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HomeMy WebLinkAboutCDP 2022-0051; ANDERSON ADU; PRELIMINARY GEOTECHNICAL INVESTIGATION STUDY; 2023-03-08A Universal Engineering Construction Testing & Engineering, Inc. Sciences Company Inspection I Testing I Geotechnical \ En'lironmental & Construction Engineering ! Civil Engineering I Surveying PRELIMINARY GEOTECHNICAL INVESTIGATION PROPOSED ANDERSON RESIDENCE ACCESSORY DWELLING UNIT 1877 HIGH RJDGE A VENUE CARLSBAD, CALIFORNIA Prepared for: CONSTRUCTION WITH PRJDE ATTN: JESSICA BRANDT 7040 A VENIDA ENCINAS CARLSBAD, CALIFORNIA 92008 Prepared by: CONSTRUCTION TESTING & ENGINEERING, INC. 1441 MONTIEL ROAD, SUITE 115 ESCONDIDO, CALIFORNIA 92026 CTE JOB NO.: 4830.2300005.0000 MARCH 8, 2023 1441 Montiel Road, Suite 115 1 Escondido, CA 92026 I Ph (760) 746-4955 I Fax (760) 746-9806 I www.cte-inc.net ' TABLE OF CONTENTS 1.0 INTRODUCTION AND SCOPE OF SERVICES...................... . ..... l 1.1 Introduction........................ . ............................................................... 1 1.2 Scope of Services ............. I 2.0 PROJECT AND SITE DESCRIPTION.. . ............ 2 3.0 FIELD INVESTIGATION AND LABORATORY TESTING ................................................ 2 3.1 Field Investigation................................... . .................... 2 3.2 Laboratory Testing. . ...... 3 4.0 GEOLOGIC AND SOIL INFORMATION.................................... . ... 4 4.1 Regional Geologic Setting. . ............................................................ 4 4.2 Site-Specific Geologic and Soil Conditions ............................. . .................... 4 4.2.1 Quaternary Undocumented Fill (Qudf).. . ....... 5 4.2.2 Quaternary Very Old Paralic Deposits, Unit 12 (Qvop12) ............................ 5 4.2.3 Tertiary Santiago Formation (Tsa): ............................................................... 5 4.4 Site Groundwater Conditions................................. . .................. 6 4.5 Geologic Hazards..................... . ......... 6 4.5.1 Surface Fault Rupture............ . ........................ 6 4.5.2 Local and Regional Faulting........................... . ........................... 7 4.5.3 Liquefaction and Seismic Settlement Evaluation ......................................... 8 4.5.4 Tsunamis and Seiche Evaluation ..... 9 4.5.5 Landsliding............................ . ......................... 9 4.5.6 Compressible and Expansive Soils.................. . .............. 9 4.5.7 Corrosive Soils ..................................... 10 5.0 CONCLUSIONS AND RECOMMENDATIONS......................................... . ....... 11 5. I General.... . ............... 11 5.2 Site Preparation...... . ............ 12 5.2.1 Stripping and Clearing.... . ... 12 5.2.2 Building Pad Grading............................... . ................... 12 5.2.3 Pavement and Hardscape Areas Grading ........ 13 5.3 Site Excavatability .. . ................................................................................. 14 5.4 Cut-Fill Transitions............. . ........................................................... 14 5.5 Fill Placement and Compaction......... . .................. 14 5.6 Fill Materials...... . ......... 15 5.7 Temporary Construction Cuts and Slopes....... .. 16 5.8 Foundation and Slab Recommendations........... . .................. 17 5.8. l New Shallow-Conventional Footing Foundations ...................................... 17 5.8.2 Minimum Steel Reinforcement.. . .... I 7 5.8.3 Foundation Setback.................. . ........................... 18 5.8.4 Bearing Values ............................................................................................ 18 5.8.5 Foundation Settlement... . ........... 18 5.8.6 Interior Concrete Slabs.............. . ......................... 19 5. 9 Seismic Design Criteria .................. 20 5.10 Lateral Resistance and Earth Pressures......... . ......... 21 5.11 Exterior Flatwork .................................... . ......................... 23 5.12 Drainage. . ..................................................................................................... 24 5.13 Permanent Slopes....................... . ... 24 5.14 Controlled Low Strength Materials (CLSM)....... . .......... 25 5.15 Plan Review....................................... . ............................................................ 26 5.16 Construction Observation.... . .............................. 26 6.0 LIMITATIONS OF INVESTIGATION.............. . ....... 27 FIGURES FIGURE I FIGURE 2 FIGURE3 FIGURE4 APPENDICES APPENDIX A APPENDIX B APPENDIXC APPENDIXD SITE INDEX MAP GEOTECHNICAL EXPLORATION MAP REGIONAL FAULT AND SE!SMICITY MAP RETAINING WALL DRAINAGE DETAIL REFERENCES FIELD EXPLORATION LOGS LABORATORY METHODS AND RESULTS STANDARD GRADING SPECIFICATIONS Preliminary Gcotechnical Investigation Proposed Anderson Residence Accessory Dwelling Unit 1877 High Ridge A venue, Carlsbad, California Page 1 March 8, 2023 CTE Job No. 4830.2300005.0000 1.0 INTRODUCTION AND SCOPE OF SERVICES 1.1 Introduction In accordance with your request and CTE proposal number4830.0123.00006 dated January 5, 2023, CTE, Inc. has performed a preliminary geotechnical investigation for the proposed project located at the subject site. The investigation was limited to the area of the proposed Accessory Dwelling Unit (ADU). This report presents the field and laboratory data collected, and provides preliminary conclusions and recommendations, from a geotcchnical standpoint, pertinent to the proposed project. Based on our geotechnical analysis of the data and information obtained, the project is considered to be feasible from a geotcchnical standpoint, provided the recommendations herein are incorporated into the project design and construction. 1.2 Scope of Services The scope of services provided included: • Review of readily available geologic and geotechnical literature pertaining to the site vicinity. • Review of preliminary project plans. • Excavation of three (3) exploratory borings using a portable tripod drill rig and manual drilling equipment. • Performance oflaboratory testing on selected samples of the encountered materials. • Geotechnical engineering analysis of the accumulated data obtained. • Evaluation of potential geologic hazards within the proposed development area. • Preparation of this limited geotechnical report. S.\Projccts\4R30 (GEOJ\4830.2300005.0()(I() (Ander:;on Re:;idence ADU)\Geo Report Filcs\Rpt_ Geotechnical (Anderson Residence ADL').doc Preliminary Geotechnical Investigation Proposed Anderson Residence Accessory Dwelling Unit 1877 High Ridge A venue, Carlsbad, California Page 2 March 8, 2023 CTE Job No. 4830.2300005.0000 2.0 PROJECT AND SITE DESCRJPTION The subject site is located at 1877 High Ridge A venue in the Carlsbad area of San Diego, California (Figure 1). CTE understands that an approximately 560-square-foot Accessory Dwelling Unit (ADU) is proposed in the rear yard of the subject site. Associated retaining wall and hardscapc improvements are also proposed along the southwest edge of the proposed ADU. An existing 2: l slope descends to the rear yard. The proposed ADU is proposed to be constructed into the toe of the slope, with approximate surface elevations of275 feet above mean sea level (msl) at the slope (where a retaining wall is proposed) and 272 feet above msl at the bottom of slope. Approximate elevation information for the development area was obtained from Google Earth satellite imagery (2023). The existing site conditions and approximate location of the proposed ADU are displayed in Figure 2. 3.0 FIELD INVESTIGATION AND LABORATORY TESTING 3.1 Field Investigation CTE perfonncd a limited geotcchnical investigation at the site on January 25, 2023, consisting of a surface reconnaissance and a subsurface exploration program to evaluate current geotcchnical conditions within the proposed ADU development area. The subsurface exploration consisted of the excavation of three exploratory borings using manual drilling equipment and a limited access tripod drill rig equipped with 4.5-inch solid flight augers to final explored depths of approximately 13.5 feet below existing ground surface (bgs). The approximate locations of the exploratory borings are displayed in Figure 2. s.,Projects\4830 (Gf:O)'4830.2300005.00(>0 (Anderson Residence ADL')\Geo Report File~\Rpc_ Geocechmcal (Anden.on Re;idence ADL").dm: Preliminary Geotechnieal Investigation Proposed Anderson Residence Accessory Dwelling Unit 1877 High Ridge A venue, Carlsbad, California March 8, 2023 Page 3 CTE Job No. 4830.2300005.0000 The excavations were continuously logged in the field by a CTE Geologist and were visually classified in general accordance with the Unified Soil Classification System (USCS/ASTM D2487). The field descriptions have been modified, where appropriate, to reflect the laboratory test results. Detailed logs of the excavations are included in Appendix B. Representative bulk samples of the materials encountered were collected at selected locations and depths deemed appropriate to the investigation. The samples were labeled in the field and transported to CTE's laboratory for observation, testing, and geotechnical engineering analysis. 3.2 Laboratory Testing Laboratory testing was performed on select samples of the materials obtained from the exploratory borings to aid in the material classifications and to evaluate gcotechnical engineering properties of the materials encountered. The following tests were performed: • In-situ Moisture Content and Dry Density (ASTM D2216 and D2937) • Particle-Size Distribution Analysis (ASTM D6913) • Expansion Index (ASTM D4829) • Maximum Dry Density and Optimum Moisture Content-Modified Proctor (ASTM DI 557) • Direct Shear (ASTM D3080) • Corrosivity test series, including sulfate content, chloride content, pH-value, and resistivity (CTM 417,422, and 532/643) Testing was performed in general accordance with applicable ASTM standards and California Test Methods (CTM). A summary of the laboratory testing program and the laboratory test results arc presented in Appendix C. S.\Project,\4830 (GEO)\4830.2300005.0000 (Anderson Re,idrnce ADU)\Geo Report File;\Rpt_ Geotechmcal (Andem>n Residence ADU).doc Preliminary Geotechnical Investigation Proposed Anderson Residence Accessory Dwelling Unit 1877 High Ridge A venue, Carlsbad, California March 8, 2023 Page 4 CTE Job No. 4830.2300005.0000 4.0 GEOLOGIC AND SOIL INFORMATION 4.1 Regional Geologic Setting The site is located in the Carlsbad area of San Diego County and within the Peninsular Ranges physiographic province of California that is characterized by northwest-trending mountain ranges, intervening valleys, and predominantly northwest trending active regional faults. The greater San Diego Region can be further subdivided into the coastal plain area, a central mountain-valley area, and the eastern mountain valley area. The project site is specifically located within the coastal plain area. This area is characterized by outcrops of incised and eroded Tertiary sedimentary bedrock overlain in some areas by broad Quaternary terrace and flood plain deposits, and with Quaternary colluvial and alluvial deposits along hillsides and on valley floors. 4.2 Site-Specific Geologic and Soil Conditions Reference to the published regional geologic map, Geologic Map of the Oceanside 30 'x60' Quadrangle, Kennedy & Tan, 2007, indicates that the site is underlain by Quaternary Very Old Paralic Deposits, Unit 12 (Map Symbol: Qvop12). These fonnational materials were encountered during the field investigation at all of the exploratory boring locations underlying existing undocumented fill. The fill soils were encountered to a maximum encountered depth of approximately three feet bgs in Boring, B-1. T crtiary Santiago Formation (Map Symbol: Tsa) was encountered beneath the Very Old Paralic Deposits in Borings, B-1 and 8-2 at approximate depths of nine and eight feet bgs, respectively. The site geologic units encountered during the investigation and general stratigraphic sequence are depicted on Figure 2. Detailed descriptions and information S:\Projects\4830 (GEO)\4830.2300005.0000 (Anderson Residence ADU)1Gco Report F1le~1Rp1_ Gcotechnical (Anderson Residence ADt:l doc Preliminary Geotechnical Investigation Proposed Anderson Residence Accessory Dwelling Unit 1877 High Ridge A venue, Carlsbad, California March 8, 2023 Page 5 CTE Job No. 4830.2300005.0000 concerning the geologic units encountered arc provided in the following paragraphs and on the boring logs in Appendix B. 4.2. l Quaternary Undocumented Fill (QudQ Existing undocumented fill material was encountered at all exploratory boring locations at the surface and was found to be approximately two to three feet in thickness. As observed in the exploratory excavations, the encountered fill generally consists of medium dense, moist, red-brown, fine-to medium-grained silty sand. The fill materials were also observed to contain some organic debris. 4.2.2 Quaternary Very Old Paralic Deposits, Unit 12 (Qvopl2) Very Old Paralic Deposits, Unit 12 (Paralic Deposits) were encountered beneath the fill at all exploratory boring locations at a depth of approximately two to three feet below the existing ground surface. As observed in the exploratory borings, these materials generally consist of dense, slightly moist, red-brown, fine-to medium-grained silty sand, or weathered sandstone. These materials were encountered to a maximum depth of approximately nine feet bgs in Boring, B-1. 4.2.3 Tertiary Santiago Formation (Tsa): Santiago Formation was observed beneath the Very Old Paralic Deposits and was found to be the underlying geologic unit at the site. As observed in Borings, B-1 and B-2, these materials generally consist of hard, slightly moist, light gray, sandy clay to very dense, silty, fine-grained sand, or sandstone. These materials were encountered to the maximum explored depth of approximately 13.5 feet bgs. S:\ProJeces\4830 (GEO)l48.'l0 2300005 0000 (Anderson Residence ADU)IGco Report F1ks\Rpt_ Geotcchnical (Anderson Residence ADUJ.doc Preliminary Geotechnical Investigation Proposed Anderson Residence Accessory Dwelling Unit 1877 High Ridge A venue, Carlsbad, California March 8, 2023 4.4 Site Groundwater Conditions Page 6 CTE Job No. 4830.2300005.0000 Groundwater was not encountered to the maximum explored depth of approximately 13.5 feet bgs. Groundwater is generally not anticipated to be a constraint during project construction. However, it should be understood that groundwater may occur in locations where previously not encountered, especially following periods of sustained precipitation and/or excessive irrigation. Localized seepage or perched water may be encountered during grading and construction. 4.5 Geologic Hazards Geologic hazards that were considered to have potential impacts to site development were evaluated based on field observations, literature review, and laboratory test results. The following paragraphs discuss the geologic hazards considered and their potential risk to the site development. 4.5.1 Surface Fault Rupture In accordance with the Alquist-Priolo Earthquake Fault Zoning Act, (ACT), the State of California established Earthquake Fault Zones around known active faults. The purpose of the ACT is to regulate the development of structures intended for human occupancy near active fault traces in order to mitigate hazards associated with surface fault rupture. According to the California Geological Survey (Special Publication 42, Revised 2018), a fault that has had surface displacement within the last 11,700 years is defined as a Holocene- active fault and is either already zoned or is pending zonation in accordance with the ACT. There arc several other definitions of fault activity that are used to regulate dams, power plants, and other critical facilities, and some agencies designate faults that are documented as older than Holocene (last 11,700 years) and younger than late Quaternary (1.6 million years) as potentially active faults that are subject to local jurisdictional regulations. S 1Projects\4k30 (GEO)\4830.2300005.0000 (Anderson Residence ADC)\Gco Report Files\Rpt_ Gcotechmcal (Anden;on Res,dence ADL") doc Preliminary Geotcchnical Investigation Proposed Anderson Residence Accessory Dwelling Unit 1877 High Ridge A venue, Carlsbad, California March 8, 2023 Page 7 CTE Job No. 4830.2300005.0000 Based on the site reconnaissance and review of referenced literature, the site is not located within a State-designated Earthquake Fault Zone, no known active fault traces underlie or project toward the site, and no known potentially active fault traces underlie or project toward the site. Therefore, the potential for ground surface rupture occurring at the site is considered very low. 4.5.2 Local and Regional Faulting The United States Geological Survey (USGS), with support of State Geological Surveys, and reviewed published work by various researchers, have developed a Quaternary Fault and Fold Database of faults and associated folds that arc believed to be sources of earthquakes with magnitudes greater than 6.0 that have occurred during the Quaternary (the past 1.6 million years). The faults and folds within the database have been categorized into four Classes (Class A-D) based on the level of evidence confinning that a Quaternary fault is of tectonic origin and whether the structure is exposed for mapping or inferred from fault related defonnational features. Class A faults have been mapped and categorized based on age of documented activity ranging from Historical faults (activity within last 150 years), Latest Quaternary faults (activity within last 15,000 years), Late Quaternary (activity within last 130,000 years), to Middle to late Quaternary (activity within last 1.6 million years). The Class A faults are considered to have the highest potential to generate earthquakes and/or surface rupture, and the earthquakes and surface rupture potential generally increases from oldest to youngest. The evidence for Quaternary deformation and/or tectonic activity progressively decreases for Class B and Class C faults. When geologic evidence indicates S.\Projects\4830 (GEO)\4830 2300005.0000 (Anderson Residence ADU)IGeo Report F1kslRpt_ Gcotcchnical (Anderson Residence ADL').doc Preliminary Geotechnical Investigation Proposed Anderson Residence Accessory Dwelling Unit 1877 High Ridge A venue, Carlsbad, California March 8, 2023 Page 8 CTE Job No. 4830.2300005.0000 that a fault is not of tectonic origin it is considered to be a Class D structure. Such evidence includes joints, fractures, landslides, or erosional and tluvial scarps that resemble fault features, but demonstrate a non-tectonic origin. The nearest known Class A fault is the Newport-Inglewood-Rose Canyon Fault Zone ( <1.6 million years), which is approximately 4.0 miles west of the site. The attached Figure 3 shows regional faults and seismieity with respect to their distance from the site. 4.5.3 Liquefaction and Seismic Settlement Evaluation Liquefaction occurs when saturated fine-grained sands or silts lose their physical strengths during earthquake-induced shaking and behave like a liquid. This is due to loss of point-to-point grain contact and transfer of normal stress to the pore water. Liquefaction potential varies with water level, soil type, material gradation, relative density, and probable intensity and duration of ground shaking. Seismic settlement occurs when poorly consolidated silts or sands densify during strong ground shaking. The investigation revealed that the site is underlain at relatively shallow depth by dense Tertiary deposits. Based on the noted subsurface conditions and regional published geology, the potential for liquefaction or significant seismic induced settlement occurring at the site is generally considered to be low. S:\Projccts\4~30 (GEO)\4830.2300005.0000 \Ander,on Residence ADU)\Geo Report tiles\Rpt_ Geotechmca! (Anderson Resitlcnce ADU).iloc Preliminary Geotechnieal Investigation Proposed Anderson Residence Accessory Dwelling Unit 1877 High Ridge A venue, Carlsbad, California March 8, 2023 4.5.4 Tsunamis and Seiche Evaluation Page 9 CTE Job No. 4830.2300005.0000 The site is located well inland of the Pacific Ocean and is at an elevation greater than 200 feet msl. Therefore, the probability of a tsunami reaching the site is considered negligible. Additionally, the site is not located near confined bodies of water. Therefore, the potential for occurrence of seiches caused by seismic or other factors is considered to be low. 4.5.5 Landsliding According to Tan and Giffen (1995), the site is mapped in an urbanized area designated as "generally susceptible" to landsliding. However, no landslides are mapped at the site or site area, and evidence of landsliding or slope instability was not observed. Based on the noted site conditions, if the recommendations provided herein are adhered to and appropriately incorporated into the design and construction of the project, the potential for slope instability from deep-seated landsliding is generally considered low. 4.5.6 Compressible and Expansive Soils The investigation revealed that the proposed development area is underlain by a relatively thin layer of undocumented fill that is potentially compressible in current condition. However, the fonnational materials encountered below the fill are dense and not significantly compressible given the anticipated relatively light foundation loads for the proposed ADU. As such, if the minimum site preparation recommendations provided herein are adhered to, the potential for settlement due to soil compression is considered low. S.\ProJects\4830 (GE0)\4830.23(1(1005.0000 (Anderson Re~it!cnce AD!;)\Geo Report Files\Rpl_ Geotechnical (Anderson Residence ADC}.doc Preliminary Geotechnical Investigation Proposed Anderson Residence Accessory Dwelling Unit 1877 High Ridge A venue, Carlsbad, California March 8, 2023 Page 10 CTE Job No. 4830.2300005.0000 Heaving from expansive soils is a leading cause of damage and damage related claims to structures in the U.S. each year. Clayey soils possess a "sponge-like" hydro-shrink/swell mechanism in which they will expand when provided a water source and will contract when drying. These shrink/swell mechanisms can cause considerable damage to structures, pavements and/or improvements when not properly treated and/or mitigated, particularly when occurring cyclically. Laboratory testing was performed on a representative sample of the fill and shallow native materials to assess their expansion potential characteristics. The test results indicate that these soils possess a low expansion potential. Units of the underlying Paralic Deposits and Tertiary Santiago Formation are occasionally known to possess a medium to high expansion potential in the general site area. Therefore, special care should be taken during grading activities to ensure that potentially expansive site materials are not distributed near-surface of the proposed finished grade. Additional evaluation of exposed materials should be performed during excavation and grading to evaluate expansion potential characteristics. 4.5.7 Corrosive Soils Testing of representative site soils was performed to evaluate the potential corrosive effects on concrete foundations and buried metallic utilities (refer to Appendix C for chemical testing results). Soil environments detrimental to concrete generally have elevated levels of soluble sulfates and/or pH levels less than 5.5. According to the American Concrete Institute (ACI) Table 318 4.3.1, specific guidelines have been provided for concrete where concentrations of soluble sulfate (SO4) in soil exceed 0.10 percent by weight. These S:\Projects\4830 (GEO)'-4830 2300005.0000 (Anderson Residence ADU)\Gen Report tiles\Rpt_ Gentechmcal (Andcn;on Re~idence ADU).doc Preliminary Geotechnical Investigation Proposed Anderson Residence Accessory Dwelling Unit 1877 High Ridge Avenue, Carlsbad, California Page 11 March 8, 2023 CTE Job No. 4830.2300005.0000 guidelines include low water:cement ratios, increased compressive strength, and specific cement type requirements. A minimum resistivity value less than approximately 5,000 ohm- cm and/or soluble chloride levels in excess of 200 ppm generally indicate a corrosive environment for buried metallic utilities and untreated conduits. Chemical test results indicate that near-surface soils at the site present a negligible corrosion potential for Portland cement concrete. Based on resistivity and chloride testing, regional soils have been interpreted to generally have a moderate corrosivity potential to buried metallic improvements. Based on these findings, it may be prudent to utilize plastic piping and conduits where buried and feasible. CTE does not practice corrosion engineering. Therefore, if corrosion of metallic or other improvements is of more significant concern, a qualified corrosion engineer could be consulted. 5.0 CONCLUSIONS AND RECOMMENDATIONS 5.1 General Based on analysis of the presented data and geotechnical information, CTE concludes that the proposed project is feasible, from a geotechnical perspective, provided the preliminary recommendations in this report are incorporated into the design and construction of the project. Preliminary recommendations for the proposed earthwork and improvements arc included in the following sections and Appendix D. However, recommendations in the text of this report supersede those presented in Appendix D should conflicts exist. These preliminary recommendations should either be confirmed as appropriate or updated following preparation of more precise project plans S:\ProJects\4830 (GEO)\4830.2300005.0000 (Anden;on Residence ADU)\Gen Report hlcs1Rpt_ Geotec·hmcal (Anderson Residence ADU).doc Preliminary Gcotechnical Investigation Proposed Anderson Residence Accessory Dwelling Unit 1877 High Ridge Avenue, Carlsbad, California March 8, 2023 Page 12 CTE Job No. 4830.2300005.0000 and following required excavations and observations during site preparation. When final construction plans arc completed, they should be made available for our review, and additional geotechnical analysis and recommendations may be warranted. 5.2 Site Preparation The following recommendations are provided to prepare the site subgrade for development of structures and other associated improvements. 5.2.l Stripping and Clearing Prior to grading activities, areas to receive improvements should be cleared of any existing debris and/or deleterious materials. Any objectionable materials not suitable for structural backfill, such as construction or demolition debris and vegetation, should be properly disposed of off-site. 5.2.2 Building Pad Grading The proposed ADU development area should be over-excavated to a minimum depth of three feet below the existing or proposed grade, to 1.5 feet beneath the bottoms of proposed footings, or to the depth of competent native materials, whichever is deeper. Additionally, differences in overexcavation depths should not be greater than 3: I across the site beneath footings. Localized deeper remedial excavations may be necessary based on exposed conditions encountered during grading activities. S:\ProJec!s\4830 (GEO)\4830.2300005.0000 (Anderson Residence ADU)IGeo Report Files\Rpt_ G~-otechnical (Anderson Re.sidencc ADU) doc Preliminary Gcotechnical Investigation Proposed Anderson Residence Accessory Dwelling Unit 1877 High Ridge Avenue, Carlsbad, California March 8, 2023 Page 13 CTE Job No. 4830.2300005.0000 The over-excavations should extend horizontally at least five feet outside the perimeter of building footprint or to a distance equal to the adjacent vertical over-excavation depth, whichever is greater and where feasible. Overexcavations extending laterally into the existing slope may create an over steepened temporary cut slope condition and therefore, the lateral extent of excavation into the slope may be reduced as necessary. Excavation bottoms should be observed and verified for competency by a CTE geotechnical representative prior to placement of any new fill, and the excavation bottoms should be scarified to a minimum depth of eight inches, moisture conditioned, and compacted as recommended herein. Depending upon proximity and condition of exposed soils, ovcrexcavation in slot cuts may be recommended by the geotcchnical engineer. 5.2.3 Pavement and Hardscape Areas Grading In general, pavement and hardscape areas should be overexcavated to a minimum depth of two-feet below existing grades or to the depth of competent underlying native material, whichever is deeper. CTE should observe the exposed excavation bottom to determine if further removals arc necessary. Excavations should extend horizontally at least two feet outside the perimeter of proposed improvements, as feasible. Excavation bottoms should be observed and verified for competency by a CTE geotechnical representative prior to placement of any new fill, and the excavation bottoms should be scarified to a minimum depth of eight inches, moisture conditioned, and compacted as recommended herein. S·\Project;\4830 (GEO)'4830.2300005.0000 (Anden;on Residence ADL')\Geo Repon Files\Rp!_Geotechnical (Anderson Residence ADL) doc Preliminary Geotechnical Investigation Proposed Anderson Residence Accessory Dwelling Unit 1877 High Ridge Avenue, Carlsbad, California March 8, 2023 5.3 Site Excavatability Page 14 CTE Job No. 4830.2300005.0000 Based on CTE 's observations and experience with similar materials in the area, shallow excavations at the site should generally be feasible using standard, heavy-duty excavation equipment. However, contractors should be responsible for making their own independent assessment of the site excavatability characteristics. 5.4 Cut-Fill Transitions Although not anticipated based on the pad mm1mum over-excavation and foundation recommendations, foundation bottoms for proposed structures or site improvements should not span across cut-fill transitions. Should a cut-fill transition exist in improvement areas, CTE should be contacted for additional recommendations, as necessary. 5.5 Fill Placement and Compaction Any fill or backfill placed on the site should be compacted to a minimum relative compaction of 90 percent (95 percent in the upper 12 inches of pavement soil subgradc) at a minimum two percent above optimum moisture content, as determined by ASTM D 1557. The optimum lift thickness for fill depends on soil type and on the type of compaction equipment used. Generally, backfill should be placed in uniform, horizontal lifts not exceeding eight inches in loose thickness. Fill placement and compaction should be conducted in conformance with local ordinances and should be observed and tested by a CTE geotechnical representative. S:IProiects,4830 {GEO)14830.2300005 0000 (Anderson Residence ADLIJ\Geo Report Files\Rpt_ Cieotechnica! (Anderson Residence ADU).doc Preliminary Geotechnical Investigation Proposed Anderson Residence Accessory Dwelling Unit 1877 High Ridge A venue, Carlsbad, California March 8, 2023 5.6 Fill Materials Page 15 CTE Job No. 4830.2300005.0000 On-site soils are generally considered suitable for reuse on the site as structural fill if they are screened of organics and deleterious materials and contain no irreducible lumps greater than six inches in maximum dimension. Fill within the upper three feet of planned finished grades should not contain irreducible lumps or materials greater than approximately three inches in maximum dimension. Total rock content of fill soils should adhere to the specifications provided in Appendix D. In utility trenches, granular soil without lumps or rock should be utilized surrounding pipes to ensure proper encasement during compaction. If utilized, imported fill should have an Expansion Index of 20 or less (ASTM D4829) and be free of lumps and oversized rock (refer to Appendix D for maximum rock content criteria). Potential import sources should be observed and sampled by a representative of CTE prior to delivery on-site. Retaining wall backfill located within a 45-degree wedge extending up from the bottom of the heel foundation of the wall should consist of soil having an Expansion Index of 20 or less (ASTM D 4829) with less than 30 percent passing the No. 200 sieve. The upper 12 to 18 inches of wall backfill should consist oflower penneability soils (fine-grained), in order to reduce surface water infiltration behind walls. The project structural engineer and/or architect should detail proper wall backdrains, including gravel drain zones, fills, filter fabric and perforated drainpipes. A conceptual wall drainage detail is provided in Figure 4. S:\Projects\4830 (GEO)\4830.2300005.0000 (Ander:;on Residence ADL')IGeo Report hles\Rpt_ Geotechmcal (An<lerson Re~idence ADU).doc Preliminary Geotechnical Investigation Proposed Anderson Residence Accessory Dwelling Unit 1877 High Ridge A venue, Carlsbad, California March 8, 2023 5.7 Temporary Construction Cuts and Slopes Page 16 CTE Job No. 4830.2300005.0000 The following recommendations for temporary cuts and slopes should be relatively stable against deep-seated failure but may experience a degree oflocalized sloughing. Surcharging from material stockpiles, grading equipment, or construction materials at tops of cuts and/or slopes should be avoided within a minimum distance equal to the total vertical height of the excavation. Overexcavation into the slope may create an over steepened cut slope condition. Therefore, the geotechnical representative should observe the exposed cut during grading to confinn temporary stability, as necessary. The following criteria should be considered for unbraced/ unshared temporary excavations and/or trenches without the use of proper shoring. The on-site soils are considered Type Band C soils with recommended slope ratios as set forth in Table 5.7. TABLE5.7 RECOMMENDED TEMPORARY SLOPE RATIOS SOIL TYPE SLOPE RATIO MAXTh1UM HEIGHT (Horizontal: vertical) C (Existing fill and/or any soils not 1.5:1 (OR FLATTER) 5 Feet identified durinQ the mvestiQation) B (Para\ic Deposits and Santiago 1:1 (OR FLATTER) 5 Feet Formation) Actual field conditions and soil type designations for all temporary slopes must be verified by a "competent person" while excavations exist, according to Cal-OSHA regulations. In addition, the S:\Projects\4830 (GEO)\4830.2300005.0000 (Anderson Residence ADU)IGeo Rcpon fi\es\Rpt_ Gentechnical (Anderson ResidL-nce ADL.:).doc Preliminary Geotechnical Investigation Proposed Anderson Residence Accessory Dwelling Unit 1877 High Ridge Avenue, Carlsbad, California March 8, 2023 Page 17 CTE Job No. 4830.2300005.0000 above sloping recommendations do not allow for surcharge loading at the top of slopes by vehicular traffic, equipment or materials. Appropriate surcharge setbacks must be maintained from the top of all unshared slopes. 5.8 Foundation and Slab Recommendations The following recommendations are for preliminary design purposes only. These foundation recommendations should be re-evaluated after review of the project grading and foundation/building plans, and after completion of rough grading of the development area. 5.8. l New Shallow-Conventional Footing Foundations The proposed ADU may be supported on shallow-conventional continuous and spread- isolated footing foundations bearing entirely into new engineered fill. All footings should be embedded at least 18 inches below lowest adjacent subgrade and possess a minimum width of 15 inches; however, spread-isolated footings should possess a minimum square width of 24 inches. 5.8.2 Minimum Steel Reinforcement CTE recommends that continuous footings be reinforced using a minimum of four No. 5 reinforcing bars, with two placed near the top and two near the bottom. If deemed by the structural engineer to be appropriate, a different reinforcing steel layout may be designated. A minimum clearance of 3-inches should be maintained between steel reinforcement and the bottom or sides of the footing to ensure proper concrete encasement of steel reinforcement. S:\Projects'4830 (GEO)\4830.2300005.0000 (Anden,on Residence ADL1)'.Geo Report hles\Rpt_ Geotechnical (Anderson Residence ADUJ.doc Preliminary Geotechnical Investigation Proposed Anderson Residence Accessory Dwelling Unit 1877 High Ridge A venue, Carlsbad, California March 8, 2023 Page 18 CTE Job No. 4830.2300005.0000 These reinforcing recommendations are provided as a minimum to reduce the potential for cracking and/or distress. The project civil or structural engineer should design isolated footing reinforcement and review all steel reinforcing schedules. 5.8.3 Foundation Setback Properly embedded footings for the proposed structure should be designed such that the horizontal distance from the face of adjacent descending slopes to the outer edge of the footing is a minimum often feet. In addition, foundations should bear beneath an imaginary 1: 1 plane extended up from the nearest bottom edge of adjacent parallel trenches or excavations located generally within ten feet. Deepening of affected footings should be a suitable means of attaining the prescribed setbacks. 5.8.4 Bearing Values Continuous and isolated footing foundations at the recommended embedment depth bearing entirely into new engineered fill may be designed for an allowable bearing pressure of2,500 pounds per square foot (psf) for dead loads. An additional 1/3 increment may be used for short duration live load analysis, which includes the effects of wind or seismic forces. 5.8.5 Foundation Settlement For structures founded on properly embedded footings, the total and differential static settlements arc expected to be on the order of I-inch total and ½-inch differential over a distance of 40 feet. Due to the generally dense nature of relatively shallow underlying natural materials, dynamic settlement is not expected to adversely affect the proposed improvements. S:\Projects\4830 (GE0)\4830.23()0005.0000 (Anderson Residence ADL")\Gco Report Files\Rp!_Geo!eclmical (Anderson Residence ADU).doc Preliminary Geotechnical Investigation Proposed Anderson Residence Accessory Dwelling Unit 1877 High Ridge A venue, Carlsbad, California March 8, 2023 5.8.6 Interior Concrete Slabs Page 19 CTE Job No. 4830.2300005.0000 Lightly loaded interior concrete slab-on-grade for non-traffic areas should be a minimum of 4.5 inches thick, or slabs should be designed and detailed per recommendations of the project structural engineer. Minimum reinforcement for lightly loaded slabs should consist of #4 reinforcing bars placed on maximum 18-inch centers, each way, at or above mid-slab height, but with proper cover or as per the recommendations of the project structural engineer. Slabs subjected to heavier loads or traffic will require thicker slab sections and/or increased reinforcement. In moisture-sensitive non-traffic floor areas, a suitable vapor retarder of at least 15-mil thickness (with all laps or penetrations sealed or taped) overlying a four-inch layer of consolidated aggregate base or gravel (or sand with SE of 30 or more) should be installed. An optional maximum two-inch layer of similar material may be placed above the vapor retarder to help protect the membrane during steel and concrete placement. This recommended protection is generally considered typical in the industry. If proposed floor areas or coverings are considered especially sensitive to moisture emissions, additional recommendations from a specialty consultant could be obtained. CTE is not an expert at preventing moisture penetration through slabs. A qualified architect or other experienced professional should be contacted if moisture penetration is a more significant concern. S:\Projects\4830 (GEO)\4830.2300005.0000 (Anderson Residence ADL')\Geo Repon Files\Rpt_ GeoK.:hnical (Anderson Res,dence ADU).doc Preliminary Geotechnical Investigation Proposed Anderson Residence Accessory Dwelling Unit 1877 High Ridge Avenue, Carlsbad, California March 8, 2023 Page 20 CTE Job No. 4830.2300005.0000 A 110-pci subgrade modulus is considered suitable for elastic design of minimally embedded improvements such as slabs-on-grade. Subgrade materials should be maintained at a minimum of two percent above optimum moisture content until slab underlayment and concrete are placed. 5.9 Seismic Design Criteria The seismic ground motion values listed in Table 5.9 below were derived in accordance with the ASCE 7-16 Standard that is incorporated into the 2022 California Building Code. This was accomplished by establishing the Site Class based on the subsurface conditions at the site and calculating site coefficients and parameters using the using the SEAOC-OSHPD U.S. Seismic Design Maps application. These values are intended for the design of structures to resist the effects of earthquake ground motions for the site coordinates 33.1526106° latitude and -117.3172294° longitude, as underlain by soils corresponding to site Class C-Very Dense Soil and Soft Rock. s.,Projects\4830 (GE0)14830 2300005.0000 (Anderson Residence ADU)\Geo Report Files\Rpt_ Veoted1rucal (Anderson Res,dence ADL").doc Preliminary Geotechnical Investigation Proposed Anderson Residence Accessory Dwelling Unit 1877 High Ridge A venue, Carlsbad, California March 8, 2023 TABLES.9 Page 21 CTE Job No. 4830.2300005.0000 SEISMIC GROUND MOTION VALUES (CODE-BASED) 2022 CBC AND ASCE 7-16 PARAMETER VALUE 2022 CBC/ASCE 7-16 REFERENCE Site Class C ASCE 16, Chapter 20 Mapped Spectral Response 1.015 Figure 1613.2.1 (1) Acceleration Parameter, Ss Mapped Spectral Response 0.369 Figure 1613.2.1 (2) Acceleration Parameter, S1 Seismic Coefficient, Fa 1.200 Table 1613.2.3 (1) Seismic Coefficient. F, 1.500 Table 1613.2.3 (2) MCE Spectral Response 1.218 Section 1613.2.3 Acceleration Parameter, SMs MCE Spectral Response 0.554 Section 1613.2.3 Acceleration Parameter, Sr,t1 Design Spectral Response 0.812 Section 1613.2.5(1) Acceleration, Parameter SDs Design Spectral Response 0.369 Section 1613.2.5 (2) Acceleration, Parameter SD 1 Peak Ground Acceleration PGAM 0.534 ASCE 16, Section 11.8.3 5.10 Lateral Resistance and Earth Pressures Lateral loads acting against structures may be resisted by friction between the footings and the supporting soil or passive pressure acting against structures. If frictional resistance is used, allowable coefficients of friction of0.30 (total frictional resistance equals the coefficient of friction multiplied by the dead load) for concrete cast directly against new engineered fill or relatively undisturbed competent natural materials is recommended. A design passive resistance value of250 pounds per square foot per foot of depth (with a maximum value of2,500 pounds per square foot) may be used for structures embedded in either new engineered fill or undisturbed competent natural materials. The allowable lateral resistance can be taken as the sum of the frictional resistance and the passive resistance, provided the passive resistance does not exceed two-thirds of the total allowable resistance. S.\Projects\4830 (GEO}',4830.2300005.0000 (Andcrwn Residence ADL")\Geo Report files\Rpt_ Geotechnical (Anderson Residence ADIJ).doc Preliminary Geotechnical Investigation Proposed Anderson Residence Accessory Dwelling Unit 1877 High Ridge Avenue, Carlsbad, California Page 22 March 8, 2023 CTE Job No. 4830.2300005.0000 Proposed retaining walls backfilled using granular low expansion potential soils may be designed using the equivalent fluid unit weights given in Table 5.10 below. WALL TYPE LEVEL BACKFILL SLOPE BACKFILL 2:1 (HORIZONTAL: CANTILEVER WALL (YIELDING) RESTRAINED WALL 45 55 VERTICAL 65 80 Lateral pressures on cantilever retaining walls (yielding walls) over six feet high due to earthquake motions may be calculated based on work by Seed and Whitman ( 1970). The total lateral earth pressure against a properly drained and backfilled cantilever retaining wall above the groundwater level can be expressed as: PAE= PA+ dPAE For non~yielding (or "restrained'') walls, the total lateral earth pressure may be similarly calculated based on work by Wood ( 1973): Where PAlh = Static Active Earth Pressure= GhH2/2 PK!b = Static Restrained Wall Earth Pressure= GhH2/2 dPArJb = Dynamic Active Earth Pressure Increment= (3/8) lo. yH2 dPK.Ub = Dynamic Restrained Earth Pressure Increment= kh yH2 b = unit length of wall (usually l foot) kh = 1/2* PGAm (PGAm given previously Table 5.9) Gh = Equivalent Fluid Unit Weight (given previously Table 5.10) H = Total Height of the retained soil S:'Proje<·rs\4830 (GE0)\4S30.2300(105.0000 (Andcr.,on Residence AOUJ1Geo Report F,les\Rpt_ Geotechnical ( Anderson Residence ADU).doc Preliminary Geotechnical Investigation Proposed Anderson Residence Accessory Dwelling Unit 1877 High Ridge Avenue, Carlsbad, California March 8, 2023 Page 23 CTE Job No. 4830.2300005.0000 y = Total Unit Weight of Soil::::: 135 pounds per cubic foot *It is anticipated that the 1/2 reduction factor will be appropriate for proposed walls that are not substantially sensitive to movement during the design seismic event. Proposed wal!s that are more sensitive to such movement could utilize a 2/3 reduction factor. If any proposed walls require minimal to no movement during the design seismic event, no reduction factor to the peak ground acceleration should be used. The project structural engineer of record should determine the appropriate reduction factor to use (if any) based on the specific proposed wall characteristics. The static and increment of dynamic earth pressure in both cases may be applied with a line of action located at H/3 above the bottom of the wall (SEAOC, 2013). These values assume non-expansive backfill and free-draining conditions. Measures should be taken to prevent moisture buildup behind all retaining walls. Drainage measures should include free- draining backfill materials and sloped, perforated drains. These drains should discharge to an appropriate off-site location. Waterproofing and proper drainage are critical components of retaining walls. critical to the anticipated large and deep retaining/basement walls. It is highly recommended that any and all wall drains be constructed low enough so that water cannot rise above the top of interior building slab or finish floor elevation, and preferably well below the bottom of slab elevations. Waterproofing should be as specified and detailed by the project architect or other specialty consultant. 5 .11 Exterior Flatwork Lightly loaded exterior flatwork for non-traffic areas should be a minimum of 4.5 inches in thickness and installed with crack-control joints at appropriate spacing as designed by the project architect to reduce the potential for cracking in exterior flatwork caused by minor movement of subgrade soils and concrete shrinkage. Additionally, it is recommended that flatwork be installed with at least #4 S \ProJects\4830 (GEO)\4830.2300005.0000 (Anderson ReSJ<lCTice ADU)\Geo Report Files1Rpt_ Geoteduucal (An den.on Residence AOL') doc Preliminary Geotechnical Investigation Proposed Anderson Residence Accessory Dwelling Unit 1877 High Ridge A venue. Carlsbad, California March 8, 2023 Page 24 CTE Job No. 4830.2300005.0000 reinforcing bars at 18-inch centers, each way, at or above mid-height of slab, but with proper concrete cover, or with other reinforcement per the applicable project designer. Flatwork that should be installed with crack control joints, includes sidewalks, and architectural features. All subgradcs should be prepared according to the earthwork recommendations previously given before placing concrete. Positive drainage should be established and maintained next to all flatwork. Subgrade materials should be maintained at a minimum of two percent above optimum moisture content until the time of concrete placement. 5.12 Drainage Surface runoff should be collected and directed away from improvements by means of appropriate erosion-reducing devices and positive drainage should be established around the proposed improvements. Positive drainage should be directed away from improvements at a gradient of at least two percent for a distance of at least five feet. However, the project civil engineers should evaluate the on-site drainage and make necessary provisions to keep surface water from affecting the site. Generally, CTE recommends against allowing water to infiltrate building pads or adjacent to slopes. CTE understands that some agencies arc encouraging the use of storm-water c1eansing devices. Use of such devices tends to increase the possibility of adverse effects associated with high groundwater. 5.13 Permanent Slopes Any proposed permanent cut and/or fill slopes should be constructed at a ratio of 2: 1 (horizontal: vertical) or flatter. Based on anticipated soil strength characteristics slopes of the cut and/or fill materials, these 2: 1 slope inclinations should exhibit factors of safety greater than 1.5. S:\Projecn.14830 (GEO)\4830.2300005 0000 (Anderson Residence ".DL")iGeo Report hlcs\Rpt_ Geotechnical (Ander.;on Residence ADU) doc Preliminary Geotechnical Investigation Proposed Anderson Residence Accessory Dwelling Unit 1877 High Ridge Avenue, Carlsbad, California March 8, 2023 Page 25 CTE Job No. 4830.2300005.0000 Although properly constructed slopes on this site should be grossly stable, the soils will be somewhat erodible. Therefore, runoff water should not be permitted to drain over the edges of slopes unless that water is confined to properly designed and constructed drainage facilities. Erosion-resistant vegetation should be maintained on the face of all slopes. Typically, soils along the top portion of a fill slope face will creep laterally. CTE recommends against building distress- sensitive hardscape improvements within five feet of slope crests. 5.14 Controlled Low Strength Materials (CLSM) Where approved, Controlled Low Strength Materials (CLSM) may be used in deepened footing excavation areas, building pads, and/or adjacent to retaining walls or other structures, provided the appropriate following recommendations are also incorporated. Minimum over-excavation depths recommended herein beneath slabs, flatwork, and other areas may be applicable beneath CLSM if/where CLSM is to be used, and excavation bottoms should be observed by CTE prior to placement of CLSM. Prior to CLSM placement, the excavation should be free of debris, loose soil materials, and water. Once specific areas to utilize CLSM have been determined, CTE should review the locations to determine if additional recommendations are appropriate. CLSM should consist of a minimum three-sack cement/sand slurry with a minimum 28-day compressive strength of 100 psi (or equal to or greater than the maximum allowable short term soil bearing pressure provided herein, whichever is higher) as determined by ASTM D4832. If re- excavation is anticipated, the compressive strength of CLSM should generally be limited to a maximum of 150 psi per ACI 229R-99. Where re-excavation is required, two-sack cement/sand S:\ProJccts\4830 1GEO)\4830.2300005.0000 (Ander.;on Residence ADU)\Geo Report F,b1Rpt_Geotechnical (Anderson Residence ADl.i) doc Preliminary Geotechnical Investigation Proposed Anderson Residence Accessory Dwelling Unit 1877 High Ridge A venue, Carlsbad, California March 8, 2023 Page 26 CTE Job No. 4830.2300005.0000 slurry may be used to help limit the compressive strength. The allowable soils bearing pressure and coefficient of friction provided herein should still govern foundation design. CLSM may not be used in lieu of structural concrete where required by the structural engineer. 5.15 Plan Review CTE should be authorized to review the project grading and/or foundation/building plans prior to commencement of earthwork in order to provide additional evaluation and recommendations, as is anticipated to be necessary. 5.16 Construction Observation The recommendations provided in this report are based on preliminary design information for the proposed construction and the subsurface conditions observed in the subsurface explorations. The interpolated subsurface conditions should be confirmed by CTE once more precise project plans are available and during construction with respect to anticipated conditions. Upon completion of precise grading, if necessary, soil samples will be collected to evaluate as-built Expansion Index. Foundation recommendations may be revised upon completion of grading, and as-built laboratory tests results. Additionally, soil samples should be taken in pavement subgrade areas upon rough grading to refine pavement recommendations as necessary. Recommendations provided in this report are based on the understanding and assumption that CTE will provide the observation and testing services for the project. All earthwork should be observed and tested in accordance with recommendations contained within this report. CTE should evaluate footing excavations before reinforcing steel placement. S:\J'roJecls\4830 (GEO)\4830.2300005.0000 (Anderson Residen~e ADU)IGeo Repon File~·!Rp!_ Geo!echnical (Anderson Residence ADU) doc Preliminary Gcotechnical Investigation Proposed Anderson Residence Accessory Dwelling Unit 1877 High Ridge Avenue, Carlsbad, California March 8, 2023 Page 27 CTE Job No. 4830.2300005.0000 6.0 LIMITATIONS OF INVESTIGATION The field evaluation, laboratory testing, and geotechnical analysis presented in this report have been conducted according to current engineering practice and the standard of care exercised by reputable gcotechnical consultants performing similar tasks in this area. No other warranty, expressed or implied, is made regarding the conclusions, recommendations and opinions expressed in this report. Variations may exist and conditions not observed or described in this report may be encountered during construction. This report is prepared for the project as described. It is not prepared for any other property or party. The recommendations provided herein have been developed in order to reduce the post-construction movement of site improvements related to soil settlement and expansion. However, even with the design and construction recommendations presented herein, some post-construction movement and associated distress may occur. The findings of this report are valid as of the present date. However, changes in the conditions of a property can occur with the passage of time, whether they are due to natural processes or the works of man on this or adjacent properties. In addition, changes in applicable or appropriate standards may occur, whether they result from legislation or the broadening of knowledge. Accordingly, the findings of this report may be invalidated wholly or partially by changes outside CTE's involvement. Therefore, this report is subject to review and should not be relied upon after a period of three years. S:\Projects\4830 (GEO)l4830.2300005.0000 {Anderson Residence ADU)\Gco Report HblRpt_ Gcotechn,cal (Anderson Residence ADU).doc Preliminary Geotechnical Investigation Proposed Anderson Residence Accessory Dwelling Unit 1877 High Ridge Avenue, Carlsbad, California March 8, 2023 Page 28 CTE Job No. 4830.2300005.0000 CTE's conclusions and recommendations are based on an analysis of the observed conditions. If conditions different from those described in this report arc encountered, CTE should be notified and additional recommendations, if required, will be provided subject to CTE remaining as authorized geotechnical consultant ofrecord. This report is for use of the project as described. It should not be utilized for any other project. CTE appreciates this opportunity to be of service on this project. If you have any questions regarding this report, please do not hesitate to contact the undersigned. Respectfully submitted, CONSTRUCTION TESTING & ENGINEERING, INC. David J. Tamborrell, GIT #947 Project Geologist DJT/DAKIDTM :ach Dennis A. Kilian, CEG #2672 Senior Engineering Geologist S IProjects\4~30 (GEO)',4830.230(l{)()5.0000 (Anderson Residence ADIJ)\Gco Repon Filcs\Rpt_ Geotechnical (Anderson Residence ADUJ.doc /ons9 " .. ~ c/11"''~ 1,....,_., Rancho Cad 0 .11ne•& Assoc, ; ~ Construclion Testing & E~neering,_I~ __ l Compean, ~, .... , ~, ~•ta:..,..,"\1'W'V 1 °"'~I ~ I SITB INDEX KAP PROPOSED J.NDDSON !DDfflONil DRWNG UNIT 1877 mGB RIDGI AVINUI CARISJW), c.wroRNJA SCALE: AS SIIOIM DATE: 1/2023 CTE JOB NO.: FIGURE: 4830.2300005 EXPLANATION 8-1 ♦ APPROXIMATE BORING LOCATION Qudf QUATERNARY UNDOCUMENTED Fill OVER Qvop, 12 QUATERNARY VERY OLD PARALIC DEPOSITS, UNIT 12 OVER Tsa TERTIARY SANTIAGO FORMATION ~910-&WttLE. fORJION.OFf" FIIOMltU.SICll 1_0 ___ _,,.0.-----------=-10 2oc._ ___ 30 • ■ • I I ' l:U)l■C11■1f"''.llll--=== , SCALE 1" 10' \ \ \ I \ I I ! l "'0 j s ),.,~, t f..ttf.-:./1, ~C,,.E...~::>t:J't•~.SC.'!' F~RE"".'~~EJCCA./At'l(»( VCPOFrs.$$C Y P~C~O-S~'E. ,oR Jt'JN.oeF FR~ ..U.$0!' z APN: 207-385 390-0 EXISTING SFR W/ ATTA HEO 2 CAR GARAGE 1877 HIGH RIDGE ORI J GEOTECHNICAL EXPLORATION KAP PROPOSED ANDERSON ADDfflONAL DllEWNG UNIT urn HIGH RIDGE AVENUB CARIS C 1873 HIGH RI LEGEND 6 , 12 j 1 inch -12 ml. 11<> """'S-4/JMM!i!!'ll!M!Glftll!-111,.1!1,o HISTORIC FAULT DISPLACEMENT (LAST 200 YEARS) HOLOCENE FAULT DISPLACEMENT (DURING PAST 11,700 YEARS) ,_...,_,,_,_.,;.,..,. LATE QUATERNARY FAULT DISPLACMENT (DURING PAST 700,000 YEARS) , __ ..,,,.., -QUATERNARY FAULT DISPLACEMENT (AGE UNDIFFERENTIATED) 1800-1869- 1868 1931 ~7.0 ®. 6.~.9 ~ - 55-5.9 @ • 5.0-5.4 e') • M : PAUl.T ACfflllT 1W' OP C4U10IUII&, 2010, cmPOtN1A GIOWGIC DlU II.IP SIIIIS IIAP NO. e: E I .......,_C 1932- 2010 ., IPICIN'TIIS or ,lllJ) uus DAlllGID BY~CW10ID01 ••-u.1119. 1aoo-111111 .\D.IJ'TID @»I REGIONAL FAULT AND SEISKICJTY KAP , -===---1 u_ ,,_ .,..... a-_,..... Pih• c ~-~~C"..tt'lllll,~t-,r:,_lfffing ... -.;. PROPOSED '""'"""O" '"Dm AL D..,,, ... G .. ~ -·-'IOPPO...i,I, BIWIUII, ,.,__ Ill, CUIIIII, .IND 111 ........ 2000, ,I, ,-----~ -~-NW=-> n au ON ........... UN1T ~ .. _....;;CD;;;;ll&=IIAP=~-~="==-===::.i.==;;...;.:.:.:.=;..:::~=-===-=;:.;.------''----~-l/,-= __ -_' __ ,_-__ ,,::_·.._ __ • ...... __ , •• _ ....... __ -_____ _,L _____ 1_e.l:77=mo1.GlljH:lfu..RIDG.l:J!!dE~A~VENUE.l!!.!ii!_ _____ u:.:::::::..J1-..::.-.J ; ~ JOI &DDITIOIW. UPWU.TIOII; IIODIPIIII 11TB Cl8II ,lllJ) IJSCS SIISIIIC ll.lPS CAR C ORNIA RETAINING WALL WATERPROOFING TO BE SPECIFIED BY ARCHITECT FINISH GRADE *CONCEPTUAL ORA WII\G 4 <1 12" TO 18" OF LOWER PERMEABILITY MATERIAL COMPACTED TO 90% RELATIVE COMPACTION •• SELECT GRANULAR WALL / BACKFILL COMPACTED / -. ; TO 90% RELATIVE COMPACTION .--- 3/4" GRAVEL SURROUNDED BY FILTER FABRIC (MIRA FI 140 N. OR EQUIVALENT) -OR- PREFABRICATED DRAINAGE BOARD !'MIN 4" DIA PERFORATED PVC PIPE (SCHEDULE 40 OR EQUIVALENT). MINIMUM 1 % GRADIENT TO SUIT ABLE OUTLET '"·-·· ii!'""',,,_..., Constructioo Testing & Eng,Mering, Inc. "'-e'f::1/-~: ~---,_.,.,.,.,.,...,.,,_,_,""'_' ___ RBTAINIIIG 11'.lll. DIWIWlll DIIT.U. SCALE: DATE: NO SCAIJ: 1/2023 CTE JOB r.Q.: RGURE: ..,..,,..... . APPENDIX A REFERENCES REFERENCES 1. American Society for Civil Engineers, 2019, "Minimum Design Loads for Buildings and Other Structures," ASCE/SEI 7-16. 2. ASTM, 2002, "Test Method for Laboratory Compaction Characteristics of Soil Using Modified Effort," Volume 04.08 3. California Building Code, 2022, "California Code of Regulations, Title 24, Part 2, Volume 2 of2," California Building Standards Commission, published by ICBO. 4. California Division of Mines and Geology, CD 2000-003 "Digital Images of Official Maps of Alquist-Priolo Earthquake Fault Zones of California, Southern Region," compiled by Martin and Ross. 5. California Emergency Management Agency/California Geological Survey, "Tsunami Inundation Maps for Emergency Planning." 6. Hart, Earl W., Revised 1994, Revised 2018, "Fault-Rupture Hazard Zones in California, Alquist Priolo, Special Studies Zones Act of 1972," California Division of Mines and Geology, Special Publication 42. 7. Jennings, Charles W., 1994, "Fault Activity Map of California and Adjacent Areas" with Locations and Ages of Recent Volcanic Eruptions. 8. M.P. Kennedy, S.S. Tann, 2007, "Geologic Map of the Oceanside 30'x60' Quadrangle, California", California Geological Survey. 9. Reichle, M., Bodin, P., and Brune, J., 1985, The June 1985 San Diego Bay Earthquake swarm (abs.]: EOS, v. 66, no. 46, p.952. 10. Seed, H.B., and R.V. Whitman, 1970, "Design of Earth Retaining Structures for Dynamic Loads," in Proceedings, ASCE Specialty Conference on Lateral Stresses in the Ground and Design of Earth-Retaining Structures, pp. I 03-147, Ithaca, New York: Cornell University. 11. Tan, Siang S. and Giffen, Desmond G., 1995, "Landslide Hazards in the Northern Part of the San Diego Metropolitan Area, San Diego County, California", Landslide Hazard Identification Map No. 35, Plate 35A, California Division of Mines and Geology. 12. Wood, J.H. 1973, Earthquake-Induced Soil Pressures on Structures, Report EERL 73-05. Pasadena: California Institute of Technology. APPENDIX B FIELD EXPLORATION LOGS C ~ Constrvclion Testing & Engineering, Inc. ~ ·--' , C-i,or,y ,._:-,: -,_._1-.-,f-<A<<.~ - DEFINITION OF TERMS PRIMARY DIVISIONS SYMBOLS SECONDARY DIVISIONS CLEAN ~ 41 GW t WELL GRADED GRAVELS, GRAVEL-SAND MIXTL'RES GRAVELS GRAVELS -21 ---UTILE OR NO FINES MORE THAI\' POORLY GRADED GRAVELS OR GRAVEL SAND MIXTIJRES. z HALF OF < 5% FINES !\ .. (jp;.. • < LITTLE OF NO FINES "•a COARSE SIL TY GRA \'ELS, GRAVEL-SA:-.'D-SILT MIXTURES, Co ii: FRACTION 1S GM rr. ~~!:::, GRAVELS NON PLASTIC FINES 0 "< ". LARGER THAN WITH FNES i.l '-' w NO. 4 STEVE GC CLAYEY GRAVELS.GRAVEL-SAND-CLAY MIXTURES, z;:: ~ > -z ..; [].l ' PLASTIC FINES :< ;;;<ii --------=----.:◄ ViELL GRADED SA:-.'DS. GRAVELLY SANDS. UTTLE OR NO '-'i=:::s SA'.'IIDS CLEAN -~:.:..i''Y.~:-c FINES i.iw <"' MORETHAJ.J SAJ\'DS POORLY GRADED SANDS, GRAVELLY SANDS, LJTTLE OR ~ ~ ;;2 ci HALF OF < 5% FINES SP <,~w7. COARSE NOFIJ\'ES 0 r SMUS ~ SM I u ~ FRACTION IS SIL TI SA.'\JDS, SAND-SILT MIXTURES, !\'ON-PLASTIC FINES SMALLER THAN NO. 4 SIEVE \HfH FTh'ES CLAYEY SANDS, SAND..CLA Y MIXTIJRES, PLASTIC FINES SC ML INORGANIC SILTS, VERY FINE SA.'IDS, ROCK FLOUR. SILTY "" OR CLAYEY FINE SANDS SLIGI-JTL Y PLASTIC CLAYEY SIL TS "'.,,, c,J t:::I SILTSA:'IIDCLAYS -0 ...l"' INORGANIC CLAYS OF LOW TO MEDIUM PLASTICITY, 0"" ~ u.i LIQUID LIMIT IS CL GRAVELLY. SAJ\'DY SILTS OR LEAN CLAYS "'~;;.: > LESS THAl\" 50 ~ :i:; "'~ OL I ORGANIC SIL TS Al\'D ORGANIC CLAYS OF LOW PLASTJcm· ' 2Z~o ,<~~ MH INORGANIC SIL TS. MICACEOUS OR DIATOMACEOUS FNE i:i:: i= ci SANDY OR SILTY SOILS. ELASTIC SILTS -'u.i~z SILTS AND CLAYS ""~ LJQUID UMIT IS CH i NORGANJC CLAYS OF HIGH PLASTICITY, FAT CLAYS i:!:; O,r:~ ... :.::;;:= GREATER THA.'1 50 m " ORGANIC CLAYS OF MEDIUM TO HIGH PLASTICITY. ORGANIC SIL TY CLAYS HIGHLY ORGANIC SOILS PEAT AND OTHER HIGHLY ORGA}l!C SOILS T GRAIN SIZES BOULDERS COBBLES GRAVEL SAND I COARSE I FINE COARSE I MEDIUM I FINE I SILTS AND CLAYS 12" 3" 3/4" 4 10 40 200 CLEAR SQUARE SIEVE OPENING U.S. STANDARD SIEVE SIZE ADDITIONAL TESTS (OTHER THAN TEST PIT AND BORING LOG COLUMN HEADINGS) MAX-Maximum Dry Density PM-Permeability PP-Pocket Pcnctrometer GS-Grain Size Distribution SG-Specific Gravity WA-Wash Analysis SE-Sand Equivalent HA-Hydrometer Analysis OS-Direct Shear El-Expansion Index AL-Atterberg Limits UC-Unconfined Compression CHM-Sulfate and Chloride RV-R-Value MD-Moisture/Density Content , pH, Resistivity CN-Consolidation M-Moisture COR -Corrosivity CP-Collapse Potential SC-Swell Compression SD-Sample Disturbed HC-Hydrocollapsc OT-Organic Impurities REM-Remolded FIGURE:I BL! FRQ.ECT: CTE..08 NO· LOGGED BY: • g i~ l l ! ,- " ~ ; ~ • ~ Q ~ 'Q'. • ~ s > ~ ·a C a; Q • Q Q ~ -o - - - - -5- ,_ - - - ,_ - 10 -.. - ,_ -] - 15 - f--~ - f-- 20 " " ~ ,_ - t-25· ~ - C~II!..,.~ Construction Testing & Engineering, Inc. ~ j~ •-¼•, -<fl~ i •-!'.-~k-<P-"1': °"'"'I"'"'~ i DRILLER DRILL METHOD: ~MPLE METHOD: SHEET: of DRILLING DATE. ELEVATION: if;' ~ J BORING LOG LEGEND L rooraory Tests 0 0 0 ~ 0 j " DESCHIPTION Block or Chunk Sanple Bulk Semple Sta"lda-d Pa'larci.i on Test Modifia:::l Split-Ba-re Drive Srnpler (Ca Sanplerl Thin Waled Armv Corp_ of Enqinea-sSanple Groundwaer Tcble -.--------------------------------------------------------------------------- \_ -Soi I Type or Cl a;s fi ccti on ChalQe -, __ , __ , __ , __ , __ , __ ,_ \_ ForITTi.ion ~hcnoe f (A~roxi ma:~ boundai~ queried ;?)l • st./1" Quotes a-e pl a::a:I a-OU"ld d a;s fi ccti ons wha'"e the ooi Is exist in Stu as t:Jejrock FIGURE: I BL2 PROJECT: CTT JOB NO LOGGED BY: 0 - - s- - rn - - - - 22 23 25 22 30 30 20 40 50/4" A Universal Engineering Construction Testing & Engineering, Inc. Sdenees Company 1ospec1;,,, I T...t1ng I Geotvdlrvcal I 8Mror,merrtaJ & CormnJclioo Eng1neemg I CM! &gineeOng I Sur,ey,og DRILLER: Nat1ve Drilling SllEET: Anderson ADU 4830.23000]5 OXIO DJT DRILL METI-1OD. Tripod,Beaver: 4.5" Auger DRILLING DA TE: of 1125/2023 -275' SAMPLE METIIOD: CAL. SPT. and Bulk ELEVATION: 3 BORING: B-1 ' l~--------------------------1 DESCRIPTION SM "SM" "CL" QUATERNARY UNDOCUMENTED FILL: Medium dense, moist, red-brown, fine-to medium-grained Silty Sand. QUATERNARY VERY OLD PARALIC DEPSOITS, UNIT 12: Dense, slgihtly moist, red-brown, fine-to medium-grained Silty Sand. Weathered Sand~tone TERTIARY SANTIAGO FORMATION: Hard, slightly moist. light gray, Sandy Clay. -------"SM" Very dense, slightly moist, light-gray, fine-grained Silty Sand. Total Depth: 13.5' No Groundwater Encountered Backfilled with Soil Cuttings Laboratory Tests MAX,EI,CHM MD.OS MD,DS I 8-1 PROJECT: CTI JOB ;,.,/0: LOGGED BY: -o - - - - 5- - - - 1• - - - - - -- " I-" 12 12 10 15 37 so A Universal C ~~lneerlng ~~:mstruc.t.io.n .. Testing ... & E~~.in.E?ering, -~nc •..................... C~~~c:~y lospectio,, I T""ting I Gectecti,.cal I EoWt>mlOnlal & Con•tn1ct1on Er,,irooenr>g I Civil En!J101$'1l'l\1 I &JM)'log Anderson ADU 4830.2300005.0000 DJT DRILLER: Na11ve Drilling DRILL METHOD: Tripod/Beaver 4.5" Auger SAMPLE METHOD: CAL, SPT, and Bulk SHEET: DRILLING DATE: ELEVATION: cf 1/2512023 ~272' • 3 BORING: B-2 Laboratory Tests i SM "SM" "CL" f-------~--=---------, DESCRIPTION QUATERNARY UNDOCUMENTED FILL: Medium dense, moist, red-brown, fine-to medium-grained Silty Sand. QUATERNARY VERY OLD PARALJC DEPSOITS, UNIT 12: Medium dense, slgihtly moist, red-brown, fine-to medium-grained Silty Sand. Weathered Sandstone Secnane at 8 feet. TERTIARY SANTIAGO FORMATION: Hard, slightly moist, light gray, Sandy Clay. Total Depth: 9.5' No Groundwater Encountered Backfilled with Soil Cuttings GS GS I B-2 PROJECT: CTEJOB-:-.'O: LOGGED BY: >-0 - - -- 5- AUnivenol Engineering Construction Testing & Engineering, Inc. Sciences Company Anderson ADU 4830.2300005.0000 DJT SM "SM" • .3 0 l Jnspectior, I Tosfug I Gecleeho1cal I Er..;roo"""'1al &Constnlctioe Eng1-"og I ct,,;I Engineering I Su,veymg DRILLER: '.'Jative Drilling DRILL METHOD: TripocliBeavcr: 4.5" Auger SAMPLE METHOD: CAL, SPT, and Bulk SHEET· DRILLING DATE· ELEVATION: of ] 125/2023 -275' BORING: B-3 Laboratory Tests I--------DccEc-S"c"RJ"P"'T"'r-=o"N,-------------1 QUATERNARY UNDO' UMENTED FILL: Medium dense, moist, red-brown, fine-to medium-grained Silty Sand. QUATERNARY VERY OLD PARALIC DEPSOITS, UNIT 12: Dense, s\gihtly moist, red-brown, fine-to medium-grained Silty Sand. Weathered Sandstone >-++-l----1--+----l----1--1------------------+------l - - f-10 - - f-- f-- - - -,. ,-. Total Depth: 6' No Groundwater Encountered Backfilled with Soil Cuttings I 8-13 APPENDIXC LABORATORY METHODS AND RESULTS A Universal , , . , eng;neering Construction Testing & Engmeermg, Inc. Sciences Company Inspection I TesUng I Geotectmk:al I Environmental & Construction Engineenng ! Civl Engineering I Surveying LABO RA TORY TEST METHODS In-situ Moisture Content and Dry Density Tests (ASTM D2216 and D2937) The in-situ moisture content and dry density of selected samples obtained during the subsurface investigations were evaluated in general accordance with the latest versions of the ASTM D2216 and D2937 test methods. The methods involve obtaining the moist weight of the sample and then drying the sample to obtain its dry weight. The moisture content is calculated by taking the difference between the wet and dry weights, dividing it by the dry weight of the sample and expressing the result as a percentage. The dry weight and the measured volume of the tested sample are then used to calculate the samples dry density. The results of the in-situ moisture content and dry density tests are presented in the following section of this appendix and on the logs of the exploratory excavations presented in Appendix B. Classification (ASTM D2487) Earth materials encountered were visually and texturally classified in accordance with the Unified Soil Classification System (USCS/ASTM D2487) and ASTM D2488. Material classifications are indicated on the logs of the exploratory borings presented in Appendix B. Particle-size Distribution Tests (ASTM D6913) Particle-size distribution (gradation) testing was performed on selected samples of the materials encountered in general accordance with the latest version of the ASTM D6913 test method. The test results were utilized in evaluating the soil classifications in accordance with the Unified Soil Classification System and to evaluate the geotechnical engineering characteristics of the tested material. The test results are plotted on grain-size distribution graphs and are presented in the following section of this appendix. Expansion Index Test (ASTM D4829) Expansion index testing was performed on selected samples of the earth materials encountered in general accordance with the ASTM D4829 test method. The test determines the expansion potential of the materials encountered. The test results are presented in the following section of this appendix. Laboratory Compaction Characteristics Test (ASTM D1557) Laboratory compaction characteristics testing was performed on selected samples of the earth materials encountered in general accordance with the ASTM D1557 test method. The test establishes the laboratory maximum dry density and optimum moisture content of the tested materials and are also used to aid in evaluating the strength characteristics of the materials. (4830.2300005) Appendix. C (Anderson ADU) C ~n?;needng Construction Testing & Engineering, Inc. .. .. .. .. .. © A Universal Cciences Inspection I Tesling I Geotechnical I E!l'liromnental & Construction Engineenng j CM Engineering I Surveying ompany Direct Shear Test (ASTM D3080) Direct Shear testing was performed in general accordance with the ASTM D3080 test method to aid in evaluating the soil strength characteristics of the on-site earth materials encountered. Testing is performed on undisturbed specimens obtained from drive-samples and/or on specimens remolded in the laboratory to a specific moisture content and density. The test consists of placing the specimen in a direct shearing device, applying a specified normal stress, and then shearing the sample at a constant rate under drained conditions. This is repeated under a series of specified normal stresses. The shearing resistance and honzontal displacements are measured and recorded as the soil specimen is sheared. The shearing is continued well beyond the point of maximum resistance (peak strength) to determine a constant or residual value (ultimate strength). The test results arc presented in the following section of this appendix. Soil Corrosivity Tests The water-soluble sulfate and chloride content, and the resistivity and pH of selected samples was performed by a third-party laboratory in general accordance with California Test Methods. The tests results are useful in the assessment of the degree of corrosivity of the earth materials encountered with regard to concrete and normal grade steel. IN SITU DRY DENSITY & MOISTURE CONTENT (ASTM D2937 and D22I6) Sample Location I Depth (feet) Moisture' Content Dry Densiry , .... cent> (nounds ne,-ci,bic foot) B-2@4 13.4 120.5 B-2@ 8 16.3 110.9 RESULTS OF THE EXPANSION INDEX TESTS (ASTM D4829) Sample Location/ Depth (feet) Expansion lndex Expansion l\,tentiai B-1@ 0-4 l VERY LOW RESULTS OF THE LABORATORY COMPACTION CHARACTERISTICS TESTS (ASTM Dl557) S3Jllple Location Maximum Dry Density -Optimum Moisture / nenth (feet\ '-••ds per<;ubic foot) (perceot) B-1 @ 0-4 128.2 10.2 (4830.2300005) Appendix C (Anderson ADU) A Universal , . . . Eng;nee,;ng Construct1on Testing & Engmeenng, Inc. Sciences Company Inspection I Testing I Geotectmical I Environmental & Construction Engineering I CMI Engineering I Surveying RESULTS OF THE CHEMICAL ANALYSIS FOR SULFATE (CALIFORNIA TEST 422) Sample Location B-1 Depth (feet) • 0-4 R,sults ppm 44.5 RESULTS OF THE CHEMICAL ANALYSIS FOR CHLORIDE (CALIFORNIA TEST 422) Sample Locatiori B-1 Depth (feet) 0-4 RES UL TS OF THE CHEMICAL ANALYSIS FOR p.H. Sample Location B-1 Depth (feer) 0-4 Results ppm 3.63 Results 7.31 RESULTS OF THE CHEMICAL ANALYSIS FOR RESISTIVITY Sample LOCation _ B-1 (4830.2300005) (Anderson ADU) /CALIFORNIA TEST 643) . Depth /feet\ 0-4 Results . obms--cm 7210 Appendix C U.S. STANDARD SIEVE SIZE 0 ~ ~ " 0 0 ~/ ' ~ .o <O 00 0 0 0 ---• -N -· 0 -N 100 f\, ~ 90 -\ 611 --- I \ I\ 70 \ , ,., 60 ~ 7 ~ '---~ < 50 • \ '" ' " u " 40 • -- • ' 30 - 20 ----- 10 - i 0 100 10 1 0.1 0.0! 0.001 PARTICI.E SIZE (mm) PARTICLE SIZE ANALYSIS ~,mplo U.>1~nation Sample D")'th if«O Symh,:,I l ,9md I.om!(%) P<lst,c1ty Ind"" ("],.,"f"'''"'" c@) AIJn!vanol B-2 4 • en91,,.....,1n9 Construction Testing & Engineering, Inc. SM/SC Seler,e<>~ -I To,l<ilt I o.oto<t;,,cal I ;;__,,,"""""1&Cons,nl<,,00EOQ1-I c,,,,Et,g1,-iOQ I~ B-2 8 • SC/CL Compo"}' CTE JOB NUMBER: 4830.2300005 FIGURE: C-1 PRECONSOLIDATION I SHEARING DAT A I ' '""° ' "'''" ' ~ "' I • .-' " • 0 ,000 ~ 0 u w C J ~ ~ ' " z 0 ~ ~ ,ooo " w 0 ' % 0 ,o□n • f ' ' ' ' ' ' " " " " " • ,. ' ' rn ,oo --1000psf STRAIN(%) TIME (mini.Iles) I VERTICAL --JOO0psf ' STRESS I -5000psf FAILURE ENVELOPE 5000 4000 "' I • " 0 0 3000 w ~ t; " z a • w 2000 % 0 1000 J,-OOl!mm./nun I c@) A Universol Engineering Sciences 0 Company 0 1000 VE~ STRES&Jpsf) 4000 5000 SHEAR STRENGTH TEST -ASTM D3080 Job Name: Anderson Residence ADU Initial Dry Density (pcf): 120.5 Project Number: 4830.2300005. Sample Date: 1/25/2023 Initial Moisture(%): 13.4 Lab Number: 34241 Test Date: 2/8/2023 Final Moisture(%): 15.4 Sample Location: 8-1 @4' Tested By: L.S. Cohesion: 560 nsf Sample Description: Reddish Brown (SM) Angle Of Friction: 39.4 PRECONSOLIOATION SHEARING DATA " ,,. "·' ~ ,oo, • '° I • ;;; " • u • ,ooo < ' 0 ' • I ~ e. w " ' " i • " ,., cs ~ ~ • • ' ,oo, / as 111 ' ' ' • • • " " " " " " • 0, • '" mo I 1 --1000 ps1;[ STRAIN {%) TIME (minutes) VERTICAL __ 3000 psi STRESS -5000 psfl FAILURE ENVELOPE 5000 4000 '° ' ~ • 3000 • ~ " • 0 z • 2000 • w • • 1000 I d,:O O> mmtmm I c@) A Universal Engineering 0 Sciences 0 1000 2000 3000 4000 5000 Company VERTICAL STRESS (psf} SHEAR STRENGTH TEST -AST'1 o,oso Job Name: Anderson Residence ADU Initial Dry Density (pd): 110.9 Project Number: 4830.2300005. Sample Date: 1/25/2023 Initial Moisture(%): 16.3 Lab Number: 34241 Test Date: 2/10/2023 Final Moisture(%): 18.9 Sample Location: B-1 @8' Tested By: LS. Cohesion: 460 nsf Sample Description: Moderate Brown (SM/CL) Angle OfFriction: 38.4 APPENDIX D STANDARD GRADING SPECIFICATIONS Appendix D Page D-1 Standard Specifications for Grading Section 1 -General Construction Testing & Engineering, Inc. presents the following standard recommendations for grading and other associated operations on construction projects. These guidelines should be considered a portion of the project specifications. Recommendations contained in the body of the previously presented soils report shall supersede the recommendations and or requirements as specified herein. The project geotechnical consultant shall intetpret disputes arising out of inteipretation of the recommendations contained in the soils report or specifications contained herein. Section 2 -Responsibilities of Project Personnel The geotechnical consultant should provide observation and testing services sufficient to general conformance with project specifications and standard grading practices. The geotcchnical consultant should report any deviations to the client or his authorized representative. The Client should be chiefly responsible for all aspects of the project. He or his authorized representative has the responsibility of reviewing the findings and recommendations of the geotechnical consultant. He shall authorize or cause to have authorized the Contractor and/or other consultants to perform work and/or provide services. During grading the Client or his authorized representative should remain on-site or should remain reasonably accessible to all concerned parties in order to make decisions necessary to maintain the flow of the project. The Contractor is responsible for the safety of the project and satisfactory completion of all grading and other associated operations on construction projects, including, but not limited to, earth work in accordance with the project plans, specifications and controlling agency requirements. Section 3 -Prcconstruction Meeting A preconstruction site meeting should be arranged by the owner and/or client and should include the grading contractor, design engineer, geotechnical consultant, owner's representative and representatives of the appropriate governing authorities. Section 4 -Site Preparation The client or contractor should obtain the required approvals from the controlling authorities for the project prior, during and/or after demolition, site preparation and removals, etc. The appropriate approvals should be obtained prior to proceeding with grading operations. STANDARD SPECIFICATIONS OF GRADING Page 1 of 26 Appendix D Page D-2 Standard Specifications for Grading Clearing and grubbing should consist of the removal of vegetation such as brush, grass, woods, stumps, trees, root of trees and otherwise deleterious natural materials from the areas to be graded. Clearing and grubbing should extend to the outside of all proposed excavation and fill areas. Demolition should include removal of buildings, structures, foundations, reservoirs, utilities (including underground pipelines, septic tanks, leach fields, seepage pits, cisterns, mining shafts, tunnels, etc.) and other man-made surface and subsurface improvements from the areas to be graded. Demolition of utilities should include proper capping and/or rerouting pipelines at the project perimeter and cutoff and capping of wells in accordance with the requirements of the governing authorities and the recommendations of the geotechnical consultant at the time of demolition. Trees, plants or man-made improvements not planned to be removed or demolished should be protected by the contractor from damage or injury. Debris generated during clearing, grubbing and/or demolition operations should be wasted from areas to be graded and disposed off-site. Clearing, grubbing and demolition operations should be performed under the observation of the geotechnical consultant. Section 5 -Site Protection Protection of the site during the period of grading should be the responsibility of the contractor. Unless other provisions are made in writing and agreed upon among the concerned parties, completion of a portion of the project should not be considered to preclude that portion or adjacent areas from the requirements for site protection until such time as the entire project is complete as identified by the geotechnical consultant, the client and the regulating agencies. Precautions should be taken during the performance of site clearing, excavations and grading to protect the work site from flooding, ponding or inundation by poor or improper surface drainage. Temporary provisions should be made during the rainy season to adequately direct surface drainage away from and off the work site. Where low areas cannot be avoided, pumps should be kept on hand to continually remove water during periods of rainfall. Rain related damage should be considered to include, but may not be limited to, erosion, silting, saturation, swelling, structural distress and other adverse conditions as determined by the geotechnical consultant. Soil adversely affected should be classified as unsuitable materials and should be subject to overexcavation and replacement with compacted fill or other remedial grading as recommended by the geotechnical consultant. STANDARD SPECIFICATIONS OF GRADING Page 2 of 26 AppendixD Page D-3 Standard Specifications for Grading The contractor should be responsible for the stability of all temporary excavations. Recommendations by the geotechnical consultant pertaining to temporary excavations (e.g., backcuts) are made in consideration of stability of the completed project and, therefore, should not be considered to preclude the responsibilities of the contractor. Recommendations by the geotechnical consultant should not be considered to preclude requirements that arc more restrictive by the regulating agencies. The contractor should provide during periods of extensive rainfall plastic sheeting to prevent unprotected slopes from becoming saturated and unstable. When deemed appropriate by the geotcchnical consultant or governing agencies the contractor shall install checkdams, desilting basins, sand bags or other drainage control measures. In relatively level areas and/or slope areas, where saturated soil and/or erosion gullies exist to depths of greater than 1.0 foot; they should be ovcrexcavated and replaced as compacted fill in accordance with the applicable specifications. Where affected materials exist to depths of 1.0 foot or less below proposed finished grade, remedial grading by moisture conditioning in-place, followed by thorough recompaction in accordance with the applicable grading guidelines herein may be attempted. If the desired results are not achieved, all affected materials should be overexcavated and replaced as compacted fill in accordance with the slope repair recommendations herein. If field conditions dictate, the gcotechnical consultant may recommend other slope repair procedures. Section 6 -Excavations 6.1 Unsuitable Materials Materials that arc unsuitable should be excavated under observation and recommendations of the geotechnical consultant. Unsuitable materials include, but may not be limited to, dry, loose, soft, wet, organic compressible natural soils and fractured, weathered, soft bedrock and noncngineered or otherwise deleterious fill materials. Material identified by the gcotechnical consultant as unsatisfactory due to its moisture conditions should be overexcavated; moisture conditioned as needed, to a uniform at or above optimum moisture condition before placement as compacted fill. If during the course of grading adverse gcotechnical conditions are exposed which were not anticipated in the preliminary soil report as determined by the gcotechnical consultant additional exploration, analysis, and treatment of these problems may be recommended. STANDARD SPECIFICATIONS OF GRADING Page 3 of 26 Appendix D Page D-4 Standard Specifications for Grading 6.2 Cut Slopes Unless otherwise recommended by the geotechnical consultant and approved by the regulating agencies, permanent cut slopes should not be steeper than 2:1 (horizontal: vertical). The geotechnical consultant should observe cut slope excavation and if these excavations expose loose cohesionless, significantly fractured or otherwise unsuitable material, the materials should be overexcavatcd and replaced with a compacted stabilization fill. If encountered specific cross section details should be obtained from the Geotechnieal Consultant. When extensive cut slopes are excavated or these cut slopes arc made in the direction of the prevailing drainage, a non-erodible diversion swale (brow ditch) should be provided at the top of the slope. 6.3 Pad Areas All lot pad areas, including side yard terrace containing both cut and fill materials, transitions, located less than 3 feet deep should be overexcavated to a depth of 3 feet and replaced with a uniform compacted fill blanket of 3 feet. Actual depth of overexcavation may vary and should be delineated by the gcotechnical consultant during grading, especially where deep or drastic transitions are present. For pad areas created above cut or natural slopes, positive drainage should be established away from the top-of-slope. This may be accomplished utilizing a berm drainage swale and/or an appropriate pad gradient. A gradient in soil areas away from the top-of-slopes of 2 percent or greater is recommended. Section 7 -Compacted Fill All fill materials should have fill quality, placement, conditioning and compaction as specified below or as approved by the geotcchnical consultant. 7.1 Fill Material Quality Excavated on-site or import materials which are acceptable to the geotcchnical consultant may be utilized as compacted fill, provided trash, vegetation and other deleterious materials are removed prior to placement. All import materials anticipated for use on-site should be sampled tested and approved prior to and placement is in conformance with the requirements outlined. STANDARD SPECIFICATIONS OF GRADING Page 4 of 26 Appendix D Page D-5 Standard Specifications for Grading Rocks 12 inches in maximum and smaller may be utilized within compacted fill provided sufficient fill material is placed and thoroughly compacted over and around all rock to effectively fill rock voids. The amount of rock should not exceed 40 percent by dry weight passing the 3/4-inch sieve. The geotcchnical consultant may vary those requirements as field conditions dictate. Where rocks greater than 12 inches but less than four feet of maximum dimension are generated during grading, or otherwise desired to be placed within an engineered fill, special handling in accordance with the recommendations below. Rocks greater than four feet should be broken down or disposed off-site. 7.2 Placement of Fill Prior to placement of fill material, the geotechnical consultant should observe and approve the area to receive fill. After observation and approval, the exposed ground surface should be scarified to a depth of 6 to 8 inches. The scarified material should be conditioned (i.e. moisture added or air dried by continued discing) to achieve a moisture content at or slightly above optimum moisture conditions and compacted to a minimum of 90 percent of the maximum density or as otherwise recommended in the soils report or by appropriate government agencies. Compacted fill should then be placed in thin horizontal lifts not exceeding eight inches in loose thickness prior to compaction. Each lift should be moisture conditioned as needed, thoroughly blended to achieve a consistent moisture content at or slightly above optimum and thoroughly compacted by mechanical methods to a minimum of 90 percent of laboratory maximum dry density. Each lift should be treated in a like manner until the desired finished grades are achieved. The contractor should have suitable and sufficient mechanical compaction equipment and watering apparatus on the job site to handle the amount of fill being placed m consideration of moisture retention properties of the materials and weather conditions. When placing fill in horizontal lifts adjacent to areas sloping steeper than 5:1 (horizontal: vertical), horizontal keys and vertical benches should be excavated into the adjacent slope area. Keying and benching should be sufficient to provide at least six-foot wide benches and a minimum of four feet of vertical bench height within the firm natural ground, firm bedrock or engineered compacted fill. No compacted fill should be placed in an area after keying and benching until the geotechnical consultant has reviewed the area. Material generated by the benching operation should be moved sufficiently away from STANDARD SPECIFICATIONS OF GRADING Page 5 of 26 Appendix D Page D-6 Standard Specifications for Grading the bench area to allow for the recommended review of the horizontal bench prior to placement of fill. Within a single fill area where grading procedures dictate two or more separate fills, temporary slopes (false slopes) may be created. When placing fill adjacent to a false slope, benching should be conducted in the same manner as above described. At least a 3.foot vertical bench should be established within the finn core of adjacent approved compacted fill prior to placement of additional fill. Benching should proceed in at least 3.foot vertical increments until the desired finished grades arc achieved. Prior to placement of additional compacted fill following an overnight or other grading delay, the exposed surface or previously compacted fill should be processed by scarification, moisture conditioning as needed to at or slightly above optimum moisture content, thoroughly blended and recompacted to a minimum of 90 percent of laboratory maximum dry density. Where unsuitable materials exist to depths of greater than one foot, the unsuitable materials should be ovcr•excavated. Following a period of flooding, rainfall or overwatering by other means, no additional fill should be placed until damage assessments have been made and remedial grading pcrfonned as described herein. Rocks 12 inch in maximum dimension and smaller may be utilized in the compacted fill provided the fill is placed and thoroughly compacted over and around all rock. No oversize material should be used within 3 feet of finished pad grade and within 1 foot of other compacted fill areas. Rocks 12 inches up to four feet maximum dimension should be placed below the upper 10 feet of any fill and should not be closer than 15 feet to any slope face. These recommendations could vary as locations of improvements dictate. Where practical, oversized material should not be placed below areas where structures or deep utilities are proposed. Oversized material should be placed in windrows on a clean, overexcavatcd or unyielding compacted fill or firm natural ground surface. Select native or imported granular soil (S.E. 30 or higher) should be placed and thoroughly flooded over and around all windrowed rock, such that voids are filled. Windrows of oversized material should be staggered so those successive strata of oversized material are not in the same vertical plane. It may be possible to dispose of individual larger rock as field conditions dictate and as recommended by the geotechnical consultant at the time of placement. STANDARD SPECIFICATIONS OF GRADING Page 6 of 26 Appendix D Page D-7 Standard Specifications for Grading The contractor should assist the geotechnical consultant and/or his representative by digging test pits for removal determinations and/or for testing compacted fill. The contractor should provide this work at no additional cost to the owner or contractor's client. Fill should be tested by the geotechnical consultant for compliance with the recommended relative compaction and moisture conditions. Field density testing should conform to ASTM Method of Test D 1556-00, D 2922-04. Tests should be conducted at a minimum of approximately two vertical feet or approximately 1,000 to 2,000 cubic yards of fill placed. Actual test intervals may vary as field conditions dictate. Fill found not to be in conformance with the grading recommendations should be removed or otherwise handled as recommended by the geotechnical consultant. 7.3 Fill Slopes Unless otherwise recommended by the geotechnical consultant and approved by the regulating agencies, permanent fill slopes should not be steeper than 2: 1 (horizontal: vertical). Except as specifically recommended in these grading guidelines compacted fill slopes should be over-built two to five feet and cut back to grade, exposing the firm, compacted fill inner core. The actual amount of overbuilding may vary as field conditions dictate. If the desired results are not achieved, the existing slopes should be overexcavated and reconstructed under the guidelines of the geotechnical consultant. The degree of overbuilding shall be increased until the desired compacted slope surface condition is achieved. Care should be taken by the contractor to provide thorough mechanical compaction to the outer edge of the overbuilt slope surface. At the discretion of the geotechnical consultant, slope face compaction may be attempted by conventional construction procedures including backrolling. The procedure must create a firmly compacted material throughout the entire depth of the slope face to the surface of the previously compacted firm fill intercore. During grading operations, care should be taken to extend compactive effort to the outer edge of the slope. Each lift should extend horizontally to the desired finished slope surface or more as needed to ultimately established desired grades. Grade during construction should not be allowed to roll off at the edge of the slope. It may be helpful to elevate slightly the outer edge of the slope. Slough resulting from the placement of individual lifts should not be allowed to drift down over previous lifts. At intervals not STANDARD SPECIFICATIONS OF GRADING Page 7 of 26 Appendix D Page D-8 Standard Specifications for Grading exceeding four feet in vertical slope height or the capability of available equipment, whichever is less, fill slopes should be thoroughly dozer trackrolled. For pad areas above fill slopes, positive drainage should be established away from the top-of-slope. This may be accomplished using a benn and pad gradient of at least two percent. Section 8 -Trench Backfill Utility and/or other excavation of trench backfill should, unless otherwise recommended, be compacted by mechanical means. Unless otherwise recommended, the degree of compaction should be a minimum of90 percent of the laboratory maximum density. Within slab areas, but outside the influence of foundations, trenches up to one foot wide and two feet deep may be backfilled with sand and consolidated by jetting, flooding or by mechanical means. If on-site materials are utilized, they should be wheel-rolled, tamped or otherwise compacted to a finn condition. For minor interior trenches, density testing may be deleted or spot testing may be elected if deemed necessary, based on review of backfill operations during construction. If utility contractors indicate that it is undesirable to use compaction equipment in close proximity to a buried conduit, the contractor may elect the utilization of light weight mechanical compaction equipment and/or shading of the conduit with clean, granular material, which should be thoroughly jetted in-place above the conduit, prior to initiating mechanical compaction procedures. Other methods of utility trench compaction may also be appropriate, upon review of the gcotcchnical consultant at the time of construction. In cases where clean granular materials arc proposed for use in lieu of native materials or where flooding or jetting is proposed, the procedures should be considered subject to review by the gcotechnical consultant. Clean granular backfill and/or bedding are not recommended in slope areas. Section 9 -Drainage Where deemed appropriate by the gcotechnical consultant, canyon subdrain systems should be installed in accordance with CTE's recommendations during grading. Typical subdrains for compacted fill buttresses, slope stabilization or sidehill masses, should be installed in accordance with the specifications. STANDARD SPECIFICATIONS OF GRADING Page 8 of 26 Appendix D Page D-9 Standard Specifications for Grading Roof, pad and slope drainage should be directed away from slopes and areas of structures to suitable disposal areas via non-erodible devices (i.e., gutters, downspouts, and concrete swalcs). For drainage in extensively landscaped areas near structures, (i.e., within four feet) a minimum of 5 percent gradient away from the structure should be maintained. Pad drainage of at least 2 percent should be maintained over the remainder of the site. Drainage patterns established at the time of fine grading should be maintained throughout the life of the project. Property owners should be made aware that altering drainage patterns could be detrimental to slope stability and foundation perfonnance. Section IO -Slope Maintenance IO. I -Landscape Plants To enhance surficial slope stability, slope planting should be accomplished at the completion of grading. Slope planting should consist of deep-rooting vegetation requiring little watering. Plants native to the southern California area and plants relative to native plants are generally desirable. Plants native to other semi-arid and arid areas may also be appropriate. A Landscape Architect should be the best party to consult regarding actual types of plants and planting configuration. I 0.2 -Irrigation Irrigation pipes should be anchored to slope faces, not placed in trenches excavated into slope faces. Slope irrigation should be minimized. If automatic timing devices are utilized on irrigation systems, provisions should be made for interrupting nonnal irrigation during periods of rainfall. I 0.3 -Repair As a precautionary measure, plastic sheeting should be readily available, or kept on hand, to protect all slope areas from saturation by periods of heavy or prolonged rainfall. This measure is strongly recommended, beginning with the period prior to landscape planting. If slope failures occur, the geotcchnical consultant should be contacted for a field review of site conditions and development of recommendations for evaluation and repair. If slope failures occur as a result of exposure to period of heavy rainfall, the failure areas and currently unaffected areas should be covered with plastic sheeting to protect against additional saturation. STANDARD SPECIFICATIONS OF GRADING Page 9 of 26 Appendix D Page D-10 Standard Specifications for Grading In the accompanying Standard Details, appropriate repair procedures arc illustrated for superficial slope failures (i.e., occurring typically within the outer one foot to three feet of a slope face). STANDARD SPECIFICATIONS OF GRADING Page 10 of 26 FINISH CUT SLOPE ----- BENCHING FILL OVER NATURAL SURFACE OF FIRM EARTH MATERIAL FILL SLOPE 2%MIN 10' TYPICAL 15' MIN. (INCLINED 2% MIN. INTO SLOPE) BENCHING FILL OVER CUT SURFACE OF FIRM EARTH MATERIAL FINISH FILL SLOPE ----- 10' TYPICAL 15' MIN OR STABILITY EQUIVALENT PER SOIL ENGINEERING (INCLINED 2% MIN. INTO SLOPE) NOTTO SCALE BENCHING FOR COMPACTED FILL DETAIL STANDARD SPECIFICATIONS FOR GRADING Page 11 of 26 MINIMUM DOWNSLOPE KEY DEPTH TOE OF SLOPE SHOWN ON GRADING PLAN FILL ---------------------:1i~?,.\P,.\.. -- ---~'t'\~p,. ----4' --·" ---s;\..'i-tr • - ----u~su,-r..~ .,.,.---=,....--------------! _.... ..----10'TYPICALBENCH // ---WIDTH VARIES A1 .,.,. ..... ;;-' --/ 1 _.,.,. COMPETENT EARTH / .,.,..,.,. MATERIAL -- 15' MINIMUM BASE KEY WIDTH TYPICAL BENCH HEIGHT PROVIDE BACKDRAIN AS REQUIRED PER RECOMMENDATIONS OF SOILS ENGINEER DURING GRADING WHERE NATURAL SLOPE GRADIENT IS 5:1 OR LESS, BENCHING IS NOT NECESSARY. FILL IS NOT TO BE PLACED ON COMPRESSIBLE OR UNSUITABLE MATERIAL. NOTTO SCALE FILL SLOPE ABOVE NATURAL GROUND DETAIL STANDARD SPECIFICATIONS FOR GRADING Page 12 of 26 ~ 2 0 :Ii 0 rJ) 1l 1l m ~ C'l "' -m :!! -C'l "' )> 0 ;:j -o "' 2 Cl rJ) "TI 0 JJ Gl JJ )> 0 2 Gl REMOVE ALL TOPSOIL, COLLUVIUM, AND CREEP MATERIAL FROM TRANSITION CUT/FILL CONTACT SHOWN ON GRADING PLAN CUT/FILL CONTACT SHOWN ON ~AS-BUILT" NATURAL TOPOGRAP~Y _ ----------------CUT SLOPE* -------2%M/N- 15' MINIMUM NOTTO SCALE 10' TYPICAL BEDROCK OR APPROVED FOUNDATION MATERIAL *NOTE: CUT SLOPE PORTION SHOULD BE MADE PRIOR TO PLACEMENT OF FILL FILL SLOPE ABOVE CUT SLOPE DETAIL [ SURFACEOF COMPETENT MATERIAL =-~-------------: -...... ...... ,,,,,.,,,,.. ,'-' COMPACTED Fill / '/ '' / I ' I TYPICAL BENCHING '' I '' / I SEE DETAIL BELOW MINIMUM 9 FT' PER LINEAR FOOT OF APPROVED Fil TER MATERIAL CAL TRANS CLASS 2 PERMEABLE MATERIAL FILTER MATERIAL TO MEET FOLLOWING SPECIFICATION OR APPROVED EQUAL: ,_,, A--""" '-/ REMOVE UNSUITABLE DETAIL 14" MINIMUM MATERIAL INCLINE TOWARD DRAIN AT 2% GRADIENT MINIMUM MINIMUM 4-DIAMETER APPROVED PERFORATED PIPE (PERFORATIONS DOWN) s-Fil TER MATERIAL BEDDING SIEVE SIZE PERCENTAGE PASSING APPROVED PIPE TO BE SCHEDULE 40 POLY-VINYL-CHLORIDE (P.V.C.) OR APPROVED EQUAL MINIMUM CRUSH STRENGTH 1000 psi 1" ¾· NO.4 NO.8 NO. 30 NO. 50 NO. 200 100 90-100 40-100 25-40 18-33 5-15 0-7 0-3 PIPE DIAMETER TO MEET THE FOLLOWING CRITERIA, SUBJECT TO FIELD REVIEW BASED ON ACTUAL GEOTECHNICAL CONDITIONS ENCOUNTERED DURING GRADING LENGTH OF RUN NOTTO SCALE INITIAL 500' 500' TO 1500' > 1500' PIPE DIAMETER 4" 6" 8" TYPICAL CANYON SUBDRAIN DETAIL STANDARD SPECIFICATIONS FOR GRADING Page 14 of 26 TYPICAL BENCHING CANYON SUBDRAIN DETAILS [ SURFACEOF COMPETENT MATERIAL :::-------------~ ..... ' ,,,.,,,,.,, <'' COMPACTED FILL / ~ '' // ' / ' ' / '' / / L-----. ' -/ A----'~ ' / REMOVE UNSUITABLE MATERIAL SEE DETAILS BELOW INCLINE TOWARD DRAIN AT 2% GRADIENT MINIMUM TRENCH DETAILS 6" MINIMUM OVERLAP OPTIONAL V-DITCH DETAIL MIRAFI 140N FABRIC OR APPROVED EQUAL 6" MINIMUM OVERLAP --------0 24" MINIMUM MINIMUM 9 FT3 PER LINEAR FOOT OF APPROVED DRAIN MATERIAL MIRAFI 140N FABRIC OR APPROVED EQUAL APPROVED PIPE TO BE SCHEDULE 40 POLY- VINYLCHLORIDE (P.V.C.) 24" MINIMUM 9 FT' PER LINEAR FOOT OR APPROVED EQUAL. MINIMUM CRUSH STRENGTH 1000 PSI. MINIMUM OF APPROVED DRAIN MATERIAL 60" TO 90° DRAIN MATERIAL TO MEET FOLLOWING SPECIFICATION OR APPROVED EQUAL: PIPE DIAMETER TO MEET THE FOLLOWING CRITERIA, SUBJECT TO FIELD REVIEW BASED ON ACTUAL GEOTECHNICAL CONDITIONS ENCOUNTERED DURING GRADING SIEVE SIZE 1 ½· 1" ¾· ¾· NO. 200 PERCENTAGE PASSING 88-100 5-40 0-17 0-7 0-3 LENGTH OF RUN INITIAL 500' 500' TO 1500' > 1500' NOT TO SCALE GEOFABRIC SUBDRAIN STANDARD SPECIFICATIONS FOR GRADING Page 15 of 26 PIPE DIAMETER 4" 6" 8" . FRONT VIEW CONCRETE !·,._. :-.. :'!· .. ·-'!•,:. !·o.' !·· ... 116" Min. . ' . ,;.+ ,_; ":'. ' .. ' . ' CUT-OFF WALL .. ~ "· ,, ... ' ' . ' . " ' '. ' ~ . ·-. ' . . -, .. • SUBDRAIN PIPE _,,,,,,.,,,,,--_;-~; .. _;~; . ' I 6" Min. . . 0 • • •r ••• , .. , . r--24" Min. -~ 6" Min. SIDE VIEW ~ 12" Min.~ 6" Min. CONCRETE CUT-OFF WALL '·· ::~ .. 6' Min. ' ... ' 0 SOILO SUBDRAIN PIPE .-r .. ,•J• .. • '"·' PE~FOf!ATE~ SU~D~IN ~IPE~ ... ·~·· ... . ' .... ... .. • ·• . NOT TO SCALE RECOMMENDED SUBDRAIN CUT-OFF WALL STANOARO SPECIFICATIONS FOR GRADING Page 16 of 26 FRONT VIEW SUBDRAIN OUTLET PIPE (MINIMUM 4" DIAMETER) SIDE VIEW ALL BACKFILL SHOULD BE COMPACTED IN CONFORMANCE WITH PROJECT -•. !►• -'►. t,. • ' t,. • b, • of> • ' "." • ... • ' .. ► _,,_ '►- ,, t,. • ' r,. • ' • I>. • ... . ' l,. ' ' .... . ' -. . . ... -... ,! b, .',! .-... : !· I>. • .... . ' .... . ' .I,. 1---24" Min. SPECIFICATIONS. COMPACTION EFFORT ------.J"f SHOULD NOT DAMAGE STRUCTURE 1---24" Min. NOTE: HEADWALL SHOULD OUTLET AT TOE OF SLOPE OR INTO CONTROLLED SURFACE DRAINAGE DEVICE ALL DISCHARGE SHOULD BE CONTROLLED THIS DETAIL IS A MINIMUM DESIGN AND MAY BE MODIFIED DEPENDING UPON ENCOUNTERED CONDITIONS AND LOCAL REQUIREMENTS NOTTO SCALE 24" Min. 12· 12· TYPICAL SUBDRAIN OUTLET HEADWALL DETAIL STANDARD SPECIFICATIONS FOR GRADING Page 17 of 26 1' 2'MI 4" DIAMETER PERFORATED PIPE BACKDRAIN 4" DIAMETER NON-PERFORATED PIPE LATERAL DRAIN SLOPE PER PLAN FILTER MATERIAL 2%MI 15' MINIMUM BENCHING AN ADDITIONAL BACKDRAIN AT MID-SLOPE WILL BE REQUIRED FOR SLOPE IN EXCESS OF 40 FEET HIGH. KEY-DIMENSION PER SOILS ENGINEER (GENERALLY 112 SLOPE HEIGHT, 15' MINIMUM) DIMENSIONS ARE MINIMUM RECOMMENDED NOT TO SCALE TYPICAL SLOPE STABILIZATION FILL DETAIL STANDARD SPECIFICATIONS FOR GRADING Page 18 of 26 1 2'M 4" DIAMETER PERFORATED PIPE BACKDRAIN 15' MINIMUM 4" DIAMETER NON-PERFORATED PIPE LATERAL DRAIN SLOPE PER PLAN FILTER MATERIAL BENCHING 2%M H/2 ADDITIONAL BACKDRAIN AT MID-SLOPE WILL BE REQUIRED FOR SLOPE IN EXCESS OF 40 FEET HIGH. KEY-DIMENSION PER SOILS ENGINEER DIMENSIONS ARE MINIMUM RECOMMENDED NOTTO SCALE TYPICAL BUTTRESS FILL DETAIL STANDARD SPECIFICATIONS FOR GRADING Page 19 of 26 20' MAXIMUM FINAL LIMIT OF EXCAVATION OVEREXCAVATE OVERBURDEN (CREEP-PRONE) DAYLIGHT LINE FINISH PAD OVEREXCAVATE 3' AND REPLACE WITH COMPACTED FILL COMPETENT BEDROCK TYPICAL BENCHING LOCATION OF BACKDRAIN AND OUTLETS PER SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST DURING GRADING. MINIMUM 2% FLOW GRADIENT TO DISCHARGE LOCATION. EQUIPMENT WIDTH (MINIMUM 15') NOTTO SCALE DAYLIGHT SHEAR KEY DETAIL STANDARD SPECIFICATIONS FOR GRADING Page 20 of 26 PROPOSED GRADING BASE WIDTH ''W" DETERMINED BY SOILS ENGINEER NATURAL GROUND COMPACTED FILL ' " NOT TO SCALE PROVIDE BACKDRAIN, PER BACKDRAIN DETAIL. AN ADDITIONAL BACKDRAIN AT MID-SLOPE WILL BE REQUIRED FOR BACK SLOPES IN EXCESS OF 40 FEET HIGH. LOCATIONS OF BACKDRAINS AND OUTLETS PER SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST DURING GRADING. MINIMUM 2% FLOW GRADIENT TO DISCHARGE LOCATION. TYPICAL SHEAR KEY DETAIL STANDARD SPECIFICATIONS FOR GRADING Page 21 of 26 FINlSH SURFACE SLOPE 3 FT3 MINIMUM PER LINEAR FOOT APPROVED FILTER ROCK* CONCRETE COLLAR PLACED NEAT A COMPACTED FILL 2.0% MINIMUM GRADIENT A 4" MINIMUM DIAMETER SOLID OUTLET PIPE SPACED PER SOIL ENGINEER REQUIREMENTS 4" MINIMUM APPROVED PE RF ORA TED PIPP* (PERFORATIONS DOWN) MINIMUM 2% GRADIENT TO OUTLET DURING GRADING TYPICAL BENCH INCLINED TOWARD DRAIN **APPROVED PIPE TYPE: MINIMUM 12" COVER SCHEDULE 40 POLYVINYL CHLORIDE (P.V.C.) OR APPROVED EQUAL. MINIMUM CRUSH STRENGTH 1000 PSI BENCHING DETAIL A-A OMPACTE BACKFILL 12" MINIMUM TEMPORARY FILL LEVEL MINIMUM 4" DIAMETER APPROVED SOLID OUTLET PIPE *FILTER ROCK TO MEET FOLLOWING SPECIFICATIONS OR APPROVED EQUAL: SIEVE SIZE 1" ¾" ¾" NO.4 NO. 30 NO. 50 NO. 200 PERCENTAGE PASSING 100 90-100 40-100 25-40 5-15 0-7 0·3 NOTTO SCALE TYPICAL BACKDRAIN DETAIL STANDARD SPECIFICATIONS FOR GRADING Page 22 of 26 FINISH SURFACE SLOPE MINIMUM 3 FP PER LINEAR FOOT OPEN GRADED AGGREGATE* TAPE AND SEAL AT COVER CONCRETE COLLAR PLACED NEAT COMPACTED Fill 2.0% MINIMUM GRADIENT MIRAFI 140N FABRIC OR APPROVED EQUAL A MINIMUM 4" DIAMETER SOLID OUTLET PIPE SPACED PER SOIL ENGINEER REQUIREMENTS MINIMUM 12" COVER *NOTE: AGGREGATE TO MEET FOLLOWING SPECIFICATIONS OR APPROVED EQUAL: SIEVE SIZE PERCENTAGE PASSING 1 ½· 100 1" 5-40 ¾· 0-17 ¾· 0-7 NO. 200 0-3 4" MINIMUM APPROVED PERFORATED PIPE (PERFORATIONS DOWN) MINIMUM 2% GRADIENT TO OUTLET TYPICAL BENCH INCLINED BENCHING TOWARD DRAIN DETAIL A-A OMPACTE BACKFILL 12" MINIMUM NOT TO SCALE TEMPORARY FILL LEVEL MINIMUM 4" DIAMETER APPROVED SOLID OUTLET PIPE BACKDRAIN DETAIL (GEOFRABIC) STANDARD SPECIFICATIONS FOR GRADING Page 23 of 26 • SOIL SHALL BE PUSHED OVER ROCKS AND FLOODED INTO VOIDS. COMPACT AROUND AND OVER EACH WINDROW. 10' FILL SLOPE /6 l FILL SLOPE 1 r CLEARZONE __/ rEQUIPMENT WIDTH_/ STACK BOULDERS END TO END. DO NOT PILE UPON EACH OTHER. /4 0 0 0 0 ~ 10' MIN O NOT TO SCALE 0 p---.----_:O'::'.._STAGGER ROWS ROCK DISPOSAL DETAIL STANDARD SPECIFICATIONS FOR GRADING Page 24 of 26 • FINISHED GRADE BUILDING 10' SLOPE FACE NO OVERSIZE, AREA FOR FOUNDATION, UTILITIE~~l AND SWIMMING POOL:_i_ 0 0 O STREET /0 ~ •·L-_ WINDROW~ 5' MINIMUM OR BELOW DEPTH OF DEEPEST UTILITY TRENCH (WHICHEVER GREATER) TYPICAL WINDROW DETAIL (EDGE VIEW) GRANULAR SOIL FLOODED TO FILL VOIDS HORIZONTALLY PLACED COMPACTION FILL PROFILE VIEW NOT TO SCALE ROCK DISPOSAL DETAIL STANDARD SPECIFICATIONS FOR GRADING Page 25 of 26 0 ------ GENERAL GRADING RECOMMENDATIONS CUTLOT -==.--------------_::~~---=:::.=-----ORIGINAL GROUND - -- ------ 5' TOPSOIL, COLLUVIUM ANO ----WEATHERED BEDROCK ---------S'MIN 3'MIN - UNWEATHERED BEDROCK OVEREXCAVATE AND REGRADE CUT/FILL LOT (TRANSITION) ---------- ORIGINAL _,,.. ... GROUND ---'MIN COMPACTED FILL ---3' MIN ---------- UNWEATHERED BEDROCK NOT TO SCALE TRANSITION LOT DETAIL STANDARD SPECIFICATIONS FOR GRADING Page 26 of 26 OVEREXCAVATE AND REGRADE