAYSTONE to clayey SILTSTONE; moist; medium stiff but weathered; broken by orange-stained, gypsum-lined joints, otherwise tight @ 12': Orange clay-lined joint set with local fractures @ 1 4'- 1 5': Soft zone very fractured and very weathered, red-brown CLAY with yellow-brown soft silty CLAYS; some gypsum; no water @ 16.5': Orange clay-lined joint; lined with gypsum; possible bedding @ 20'-30': Generally becomes less weathered/fractured, stiffer @ 2 1': Sample is: Light greenish gray clayey SILTSTONE, moist, medium stiff; some minor gypsum infilling/orange staining of small, tight fractures @ 22: Very planar shear enters from northwest wall @ 26'-28': Bag Sample: Light greenish gray SILTSTONE with clay, moist; some minor orange-brown staining of pockets/veins, but generally similar to above (a), 29.4': Pinkish band, suggests bedding is near horizontal of Tests0) g TYPE OF TESTS: ,^fe S SPLIT SPOON G GRAB SAMPLE DS DIRECT SHEAR SA SIEVE ANALYSIS ^^SP R RING SAMPLE SH SHELBY TUBE MD MAXIMUM DENSITY AT ATTERBURG LIMITS ^9£ B BULK SAMPLE CN CONSOLIDATION El EXPANSION INDEX ^^9 T TUBE SAMPLE CR CORROSION RV R-VALUE ^T LEIGHTON CONSULTING, INC. GEOTECHNICAL BORING LOG B-5 Date 1-21-08 Project Drilling Co. Hole Diameter Elevation Top of Hole CUSD/Cannon Road and College Boulevard Pacific Drilling/Larive Sheet 2 of Project No. Type of Rig 601579-003 30" 190' Drive Weight Location Drop 30" See Map °+- >,.o>u. UJ 160 155- 150 145 140 135 «« 82011- 1f\ — 35 — 40— _ 45— — _ 50— - 55— Z:A U"i.0* O I/V E ^ ' .' • V - - — - ' V ' '-•cE^"*— " • -\^ jrr-^E , .' _J. . '_ — 'r>$^XT'- ~ - r.''N O5 C7. '"'/•" - -o ~ -T ;'U V)Q>•oa5 J:40W 45NE B:N50E 11NW B:N4SE 9NW 130 in/ SAMPLE TYPES: dz V Q. raV) R-3 B-3 R-4 B-4 WO50 •2"£DQo>Q. U n •5CM-0) u QQ. ^ £5? 3c"(00 '5cS°O «(/? — Uo • |D DESCRIPTION Logged By BJO Sampled By BJO @ 30': Sample is: Greenish gray silty CLAYSTONE, moist, very stiff; generally similar to above @30.5': Tight joint §32': Horizontal upper contact 32'-35': Bed of red-brown very fine sandy CLAYSTONE, moist, stiff, abundant gypsum pockets and veins of yellow silt (limonite); otherwise tight, without evidence of shear/displacement @ 35.5': Thin dark red-brown clayey SILT with sand; somewhat fissile @ 37': Light gray SILTSTONE, with minor very fine sand and clay, moist, hard @ 38'-40': Driller notes much stiffer digging below here, too hard/cemented to drive sample @ 39'-41': Bag Sample: Light bluish gray very fine sandy SILTSTONE, damp, very stiff to hard; sand is fine but angular; spoils include cemented clasts up to 3 to 4 inches @ 41-43': Some very tight, irregular/wavy gypsum-filled veins @ 43'-55': Very fine sandy SILTSTONE with clay; damp to moist, hard; generally greenish gray color with some dark orange and dark green; includes silica cemented concretion, generally darker colored @ 46'-48': Grades slightly sandier (coarsens downward) @ 46': Sample is: Dark greenish gray very fine sandy SILTSTONE, moist, very stiff to hard @ 49'-5 1': Bag Sample: Greenish gray very fine sandy SILTSTONE with minor clay, moist, hard; cemented @ 51': Drilling difficult, use rock auger off and on through approximately 56 feet, possible Lusardi Formation? Total Depth = 56 Feet Downhofe Logged to 54 Feet No ground water encountered at time of drilling No caving Backfilled with native (bentonite plug at 35-40 feet) Tamped to Total Depth «2 «t— "o 0>§; EI,CR EI,CR TYPE OF TESTS: ^^te S SPLIT SPOON G GRAB SAMPLE DS DIRECT SHEAR SA SIEVE ANALYSIS <^^9P R RING SAMPLE SH SHELBY TUBE MD MAXIMUM DENSITY AT ATTERBURG LIMITS ^9K B BULK SAMPLE CN CONSOLIDATION El EXPANSION INDEX ^JES T TUBE SAMPLE CR CORROSION RV R-VALUE ^T LEIGHTON CONSULTING, INC. ffio o-O OO_J w£wo-o OH O w o cn: a;6)(L "c Cc/: h^ OD "o"'£ u 3 C/3 6)dW o Ow O i t/3wQ JN f-H IQ c/3 o en O (D60 I •8 enT3 S' (D 8 O O O (N II en I (/} +J 1§ 13 « I f^ T*o SH A "Iu ^LT5 60 60 'S 38 8», ? 60 O £uZ Ooo oo a PH § PH O WUso >. q o IDw na <utoil 42 "cU Qt/: 1U | Z 15<D•o5 £ <L X C.n ff C s ^S a S 2:TO ^ — ' on O 05J Zo 5wo g>i ?c:P. T3 I O •& S< o ?^CN WH 5|sgo pW Ho <: a 3 Q 2 S <U O og -42 '55 t* •§£•§:§>s — §1gloo TH i> ito C ' '3 u 4_r "O oo Z Q I U PH O cn WU en W Oon 1 ATION:SEPHICO ffiO O OO ^ 'i?pq <u •£:? H— 1 £^ W CD O 3 , , M ^cu '3 ^5o ^ § JiW "& d W g Z5 t/] § 3 C/}D C ff „cc 4 * to )c ^a T3 - , 8£ 1 1a I -g c? " o CTISn/Colleee and Cannonc aF-Jv^ r— VC TO 410fJ Rar.khnel_i<3 S "1§ 3 -gZ Z | .E, .2, -g" £ £ w y Oo c o 5wO iHH (J GTlW Q t~-o?iJN ?5 iQ CJ pjr^ ^^ 0 H OHW HO < (N 1—1 CO\5/ TJu c^ S CJE t—J '«O •a '** -fl6 "o -§ ^u ^3 si« ay^-T en<; J*T )LLUVIUWTOPSOIL0 ' : Unvegetated (dirt roadway)O'-l ' : Gray-brown silty to sandy CL1 ' - 1 . 5 ' : Grades to weathered bedroc^NTIAGO FORMATIONu ©(§)(§) S *•" s _c2 bIE IS "7^ O"u '" d | s U '§ ? 'I •§ '^G £ « _^3 u 6^ JT S .2g 2 o -as g •» «a ^ if s.J W frt /~\CO +J &l O ® ™rT-p ^ ^ T3 §Sl| ^"8 fe5|« p|g b- 1 1 s 15 ^ 8 ^ 5 z™ « w ^ ^^1 . 5 ' -3 . 5 ' : Light brownish-gray siltygrained; friable; orange stained zone3 .5 '-4' : Greenish-gray CLAYSTONstiff; generally horizontal with slightsurfaces/peds; rare root4 '-5': Grades to light greenish graysand and clay; homogeneous; not we© © © I /-t Qz H 10N K W PHO I-JC/J Wo iC/3 t-SCALE'RESENTATION: E. Wall*HHMr! , <;og 3o r^ 1 1 1 1 '/^ 1 ('', tl •M \ 1 "* i ^?i I "O I o U FT"] (^3 HH fll f^ ^ « ^ II ^ r— ^ "O ~cti- 2 oO O cSH Z 03 \ 1 a u UH O OO S.230 GO sio 5wo (T S >-.JO T3 <D 60 1 e c rt T: ^et <Daiu C QOC q tia ? »i •5R P. O <D W D 41 00 Rar.VhnefN WH J J O o<u•g1 £ 1 o' (X U O << ffiCJz O OO >%ti * — > OT TlS 5-e 1OH W (D o -2 C3"* -a bo- ,2 0 ^ 2 D w "&• de 1*U <*J O w ^MH ^Joo D o ^^ PC C ^+ £ g"° -^ PC •tc b)C IS K P. ^+- •4-V (L ^ T3 *)-i ! M g 'Soo g oO --in OhJ W J | K CJ •c « «aa: "3CJ or CJ r^-c CT> f~-•/^ VC d. ^: c.a PC C 5 C <D u ^rt c 1*1 +-i 4^ CU 0 Q_<u i> -Sir 'o5 'o1 g.IH l-< CT OH PH W CJ gfcJ ZO 5UJO Zoh—K H CJooWQ t-o f^JN (N wH<Q r •, WO tq oQo Pj fc0 HW H0< -H I" T3U 1 £s D -y % +-"1 in^ >. -s §1 t II g | w g a - z ^• » | o J§f-^-t ^J r | ^5 O T3 OO K." M " H ^ & 1 5 1£ 1 K gM <D >-, g & « ^ SL- S 'o JH- 3 >r}-<u g S 73 ^ r^g ^ « O "trt S ^ C3 +*i> ^ 1 e| 1^1 1 IIo 3 § s ^ Et^CJ ° % > g £ •*•> S o "^ 'B§ *J £ S H ^-M •- o c CJ o S g 5 e" £>£4) fe (D Z -5 (U^ o S 2; o '" Ng 5|i g fe &ii it^ i ^.?so fiser i ria^oH a^^ g ^ISfc" i 1-8-5- 2 &5Sig |o| o o|a| > £ „• • N 5 „• • S „• • .23 ^1 c t-g^'s _1 bbja ^ ro.S^i-S ^^ /^~\\ / — ^\ "^^ /^s\ / — s\CJ @© oo © © w"o ^ § ©0°2 > 1 Q *~y *§K 3a S•c K w OH O— 1oo W CJ | oo ^j- W ^CJoo RESENTATION: N. WallOH § i— 1 < CJs o •*•" * 1 ,1 \','j1 TT / 1/ .-U ', 1 X •M **> **~ \' 7^'i-T **' H1 ' \ 1 (1 j ' iU >c 'i^*^ '-•i i ••«•«• T3D 1 0 It-^tSou IH F; fa -SJQ ti1 I?5L& t^*sr 3 u Q eg 3^-3o o caH 7, m \L(iT\' r\\ '•^i -»MH ,- ,»'! "VI ll-\ \ -\\ i\ i ^M_I \ ij ^ ' 8 o S OH ffiu o O O </3 on D to) ff £ O <r T3UtsD O1<u W O•^ooJ c ICJ -c c;<aa« "c Qor t c-v V-<D +•>8 . pq O o r-0 CN GEOLOGIATTITUD-o<D Wonow"w on Z Q 1 SCALEa oo W O o Xu UH Ooo gged byevatinn-c d rtC T:p 03 DSal<D "cU C GC C C C crt~•f- v£ | 2 ON mi ^^ CN Q3 en enD Uen U oEJ Zo 5Ldo -a<ua. ^s t* j I I/r.ation/GriHLoF.lT,n<L ^ K ffi^c 6.sOH W W oo O I Shgpo <: 0o o -a<D a si ,oyScagllofinntSi00h12w• • o WU TJ- En G oc h O O O O 1 1u.r\ r* O w 5343 o ^-^T ,nr.atinn/D O TION:DESC2/27/07U gq5 e Sg SSO < 00 oo r- ffiO O a. I D (D 0 VJ «1"H ^o .a to etLCN m„••„'„' O O (N '<" Og H 3 v •8J.t•73 . „ Ml"§rll f9 i|>, ^ aa >, 8 <?° «?&C > +ja <tf ijrt ° jW CO I—I ffiO2 PL,ooo o ^s_J W 8' PH 3 <u 'O1 £ Q X4 oO x- d U </3D .a o w gfci-J Zo 5wo § CJenW Q o e3g O f-1 W H oo (D (D I otn o •a" en I •3<u O o • en IbO oo 13T: &,isQ 13 ID §N 03 §en So ^ J2 S r9 O O UH O Csl ^ >0 - O O CN en I.o a>g a> •4—> C^^ s fN I ' (D ra>-. T3 H<U ™ ,^{S'B•*-* ~ya» pjs s.3 6 ^^ •1 eis §^5 T3O "J H-S&o s>, tt <" <Dj a»o a .. •» ^ fr Sa„' l-c O^o 43 x S) en •W Dt/3 UJ ^U w en I en CL, § CJ Eu O oo o ff >,jo T3otoOtoo § 0 ^ p-J W I K T: re ublc; "cU Qv. <rc c: \£ 1 'a ^ 2OH io'$oo 0. X caa C e g.&g^w u oo ouo C--o CN CN WH M 0 0 J3 4-T N en Jfl .« u tt g2 ."2 ^S 5s s 2 &•5 > in 1 - -8 >, S. S o £?« f> QJT aj I ^ c3 S)1 ^'S5 l'i Oa *•* *S CD • S3oS o g oo'BS'otio . «> C/3 Q 1 UOHO wu D C/1 W on WallRESENTATION:UsOH O Q m Xum QJ 2 P-O Ooh-J CJonD CJ o p -3 to) c cc >>.£> T3 &> § w uo £ c -cc a;b C Cor C cc CT >r C C ^ ff C tsD •g1 o. 8•o1 £ oo CM (N W BD g PH UJ o C/3 •o OH !D g<u so U o +-T 111 *1I> Q S1 oo •"-i W i^'w y J3's p^ •H '1-8 i III fill 3SSJ- £,. 1T3 ?Nl u b oo <uQ o >->x> TJ<DbOtoo 3 o <u 3 e c re U 1 <Dtoil OO Qor: ous OH 3 S I 04 CN 03 oo 00Oon P O 05|-1 £o SwO ua.a. |5 H^ o..IIS 60 oen O H-lU f-ionH W) SbO too >'g 13 r-o ?^CN ?5 1Q C <U§ -o 2 5me^' ' <uO4 ft 2 S4 jj Ou -^ "O c b" o C <o li tl Q oN 1 w OH OJoo W CJ <J Doo w O00 ?W ZOt-H S<SE< UsOH G o OoO ,0 -O(L> bO § 0) W o<u 'o1 i-o- 1-10)I '21 PH a 2Io ' o oc/) D 1•a cu | crW OJowo JN (N w *°. VCoo o01 Tj- CN ffiO T3<ua,a, cD CJ O O U p-o oo 3c.23 co s % JO 'fL, on U J OW T)Ucx& b&| •OUbQ g» CO1(U W U •c K <Ubi<L "c Qcr C ^ z •t-1 •(->8 8 2/27/07E:o oJ 1 softbedrockrt , very moist,xed weatheredO "C *> >-<O M £"8 S ^ ^ p 31 fN rn ^S b N gi .o B INw ' O ^H 13 >, ^•g 'o w H ^5 ^ bO•dra ^ •• a &wr, .§ o.' a •« W C/3 ATIONWon §CL, CJh-HK OH O •au &§Q S o H tinOoo •8 1$ i j w c c .» <=x o ^> ' oz a.cj: cKff C fr Cc at~- V \£ * I S -Isg.W uHHO ,_ oe Owo ex r-o S j 3 •^ is oh-H 5 o(Xoo•<p§1/3 O O O CflW gWeuo<* AH O WPJ O g 6060O p p •cca: <ub)a: Oa § w n-C a-t- o •c~ u c. T a j: t 'J C a. .1—O ' o£ C/} UonD Oso o p oHHH onWQ Ia, 1 o••&M"cL 0) w -*_r c w |1 D (DC/3 >O . T3 D § U ™ -° or- 4J•a g M<u _g <u JN IQ O ^H \o r-i i i o ^-i Co a> CL 1 W 'o P-f O X -4-^.^^00 g O1 I I•a- s£.3T3 o ooo ts<u "8 W t- O | Zts<u•g1 OH "& dS ZKJ ^on <DS.&1 §1 O Pwo zo P o wQ r-o JN 13CJ rt H <D 60 II 0S c0 53 3 >, o-a g Si*-§£f£• fc2 c£§> -S c g = |l-••88? il—I O W wZ Q 1 omioOtN u OH O J C/D W CJ p oo W 0 GO ATION: S.E. WalSEo SOH O ECO O OO c/a T^Jon S3 o.pq o> o1 W <u 1 "~ OH O "o ^^ K 4nw "e- ow | ^ G on w ^onP E r- ^ | it c. t P£ T3•a ^11a 1 -^M) g o O ^«H O -J W KJ P s:cc:C -c K ^; U f cr C T Rar.Hine.V. C o d^ rO P S J 7 155s <L> H> 2"1 'a5 'e1 '&£ £ PQ o i-i SO D O O1— ( ^t— 1 Uon Q r-0?^CN CN f— H H <^Q r ^ O3O [Jj 59 GEOLOATTITL13 fnmappe3 Jt— 1OonOHO j^ I OO C/3 i| O E3 "VI M ^-» « +^ ^^ji '§ J3 ~^'^CX ^ "tn ^ l> ^ U 1> '> ^ <u > "g pq -3 2 ^ ^ Z S t£ p j ^ on s 2 ^ S ^ &"o £- § d S^i-i r3 rt on j3 ° M "° >. <L>+2 S £ T3 bo „gH [> O ^ H 3cn O ^H ra ra X II- i-iftC o oC^ b>\ ^ S•^ fc- S CH ^H Og S > _ S» r-" 43 S^° o E.S.SO TO ^j h—H 2 fe > fi n bo O £5 2 a ^ i t .Slis i |il1 en j fc •§, « g | .... o j ^'S S ^ ^ 9 -• • § fip'"^ ^ i—J *^ (-* O. . 1 l/"l r^ 1 *H V„• • „ ' "H ^H „ o rio o ~H 2; CN bo s ^©(§)© on © I Z Q 1H O O SLOPE:wo on - „•^^ W 3Uon 1 W it— H 5 won OH § nj •^CJ HH GRAPH••• 1 ^» 1 ^- 1 StaM V «— 'V — *<u-^w**m - Hl^fc.^V V S**** ' 1^ ), ^>^"^"" ^=r ^'•Mi ^^( ^^^^^ * i ••~>-^~.'* ' i 1 .'MiY1 _• . • J 1 ^^^^^^rt^^^^ "O "r- « Ir- £ " j§ ^"3^&§2§ S"30-^ "o O njH 2; « u O OO T3a g.2 W I eK(.T: a<ub> —"c Dv a II a0. oS u Ot-HOoJo UJO &DI t t; I1 •b" 1o 8 % w g H O C/)WQ W o a o C/3PHofe: U dylayer ofGn surfic0 . 5<uMg os O *-42 ffO en 3 o bb P §,3 nedorangesed; ex5 ' -3 ' : Yellowmewhat deco1 -necavatesfusal; mecagravel/cobble3 ' : Very hard, pracwith some very fineWPHo_i&owo Dcw SCALE:ATION: E. WalSEU E PH O ffiU PL, O Oo on 'i £LjJ <L> sir? 7, jOH W u 0 3^Qi -g 0^ PM ,2o 2 W "& 6pq S Z onD C ff i> b- + % • bc„ -^ ff ex ^c. C ~£ C j ' TJ S•° S ~S-o .2 oa 1 -3g3 1 BJ annonC "C re [JSD/Collese<~ <u W J cc 0-r- c v_ aCj: t. a C £ w <D U .& '21 'S1 §•p ; OH fT1 y o 5wO oHH U w Q : 12/27/07u •<^ Q CJ pq 5 Q0 g 0 HW HO -< M ^ ^ i PQ ^ ^ 2 -t— » wrt >^ 1 •« 1o ° ^ DH ^ r^-o g "S 3 g I" S en 00O 1) "H 'S3 T3o -S S(—1 O C^ ^1-H 7^ c3 T3 § c -a 2fH " ^ 1 1 8,i-r H o- <u s3 73 o ^ >. So S J3 % G 0 "-'„ O •? (~< *-' S2 w S > S °3 S.<IH ^U JL MH W d5 ||| 1 || -a ^, on P S b" sfo >\ ? & K § lj | ^ 2 M 0 '-S g ^ b*^ ^ I* 1 J* P3 ttrl S w ^7 ^> Dy ^^ *4«3 ^ ^^ c^ ^ y o ^ ^H ?5 ,S2flj 5 *T3 -rf* O C3 O SH g 3 o K.Sb^^S ^ g jg b | l^l,-- § ,--gj> «. o vo pi O ^<t-J /•>r^^>^1 <f" ^'<^ J OOJ2>O ^Q VDOO I-J 13<; ®@ ® j ® LLI OH O_J GO UJO <SUw^uon 1 §S o S PH O Eo2; HH O OO <UbO00 gI <o c e K C T:cK o:toa. "c P5/ fc at- V ^C <aQ I?o •^ C/3 Oen D ij*c. t;£ k3 C 1 J« K PC C 5c 2a. <uS.& oPQ O fc2u 5/1 t--o W HH >D_l ^ tt O ^en I2t^o TJ>^ U en60 +2 3 O O "/"> ^ VO ^M (DO N:-g ~w § "S 5^^ M 8 | & Sg «8.S-S'5 3-2 V* CH1> '9-*-» TO ^ 60 o <UW r/ix CW 3 "~!r- Iuz IPL,ooo 6060 o 1 5 •C K «6 —c cor sQ <u is ' o Z <Jt>o ts ts1) I) I oo U o UJ O u S crW t-o CN W r ^O 5 381= O I ffiuz bO OO—I £w wu o 13o a o o ^!hJ W | £re C •cpre uto)jjj "c Por C -2 tso * r°io '138j n 4 inn<uw* on on P U H-^O O_H OwO , rta N O -a(DV*CD o H Uon QZ s- § S I | .1-a <-Tw 'S W O >p (U O2 g "» o ^" ': -s H CU3 60*+H va _jj 1 ^r M3 S .ss .S r-o CN fN W T3 ^ OT C _ '° 12 ttS H R« B o i SDh—( D I s > Q I W o 0< on Z Q 1 o uu OH OJon pq 1D&n W Oon (NI o ooo " on to) HE "860 §>-4 o | U ation/G^ sW i 1 -c c: (L0 n 32 Z t3 tj PU £ GO 8bJ £o 5wo oo0] cs on 3E SSo •< -o0)o- u tnS .ao s •1 ss I •i-T t3^ g I i-T ^ "°a g5 ^| g I"H I3 o « -o I I Jfel <*H fto ^1) U 60 JST3 «<u 3 appears.S1 § .s 'S it_ >> "-• IH rt alear. 5 ' : Lighy SILTSed zones6 . 5 ' : N2 'W OH O H-4on w (73 SCALE:ATION: S.W. WaSEoJ_^DC OH SO V I (J ftlooo >^-O -o4>6060 § e c KC T:pc:a.a<L "c Cor C1 o-z^H on 6) cx t Location/Ga^OH S OH W y o O ONoonWQ f-o oo(N Q sg2EO < T30) I oo 0) K> ^ T3& ^ «« ao H o «^ O « ^ l 3 vf>3 P' :'00131) I w o >> P «* bo S' un 'S g CO S N ooo T30>§8o SI S ISg aQ I (73 GO o<u 'o1 3 a a iK PC PH g U CJH—(Oo owo TIONDESC2/28/07UH _g_ r ^ ^y woQ MW HO •< OsO O(N PCCJ - oT: ^<u r3OH M 8 <JH <U0 X"'I--i *"• 0 S rS b W <DC CISk ^3J? <aM S •US •§ S ool c 601579-003 Appendix C Boring B-2 and Trench T-10 through T-15 Logs by Leighton from College and Cannon Road Extension Geotechnical Investigation (Leighton, 2001) GEOTECHNICAL BORING LOG B-2 Date Project Drilling Co. Hole Diameter Elevation Top of cQ ffl rt| "*•+- UJ 65 60- 55- 50 45 40 ^ +- ' Q_ 2i<u,J! 0^ o — - 5 — _ - 10 — - 15 — 20 — 25 — in — O c.Q. 11-9-00 Sheet 1 of 2 Fraser/College and Canyon Project No. 990101-002 F&C Drilling Type of Rig Mobile 61 8 in. Drive Weight 140 pounds Drop 30 in. Hole +/- 65 ft. Ref. or Datum Mean Sea Level 7)->ra_ic. /•/ t%t^ f-7./-/ I \I \ 505A( 11/77) I I / f /? I fy \ inQ) -1—o"Z. o Q, CO 2 [ Bag-3 +- 3 1 1O — ^ Q. ' 9 @5'-8'h 4 1 10 1! 5 12 6 I 10 6 1 7 i Jl c *+*01 UQ Q. c.a 114.7 108.4 113.4 114.0 £-«- '" QJ °t O 7.5 19.7 V 18.8 17.3 * {ft ^^ — . .O (/) '08 SC SC/CL SC GEOTECHNICAL DESCRIPTION Bogged By MDJ Sampled By MDJ QUATERNARY ALLUVIUM @ 2': Clayey silty medium SAND: brown, damp, medium dense @ 5': Clayey silty medium SAND: brown, damp - - @ 10': Clayey sUty medium SAND: brown, wet, loose @ 11': Ground water encountered @ 15': Same as 10' - @ 20': Sandy CLAY to clayey SAND: brown, wet, loose _ @ 25': Clayey, silty medium to coarse SAND: brown, wet, medium dense LEIGHTON & ASSOCIATES GEOTECHNICAL BORING LOG B-2 Date Project Drilling Co. Hole Diameter 11-9-00 Fraser/College and Canyon F&C Drilling Sheet 2 of 2 Project No. Type of Rig 990101-002 Mobile 61 Sin.Drive Weight 140 pounds Drop 30 in. Elevation Top of Hole +/- 65 ft. Ref. or Datum Mean Sea Level .<U 5» 1- UJ 35- 30- 25- 20- 15 10 <j Depth 1(feet) |30 — 35 — 40 — 45 — 50 — 55 — fiO Graph i c |/~'/~ii 7)3J 1 Noteso* 01 a CO 8 9 10 §8 0^ mfc 24 70 72 314- (fl/-^ C4- 01 O O Q. \-S Dl Q ^\ €*s&E OO ui^ > u^ _co °5V) SP-SM SC ML GEOTECHNICAL DESCRIPTION Logged By MDJ Sampled By MDJ QUATERNARY ALLUVIUM fContinued) @ 30': Silty medium to coarse SAND with clay: light brown, wet, medium dense @ 34.5': Becomes dense per driller @ 40': Silty SAND with CLAY: orange-brown to light brown, moist, very dense CRETACEOUS LUSARDI FORMATION @ 45': Clayey SILTSTONE: gray-green, damp, very stiff Total Depth = 46 Feet Ground water encountered at 1 1 feet at time of drilling Backfilled with native soil on 11/9/00 505A(11/77)LEIGHTON & ASSOCIATES o I CJ p.o O O b liO — e 6 oo CJ00 D O gged byo "I <a LoElc cc £ ! '•§oo_! | d CJ =3 <L>bl .2 "oCJ <5 S Backh| Z ff § POH g00 Q oo WH Q r X MCJ ciJ liO HW HO < oo oo oo to 'S S o 1"O 5 *Q §00u @0'-2': Silly, verootlets common60 c o w I00Q 001"•3 1 2<us-c0 "oo ex IT) 13 T' g 1 PQ w 300wCJ 00 U O00 TATION:00§ AH CJ KPu I EO PHOoo ooW gW OH O O w o .£>' t3(L>bO o —i-J W <I>Q cCcd00 00Ooo D o O o U 6gJ £o 5wo CD -D £ E03 32 2 o(U (Xff 8 OH i> _O-"3wW O POH2ooo«Q oo OSOj O HW HO CN 00 Ooo uwOO 00 oo o.IT3 CM)iiu(30 Oo 2-o iSO 0 W) ~ C.. (U Co ^ CQ Q 2 H ooo w OHOJoo W U Doo w U 00 §HHP f §00 U £ OH O g ~oc ™3 O8W r- «^-i C >H w -a£ 53 g•^ 3 £it*a. c ~a o o caH 2: CQ (N ffiU Ooo 0s B-6 &o D •o .1 § U •4-» --H O_l S3 S3 LocaO W 6 2IX, I 2 o o oK ff •*-» -4-» H 3CTUJ DESCRIPTION:oo r-- W 3Q ^^ o < u o GO oo onO 'o i 0 03OO CN O W) Sc S <u<L> 1 oo < C/) pi tfH £ U CM e §o >." b<u CQ Q2 SH <N w PH OhJCfl W oo W tj GO § P < H §&o §a Ok—^ffi PH SO c rs3 O u 8 uaj *-• >tt. w -5 •O S3 g eg ew CJ OO _u 0. Q 1 CO D u U U o la COo wa,O_1 CO WO DCO T3UWJ00 evationcation/GJS 6« hJ DESCRIPTION:o O 8 JH "oO oo moSAND:e« dO § P< Oo< is4—* « £X (U SbO •a cjCO W UCO 8 §1 .0 g3 +-> 8 o0 WH <\HH H § H S §CO 03 Q.1 O HiW H O < OS OH S O 0 r- U C' o. c "R<U 3 _U O f-CQ U IX, O Oo 00 W !CL, O Iw JJ a. t/3 OcoD o O O t= (-UO too «J ti o ,5-1 « O <u edz i o o ux> 3 j C«ff o £ SP., ^ <u .& t gpCL,sowuQ oo uS 3Q g^O H« HO < Ooo O oE oo Oo <L>tnOO onC •a a. U« w "O § § o>, CO CW O<;Htf (X U g cs PQ W Q I GOo w o oo WO Den W O00 zWto § OH Os DH 2 O « Ru " ^ w "5n S3 c •^ -T-i D. C "SU 3 ^ O O c3 H 2 03 ffi O O Oo Mil Dtl "^* — N t/3 Tj C Q ^E-i W « PH g CL, "S ^ O s p^ —W g-dw £ ^ rn ^^ W ^jooD S (S _ Logged by: _Elevation:co Fraser/College & Cann990101-002c cc! T3 _ Location/Gri710 BackhoeLJ• _g E 6 » | 1 § tj tj Q.u w .jr & £ W J>j §O M Wo SCRIPTION:WQ oo •^ O oo CJ QJ EOLOGITTITUD0 < CJ00 8 5CX D Oc2 T3 -4— >0o^ b" C/3o_0 j_r CO'oS o 1 1oo 2 i_, C OH^ 't o —^ .:*•* ^^f ATERNARY COLLUV@0'-4': Clayey silcommonETACEOUS LUSARDI) Q^51 < u CJoo D~2 T3 §"H -o 1bO W OHoo ^< G in r-S) OQ ^S ^ Q 1h- PJO(N W/v,MHO O\) W O 1 oo in SCALERESENTATION:PH 3 <£RAPHICO (<)V^ \-s \^^_ \/~. ~* ^S|^- '^''^\'/'•- iMl) / 'i'i'- -V' -I- !•'•'' ' ^^^^-^^^^^x*"*"^ oo •o §I~c ~3 OO <n ° <U-*-1 *" > "^ ta xj ^S -a ^ Q 1 S*ff5 O .5 H z m <^@ Appendix C Boring B-l Log by Leighton from Rancho Carlsbad Geotechnical Investigation (Leighton, 2005) GEOTECHNICAL BORING LOG B-1 •I Date 4-15-04 Project Drilling Co. Hole Diameter 8" Elevation Top of Hole 60' Rancho Carlsbad RV Park Tri-County Drilling Drive Weight Location Sheet 1 of 1 Project No. 040910-001 Type of Rig Hollow-Stem Auger 140 pound hammer Drop 30" See Map ElevationFeet60 55- 50 45^ 40 35 l«Q"- 10— -15— 25— O ECD S • . !•'w ziw/,Attitudesoz d> 0. CO V) R-l R-2 R-3 R-4 <oo C0<5Q_ 21 28 2\ 34 £Cs-0>UQQ. Q 101.2 112.1 109.7 102.3 MoistureContent, %24.0 16.4 17.7 23.5 °2- SM CL CL SC sc DESCRIPTION Logged By GJM Sampled By GJM TOPSOIL @ 0': Silty fine to medium SAND: Dark brown, damp to moist, loose QUATERNARY ALLUVIUM/COLLUVIUM (Oal/Qcol)@ 5': Fine to coarse sandy CLAY: Brown to gray-brown, moist, very stiff @ 10': Fine to medium sandy CLAY: Brown to dark gray-brown, moist, very stiff @ 15': Clayey, fine to medium SAND: Light gray, moist to wet, medium dense @ 20': Clayey fine to medium SAND: Light gray to light orange-gray, moist, medium dense Total Depth = 21.5 Feet Ground water encountered at 15 feet at time of drilling Backfilled with 7.5 cubic feet of bentonite on 4/15/04 ype of Tests1- DS CN JU ju SAMPLE TYPES: TYPE OF TESTS: ^^fcj S SPLIT SPOON 6 GRAB SAMPLE DS DIRECT SHEAR SA SIEVE ANALYSIS ^S& R RING SAMPLE SH SHELBY TUBE MD MAXIMUM DENSITY CU TRI AXIAL SHEAR 2fl£ B BULK SAMPLE CN CONSOLIDATION B EXPANSION INDEX ^B5* T TUBE SAMPLE CR CORROSION RV R-VALUE *^F LEIGHTON AND ASSOCIATES, INC.