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HomeMy WebLinkAboutCDP 2022-0062; CRUSE HOUSE REMODEL, ADU/GARAGE; LIMITED GEOTECHNICAL INVESTIGATION OF PROPOSED ADDITION; 2022-08-15LIMITED GEOTECHNICAL INVESTIGATION OF PROPOSED ADDITION, NEW CAR GARAGE, AND ACCESSORY DWELLING UNIT (ADU), 3912 GARFIELD STREET CARLSBAD, CALIFORNIA 92008 ACCESSOR’S PARCEL NUMBER (APN) 206-012-02-00 FOR MR. GARY CRUSE 3912 GARFIELD STREET CARLSBAD, CALIFORNIA 92008 W.O. 8382-A-SC AUGUST 15, 2022 Geotechnical C Geologic C Coastal C Environmental 5741 Palmer Way C Carlsbad, California 92010 C (760) 438-3155 C FAX (760) 931-0915 C www.geosoilsinc.com August 15, 2022 W.O. 8382-A-SC Mr. Gary Cruse 3912 Garfield Street Carlsbad, California 92008 Subject: Limited Geotechnical Investigation of Proposed Addition, New Car Garage, and Accessory Dwelling Unit (ADU), 3912 Garfield Street, Carlsbad, California 92008, Accessor’s Parcel Number (APN) 206-012-02-00 Dear Mr. Cruse: In accordance with your request and authorization, GeoSoils, Inc. (GSI) is pleased to present the results of our limited geotechnical investigation of the subject site. The purpose of our study was to evaluate the near-surface geologic and geotechnical conditions at the site, in order to develop preliminary recommendations for site earthwork and the design of foundations, walls, and flatwork related to the improvements planned at the existing residential property. SCOPE OF SERVICES The scope of our services has included the following: 1. Review of readily available published literature and geologic maps of the vicinity (see Appendix A), including proprietary in-house geologic/geotechnical reports for other nearby sites. 2. Reconnaissance geologic mapping, and the excavation of five (5) exploratory hand-auger borings to evaluate the formation profiles, sample representative soils, and delineate the horizontal and vertical extent of earth material units (see Appendix B). 3. General areal seismicity evaluation (see Appendix C). 4. Appropriate laboratory testing of representative bulk soil samples collected during our geologic mapping and subsurface exploration program (see Appendix D). 5. Appropriate engineering and geologic analyses of data collected, and the preparation of this summary report and accompaniments. GeoSoils, Inc. SITE DESCRIPTION AND PROPOSED DEVELOPMENT The subject site consists of a rectangular-shaped parcel, approximately 0.14 acres in size, located east of the intersection of Tamarack Avenue and Garfield Street, in the City of Carlsbad, San Diego County, California (see Figure 1 - Site Location Map). The property is bounded by residential homes to the northwest and southeast, a parking lot on the northeast, and by Garfield Street to the southwest. Topographically, the site sits atop a hill formed from an ancient beach terrace with Garfield Street running along the crest. To the northeast the hill slopes gently down bottoming at the train tracks before rising again towards the Interstate 5 freeway. To the southwest it slopes gently towards the pacific ocean. The street (Garfield Street) is at an elevation of about 65 feet MSL, and the subject lot slopes down to about 56 feet MSL, at the northeast property line, for a total relief of about 9 feet. Site drainage is generally directed offsite to the north/northeast. Existing improvements generally consist of one (1) residential home on the southwest portion of the property, with driveway access off Garfield Street, a one- (1-)story attached garage rests to the northwest of the existing residence. The property has some landscaped vegetation with little vegetation on the mostly bare ground backyard. Based on a review of the referenced documents, a review of the architectural plans by Arlen Roper Inc. (ARI 2022), and clients’ communication, the proposed development will generally consist of razing the existing garage and preparing the site for the construction of an addition and remodel of the single-family residence, a new driveway, and a new detached garage with ADU on top. The proposed addition will expand the current residential footprint to the, northeast , northwest and southwest. A site grading plan was not available for our review at the time of this study; however, given the lot slopes about 9 feet up to the southwest, fill and cut slopes are anticipated to be minor and on the order of about 5 feet or less. However, removals (i.e., 1½ feet to approximately 3½ feet deep) will be required to mitigate unsuitable underlying soils. The plans by ARI (2022) show that the construction will consist of one- and two-story structures using wood frames, with typical foundations consisting of slabs-on-grade with continuous perimeter footings. Building loads are assumed to be typical for this type of relatively light construction. Sewage disposal is anticipated to be connected into the regional, municipal system. FIELD STUDIES Site-specific field studies were conducted by GSI on June 9, 2022, and consisted of reconnaissance geologic mapping and the excavation of five (5) exploratory hand-auger borings for an evaluation of near-surface soil and geologic conditions onsite. Boring HA-1 was located along the northwest of the existing garage where the new driveway will be placed, HA-2 was within the proposed new addition near the south corner, HA-3 and HA-4 straddle the proposed garage/ADU on the east and west corners respectively, and HA-5 Gary Cruse W.O. 8382-A-SC 3912 Garfield Street, Carlsbad August 15, 2022 File:e:\wp21\8300\8382a.lgi Page 2 W.O. SITE LOCATION MAP Figure 1 8382-A-SC Base Map: TOPO!® ©2003 National Geographic, U.S.G.S. Oceanside Quadrangle, California --San Diego Co., 7.5 Minute, dated 1996, current, 2000. Base Map: Google Maps, Copyright 2022 Google, Map Data Copyright 2022 Google SITE 0 1000 2000 3000 4000 This map is copyrighted by Google 2022. It is unlawful tocopy or reproduce all or any part thereof, whether forpersonal use or resale, without permission. All rightsreserved. NOT TO SCALE SITE 0 7 -------- - Park N GeoSoils, Inc. was near the north corner of the proposed addition footprint. The geotechnical borings were logged by a representative of this office who collected representative bulk soil samples for appropriate laboratory testing. The logs of the geotechnical borings are presented in Appendix B. The approximate location of the borings are presented on the Boring Location Map (see Plate 1), which uses the “Site Plan - Gary and Deborah Cruse” (ARI, 2022) provided by the client, as a base. REGIONAL GEOLOGY The subject property lies within the coastal plain physiographic region of the Peninsular Ranges Geomorphic Province of southern California. This region consists of dissected, mesa-like terraces that transition inland to rolling hills. The encompassing Peninsular Ranges Geomorphic Province is characterized as elongated mountain ranges and valleys that trend northwesterly. This geomorphic province extends from the base of the east-west aligned Santa Monica - San Gabriel Mountains, and continues south into Baja California. The mountain ranges within this province are underlain by basement rocks consisting of pre-Cretaceous metasedimentary rocks, Jurassic metavolcanic rocks, and Cretaceous plutonic (granitic) rocks. In the southern California region, deposition occurred during the Cretaceous Period and Cenozoic Era in the continental margin of a forearc basin. Sediments, derived from Cretaceous-age plutonic rocks and Jurassic-age volcanic rocks, were deposited during the Tertiary Period (Eocene-age) into the narrow, steep, coastal plain and continental margin of the basin. These rocks have been uplifted, eroded, and deeply incised. During early Pleistocene time, a broad coastal plain was developed from the deposition of marine terrace deposits. During mid to late Pleistocene time, this plain was uplifted, eroded and incised. Alluvial deposits have since filled the lower valleys, and young marine sediments are currently being deposited/eroded within coastal and beach areas. Regional geologic mapping by Kennedy and Tan (2007) indicates the site is underlain by Quaternary-age old paralic deposits. SITE GEOLOGIC UNITS General The earth material units that were observed or encountered at the subject site consist of surficial deposits of undocumented fill or residual soils, overlying Quaternary-age old paralic deposits that generally graded from weathered to unweathered at depth. A general description of each material type is presented as follows, from youngest to oldest. Gary Cruse W.O. 8382-A-SC 3912 Garfield Street, Carlsbad August 15, 2022 File:e:\wp21\8300\8382a.lgi Page 4 GeoSoils, Inc. Quaternary-Aged Artificial Fill (Unmapped) Deposits of undocumented fill were encountered in all five borings, varying from about 1 to 2½ feet in thickness, consisting of brown to yellow brown, silty sand, noted to be dry and loose. Roots, 3/4-inch gravel, and bioturbation were noted in some of the borings. Quaternary-Aged Weathered Very Old Paralic Deposits (Map Symbol - Qvop) Deposits of weathered very old paralic deposits were encountered in all hand-auger borings at depth. Weathered old paralic deposits were encountered around 1½ to 2½ feet in depth below the ground surface on the existing single family structure building pad and approximately 1 to 1½ feet below the ground surface in the back yard. Thickness ranged from 1½ to 3½ feet thick before they transition to unweathered deposits. These sediments consisted of weathered red-brown sandstone, and typically noted to be moist and medium dense. Iron stone concretions on the order of 1cm were noted in these materials. Quaternary-Aged Very Old Paralic Deposits (Map Symbol - Qvop) Deposits of unweathered very old paralic deposits were encountered in all hand-auger borings at depth. Very old paralic deposits were encountered from 3½ to 5 feet. These sediments consisted of reddish brown to yellow brown sandstone, and typically were noted to be moist and dense. GROUNDWATER Groundwater was not encountered within any of our exploratory borings during our geotechnical investigation. GSI did not observe evidence of a regional groundwater table at depth. Regional groundwater is estimated to be within a few feet of sea level, and not anticipated to significantly affect proposed site development, provided that the recommendations contained in this report are properly incorporated into final design and construction. These observations reflect site conditions at the time of our investigation and do not preclude future changes in local groundwater conditions from excessive irrigation, precipitation, or that were not obvious, at the time of our investigation. Significant seeps, springs, or other indications of subsurface water were not noted on the subject property during the time of our field investigation. However, localized minor seepage cannot be precluded along zones of contrasting permeability/density (fill/formation contact). Additional seeps and perched water conditions may occur along geologic discontinuities. This observation and potential should be anticipated and disclosed to all interested/affected parties. Depending upon the time of year site grading occurs, perched groundwater may adversely effect site development. Effects may include, but not be limited to, special handling of wet natural or fill soils (drying, spreading, mixing, etc.) or specialized excavation equipment. These observations reflect site Gary Cruse W.O. 8382-A-SC 3912 Garfield Street, Carlsbad August 15, 2022 File:e:\wp21\8300\8382a.lgi Page 5 GeoSoils, Inc. conditions at the time of this geotechnical study and do not preclude changes in local groundwater conditions in the future. Due to the potential for post-development perched water to manifest near the surface, owing to as-graded permeability/density contrasts, more onerous slab design is necessary for any new slab-on-grade floor (State of California, 2022). Recommendations for reducing the amount of water and/or water vapor through slab-on-grade floors are provided in the “Soil Moisture Considerations” sections of this report. FAULTING AND REGIONAL SEISMICITY Regional Faults Our review indicates that there are no known active faults crossing the project and the site is not within an Alquist-Priolo Earthquake Fault Zone (California Geological Survey, 2018). However, the site is situated in an area of active faulting. The Rose Canyon fault is the closest known active fault to the site (located at a distance of approximately 5.0 miles [8.0 kilometers]) and should have the greatest effect on the site in the form of strong ground shaking, should the design earthquake occur. A list and the location of the Rose Canyon fault and other major faults relative to the site is provided in Appendix C. The possibility of ground acceleration, or shaking at the site, may be considered as approximately similar to the southern California region as a whole. Local Faulting Although active faults lie within miles of the site, no local active faulting was noted in our review, nor observed to specifically transect the site during the field investigation. Additionally, a review of available regional geologic maps does not indicate the presence of local active faults crossing the specific project site. Seismicity It is our understanding that site-specific seismic design criteria from the 2019 California Building Code ([2019 CBC], California Building Standards Commission [CBSC], 2019a), are to be used for foundation design. Much of the 2019 CBC relies on the American Society of Civil Engineers (ASCE) Minimum Design Loads for Buildings and Other Structures (ASCE Standard 7-16). The seismic design parameters provided herein are based on the 2019 CBC. The acceleration-attenuation relation of Bozorgnia, Campbell, and Niazi (1999) has been incorporated into EQFAULT (Blake, 2000a). EQFAULT is a computer program developed by Thomas F. Blake (2000a), which performs deterministic seismic hazard analyses using digitized California faults as earthquake sources. The program estimates the closest Gary Cruse W.O. 8382-A-SC 3912 Garfield Street, Carlsbad August 15, 2022 File:e:\wp21\8300\8382a.lgi Page 6 GeoSoils, Inc. distance between each fault and a given site. If a fault is found to be within a user-selected radius, the program estimates peak horizontal ground acceleration that may occur at the site from an upper bound (formerly “maximum credible earthquake”), on that fault. Upper bound refers to the maximum expected ground acceleration produced from a given fault. Site acceleration (g) was computed by one user-selected acceleration-attenuation relation that is contained in EQFAULT. Based on the EQFAULT program, a peak horizontal ground acceleration from an upper bound event on the Rose Canyon fault may be on the order of 0.625 g. The computer printouts of pertinent portions of the EQFAULT program are included within Appendix C. Historical site seismicity was evaluated with the acceleration-attenuation relation of Bozorgnia, Campbell, and Niazi (1999), and the computer program EQSEARCH (Blake, 2000b, updated to August 2018). This program performs a search of the historical earthquake records for magnitude 5.0 to 9.0 seismic events within a 100-kilometer radius, between the years 1800 through 2021. Based on the selected acceleration-attenuation relationship, a peak horizontal ground acceleration is estimated, which may have affected the site during the specific event listed. Based on the available data and the attenuation relationship used, the estimated maximum (peak) site acceleration during the period 1800 through May 2021 was about 0.360 g. A historic earthquake epicenter map and a seismic recurrence curve are also estimated/generated from the historical data. Computer printouts of the EQSEARCH program are presented in Appendix C. Seismic Shaking Parameters The following table summarizes the site-specific design criteria obtained from the 2019 CBC, Chapter 16 Structural Design, Section 1613, Earthquake Loads. The computer program Seismic Design Maps, provided by the California Office of Statewide Health Planning and Development (OSHPD, 2022) has now been used to aid in design (https://seismicmaps.org). The short spectral response uses a period of 0.2 seconds. 2019 CBC SEISMIC DESIGN PARAMETERS PARAMETER VALUE 2019 CBC or REFERENCE Risk Category I, II, or III Table 1604.5 Site Class D Section 1613.2.2/Chap. 20 ASCE 7-16 (p. 203-204) Spectral Response - (0.2 sec), Ss 1.097 g Section 1613.2.1 Figure 1613.2.1 Spectral Response - (1 sec), S1 0.395 g Section 1613.2.1 Figure 1613.2.1 Site Coefficient, Fa 1.061 Table 1613.2.3 Site Coefficient, Fv 1.905*Table 1613.2.3 Gary Cruse W.O. 8382-A-SC 3912 Garfield Street, Carlsbad August 15, 2022 File:e:\wp21\8300\8382a.lgi Page 7 GeoSoils, Inc. 2019 CBC SEISMIC DESIGN PARAMETERS PARAMETER VALUE 2019 CBC or REFERENCE Maximum Considered Earthquake Spectral Response Acceleration (0.2 sec), SMS 1.164g Section 1613.2.3 (Eqn 16-36) Maximum Considered Earthquake Spectral Response Acceleration (1 sec), SM1 0.752 g*Section 1613.2.3 (Eqn 16-37) 5% Damped Design Spectral Response Acceleration (0.2 sec), SDS 0.776 g Section 1613.2.4 (Eqn 16-38) 5% Damped Design Spectral Response Acceleration (1 sec), SD1 0.502 g Section 1613.2.4 (Eqn 16-39) PGAM - Probabilistic Vertical Ground Acceleration may be assumed as about 50% of these values. 0.541 g ASCE 7-16 (Eqn 11.8.1) Seismic Design Category D Section 1613.2.5/ASCE 7-16 (p. 85: Table 11.6-1 or 11.6-2) * FV = Per Table 11.4-2 of Supplement 1 of ASCE 7-16, this value of Fv may only be used to calculate Ts [that note is not included in Table 1613A.2.3(2)]; also note that SD1 and SM1 are functions of Fv. In addition, per Exception 2 of 11.4.8 of ASCE 7-16, special equations for Cs are required. This is in lieu of a site specific ground motion hazard analysis per ASCE 7-16 Chapter 21.2. ** Site Class D, and all of the resulting parameters in this table may only be used for structures without seismic isolation or seismic damping systems. GENERAL SEISMIC PARAMETERS PARAMETER VALUE Distance to Seismic Source (Rose Canyon fault)(1)±5.0 mi (8.0 km) Upper Bound Earthquake (Rose Canyon fault )MW = 7.2(2) (1) - From Blake (2000) (2) - Cao, et al. (2003) Based on the 2019 CBC Table 1613.2.3(2) footnote c., Fv should be determined in accordance with Section 11.4.8 of ASCE 7-16, since the mapped spectral response acceleration at 1 second is greater than 0.2g for Site Class D; in accordance with Section 11.4.8 of ASCE 7-16, a site specific seismic analysis is required. However, the values provided in the table above may be used if design is performed in accordance with Exception (2) in Section 11.4.8 of ASCE 7-16, with special requirements for the seismic response coefficient Cs) and Fv is only used for calculation of Ts. This exception does not apply (and the values in the table above would not be applicable) for proposed structures with seismic isolation or seismic damping systems. The project structural engineer should review the seismic parameters. A site specific seismic ground motion analysis can be performed upon request. Conformance to the criteria above for seismic design does not constitute any kind of guarantee or assurance that significant structural damage or ground failure will not occur in the event of a large earthquake. The primary goal of seismic design is to protect life, not Gary Cruse W.O. 8382-A-SC 3912 Garfield Street, Carlsbad August 15, 2022 File:e:\wp21\8300\8382a.lgi Page 8 I I I GeoSoils, Inc. to eliminate all damage, since such design may be economically prohibitive. Cumulative effects of seismic events are not addressed in the 2019 CBC (CBSC, 2019a) and regular maintenance and repair following locally significant seismic events (i.e., Mw5.5) will likely be necessary, as is the case in all of southern California. LABORATORY TESTING Laboratory tests were performed on representative samples of site earth materials collected during our subsurface exploration in order to evaluate their physical characteristics. Test procedures used and results obtained are presented below. Classification Soils were visually classified with respect to the Unified Soil Classification System (U.S.C.S.) in general accordance with ASTM D 2487 and D 2488. Expansion Index A test was performed on a representative soil sample in general accordance with ASTM D 4829. Test results and the soil’s expansion potential are presented in the following table: SAMPLE LOCATION DESCRIPTION EXPANSION INDEX EXPANSION POTENTIAL HA-3 @ 1'-5'Silty SAND < 5 Very Low Particle-Size Analysis A particle-size evaluation was performed on a representative sample of surficial, weathered bedrock soils (HA-4 @ 2 to 3 feet) in general accordance with ASTM D 422-63. The testing was used to evaluate the soil classification in accordance with the Unified Soil Classification System (USCS). The results of the particle-size evaluation indicate that the sample consisted of 1.1 percent gravel, 75.7 percent sand, and 23.2 percent fines, respectively. Per the USCS, site soil tested is classified as a silty sand (USCS symbol SM). The grain-size distribution curve is presented in Appendix D. Saturated Resistivity, pH, and Soluble Sulfates, and Chlorides Testing was performed on representative samples of the onsite earth materials for general soil corrosivity and soluble sulfates, and chlorides testing. The testing included evaluation of soil pH, soluble sulfates, chlorides, and saturated resistivity. GSI test results are Gary Cruse W.O. 8382-A-SC 3912 Garfield Street, Carlsbad August 15, 2022 File:e:\wp21\8300\8382a.lgi Page 9 I I GeoSoils, Inc. presented in Appendix C, and the following table, and previous test results are also shown below: SAMPLE LOCATION AND DEPTH (FT)pH SATURATED RESISTIVITY (ohm-cm) SOLUBLE SULFATES (percent by wt) SOLUBLE CHLORIDES (ppm) HA-2 @ 0 to 3 feet 7.2 5,900 0.005 21 Corrosion Summary Laboratory testing indicates that the tested samples of the onsite and near-site soils are generally neutral with respect to soil acidity/alkalinity; are moderately corrosive to exposed, buried metals when saturated; present negligible sulfate exposure to concrete (S0, per ACI 318-14); and the soluble chloride levels are slightly elevated, but below action levels. GSI does not consult in the field of corrosion engineering. Concentrations of soil chemicals can and do occur over time in hillside development and can be transported by surface and subsurface water. Therefore, additional comments and recommendations may be obtained from a qualified corrosion engineer based on the level of corrosion protection required for the project. Concrete mix design may be based on S0 and W0 conditions, per ACI 318-14. STORM WATER TREATMENT AND HYDROMODIFICATION MANAGEMENT USDA Soils Report A review of the United States Department of Agriculture database ([USDA]; 1973, 2022) indicates infiltration rates, between 0.57 to 1.98 inches per hour for the Marina loamy course sand mapped on the site. The USDA data generally characterizes surficial soil conditions. During the grading/construction process, in areas proposed for improvements, these surficial soils would generally be removed and exported, or recompacted during remedial grading, and as such, may not considered entirely representative of “as-built” site conditions, or parent material at greater depths. Infiltration Feasibility In accordance with the BMP Design Manual used by the City of Carlsbad (2016), the infiltration feasibility for this site was evaluated. Site soils are mapped as belonging to Hydrologic Soil Group B, with reported Ksat values ranging from moderately high to high 0.57 to 1.98 inches/hour (USDA; 1973, 2022). Infiltration Feasibility Checklist sheet (sheet I-8) and USDA soils report for the site is presented in Appendix E. Gary Cruse W.O. 8382-A-SC 3912 Garfield Street, Carlsbad August 15, 2022 File:e:\wp21\8300\8382a.lgi Page 10 GeoSoils, Inc. Owing to the proximity of existing improvements, including fill and backfill, as well as the potential for mounding and offsite groundwater migration causing distress, we recommend a “no infiltration” BMP design. Any basin constructed entirely of compacted fill is considered as belonging to Hydrologic Soil Group “D,” and a “no infiltration” BMP design is warranted ([EPA], Clar, et al., 2004). For hydromodification structures located within 10 feet of a structure or settlement-sensitive improvement, storm water treatment and hydromodification management should be designed for no infiltration. Deepened foundations or flatwork with thickened edges are also recommended in this area. Utility backfill in this area should consist of a two-sack mix of slurry. Infiltration feasibility is presented in Appendix E, which contains a categorization of no infiltration, as indicated on Form I-8, provided by the City of Carlsbad (2021). PRELIMINARY CONCLUSIONS AND RECOMMENDATIONS Based on our field exploration, laboratory testing, and geotechnical engineering analysis, it is our opinion that the subject site is suitable for the proposed residential development from a geotechnical engineering and geologic viewpoint, provided that the recommendations presented in the following sections are incorporated into the design and construction phases of site development. The primary geotechnical concerns with respect to the proposed development and improvements are: • Earth materials characteristics and depth to competent bearing material. • On-going expansion and corrosion potential of site soils. • Erosiveness of site earth materials. • Potential for perched water during and following site development. • Potential for infiltration to cause offsite distress to existing improvements. • Regional seismic activity. The recommendations presented herein consider these as well as other aspects of the site. The engineering analyses performed concerning site preparation and the recommendations presented herein have been completed using the information provided and obtained during our field work. If any significant changes are made to proposed site development, the conclusions and recommendations contained in this report shall not be considered valid unless the changes are reviewed and the recommendations of this report verified or modified in writing by this office. Foundation design parameters are considered preliminary until the foundation design, layout, and structural loads are provided to this office for review. Gary Cruse W.O. 8382-A-SC 3912 Garfield Street, Carlsbad August 15, 2022 File:e:\wp21\8300\8382a.lgi Page 11 GeoSoils, Inc. EARTHWORK CONSTRUCTION RECOMMENDATIONS General All earthwork should conform to the guidelines presented in the 2019 CBC (CBSC, 2019a), the requirements of the City of Carlsbad, and the General Earthwork and Grading Guidelines presented in Appendix E, except where specifically superceded in the text of this report. Prior to earthwork, a GSI representative should be present at the preconstruction meeting to provide additional earthwork guidelines, if needed, and review the earthwork schedule. This office should be notified in advance of any fill placement, supplemental regrading of the site, or backfilling underground utility trenches and retaining walls after rough earthwork has been completed. This includes grading for driveway approaches, driveways, and exterior hardscape. During earthwork construction, all site preparation and the general grading procedures of the contractor should be observed and the fill selectively tested by a representative(s) of GSI. If unusual or unexpected conditions are exposed in the field, they should be reviewed by this office and, if warranted, modified and/or additional recommendations will be offered. All applicable requirements of local and national construction and general industry safety orders, the Occupational Safety and Health Act (OSHA), and the Construction Safety Act should be met. It is the onsite general contractor and individual subcontractors responsibility to provide a safe working environment for our field staff who are onsite. GSI does not consult in the area of safety engineering. Demolition/Grubbing 1. Vegetation and any miscellaneous debris should be removed from the areas of proposed grading. 2. Any existing subsurface structures uncovered during the recommended removal should be observed by GSI so that appropriate remedial recommendations can be provided. 3. Cavities or loose soils remaining after crib wall demolition and site clearance should be cleaned out and observed by the soil engineer. The cavities should be replaced with fill materials that have been moisture conditioned to at least optimum moisture content and compacted to at least 90 percent of the laboratory standard. 4. Onsite septic systems (if encountered) should be removed in accordance with San Diego County Department of Environmental Health standards/guidelines. Gary Cruse W.O. 8382-A-SC 3912 Garfield Street, Carlsbad August 15, 2022 File:e:\wp21\8300\8382a.lgi Page 12 GeoSoils, Inc. Treatment of Existing Ground 1. Removals should consist of all surficial deposits of undocumented fill and weathered paralic deposits (if present). Based on our site work, removals depths on the order of about 3½ to 5 feet throughout the site should be anticipated. These soils may be re-used as fill, provided that the soil is cleaned of any deleterious material and moisture conditioned, and compacted to a minimum 90 percent relative compaction per ASTM D 1557. Removals should be completed until the underlying sediments are visibly free of voids, have a dry density of 105 pcf, and a relative saturation or relative density of 85 percent and throughout the entire buildings/construction area. Should removals/grading not be performed, footings would need to be deepened by about 3½ to 5 feet or more than plan, and slabs would need to be structurally designed to span between footings, and not rely on the soil for support (structural slab). 2. In addition to removals within the building envelope, and for the mitigation of adverse soil moisture, overexcavation/undercutting of the underlying bedrock soil should be performed in order to provide for at least 2 feet of compacted fill below finish grade, or 2 feet below the bottom of deepest footing; whichever is greater. Undercutting should be completed for a minimum lateral distance of at least 5 feet beyond the building footprint. Once removals and overexcavation is completed, the fill should be cleaned of deleterious materials, moisture conditioned, and recompacted to at least 90 percent relative compaction per ASTM D 1557. 3. After the above removals/overexcavation, the exposed bottom should be scarified to a depth of at least 6 to 8 inches, brought to at least optimum moisture content, and recompacted to a minimum relative compaction of 90 percent of the laboratory standard, prior to any fill placement. 4. Onsite soils may be reused as compacted fill provided that major concentrations of vegetation and miscellaneous debris are removed from the site, prior to or during fill placement. 5. Localized deeper removals may be necessary due to buried drainage channel meanders or dry porous materials, septic systems, etc. The project soils engineer/geologist should observe all removal areas during the grading. Rock Hardness and Rippability During our geotechnical evaluation, hand-auger borings HA-1 through HA-5 were advanced to a depth of about 5 to 6 feet below the existing grade. The planned cuts and fill are not anticipated to exceed 6 feet in height. As such, GSI anticipates the site will be rippable to the estimated depth of removals. Gary Cruse W.O. 8382-A-SC 3912 Garfield Street, Carlsbad August 15, 2022 File:e:\wp21\8300\8382a.lgi Page 13 GeoSoils, Inc. Earthwork Balance (Shrinkage/Bulking) The volume change of excavated materials upon compaction as engineered fill is anticipated to vary with material type and location. The overall earthwork shrinkage and bulking may be approximated by using the following parameters: Artificial Fill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10% Shrinkage Bedrock. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0-5% Shrinkage The above factors are estimates only, based on preliminary data. Any weathered bedrock may achieve higher shrinkage if organics or clay content is higher than anticipated, if a high degree of porosity is encountered, or if compaction averages more than 92 percent of the laboratory standard (ASTM D 1557). Fill Suitability Surficial onsite soils (undocumented fill or topsoil) generally appear to consist of silty sand, while weathered bedrock is anticipated to generate silty sands and unweathered bedrock is anticipated to generate silty sands. Oversize material (12-inch plus) cannot be precluded from being generated from cut excavations into the bedrock. In order to facilitate shallow onsite trenching, consideration should be given to maintaining a maximum rock fragment size of 6 inches within any future fill areas to be trenched. Materials generated from demolition of any structures, such as foundation concrete, should be cleaned of any reinforcing steel and reduced to minus 8-inch size particles before incorporating into the fill. Any asphalt disposal onsite should conform to Code and be placed in street areas, or placed at depth, below the lowest utility invert elevation. Existing fill soils are generally very low expansive, on a preliminary basis. Any soil import should be evaluated by this office prior to importing in order to assure compatibility with the onsite site soils and the recommendations presented in this report. An additional discussion of import soils is presented in the following section. Fill Placement 1. After ground preparation, fill materials should be brought to at least optimum moisture content, placed in thin 6- to 8-inch lifts, and mechanically compacted to obtain a minimum relative compaction of 90 percent of the laboratory standard. 2. Fill materials should be cleansed of major vegetation and debris prior to placement. 3. Any import materials should be observed and deemed suitable by the soils engineer prior to placement on the site. Foundation designs may be altered if import materials have a greater expansion value than the onsite materials encountered in this investigation. Any import soil should be of a similar low Gary Cruse W.O. 8382-A-SC 3912 Garfield Street, Carlsbad August 15, 2022 File:e:\wp21\8300\8382a.lgi Page 14 GeoSoils, Inc. expansive character as the onsite soils encountered, otherwise, a more onerous foundation design (with respect to expansive soils) may be required. Temporary Slopes Temporary slopes for excavations greater than 4 feet, but less than 20 feet in overall height should conform to CAL-OSHA and/or OSHA requirements for Type “B” soils. Temporary slopes, up to a maximum height of about 20 feet, may be excavated at a 1:1 (h:v) gradient, or flatter, provided groundwater and/or running sands are not exposed. Construction materials or soil stockpiles should not be placed within ‘H’ of any temporary slope where ‘H’ equals the height of the temporary slope. All temporary slopes should be observed by a licensed engineering geologist and/or geotechnical engineer prior to worker entry into the excavation. Subdrainage Based on site topography, and the soil conditions evaluated, subdrainage is not generally anticipated at this time. However, conditions exposed during site grading may warrant the construction of subdrainage, and will be evaluated during site grading. Any site retaining walls will need to be provided with back drainage, as is the standard of practice. PRELIMINARY RECOMMENDATIONS - FOUNDATIONS General Preliminary recommendations for foundation design and construction are provided in the following sections. These preliminary recommendations have been developed from our understanding of the currently planned site development, site observations, subsurface exploration, laboratory testing, and engineering analyses. Foundation design should be re-evaluated at the conclusion of site grading/remedial earthwork for the as-graded soil conditions, and revisions to these recommendations may be necessary. If the information concerning the proposed development plan is not correct, or any changes in the design, location, or loading conditions of the proposed additions are made, the conclusions and recommendations contained in this report shall not be considered valid unless the changes are reviewed and conclusions of this report are modified or approved in writing by this office. The information and recommendations presented in this section are not meant to supercede design by the project structural engineer or civil engineer specializing in structural design. Upon request, GSI could provide additional input/consultation regarding soil parameters, as related to foundation design. Gary Cruse W.O. 8382-A-SC 3912 Garfield Street, Carlsbad August 15, 2022 File:e:\wp21\8300\8382a.lgi Page 15 GeoSoils, Inc. Preliminary Foundation Design 1. An allowable bearing value of 2,000 pounds per square foot (psf) may be used for the design of one-story footings that maintain a minimum width of 12 inches and a minimum depth of 12 inches (below the lowest adjacent grade)or two-story footings that maintain a minimum width of 15 inches and a minimum depth of 18 inches, and are founded entirely into properly compacted, engineered fill. This value may be increased by 20 percent for each additional 12 inches in footing depth to a maximum value of 2,500 psf. These values may be increased by one-third when considering short duration seismic or wind loads. Isolated pad footings should have a minimum dimension of at least 24 inches square and a minimum embedment of 24 inches below the lowest adjacent grade into properly engineered fill. Foundation embedment depth excludes concrete slabs-on-grade, and/or slab underlayment. Foundations should not simultaneously bear on unweathered formation and engineered fill. 2. For foundations deriving passive resistance from engineered fill, a passive earth pressure may be computed as an equivalent fluid having a density of 250 pcf, with a maximum earth pressure of 2,500 psf. 3. The upper 6 inches of passive pressure should be neglected if not confined by slabs or pavement. 4. For lateral sliding resistance, a 0.35 coefficient of friction may be used for a concrete to soil contact when multiplied by the dead load. 5. When combining passive pressure and frictional resistance, the passive pressure component should be reduced by one-third. 6. All footing setbacks from slopes should comply with Figure 1808.7.1 of the 2019 CBC. GSI recommends a minimum horizontal setback distance of 7 feet as measured from the bottom, outboard edge of the footing to the slope face. 7. Footings for structures adjacent to retaining walls should be deepened so as to extend below a 1:1 projection from the heel of the wall. Alternatively, walls may be designed to accommodate structural loads from buildings or appurtenances as described in the “Retaining Wall” section of this report. 8. Provided that the earthwork and foundation recommendations in this reported are adhered, foundations bearing on engineered fill should be minimally designed to accommodate a differential settlement of 1 inch over a 40-foot horizontal span (angular distortion = 1/480). Gary Cruse W.O. 8382-A-SC 3912 Garfield Street, Carlsbad August 15, 2022 File:e:\wp21\8300\8382a.lgi Page 16 GeoSoils, Inc. PRELIMINARY FOUNDATION CONSTRUCTION RECOMMENDATIONS The following foundation construction recommendations are presented as a minimum criteria from a soils engineering viewpoint, and assume removal and recompaction has occurred. The following foundation construction recommendations are intended to support planned improvements underlain by at least 7 feet of non-detrimentally expansive soils (i.e., E.I.< 21 and P.I. < 15). Should foundations be underlain by expansive soils at depths of less than 7 feet, they will require specific design to mitigate expansive soil effects as required in Sections 1808.6.1 or 1808.6.2 of the 2019 CBC (CBSC, 2019a). 1. All footings should be reinforced with four No. 4 reinforcing bars, two placed near the top and two placed near the bottom of the footing. Reinforcement of pad footings should be provided by the projects structural engineer. 2. All interior and exterior column footings, and perimeter wall footings, should be tied together via grade beams in at least one direction. The grade beam should be at least 12 inches square in cross section, and should be provided with a minimum of one No.4 reinforcing bar at the top, and one No.4 reinforcing bar at the bottom of the grade beam. The base of the reinforced grade beam should be at the same elevation as the adjoining footings. 3. A grade beam, reinforced as previously recommended and at least 12 inches square, should be provided across large (garage) entrances. The base of the reinforced grade beam should be at the same elevation as the adjoining footings. 4. A minimum concrete slab-on-grade thickness of 5 inches is recommended. Recommendations for floor slab underlayment are presented in a later section of this report. 5. Concrete slabs should be reinforced with a minimum of No. 3 reinforcement bars placed at 18-inch on centers, in two horizontally perpendicular directions (i.e., long axis and short axis). 6. All slab reinforcement should be supported to ensure proper mid-slab height positioning during placement of the concrete. “Hooking” of reinforcement is not an acceptable method of positioning. 7. Specific slab subgrade pre-soaking is recommended for these soil conditions. Prior to the placement of underlayment sand and vapor retarder, GSI recommends that the slab subgrade materials be moisture conditioned to at least optimum moisture content to a minimum depth of 12 inches. Slab subgrade pre-soaking should be evaluated by the geotechnical consultant within 72 hours of the placement of the underlayment sand and vapor retarder. Gary Cruse W.O. 8382-A-SC 3912 Garfield Street, Carlsbad August 15, 2022 File:e:\wp21\8300\8382a.lgi Page 17 GeoSoils, Inc. Slab Subgrade Pre-Soaking Pre-moistening of the slab subgrade soil is recommended for detrimentally expansive soil conditions. The moisture content of the subgrade soils should be equal to or greater than optimum moisture to a depth equivalent to the perimeter grade beam or cut-off wall depth in the slab areas (typically 12 inches) for low expansive soil conditions. Pre-moistening and/or pre-soaking should be evaluated by the soils engineer 72 hours prior to vapor retarder placement. In summary: EXPANSION POTENTIAL PAD SOIL MOISTURE CONSTRUCTION METHOD SOIL MOISTURE RETENTION Very Low (E.I. < 21) Upper 12 inches of pad soil moisture 2 percent over optimum (or 1.2 times) Wetting and/or reprocessing Periodically wet or cover with plastic after trenching. Evaluation 72 hours prior to placement of concrete. Perimeter Cut-Off Walls Perimeter cut-off walls should be at least 12 inches deep for low expansive soil conditions. The cut-off walls may be integrated into the slab design or independent of the slab. The cut-off walls should be a minimum of 6 inches thick (wide). The bottom of the perimeter cut-off wall should be designed to resist tension, using cable or reinforcement per the structural engineer. SOIL MOISTURE TRANSMISSION CONSIDERATIONS GSI has evaluated the potential for vapor or water transmission through the concrete floor slab, in light of typical floor coverings and improvements. Please note that slab moisture emission rates range from about 2 to 27 lbs/24 hours/1,000 square feet from a typical slab (Kanare, 2005), while floor covering manufacturers generally recommend about 3 lbs/24 hours as an upper limit. The recommendations in this section are not intended to preclude the transmission of water or vapor through the foundation or slabs. Foundation systems and slabs should not allow water or water vapor to enter into the structure so as to cause damage to another building component or to limit the installation of the type of flooring materials typically used for the particular application (State of California, 2022). These recommendations may be exceeded or supplemented by a water “proofing” specialist, project architect, or structural consultant. Thus, the client will need to evaluate the following in light of a cost vs. benefit analysis (owner expectations and repairs/replacement), along with disclosure to all interested/affected parties. It should also be noted that vapor transmission will occur in new slab-on-grade floors as a result of chemical reactions taking place within the curing concrete. Vapor transmission through Gary Cruse W.O. 8382-A-SC 3912 Garfield Street, Carlsbad August 15, 2022 File:e:\wp21\8300\8382a.lgi Page 18 GeoSoils, Inc. concrete floor slabs as a result of concrete curing has the potential to adversely affect sensitive floor coverings depending on the thickness of the concrete floor slab and the duration of time between the placement of concrete, and the floor covering. It is possible that a slab moisture sealant may be needed prior to the placement of sensitive floor coverings if a thick slab-on-grade floor is used and the time frame between concrete and floor covering placement is relatively short. Considering the E.I. test results presented herein, and known soil conditions in the region, the anticipated typical water vapor transmission rates, floor coverings, and improvements (to be chosen by the Client and/or project architect) that can tolerate vapor transmission rates without significant distress, the following alternatives are provided: • Concrete slabs should be increased in thickness. • Concrete slab underlayment should consist of a 15-mil vapor retarder, or equivalent, with all laps sealed per the 2019 CBC and the manufacturer’s recommendation. The vapor retarder should comply with the ASTM E 1745 - Class A criteria, and be installed in accordance with ACI 302.1R-04 and ASTM E 1643. • The 15-mil vapor retarder (ASTM E 1745 - Class A) should be installed per the recommendations of the manufacturer, including all penetrations (i.e., pipe, ducting, rebar, etc.). • Concrete slabs, including the garage areas, should be underlain by 2 inches of clean sand (SE > 30) above a 15-mil vapor retarder (ASTM E-1745 - Class A, per Engineering Bulletin 119 [Kanare, 2005]) installed per the recommendations of the manufacturer, including all penetrations (i.e., pipe, ducting, rebar, etc.). The manufacturer shall provide instructions for lap sealing, including minimum width of lap, method of sealing, and either supply or specify suitable products for lap sealing (ASTM E 1745), and per Code. ACI 302.1R-04 (2004) states “If a cushion or sand layer is desired between the vapor retarder and the slab, care must be taken to protect the sand layer from taking on additional water from a source such as rain, curing, cutting, or cleaning. Wet cushion or sand layer has been directly linked in the past to significant lengthening of time required for a slab to reach an acceptable level of dryness for floor covering applications.” Therefore, additional observation and/or testing will be necessary for the cushion or sand layer for moisture content, and relatively uniform thicknesses, prior to the placement of concrete. • The vapor retarder shall be underlain by 2 inches of sand (SE > 30) placed directly on the prepared, moisture conditioned, subgrade and should be sealed to provide a continuous retarder under the entire slab, as discussed above. As discussed previously, GSI indicated this layer of import sand may be eliminated below the Gary Cruse W.O. 8382-A-SC 3912 Garfield Street, Carlsbad August 15, 2022 File:e:\wp21\8300\8382a.lgi Page 19 GeoSoils, Inc. vapor retarder, if laboratory testing indicates that the slab subgrade soil have a sand equivalent (SE) of 30 or greater. • Concrete should have a maximum water/cement ratio of 0.50. This does not supercede Table 19.3.2.1 of ACI (2014) for corrosion or other corrosive requirements. Additional concrete mix design recommendations should be provided by the structural consultant and/or waterproofing specialist. Concrete finishing and workablity should be addressed by the structural consultant and a waterproofing specialist. • Where slab water/cement ratios are as indicated herein, or admixtures used, the structural consultant should also make changes to the concrete in the grade beams and footings in kind, so that the concrete used in the foundation and slabs are designed and/or treated for more uniform moisture protection. • The owner(s) should be specifically advised which areas are suitable for tile flooring, vinyl flooring, or other types of water/vapor-sensitive flooring and which are not suitable. In all planned floor areas, flooring shall be installed per the manufacturer’s recommendations. • Additional recommendations regarding water or vapor transmission should be provided by the architect/structural engineer/slab or foundation designer and should be consistent with the specified floor coverings indicated by the architect. Regardless of the mitigation, some limited moisture/moisture vapor transmission through the slab should be anticipated. Construction crews may require special training for installation of certain product(s), as well as concrete finishing techniques. The use of specialized product(s) should be approved by the slab designer and water-proofing consultant. A technical representative of the flooring contractor should review the slab and moisture retarder plans and provide comment prior to the construction of the foundations or improvements. The vapor retarder contractor should have representatives onsite during the initial installation. WALL DESIGN PARAMETERS General Recommendations for the design and construction of conventional masonry retaining walls are provided herein. Recommendations for specialty walls (i.e., crib, earthstone, geogrid, etc.) can be provided upon request, and would be based on site specific conditions. Gary Cruse W.O. 8382-A-SC 3912 Garfield Street, Carlsbad August 15, 2022 File:e:\wp21\8300\8382a.lgi Page 20 GeoSoils, Inc. Conventional Retaining Walls The design parameters provided below assume that either very low expansive soils (typically Class 2 permeable filter material or Class 3 aggregate base) or native onsite materials with an expansion index up to 20 are used to backfill any retaining wall. Please note that the onsite soils likely meet this criteria. The type of backfill (i.e., select or native), should be specified by the wall designer, and clearly shown on the plans. Building walls, below grade, should be water-proofed. Waterproofing should also be provided for site retaining walls in order to reduce the potential for efflorescence staining. Preliminary Retaining Wall Foundation Design Preliminary foundation design for retaining walls should incorporate the following recommendations: Minimum Footing Embedment - 18 inches below the lowest adjacent grade (excluding landscape layer [upper 6 inches]). Minimum Footing Width - 24 inches. Allowable Bearing Pressure - An allowable bearing pressure of 2,000 pcf may be used in the preliminary design of retaining wall foundations provided that the footing maintains a minimum width of 24 inches and extends at least 18 inches into approved engineered fill overlying dense formational materials. This pressure may be increased by one-third for short-term wind and/or seismic loads. Passive Earth Pressure - A passive earth pressure of 250 pcf with a maximum earth pressure of 2,500 psf may be used in the preliminary design of retaining wall foundations provided the foundation is embedded into properly compacted silty to clayey sand fill. Lateral Sliding Resistance - A 0.35 coefficient of friction may be used for a concrete to soil contact when multiplied by the dead load. When combining passive pressure and frictional resistance, the passive pressure component should be reduced by one-third. Backfill Soil Density - Soil densities ranging between 120 pcf and 130 pcf should be used in the design of retaining wall foundations. This assumes an average engineered fill compaction of at least 90 percent of the laboratory standard (ASTM D 1557). Any retaining wall footings near the perimeter of the site will likely need to be deepened into slightly to unweathered formational soils for adequate vertical and lateral bearing support. All retaining wall footing setbacks from slopes should comply with Gary Cruse W.O. 8382-A-SC 3912 Garfield Street, Carlsbad August 15, 2022 File:e:\wp21\8300\8382a.lgi Page 21 GeoSoils, Inc. Figure 1808.7.1 of the 2019 CBC. GSI recommends a minimum horizontal setback distance of 7 feet as measured from the bottom, outboard edge of the footing to the slope face. Restrained Walls Any retaining walls that will be restrained prior to placing and compacting backfill material or that have re-entrant or male corners, should be designed for an at-rest equivalent fluid pressure (EFP) of 55 pcf and 65 pcf for select and very low expansive native backfill, respectively. The design should include any applicable surcharge loading. For areas of male or re-entrant corners, the restrained wall design should extend a minimum distance of twice the height of the wall (2H) laterally from the corner. Cantilevered Walls The recommendations presented below are for cantilevered retaining walls up to 10 feet high. Design parameters for walls less than 3 feet in height may be superceded by County regional standard design. Active earth pressure may be used for retaining wall design, provided the top of the wall is not restrained from minor deflections. An equivalent fluid pressure approach may be used to compute the horizontal pressure against the wall. Appropriate fluid unit weights are given below for specific slope gradients of the retained material. These do not include other superimposed loading conditions due to traffic, structures, seismic events or adverse geologic conditions. When wall configurations are finalized, the appropriate loading conditions for superimposed loads can be provided upon request. For preliminary planning purposes, the structural consultant/wall designer should incorporate the surcharge of traffic on the back of retaining walls where vehicular traffic could occur within horizontal distance “H” from the back of the retaining wall (where “H” equals the wall height). The traffic surcharge may be taken as 100 psf/ft in the upper 5 feet of backfill for light truck and cars traffic. This does not include the surcharge of parked vehicles which should be evaluated at a higher surcharge to account for the effects of seismic loading. Equivalent fluid pressures for the design of cantilevered retaining walls are provided in the following table: SURFACE SLOPE OF RETAINED MATERIAL (HORIZONTAL:VERTICAL) EQUIVALENT FLUID WEIGHT P.C.F. (SELECT BACKFILL)(2) EQUIVALENT FLUID WEIGHT P.C.F. (NATIVE BACKFILL)(3) Level(1) 2 to 1 38 55 50 65 (1) Level backfill behind a retaining wall is defined as compacted earth materials, properly drained, without a slope for a distance of 2H behind the wall, where H is the height of the wall. (2) SE > 30, P.I. < 15, E.I. < 21, and < 10% passing No. 200 sieve. (3) E.I. = 0 to 50, SE > 30, P.I. < 15, E.I. < 21, and < 20% passing No. 200 sieve. Gary Cruse W.O. 8382-A-SC 3912 Garfield Street, Carlsbad August 15, 2022 File:e:\wp21\8300\8382a.lgi Page 22 I --I GeoSoils, Inc. Seismic Surcharge For engineered retaining walls with more than 6 feet of retained materials, as measured vertically from the bottom of the wall footing at the heel to daylight , GSI recommends that the walls be evaluated for a seismic surcharge (in general accordance with 2019 CBC requirements). The site walls in this category should maintain an overturning Factor-of-Safety (FOS) of approximately 1.25 when the seismic surcharge (increment), is applied. For restrained walls, the seismic surcharge should be applied as a uniform surcharge load from the bottom of the footing (excluding shear keys) to the top of the backfill at the heel of the wall footing. This seismic surcharge pressure (seismic increment) may be taken as 15H where “H” for retained walls is the dimension previously noted as the height of the backfill to the bottom of the footing. The resultant force should be applied at a distance 0.6 H up from the bottom of the footing. For the evaluation of the seismic surcharge, the bearing pressure may exceed the static value by one-third, considering the transient nature of this surcharge. For cantilevered walls, the pressure should be applied as an inverted triangular distribution using 15H. For restrained walls, the pressure should be applied as a rectangular distribution. Please note this is for local wall stability only. The 15H is derived from a Mononobe-Okabe solution for both restrained cantilever walls. This accounts for the increased lateral pressure due to shakedown or movement of the sand fill soil in the zone of influence from the wall or roughly a 45° - N/2 plane away from the back of the wall. The 15H seismic surcharge is derived from the formula: Ph = d C ah C ãtH Where:Ph = Seismic increment.ah = Probabilistic horizontal site acceleration with a percentage of “g.”ãt =total unit weight (115 to 125 pcf for site soils @ 90 percent relative compaction).H =Height of the wall from the bottom of the footing or point of pile fixity. Retaining Wall Backfill and Drainage Positive drainage must be provided behind all retaining walls in the form of gravel wrapped in geofabric and outlets. A backdrain system is considered necessary for retaining walls that are 2 feet or greater in height. Details 1 and 2 present the back drainage options discussed below. Backdrains should consist of a 4-inch diameter perforated PVC or ABS pipe encased in either Class 2 permeable filter material or ¾-inch to 1½-inch gravel wrapped in approved filter fabric (Mirafi 140 or equivalent). For low expansive backfill, the filter material should extend a minimum of 1 horizontal foot behind the base of the walls and upward at least 1 foot. This material should be continuous (i.e., full height) behind the wall, and it should be constructed in accordance with the enclosed Detail 1 (Typical Retaining Wall Backfill and Drainage Detail). For limited access and confined areas, Gary Cruse W.O. 8382-A-SC 3912 Garfield Street, Carlsbad August 15, 2022 File:e:\wp21\8300\8382a.lgi Page 23 12 inches (1) Waterproofingmembrane Provide surface drainage via an engineered V-ditch (see civil plans for details) (5) Weep hole Proposed grade sloped to drain per precise civil drawings (4) Pipe (3) Filter fabric (2) Gravel 2:1 (h:v) slope 1:1 (h:v) or flatter backcut to be properlybenched Slope or level Native backfill Very Low to Low Expansive soils, E.I. <50, P.I. <15 (1) Waterproofing membrane. (2) Gravel: Clean, crushed, 3 4 to 11 2 inch. (3) Filter fabric: Mirafi 140N or approved equivalent. (4) Pipe: 4-inch-diameter perforated PVC, Schedule 40, or approved alternative with minimum of 1 percent gradient sloped to suitable, approved outlet point (perforations down). (5) Weep holes: For CMU walls, Omit grout every other block, at or slightly above finished surface. For reinforced concrete walls, minimum 2-inch diameter weep holesspaced at 20 foot centers along the wall and placed 3 inches above finished surface. Design civil engineer to provide drainage at toe of wall. No weep holes for below-grade walls. (6) Footing: If bench is created behind the footing greater than the footing width using level fill or cut natural earth materials, an additional "heel " drain will likely be required by geotechnical consultant. Footing and wall design by others (6) Footing Structural footing orsettlement-sensitive improvement H H/3 CMU or reinforced-concrete wall . . .-·-··._ .•• . .. - I I RETAINING WALL DETAIL -ALTERNATIVE A Detail 1 6 inches (1) Waterproofing membrane (optional)Provide surface drainage via engineered V-ditch (see civil plan details) (5) Weep hole Proposed gradesloped to drain per precise civil drawings (4) Pipe (3) Filter fabric (2) Composite drain CMU or reinforced-concretewall 2:1 (h:v) slope 1:1 (h:v) or flatterbackcut to be properly benched Slope or level Native backfill Very Low to Low Expansive soils E.I. <50, P.I. <15 (1) Waterproofing membrane (optional): Liquid boot or approved mastic equivalent. (2) Drain: Miradrain 6000 or J-drain 200 or equivalent for non-waterproofed walls; Miradrain 6200 or J-drain 200 or equivalent for waterproofed walls (all perforations down). (3) Filter fabric: Mirafi 140N or approved equivalent; place fabric flap behind core. (4) Pipe: 4-inch-diameter perforated PVC, Schedule 40, or approved alternative with minimum of 1 percent gradient to proper outlet point (perforations down). (5) Weep holes: For CMU walls, Omit grout every other block, at or slightly above finished surface. For reinforced concrete walls, minimum 2-inch diameter weep holesspaced at 20 foot centers along the wall and placed 3 inches above finished surface. Design civil engineer to provide drainage at toe of wall. No weep holes for below-grade walls. (6) Gravel: Clean, crushed, 3 4 to 11 2 inch. (7) Footing: If bench is created behind the footing greater than the footing width using level fill or cut natural earth materials, an additional "heel" drain will likely be required by geotechnical consultant. (6) 1 cubic foot of 3 4-inch crushed rock (7) Footing Footing and walldesign by others Structural footing orsettlement-sensitive improvement l_ 1- I I .-·-·._ .•• I RETAINING WALL DETAIL -ALTERNATIVE B Detail 2 GeoSoils, Inc. (panel) drainage behind the wall may be constructed in accordance with Detail 2 (Retaining Wall Backfill and Subdrain Detail Geotextile Drain). Materials with an E.I. potential of greater than 50 should not be used as backfill for retaining walls. Drain outlets should consist of a 4-inch diameter solid PVC or ABS pipe spaced no greater than ±100 feet apart, with a minimum of two outlets, one on each end. The use of weep holes, only, in walls higher than 2 feet, is not recommended. The surface of the backfill should be sealed by pavement or the top 18 inches compacted with native soil (E.I. < 50). Proper surface drainage should also be provided. For additional mitigation, consideration should be given to applying a water-proof membrane to the back of all retaining structures. The use of a waterstop should be considered for all concrete and masonry joints. Wall/Retaining Wall Footing Transitions Site walls are anticipated to be founded on footings designed in accordance with the recommendations in this report. Although not anticipated, should wall footings transition from cut to fill, the civil designer may specify either: a) A minimum of a 2-foot overexcavation and recompaction of cut materials for a distance of 2H, from the point of transition. b) Increase of the amount of reinforcing steel and wall detailing (i.e., expansion joints or crack control joints) such that a angular distortion of 1/360 for a distance of 2H on either side of the transition may be accommodated. Expansion joints should be placed no greater than 20 feet on-center, in accordance with the structural engineer’s/wall designer’s recommendations, regardless of whether or not transition conditions exist. Expansion joints should be sealed with a flexible, non-shrink grout. c) Embed the footings entirely into native formational material (i.e., deepened footings). If transitions from cut to fill transect the wall footing alignment at an angle of less than 45 degrees (plan view), then the designer should follow recommendation “a” (above) and until such transition is between 45 and 90 degrees to the wall alignment. DRIVEWAY/PARKING, FLATWORK, AND OTHER IMPROVEMENTS The effects of expansive soils are cumulative, and typically occur over the lifetime of any improvements. On relatively level areas, when the soils are allowed to dry, the dessication and swelling process tends to cause heaving and distress to flatwork and other improvements. The resulting potential for distress to improvements may be reduced, but not totally eliminated. To that end, it is important that the homeowner be aware of this long-term potential for distress. To reduce the likelihood of distress, the following recommendations are presented for all exterior flatwork: Gary Cruse W.O. 8382-A-SC 3912 Garfield Street, Carlsbad August 15, 2022 File:e:\wp21\8300\8382a.lgi Page 26 GeoSoils, Inc. 1. The subgrade area for concrete slabs should be compacted to achieve a minimum 90 percent relative compaction (sidewalks, patios), and 95 percent relative compaction (traffic pavements). If very low expansive soils are present, only optimum moisture content, or greater, is required and specific presoaking is not warranted. The moisture content of the subgrade should be proof tested within 72 hours prior to pouring concrete. 2. Concrete slabs should be cast over a non-yielding surface, consisting of a 4-inch layer of crushed rock, gravel, or clean sand, that should be compacted and level prior to pouring concrete. If very low expansive soils are present, the rock or gravel or sand may be deleted. The layer or subgrade should be wet-down completely prior to pouring concrete, to minimize loss of concrete moisture to the surrounding earth materials. 3. Exterior slabs (sidewalks, patios, etc.) should be a minimum of 4 inches thick. 4. Driveway and parking area slabs and approaches should be at least 6 inches thick. Pavement slabs at trash enclosures should be at least 8 inches in thickness. A thickened edge (12 inches) should also be considered adjacent to all landscape areas, to help impede infiltration of landscape water under the slab(s). All pavement construction should minimally be performed in general accordance with industry standards and properly transitioned. Concrete flat work/pavement may consist of plain concrete. However, the use of reinforcing steel may be considered, if desired. 5. The use of transverse and longitudinal control joints may be considered to help control slab cracking due to concrete shrinkage or expansion. Two ways to mitigate such cracking are: a) add a sufficient amount of reinforcing steel, increasing tensile strength of the slab; and, b) provide an adequate amount of control and/or expansion joints to accommodate anticipated concrete shrinkage and expansion. 6. In order to reduce the potential for unsightly cracks, slabs should be reinforced at mid-height with a minimum of No. 3 bars placed at 18 inches on center, in each direction. If subgrade soils within the top 7 feet from finish grade are very low expansive soils (i.e., E.I. #20), then 6 x 6 - W1.4 x W1.4 welded-wire mesh may be substituted for the rebar, provided the reinforcement is placed on chairs, at slab mid-height. The exterior slabs should be scored or saw cut, ½ to d inches deep, often enough so that no section is greater than 10 feet by 10 feet. For sidewalks or narrow slabs, control joints should be provided at intervals of every 6 feet. The slabs should be separated from the foundations and sidewalks with expansion joint filler material. 7. No traffic should be allowed upon the newly poured concrete slabs until they have been properly cured to within 75 percent of design strength. Concrete compression Gary Cruse W.O. 8382-A-SC 3912 Garfield Street, Carlsbad August 15, 2022 File:e:\wp21\8300\8382a.lgi Page 27 GeoSoils, Inc. strength should be a minimum of 2,500 psi for sidewalks and patios, and a minimum 3,250 psi for traffic pavements. 8. Driveways, sidewalks, and patio slabs adjacent to the structure should be separated from the structure with thick expansion joint filler material. In areas directly adjacent to a continuous source of moisture (i.e., irrigation, planters, etc.), all joints should be additionally sealed with flexible mastic. 9. Planters and walls should not be tied to the structure. 10. Overhang structures should be supported on the slabs, or structurally designed with continuous footings tied in at least two directions. If very low expansion soils are present, footings need only be tied in one direction. 11. Any masonry landscape walls that are to be constructed throughout the property should be grouted and articulated in segments no more than 20 feet long. These segments should be keyed or doweled together. 12. Utilities should be enclosed within a closed utilidor (vault) or designed with flexible connections to accommodate differential settlement and expansive soil conditions. 13. Positive site drainage should be maintained at all times. Finish grade on the lot should provide a minimum of 1 to 2 percent fall to the street, or to some suitable outlet. Drainage reversals could occur, including post-construction settlement, if relatively flat yard drainage gradients are not periodically maintained by the homeowner. 14. Air conditioning (A/C) units should be supported by slabs that are incorporated into the building foundation or constructed on a rigid slab with flexible couplings for plumbing and electrical lines. A/C waste water lines should be drained to a suitable non-erosive outlet. 15. Shrinkage cracks could become excessive if proper finishing and curing practices are not followed. Finishing and curing practices should be performed per the Portland Cement Association Guidelines. Mix design should incorporate rate of curing for climate and time of year, sulfate content of soils, corrosion potential of soils, and fertilizers used on site. DEVELOPMENT CRITERIA Slope Maintenance and Planting Water has been shown to weaken the inherent strength of all earth materials. Slope stability is significantly reduced by overly wet conditions. Positive surface drainage away Gary Cruse W.O. 8382-A-SC 3912 Garfield Street, Carlsbad August 15, 2022 File:e:\wp21\8300\8382a.lgi Page 28 GeoSoils, Inc. from slopes should be maintained and only the amount of irrigation necessary to sustain plant life should be provided for planted slopes. Over-watering should be avoided as it adversely affects site improvements, and causes perched groundwater conditions. Graded slopes constructed using onsite materials would be erosive. Eroded debris may be minimized and surficial slope stability enhanced by establishing and maintaining a suitable vegetation cover soon after construction. Compaction to the face of fill slopes would tend to minimize short-term erosion until vegetation is established. Plants selected for landscaping should be light weight, deep rooted types that require little water and are capable of surviving the prevailing climate. Jute-type matting or other fibrous covers may aid in allowing the establishment of a sparse plant cover. Using plants other than those recommended above will increase the potential for perched water, staining, mold, etc., to develop. A rodent control program to prevent burrowing should be implemented. Irrigation of natural (ungraded) slope areas is generally not recommended. These recommendations regarding plant type, irrigation practices, and rodent control should be provided to all interested/affected parties. Over-steepening of slopes should be avoided during building construction activities and landscaping. Drainage Adequate surface drainage is a very important factor in reducing the likelihood of adverse performance of foundations, hardscape, and slopes. Surface drainage should be sufficient to mitigate ponding of water anywhere on the property, and especially near structures and tops of slopes. Surface drainage should be carefully taken into consideration during fine grading, landscaping, and building construction. Therefore, care should be taken that future landscaping or construction activities do not create adverse drainage conditions. Positive site drainage within the property should be provided and maintained at all times. Drainage should not flow uncontrolled down any descending slope. Water should be directed away from foundations and tops of slopes, and not allowed to pond or seep into the ground. In general, site drainage should conform to Section 1804.3 of the 2019 CBC. Consideration should be given to avoiding construction of planters adjacent to structures (buildings, pools, spas, etc.). Building pad drainage should be directed toward the street or other approved area(s). Downspouts, or drainage devices should outlet a minimum of 5 feet from structures or into a subsurface drainage system. Areas of seepage may develop due to irrigation or heavy rainfall, and should be anticipated. Minimizing irrigation will lessen this potential. If areas of seepage develop, recommendations for minimizing this effect could be provided upon request. Erosion Control Cut and fill slopes will be subject to surficial erosion during and after grading. Onsite earth materials have a moderate to high erosion potential. Consideration should be given to providing hay bales and silt fences for the temporary control of surface water, from a geotechnical viewpoint. Gary Cruse W.O. 8382-A-SC 3912 Garfield Street, Carlsbad August 15, 2022 File:e:\wp21\8300\8382a.lgi Page 29 GeoSoils, Inc. Landscape Maintenance Only the amount of irrigation necessary to sustain plant life should be provided. Over-watering the landscape areas will adversely affect proposed site improvements. We would recommend that any proposed open-bottom planters adjacent to proposed structures be eliminated for a minimum distance of 10 feet. As an alternative, closed-bottom type planters could be used. An outlet placed in the bottom of the planter, could be installed to direct drainage away from structures or any exterior concrete flatwork. If planters are constructed adjacent to structures, the sides and bottom of the planter should be provided with a moisture retarder to prevent penetration of irrigation water into the subgrade. Provisions should be made to drain the excess irrigation water from the planters without saturating the subgrade below or adjacent to the planters. Graded slope areas should be planted with drought resistant vegetation. Consideration should be given to the type of vegetation chosen and their potential effect upon surface improvements (i.e., some trees will have an effect on concrete flatwork with their extensive root systems). From a geotechnical standpoint leaching is not recommended for establishing landscaping. If the surface soils are processed for the purpose of adding amendments, they should be recompacted to 90 percent minimum relative compaction. Subsurface and Surface Water Subsurface and surface water are not anticipated to affect site development, provided that the recommendations contained in this report are incorporated into final design and construction and that prudent surface and subsurface drainage practices are incorporated into the construction plans. Perched groundwater conditions along zones of contrasting permeabilities may not be precluded from occurring in the future due to site irrigation, poor drainage conditions, or damaged utilities, and should be anticipated. Should perched groundwater conditions develop, this office could assess the affected area(s) and provide the appropriate recommendations to mitigate the observed groundwater conditions. Groundwater conditions may change with the introduction of irrigation, rainfall, or other factors. Site Improvements If any additional improvements (e.g., pools, spas, etc.) are planned for the site, recommendations concerning the geological or geotechnical aspects of design and construction of said improvements could be provided upon request. Pools and/or spas should not be constructed without specific design and construction recommendations from GSI, and this construction recommendation should be provided to all interested/affected parties. This office should be notified in advance of any fill placement, grading of the site, or trench backfilling after rough grading has been completed. This includes any grading, utility trench and retaining wall backfills, flatwork, etc. Gary Cruse W.O. 8382-A-SC 3912 Garfield Street, Carlsbad August 15, 2022 File:e:\wp21\8300\8382a.lgi Page 30 GeoSoils, Inc. Tile Flooring Tile flooring can crack, reflecting cracks in the concrete slab below the tile, although small cracks in a conventional slab may not be significant. Therefore, the designer should consider additional steel reinforcement for concrete slabs-on-grade where tile will be placed. The tile installer should consider installation methods that reduce possible cracking of the tile such as slipsheets. Slipsheets or a vinyl crack isolation membrane (approved by the Tile Council of America/Ceramic Tile Institute) are recommended between tile and concrete slabs on grade. Additional Grading This office should be notified in advance of any fill placement, supplemental regrading of the site, or trench backfilling after rough grading has been completed. This includes completion of grading in the street, driveway approaches, driveways, parking areas, and utility trench and retaining wall backfills. Footing Trench Excavation All footing excavations should be observed by a representative of this firm subsequent to trenching and prior to concrete form and reinforcement placement. The purpose of the observations is to evaluate that the excavations have been made into the recommended bearing material and to the minimum widths and depths recommended for construction. If loose or compressible materials are exposed within the footing excavation, a deeper footing or removal and recompaction of the subgrade materials would be recommended at that time. Trenching/Temporary Construction Backcuts Considering the nature of the onsite earth materials, caving or sloughing could be a factor in subsurface excavations and trenching. Shoring or excavating the trench walls/backcuts at the angle of repose (typically 25 to 45 degrees [except as specifically superceded within the text of this report]), should be anticipated. All excavations should be observed by an engineering geologist or soil engineer from GSI, prior to workers entering the excavation or trench, and minimally conform to CAL-OSHA, state, and local safety codes. Should adverse conditions exist, appropriate recommendations would be offered at that time. The above recommendations should be provided to any contractors and/or subcontractors, or homeowners, etc., that may perform such work. Utility Trench Backfill 1. All interior utility trench backfill should be brought to at least 2 percent above optimum moisture content and then compacted to obtain a minimum relative compaction of 90 percent of the laboratory standard. As an alternative for shallow Gary Cruse W.O. 8382-A-SC 3912 Garfield Street, Carlsbad August 15, 2022 File:e:\wp21\8300\8382a.lgi Page 31 GeoSoils, Inc. (12-inch to 18-inch) under-slab trenches, sand having a sand equivalent value of 30 or greater may be utilized and jetted or flooded into place. Observation, probing and testing should be provided to evaluate the desired results. 2. Exterior trenches adjacent to, and within areas extending below a 1:1 plane projected from the outside bottom edge of the footing, and all trenches beneath hardscape features and in slopes, should be compacted to at least 90 percent of the laboratory standard. Sand backfill, unless excavated from the trench, should not be used in these backfill areas. Compaction testing and observations, along with probing, should be accomplished to evaluate the desired results. 3. All trench excavations should conform to CAL-OSHA, state, and local safety codes. 4. Utilities crossing grade beams, perimeter beams, or footings should either pass below the footing or grade beam utilizing a hardened collar or foam spacer, or pass through the footing or grade beam in accordance with the recommendations of the structural engineer. SUMMARY OF RECOMMENDATIONS REGARDING GEOTECHNICAL OBSERVATION AND TESTING We recommend that observation and/or testing be performed by GSI at each of the following construction stages: • During grading/recertification. • During excavation. • During placement of subdrains or other subdrainage devices, prior to placing fill and/or backfill. • After excavation of building footings, retaining wall footings, and free standing walls footings, prior to the placement of reinforcing steel or concrete. • Prior to pouring any slabs or flatwork, after presoaking/presaturation of building pads and other flatwork subgrade, before the placement of concrete, reinforcing steel, capillary break (i.e., sand, pea-gravel, etc.), or vapor retarders (i.e., visqueen, etc.). • During retaining wall subdrain installation, prior to backfill placement. • During placement of backfill for area drain, interior plumbing, utility line trenches, and retaining wall backfill. • During slope construction/repair. Gary Cruse W.O. 8382-A-SC 3912 Garfield Street, Carlsbad August 15, 2022 File:e:\wp21\8300\8382a.lgi Page 32 GeoSoils, Inc. • When any unusual soil conditions are encountered during any construction operations, subsequent to the issuance of this report. • When any homeowner improvements, such as flatwork, spas, pools, walls, etc., are constructed, prior to construction. • A report of geotechnical observation and testing should be provided at the conclusion of each of the above stages, in order to provide concise and clear documentation of site work, and/or to comply with code requirements. OTHER DESIGN PROFESSIONALS/CONSULTANTS The design civil engineer, structural engineer, post-tension designer, architect, landscape architect, wall designer, etc., should review the recommendations provided herein, incorporate those recommendations into all their respective plans, and by explicit reference, make this report part of their project plans. This report presents minimum design criteria for the design of slabs, foundations and other elements possibly applicable to the project. These criteria should not be considered as substitutes for actual designs by the structural engineer/designer. Please note that the recommendations contained herein are not intended to preclude the transmission of water or vapor through the slab or foundation. The structural engineer/foundation and/or slab designer should provide recommendations to not allow water or vapor to enter into the structure so as to cause damage to another building component, or so as to limit the installation of the type of flooring materials typically used for the particular application. The structural engineer/designer should analyze actual soil-structure interaction and consider, as needed, bearing, expansive soil influence, and strength, stiffness and deflections in the various slab, foundation, and other elements in order to develop appropriate, design-specific details. As conditions dictate, it is possible that other influences will also have to be considered. The structural engineer/designer should consider all applicable codes and authoritative sources where needed. If analyses by the structural engineer/designer result in less critical details than are provided herein as minimums, the minimums presented herein should be adopted. It is considered likely that some, more restrictive details will be required. If the structural engineer/designer has any questions or requires further assistance, they should not hesitate to call or otherwise transmit their requests to GSI. In order to mitigate potential distress, the foundation and/or improvement’s designer should confirm to GSI and the governing agency, in writing, that the proposed foundations and/or improvements can tolerate the amount of differential settlement and/or expansion characteristics and other design criteria specified herein. Gary Cruse W.O. 8382-A-SC 3912 Garfield Street, Carlsbad August 15, 2022 File:e:\wp21\8300\8382a.lgi Page 33 GeoSoils, Inc. PLAN REVIEW Final project plans (grading, precise grading, foundation, retaining wall, landscaping, etc.), should be reviewed by this office prior to construction, so that construction is in accordance with the conclusions and recommendations of this report. Based on our review, supplemental recommendations and/or further geotechnical studies may be warranted. LIMITATIONS The materials encountered on the project site and used for our analysis are believed representative of the area; however, soil and bedrock materials vary in character between excavations and natural outcrops or conditions exposed during mass grading. Site conditions may vary due to seasonal changes or other factors. Inasmuch as our study is based upon our review and engineering analyses and laboratory data, the conclusions and recommendations are professional opinions. These opinions have been derived in accordance with current standards of practice, and no warranty, either express or implied, is given. Standards of practice are subject to change with time. GSI assumes no responsibility or liability for work or testing performed by others, or their inaction; or work performed when GSI is not requested to be onsite, to evaluate if our recommendations have been properly implemented. Use of this report constitutes an agreement and consent by the user to all the limitations outlined above, notwithstanding any other agreements that may be in place. In addition, this report may be subject to review by the controlling authorities. Thus, this report brings to completion our scope of services for this portion of the project, and in no way is an environmental/hazardous waste evaluation of the site and surroundings. All samples will be disposed of after 30 days, unless specifically requested by the client, in writing. Gary Cruse W.O. 8382-A-SC 3912 Garfield Street, Carlsbad August 15, 2022 File:e:\wp21\8300\8382a.lgi Page 34 GeoSoils, Inc. The opportunity to be of service is sincerely appreciated. If you should have any questions, please do not hesitate to contact our office. Respectfully submitted, GeoSoils, Inc. John P. Franklin Stephen J. Coover Engineering Geologist, CEG 1340 Geotechnical Engineer, GE 2057 DRE/JPF/SJC/sh Distribution: (3) Addressee (2 wet signed, 1 copy, and PDF via email) Gary Cruse W.O. 8382-A-SC 3912 Garfield Street, Carlsbad August 15, 2022 File:e:\wp21\8300\8382a.lgi Page 35 GeoSoils, Inc. APPENDIX A REFERENCES GeoSoils, Inc. APPENDIX A REFERENCES American Concrete Institute, 2014a, Building code requirements for structural concrete (ACI 318-14), and commentary (ACI 318R-14): reported by ACI Committee 318, dated September. _____, 2014b, Building code requirements for concrete thin shells (ACI 318.2-14), and commentary (ACI 318.2R-14), dated September. _____, 2004, Guide for concrete floor and slab construction: reported by ACI Committee 302; Designation ACI 302.1R-04, dated March 23. ACI Committee 302, 2004, Guide for concrete floor and slab construction, ACI 302.1R-04, dated June. American Society for Testing and Materials (ASTM),1998, Standard practice for installation of water vapor retarder used in contact with earth or granular fill under concrete slabs, Designation: E 1643-98 (Reapproved 2005). _____, 1997, Standard specification for plastic water vapor retarders used in contact with soil or granular fill under concrete slabs, Designation: E 1745-97 (Reapproved 2004). American Society of Civil Engineers, 2018a, Supplement 1 to Minimum Design Loads and Associated Criteria for Buildings and Other Structures (ASCE/SEI 7-16), first printing, dated December 13. _____, 2018b, Errata for Minimum Design Loads and Associated Criteria for Buildings and Other Structures (ASCE/SEI 7-16), by ASCE, dated July 9. _____, 2017, Minimum design loads and associated criteria and other structures, ASCE Standard ASCE/SEI 7-16, published online June 19. _____, 2010, Minimum design loads for buildings and other structures, ASCE Standard ASCE/SEI 7-10. Arlen Roper, Inc., 2022, A residential renovation for: Gary & Debra Cruse, 3912 Garfield St., Carlsbad, CA 92008,” sheets A1.1, A1.2, A2, A2.1, A2.2, A3, A4, A4.1,, A4.2, dated May 23. Blake, Thomas F., 2000a, EQFAULT, A computer program for the estimation of peak horizontal acceleration from 3-D fault sources; Windows 95/98 version. GeoSoils, Inc. _____, 2000b, EQSEARCH, A computer program for the estimation of peak horizontal acceleration from California historical earthquake catalogs; Updated to December 2009, Windows 95/98 version. Bozorgnia, Y., Campbell K.W., and Niazi, M., 1999, Vertical ground motion: Characteristics, relationship with horizontal component, and building-code implications; Proceedings of the SMIP99 seminar on utilization of strong-motion data, September 15, Oakland, pp. 23-49. Bryant, W.A., and Hart, E.W., 2007, Fault-rupture hazard zones in California, Alquist-Priolo earthquake fault zoning act with index to earthquake fault zones maps; California Geological Survey, Special Publication 42, interim revision. California Building Standards Commission, 2019a, California Building Code, California Code of Regulations, Title 24, Part 2, Volume 2 of 2, based on the 2018 International Building Code, effective January 1, 2020. _____, 2019b, California Building Code, California Code of Regulations, Title 24, Part 2, Volume 1 of 2, Based on the 2018 International Building Code, effective January 1, 2020. _____, 2016c, California green building standard code of regulations, Title 24, Part 11, ISBN 978-1-60983-462-3. California Geological Survey, 2018, Earthquake Fault Zones, a guide for government agencies, property owners/developers, and geoscience practitioners for assessing fault rupture hazards in California, Special Publication 42, revised. California Office of Statewide Health Planning and Development (OSHPD), 2022, Seismic design maps, https://seismicmaps.org/. Cao, T., Bryant, W.A., Rowshandel, B., Branum, D., and Wills, C.J., 2003, The revised 2002 California probabilistic seismic hazard maps, dated June, http://www.conservation.ca.gov/cgs/rghm/psha/fault_parameters/pdf/Documents /2002_CA_Hazard_Maps.pdf Church, H.K., 1981, Excavation handbook, 1,024 pp., McGraw-Hill. Clar, M.L., Bartfield, B.J., O’Conner, T.P., 2004, Stormwater best management practice design guide, volume 3, basin best management practices, US EPA/600/R-04/121B, dated September. County of San Diego, Department of Planning and Land Use, 2007, Low impact development (LID) handbook, stormwater management strategies, dated December 31. Gary Cruse Appendix A File:e:\wp21\8300\8382a.lgi Page 2 GeoSoils, Inc. County of San Diego, Department of Public Works, 2019, BMP design manual, for permanent site design, storm water treatment and hydromodification management, storm water requirements for development applications, effective January 1. Jennings, C.W., 1994, Fault activity map of California and adjacent areas: California Division of Mines and Geology, Map Sheet No. 6, scale 1:750,000. Kanare, H.M., 2005, Concrete floors and moisture, Engineering Bulletin 119, Portland Cement Association. Kennedy, M.P., and Tan, SS., 2007, Geologic map of the Oceanside 30' by 60' quadrangle, California, regional geologic map series, scale 1:100,000, California Geologic Survey Map No. 2. Norris, R.M. and Webb, R.W., 1990, Geology of California, second edition, John Wiley & Sons, Inc. Romanoff, M., 1957, Underground corrosion, originally issued April 1. Seed, 2005, Evaluation and mitigation of soil liquefaction hazard “evaluation of field data and procedures for evaluating the risk of triggering (or inception) of liquefaction”, in Geotechnical earthquake engineering; short course, San Diego, California, April 8-9. Sowers and Sowers, 1979, Unified soil classification system (After U. S. Waterways Experiment Station and ASTM 02487-667) in Introductory Soil Mechanics, New York. State of California, 2022, Civil Code, Sections 895 et seq. State of California Department of Transportation, Division of Engineering Services, Materials Engineering, and Testing Services, Corrosion Technology Branch, 2003, Corrosion Guidelines, Version 1.0, dated September. Structural Engineers Association of California and California Office of Statewide Health Planning and Development, 2019, Seismic design maps, https://seismicmaps.org/ Tan, S.S., and Giffen, D.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 35B, Department of Conservation, Division of Mines and Geology, DMG Open File Report 95-04. Tan, S.S., 1986, Landslide hazards in the Encinitas Quadrangle, San Diego County, California, Landslide hazard identification map no. 4, open file report 86-8 LA. Gary Cruse Appendix A File:e:\wp21\8300\8382a.lgi Page 3 GeoSoils, Inc. United States Department of Agriculture, National Resources Conservation Service, 2020, Custom soils report for San Diego County area, York Drive, dated February. United States Department of Agriculture, 1973, Soil survey, San Diego area, California, Part I and Part II. United States Department of the Interior, Bureau of Reclamation, 1984, Drainage manual, a water resources technical publication, second printing, Denver, U.S. Department of the Interior, Bureau of Reclamation, 286 pp. Wire Reinforcement Institute, 1996, Design of slab-on-ground foundations, an update, dated March. Gary Cruse Appendix A File:e:\wp21\8300\8382a.lgi Page 4 GeoSoils, Inc. APPENDIX B HAND-AUGER BORING LOGS UNIFIED SOIL CLASSIFICATION SYSTEM CONSISTENCY OR RELATIVE DENSITY Major Divisions Group Symbols Typical Names CRITERIA Co a r s e - G r a i n e d S o i l s Mo r e t h a n 5 0 % r e t a i n e d o n N o . 2 0 0 s i e v e Gr a v e l s 50 % o r m o r e o f co a r s e f r a c t i o n re t a i n e d o n N o . 4 s i e v e Cl e a n Gr a v e l s GW Well-graded gravels and gravel-sand mixtures, little or no fines Standard Penetration Test Penetration Resistance N Relative (blows/ft)Density 0 - 4 Very loose 4 - 10 Loose 10 - 30 Medium 30 - 50 Dense > 50 Very dense GP Poorly graded gravels andgravel-sand mixtures, little or no fines Gr a v e l wi t h GM Silty gravels gravel-sand-silt mixtures GC Clayey gravels, gravel-sand-clay mixtures Sa n d s mo r e t h a n 5 0 % o f co a r s e f r a c t i o n pa s s e s N o . 4 s i e v e Cle a n Sa n d s SW Well-graded sands and gravelly sands, little or no fines SP Poorly graded sands andgravelly sands, little or no fines Sa n d s wi t h Fi n e s SM Silty sands, sand-silt mixtures SC Clayey sands, sand-clay mixtures Fi n e - G r a i n e d S o i l s 50 % o r m o r e p a s s e s N o . 2 0 0 s i e v e Sil t s a n d C l a y s Liq u i d l i m i t 50 % o r l e s s ML Inorganic silts, very fine sands,rock flour, silty or clayey finesands Standard Penetration Test Unconfined Penetration Compressive Resistance N Strength (blows/ft)Consistency (tons/ft2) <2 Very Soft <0.25 2 - 4 Soft 0.25 - .050 4 - 8 Medium 0.50 - 1.00 8 - 15 Stiff 1.00 - 2.00 15 - 30 Very Stiff 2.00 - 4.00 >30 Hard >4.00 CL Inorganic clays of low to medium plasticity, gravelly clays, sandy clays, silty clays, lean clays OL Organic silts and organic silty clays of low plasticity Si l t s a n d C l a y s Li q u i d l i m i t gr e a t e r t h a n 5 0 % MH Inorganic silts, micaceous or diatomaceous fine sands or silts, elastic silts CH Inorganic clays of high plasticity, fat clays OH Organic clays of medium to high plasticity Highly Organic Soils PT Peat, mucic, and other highly organic soils 3"3/4"#4 #10 #40 #200 U.S. Standard Sieve Unified Soil Classification Cobbles Gravel Sand Silt or Clay coarse fine coarse medium fine MOISTURE CONDITIONS MATERIAL QUANTITY OTHER SYMBOLS Dry Absence of moisture: dusty, dry to the touch trace 0 - 5 %C Core Sample Slightly Moist Below optimum moisture content for compaction few 5 - 10 %S SPT Sample Moist Near optimum moisture content little 10 - 25 %B Bulk Sample Very Moist Above optimum moisture content some 25 - 45 %–Groundwater Wet Visible free water; below water table Qp Pocket Penetrometer BASIC LOG FORMAT: Group name, Group symbol, (grain size), color, moisture, consistency or relative density. Additional comments: odor, presence of roots, mica, gypsum, coarse grained particles, etc. EXAMPLE: Sand (SP), fine to medium grained, brown, moist, loose, trace silt, little fine gravel, few cobbles up to 4" in size, some hair roots and rootlets. File:Mgr: c;\SoilClassif.wpd PLATE B-1 I I I I I I I I I - 0 5 10 15 20 25 30 SM SM SP-SM 5.1 6.3 UNDOCUMENTED FILL:@ 0', SILTY SAND, brown, dry, loose; roots, sparse GRAVEL to 1/2". WEATHERED PARALIC DEPOSITS:@ 2', SILTY SAND, reddish brown, moist, medium dense; fine grainedSAND. PARALIC DEPOSITS:@ 3.5', SAND with SILT/SILTY SAND, reddish brown, moist, mediumdense to dense; medium to fine grained, some dark red brown nodules to1/4".@ 5', Yellow brown with reddish brown nodules, dense. Total Depth = 6'No Caving. No Seepage.Backfilled 6-24-22. GeoSoils, Inc.BORING LOG PROJECT:3912 GARFIELD STREET, CARLSBAD W.O.8382-A-SC BORING HA-1 SHEET 1 OF DATE EXCAVATED 6-24-22 LOGGED BY:DRE APPROX. ELEV.:62'MSL SAMPLE METHOD:Hand-auger Standard Penetration Test Groundwater Undisturbed, Ring Sample Seepage GeoSoils, Inc. PLATE De p t h ( f t . ) Bu l k Sample Un d i s t u r b e d Bl o w s / F t . US C S S y m b o l Dr y U n i t W t . ( p c f ) Mo i s t u r e ( % ) Sa t u r a t i o n ( % ) Material Description 1 B-2 H ~ _l _l _l l l _l I I t;; : ; ~ ; ; ; : ; ro ,11 1 - 1 0 5 10 15 20 25 30 SM SP-SMSM SM 5.1 5.2 UNDOCUMENTED FILL:@ 0', SILTY SAND, brown, dry, loose; rootlets, fine SAND, 1" CLAYchunks.@ 1', Reddish brown, moist, 1.5" concrete chunks at 1/25', WEATHERED PARALIC DEPOSTIS:@ 1.5', SAND/SILTY SAND, red brown, moist, medium dense. PARALIC DEPOSITS:@ 5', SILTY SAND, yellow brown, moist, dense. Total Depth = 6'No Caving. No Seepage. Backfilled 6-24-22. GeoSoils, Inc.BORING LOG PROJECT:3912 GARFIELD STREET, CARLSBAD W.O.8382-A-SC BORING HA-2 SHEET 1 OF DATE EXCAVATED 6-24-22 LOGGED BY:DRE APPROX. ELEV.:61.5' SAMPLE METHOD:Hand-auger Standard Penetration Test Groundwater Undisturbed, Ring Sample Seepage GeoSoils, Inc. PLATE De p t h ( f t . ) Bu l k Sample Un d i s t u r b e d Bl o w s / F t . US C S S y m b o l Dr y U n i t W t . ( p c f ) Mo i s t u r e ( % ) Sa t u r a t i o n ( % ) Material Description 1 B-3 HC J I ' ' I ' ' ' ' I ' ' ' ' I ' ' ' ' I ' I ' • ' ■I• I I J·: · · · · · · · i · · · · · · · · · · , · · · · · · · · · · · · · · · • t J l $ i ro ,11 1 - 1 0 5 10 15 20 25 30 SM/GMSP-SMSM SP-SMSM 4.0 UNDOCUMENTED FILL:@ 0', GRAVELLY SILTY SAND/SILTY SANDY GRAVEL, light brown, dry,loose; GRAVEL to 3/4" in plutonic granitic rock. WEATHERED PARALIC DEPOSITS:@ 1', SILTY SAND/SAND, red brown, moist, medium dense to dense;rootlets. PARALIC DEPOSITS:@ 4', SILTY SAND/SAND with SILT, yellow brown, moist, dense. Total Depth - 5'No Caving. No Seepage.Backfilled 6-24-22. GeoSoils, Inc.BORING LOG PROJECT:3912 GARFIELD STREET, CARLSBAD W.O.8382-A-SC BORING HA-3 SHEET 1 OF DATE EXCAVATED 6-24-22 LOGGED BY:DRE APPROX. ELEV.:57.5' SAMPLE METHOD:Hand-auger Standard Penetration Test Groundwater Undisturbed, Ring Sample Seepage GeoSoils, Inc. PLATE De p t h ( f t . ) Bu l k Sample Un d i s t u r b e d Bl o w s / F t . US C S S y m b o l Dr y U n i t W t . ( p c f ) Mo i s t u r e ( % ) Sa t u r a t i o n ( % ) Material Description 1 B-4 H ~ _l _l _l l l [ [ i- : H : 1 1 ro ,11 1 - 1 0 5 10 15 20 25 30 SM SM SM 4.8 3.0 UNDOCUMENTED FILL:@ 0', SILTY SAND with GRAVEL, light brown, dry to moist, loose;bioturbated roots. WEATHERED PARALIC DEPOSITS:@ 1.5', SILTY SAND, red brown, moist, medium dense to dense; roots. PARALIC DEPOSTIS:@ 4', SILTY SAND, yellow brown, moist, dense. Total Depth = 6'No Caving. No Seepage.Backfilled 6-24-22. GeoSoils, Inc.BORING LOG PROJECT:3912 GARFIELD STREET, CARLSBAD W.O.8382-A-SC BORING HA-4 SHEET 1 OF DATE EXCAVATED 6-24-22 LOGGED BY:DRE APPROX. ELEV.:58' SAMPLE METHOD:Hand-auger Standard Penetration Test Groundwater Undisturbed, Ring Sample Seepage GeoSoils, Inc. PLATE De p t h ( f t . ) Bu l k Sample Un d i s t u r b e d Bl o w s / F t . US C S S y m b o l Dr y U n i t W t . ( p c f ) Mo i s t u r e ( % ) Sa t u r a t i o n ( % ) Material Description 1 B-5 H ~ ,,i 0 5 10 15 20 25 30 SM SM SP-SMSM 3.9 5.4 6.4 UNDOCUMENTED FILL:@ 0', SILTY SAND with GRAVEL, yellow brown, dry, loose; 3/4"GRAVEL. WEATHERED PARALIC DEPOSITS:@ 2.5', SILTY SAND, red brown, moist, medium dense; roots. PARALIC DEPOSITS:@ 4.5', SILTY SAND/SAND with SILT, yellow to yellow brown, moist, dense; no roots. Total Depth = 6'No Caving. No Seepage.Backfilled 6-24-22. GeoSoils, Inc.BORING LOG PROJECT:3912 GARFIELD STREET, CARLSBAD W.O.8382-A-SC BORING HA-5 SHEET 1 OF DATE EXCAVATED 6-24-22 LOGGED BY:DRE APPROX. ELEV.:61' SAMPLE METHOD:Hand-auger Standard Penetration Test Groundwater Undisturbed, Ring Sample Seepage GeoSoils, Inc. PLATE De p t h ( f t . ) Bu l k Sample Un d i s t u r b e d Bl o w s / F t . US C S S y m b o l Dr y U n i t W t . ( p c f ) Mo i s t u r e ( % ) Sa t u r a t i o n ( % ) Material Description 1 B-6 H ~ I I I I I l 1 C [ I IH ~ l .. . . . . . . . . . . . . ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - '( J •ii~ I I GeoSoils, Inc. APPENDIX C SEISMICITY *********************** * * * E Q F A U L T * * * * Version 3.00 * * * *********************** DETERMINISTIC ESTIMATION OF PEAK ACCELERATION FROM DIGITIZED FAULTS JOB NUMBER: 8382-A-SC DATE: 07-06-2022 JOB NAME: Cruse CALCULATION NAME: Test Run Analysis FAULT-DATA-FILE NAME: C:\Users\Matt\Desktop\EQFAULT1\CGSFLTE.DAT SITE COORDINATES: SITE LATITUDE: 33.1482 SITE LONGITUDE: 117.3436 SEARCH RADIUS: 62.3 mi ATTENUATION RELATION: 12) Bozorgnia Campbell Niazi (1999) Hor.-Soft Rock-Cor. UNCERTAINTY (M=Median, S=Sigma): S Number of Sigmas: 1.0 DISTANCE MEASURE: cdist SCOND: 0 Basement Depth: 5.00 km Campbell SSR: 1 Campbell SHR: 0 COMPUTE PEAK HORIZONTAL ACCELERATION FAULT-DATA FILE USED: C:\Users\Matt\Desktop\EQFAULT1\CGSFLTE.DAT MINIMUM DEPTH VALUE (km): 3.0 W.O. 8382-A-SC PLATE C-1 --------------- EQFAULT SUMMARY --------------- ----------------------------- DETERMINISTIC SITE PARAMETERS ----------------------------- Page 1 ------------------------------------------------------------------------------- | |ESTIMATED MAX. EARTHQUAKE EVENT | APPROXIMATE |------------------------------- ABBREVIATED | DISTANCE | MAXIMUM | PEAK |EST. SITE FAULT NAME | mi (km) |EARTHQUAKE| SITE |INTENSITY | | MAG.(Mw) | ACCEL. g |MOD.MERC. ================================|==============|==========|==========|========= ROSE CANYON | 5.0( 8.0)| 7.2 | 0.625 | X NEWPORT-INGLEWOOD (Offshore) | 5.3( 8.5)| 7.1 | 0.588 | X CORONADO BANK | 20.6( 33.2)| 7.6 | 0.275 | IX ELSINORE (TEMECULA) | 24.7( 39.8)| 6.8 | 0.134 | VIII ELSINORE (JULIAN) | 24.9( 40.0)| 7.1 | 0.164 | VIII ELSINORE (GLEN IVY) | 34.2( 55.1)| 6.8 | 0.096 | VII SAN JOAQUIN HILLS | 35.6( 57.3)| 6.6 | 0.114 | VII PALOS VERDES | 35.8( 57.6)| 7.3 | 0.130 | VIII EARTHQUAKE VALLEY | 44.2( 71.1)| 6.5 | 0.060 | VI NEWPORT-INGLEWOOD (L.A.Basin) | 46.2( 74.3)| 7.1 | 0.086 | VII SAN JACINTO-ANZA | 47.3( 76.1)| 7.2 | 0.090 | VII SAN JACINTO-SAN JACINTO VALLEY | 47.8( 76.9)| 6.9 | 0.073 | VII CHINO-CENTRAL AVE. (Elsinore) | 48.2( 77.5)| 6.7 | 0.088 | VII WHITTIER | 52.1( 83.8)| 6.8 | 0.062 | VI SAN JACINTO-COYOTE CREEK | 52.9( 85.1)| 6.6 | 0.053 | VI ELSINORE (COYOTE MOUNTAIN) | 58.2( 93.7)| 6.8 | 0.055 | VI W.O. 8382-A-SC PLATE C-2 SAN JACINTO-SAN BERNARDINO | 60.4( 97.2)| 6.7 | 0.049 | VI PUENTE HILLS BLIND THRUST | 61.8( 99.5 )| 7.1 | 0.090 | VII ******************************************************************************* -END OF SEARCH- 18 FAULTS FOUND WITHIN THE SPECIFIED SEARCH RADIUS. THE ROSE CANYON FAULT IS CLOSEST TO THE SITE. IT IS ABOUT 5.0 MILES (8.0 km) AWAY. LARGEST MAXIMUM-EARTHQUAKE SITE ACCELERATION: 0.6250 g W.O. 8382-A-SC PLATE C-3 SITE CALIFORNIA FAULT MAP 3912 Garfield Street -100 0 100 200 300 400 500 600 700 800 900 1000 1100 -400 -300 -200 -100 0 100 200 300 400 500 600 W.O. 8382-A-SC PLATE C-4 MAXIMUM EARTHQUAKES 3912 Garfield Street Ac c e l e r a t i o n ( g ) Distance (mi) .001 .01 .1 1 .1 1 10 100 W.O. 8382-A-SC PLATE C-5 ., ◄ ► ♦ ♦ 11 I EARTHQUAKE MAGNITUDES & DISTANCES 3912 Garfield Street Ma g n i t u d e ( M ) Distance (mi) 6.5 6.6 6.7 6.8 6.9 7.0 7.1 7.2 7.3 7.4 7.5 7.6 .1 1 10 100 W.O. 8382-A-SC PLATE C-6 --------------.... ..,, --------..... ... ..., ... --------... ... ----.... .... ..., ,., --------.... ... ..,, ,., ----.... ,., -- ************************* * * * E Q S E A R C H * * * * Version 3.00 * * * ************************* ESTIMATION OF PEAK ACCELERATION FROM CALIFORNIA EARTHQUAKE CATALOGS JOB NUMBER: 8382-A-SC DATE: 07-07-2022 JOB NAME: 3912 Garfield Street EARTHQUAKE-CATALOG-FILE NAME: C:\Users\Matt\Desktop\EQSEARCH\ALLQUAKE.DAT MAGNITUDE RANGE: MINIMUM MAGNITUDE: 5.00 MAXIMUM MAGNITUDE: 9.00 SITE COORDINATES: SITE LATITUDE: 33.1482 SITE LONGITUDE: 117.3436 SEARCH DATES: START DATE: 1800 END DATE: 2021 SEARCH RADIUS: 62.3 mi 100.3 km ATTENUATION RELATION: 12) Bozorgnia Campbell Niazi (1999) Hor.-Soft Rock-Cor. UNCERTAINTY (M=Median, S=Sigma): S Number of Sigmas: 1.0 ASSUMED SOURCE TYPE: DS [SS=Strike-slip, DS=Reverse-slip, BT=Blind-thrust] SCOND: 0 Depth Source: A Basement Depth: 5.00 km Campbell SSR: 1 Campbell SHR: 0 COMPUTE PEAK HORIZONTAL ACCELERATION MINIMUM DEPTH VALUE (km): 3.0 W.O. 8382-A-SC PLATE C-7 ------------------------- EARTHQUAKE SEARCH RESULTS ------------------------- Page 1 ------------------------------------------------------------------------------- | | | | TIME | | | SITE |SITE| APPROX. FILE| LAT. | LONG. | DATE | (UTC) |DEPTH|QUAKE| ACC. | MM | DISTANCE CODE| NORTH | WEST | | H M Sec| (km)| MAG.| g |INT.| mi [km] ----+-------+--------+----------+--------+-----+-----+-------+----+------------ DMG |33.0000|117.3000|11/22/1800|2130 0.0| 0.0| 6.50| 0.360 | IX | 10.5( 17.0) MGI |33.0000|117.0000|09/21/1856| 730 0.0| 0.0| 5.00| 0.068 | VI | 22.4( 36.0) MGI |32.8000|117.1000|05/25/1803| 0 0 0.0| 0.0| 5.00| 0.054 | VI | 27.9( 44.9) DMG |32.7000|117.2000|05/27/1862|20 0 0.0| 0.0| 5.90| 0.081 | VII| 32.0( 51.6) PAS |32.9710|117.8700|07/13/1986|1347 8.2| 6.0| 5.30| 0.055 | VI | 32.8( 52.8) T-A |32.6700|117.1700|12/00/1856| 0 0 0.0| 0.0| 5.00| 0.044 | VI | 34.5( 55.5) T-A |32.6700|117.1700|05/24/1865| 0 0 0.0| 0.0| 5.00| 0.044 | VI | 34.5( 55.5) T-A |32.6700|117.1700|10/21/1862| 0 0 0.0| 0.0| 5.00| 0.044 | VI | 34.5( 55.5) DMG |33.2000|116.7000|01/01/1920| 235 0.0| 0.0| 5.00| 0.040 | V | 37.4( 60.1) DMG |33.7000|117.4000|05/13/1910| 620 0.0| 0.0| 5.00| 0.039 | V | 38.2( 61.5) DMG |33.7000|117.4000|04/11/1910| 757 0.0| 0.0| 5.00| 0.039 | V | 38.2( 61.5) DMG |33.7000|117.4000|05/15/1910|1547 0.0| 0.0| 6.00| 0.071 | VI | 38.2( 61.5) DMG |33.6990|117.5110|05/31/1938| 83455.4| 10.0| 5.50| 0.051 | VI | 39.2( 63.1) DMG |32.8000|116.8000|10/23/1894|23 3 0.0| 0.0| 5.70| 0.057 | VI | 39.6( 63.7) MGI |33.2000|116.6000|10/12/1920|1748 0.0| 0.0| 5.30| 0.041 | V | 43.1( 69.4) DMG |33.7100|116.9250|09/23/1963|144152.6| 16.5| 5.00| 0.032 | V | 45.7( 73.5) DMG |33.7500|117.0000|06/06/1918|2232 0.0| 0.0| 5.00| 0.032 | V | 46.0( 74.1) W.O. 8382-A-SC PLATE C-8 DMG |33.7500|117.0000|04/21/1918|223225.0| 0.0| 6.80| 0.099 | VII| 46.0( 74.1) DMG |33.5750|117.9830|03/11/1933| 518 4.0| 0.0| 5.20| 0.035 | V | 47.2( 76.0) MGI |33.8000|117.6000|04/22/1918|2115 0.0| 0.0| 5.00| 0.031 | V | 47.4( 76.2) DMG |33.6170|117.9670|03/11/1933| 154 7.8| 0.0| 6.30| 0.067 | VI | 48.4( 77.8) DMG |33.8000|117.0000|12/25/1899|1225 0.0| 0.0| 6.40| 0.071 | VI | 49.2( 79.1) DMG |33.6170|118.0170|03/14/1933|19 150.0| 0.0| 5.10| 0.031 | V | 50.5( 81.3) GSP |33.5290|116.5720|06/12/2005|154146.5| 14.0| 5.20| 0.032 | V | 51.7( 83.2) DMG |33.9000|117.2000|12/19/1880| 0 0 0.0| 0.0| 6.00| 0.051 | VI | 52.6( 84.6) GSG |33.4200|116.4890|07/07/2010|235333.5| 14.0| 5.50| 0.037 | V | 52.8( 84.9) DMG |33.0000|116.4330|06/04/1940|1035 8.3| 0.0| 5.10| 0.029 | V | 53.7( 86.4) PAS |33.5010|116.5130|02/25/1980|104738.5| 13.6| 5.50| 0.037 | V | 53.8( 86.5) GSP |33.5080|116.5140|10/31/2001|075616.6| 15.0| 5.10| 0.029 | V | 53.9( 86.8) DMG |33.5000|116.5000|09/30/1916| 211 0.0| 0.0| 5.00| 0.027 | V | 54.4( 87.5) DMG |33.6830|118.0500|03/11/1933| 658 3.0| 0.0| 5.50| 0.036 | V | 55.0( 88.4) GSP |33.4315|116.4427|06/10/2016|080438.7| 12.3| 5.19| 0.029 | V | 55.5( 89.4) DMG |33.7000|118.0670|03/11/1933| 85457.0| 0.0| 5.10| 0.027 | V | 56.5( 90.9) DMG |33.7000|118.0670|03/11/1933| 51022.0| 0.0| 5.10| 0.027 | V | 56.5( 90.9) DMG |34.0000|117.2500|07/23/1923| 73026.0| 0.0| 6.25| 0.053 | VI | 59.1( 95.0) DMG |33.3430|116.3460|04/28/1969|232042.9| 20.0| 5.80| 0.040 | V | 59.2( 95.2) MGI |34.0000|117.5000|12/16/1858|10 0 0.0| 0.0| 7.00| 0.087 | VII| 59.5( 95.7) DMG |33.7500|118.0830|03/11/1933| 323 0.0| 0.0| 5.00| 0.025 | V | 59.5( 95.8) DMG |33.7500|118.0830|03/13/1933|131828.0| 0.0| 5.30| 0.029 | V | 59.5( 95.8) DMG |33.7500|118.0830|03/11/1933| 2 9 0.0| 0.0| 5.00| 0.025 | V | 59.5( 95.8) DMG |33.7500|118.0830|03/11/1933| 230 0.0| 0.0| 5.10| 0.026 | V | 59.5( 95.8) DMG |33.7500|118.0830|03/11/1933| 910 0.0| 0.0| 5.10| 0.026 | V | 59.5( 95.8) GSG |33.9530|117.7610|07/29/2008|184215.7| 14.0| 5.30| 0.029 | V | 60.5( 97.4) DMG |33.9500|116.8500|09/28/1946| 719 9.0| 0.0| 5.00| 0.023 | IV | 62.2(100.1) ******************************************************************************* -END OF SEARCH- 44 EARTHQUAKES FOUND WITHIN THE SPECIFIED SEARCH AREA. TIME PERIOD OF SEARCH: 1800 TO 2021 LENGTH OF SEARCH TIME: 222 years THE EARTHQUAKE CLOSEST TO THE SITE IS ABOUT 10.5 MILES (17.0 km) AWAY. LARGEST EARTHQUAKE MAGNITUDE FOUND IN THE SEARCH RADIUS: 7.0 LARGEST EARTHQUAKE SITE ACCELERATION FROM THIS SEARCH: 0.360 g W.O. 8382-A-SC PLATE C-9 COEFFICIENTS FOR GUTENBERG & RICHTER RECURRENCE RELATION: a-value= 1.004 b-value= 0.390 beta-value= 0.897 ------------------------------------ TABLE OF MAGNITUDES AND EXCEEDANCES: ------------------------------------ Earthquake | Number of Times | Cumulative Magnitude | Exceeded | No. / Year -----------+-----------------+------------ 4.0 | 44 | 0.19820 4.5 | 44 | 0.19820 5.0 | 44 | 0.19820 5.5 | 15 | 0.06757 6.0 | 8 | 0.03604 6.5 | 3 | 0.01351 7.0 | 1 | 0.00450 W.O. 8382-A-SC PLATE C-10 SITE LEGEND M = 4 M = 5 M = 6 M = 7 M = 8 -100 0 100 200 300 400 500 600 700 800 900 1000 1100 -400 -300 -200 -100 0 100 200 300 400 500 600 EARTHQUAKE EPICENTER MAP 3912 Garfield Street W.O. 8382-A-SC PLATE C-11 \ .001 .01 .1 1 10 100 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 EARTHQUAKE RECURRENCE CURVE 3912 Garfield Street Cu m m u l a t i v e N u m b e r o f E v e n t s ( N ) / Y e a r Magnitude (M) W.O. 8382-A-SC PLATE C-12 r--... -... '" " "-~" '- ' " 4 "" ~-... ... ... ... ' " 1' - I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 10 100 4.0 4.5 5.0 5.5 6.0 6.5 7.0 Number of Earthquakes (N) Above Magnitude (M) 3912 Garfield Street Cu m u l a t i v e N u m b e r o f E v e n t s ( N ) Magnitude (M) W.O. 8382-A-SC PLATE C-13 GeoSoils, Inc. APPENDIX D LABORATORY TESTING Tested By: TR Checked By: TR 8-1-22 (no specification provided) PL=LL=PI= D90=D85=D60=D50=D30=D15=D10=Cu=Cc= USCS=AASHTO= * Dark Brown Silty Sand 0.375 #4 #10 #20 #40 #60 #100 #200 100.0 98.9 98.8 97.7 73.6 41.8 28.7 23.2 0.6133 0.5359 0.3415 0.2911 0.1647 SM Gary Cruse 3912 Garfield St. 8382-A-SC Material Description Atterberg Limits Coefficients Classification Remarks Source of Sample: HA-4 Depth: 2-3 Sample Number: HA-4 Date: Client: Project: Project No:Plate SIEVE PERCENT SPEC.*PASS? SIZE FINER PERCENT (X=NO) PE R C E N T F I N E R 0 10 20 30 40 50 60 70 80 90 100 GRAIN SIZE - mm. 0.0010.010.1110100 % +3"Coarse % Gravel Fine Coarse Medium % Sand Fine Silt % Fines Clay 0.0 0.0 1.1 0.1 25.2 50.4 23.2 6 i n . 3 i n . 2 i n . 1½ i n . 1 i n . ¾ i n . ½ i n . 3/ 8 i n . #4 #1 0 #2 0 #3 0 #4 0 #6 0 #1 0 0 #1 4 0 #2 0 0 Particle Size Distribution Report W.O. 8382-A-SC PLATE D-1 ' I 1' I I ' I I ' : I I ~ \ ' \ :\ \ N~~ r-r I I I I I I I I I I I I I ~@H· 7.2 21 Samples testing in accordance with:pH - CTM 643, Resistivity - CTM 643 Sulfate - CTM 417, Chloride - CTM 422 Remarks: Chloride Content (mg/kg) HA-2, 0-3ft 5900 0.005 Report Date:July 21, 2022 SAMPLE ID pH (H+) Minimum Resistivity (ohm/cm) Sulfate Content (wt%) 5741 Palmer Way, Carlsbad CA 92010 Phone (760) 438-3155 CORROSION REPORT SUMMARY Project No:8382-A-SC Project Name:Gary Cruse W.O. 8382-A-SC PLATE D-2 Jae. GeoSoils, Inc. APPENDIX E GENERAL EARTHWORK AND GRADING GUIDELINES GeoSoils, Inc. GENERAL EARTHWORK AND GRADING GUIDELINES General These guidelines present general procedures and requirements for earthwork and grading as shown on the approved grading plans, including preparation of areas to be filled, placement of fill, installation of subdrains, excavations, and appurtenant structures or flatwork. The recommendations contained in the geotechnical report are part of these earthwork and grading guidelines and would supercede the provisions contained hereafter in the case of conflict. Evaluations performed by the consultant during the course of grading may result in new or revised recommendations which could supercede these guidelines or the recommendations contained in the geotechnical report. Generalized details follow this text. The contractor is responsible for the satisfactory completion of all earthwork in accordance with provisions of the project plans and specifications and latest adopted code. In the case of conflict, the most onerous provisions shall prevail. The project geotechnical engineer and engineering geologist (geotechnical consultant), and/or their representatives, should provide observation and testing services, and geotechnical consultation during the duration of the project. EARTHWORK OBSERVATIONS AND TESTING Geotechnical Consultant Prior to the commencement of grading, a qualified geotechnical consultant (soil engineer and engineering geologist) should be employed for the purpose of observing earthwork procedures and testing the fills for general conformance with the recommendations of the geotechnical report(s), the approved grading plans, and applicable grading codes and ordinances. The geotechnical consultant should provide testing and observation so that an evaluation may be made that the work is being accomplished as specified. It is the responsibility of the contractor to assist the consultants and keep them apprised of anticipated work schedules and changes, so that they may schedule their personnel accordingly. All remedial removals, clean-outs, prepared ground to receive fill, key excavations, and subdrain installation should be observed and documented by the geotechnical consultant prior to placing any fill. It is the contractor’s responsibility to notify the geotechnical consultant when such areas are ready for observation. Laboratory and Field Tests Maximum dry density tests to determine the degree of compaction should be performed in accordance with American Standard Testing Materials test method ASTM designation D-1557. Random or representative field compaction tests should be performed in GeoSoils, Inc. accordance with test methods ASTM designation D-1556, D-2937 or D-2922, and D-3017, at intervals of approximately ±2 feet of fill height or approximately every 1,000 cubic yards placed. These criteria would vary depending on the soil conditions and the size of the project. The location and frequency of testing would be at the discretion of the geotechnical consultant. Contractor's Responsibility All clearing, site preparation, and earthwork performed on the project should be conducted by the contractor, with observation by a geotechnical consultant, and staged approval by the governing agencies, as applicable. It is the contractor's responsibility to prepare the ground surface to receive the fill, to the satisfaction of the geotechnical consultant, and to place, spread, moisture condition, mix, and compact the fill in accordance with the recommendations of the geotechnical consultant. The contractor should also remove all non-earth material considered unsatisfactory by the geotechnical consultant. Notwithstanding the services provided by the geotechnical consultant, it is the sole responsibility of the contractor to provide adequate equipment and methods to accomplish the earthwork in strict accordance with applicable grading guidelines, latest adopted codes or agency ordinances, geotechnical report(s), and approved grading plans. Sufficient watering apparatus and compaction equipment should be provided by the contractor with due consideration for the fill material, rate of placement, and climatic conditions. If, in the opinion of the geotechnical consultant, unsatisfactory conditions such as questionable weather, excessive oversized rock or deleterious material, insufficient support equipment, etc., are resulting in a quality of work that is not acceptable, the consultant will inform the contractor, and the contractor is expected to rectify the conditions, and if necessary, stop work until conditions are satisfactory. During construction, the contractor shall properly grade all surfaces to maintain good drainage and prevent ponding of water. The contractor shall take remedial measures to control surface water and to prevent erosion of graded areas until such time as permanent drainage and erosion control measures have been installed. SITE PREPARATION All major vegetation, including brush, trees, thick grasses, organic debris, and other deleterious material, should be removed and disposed of off-site. These removals must be concluded prior to placing fill. In-place existing fill, soil, alluvium, colluvium, or rock materials, as evaluated by the geotechnical consultant as being unsuitable, should be removed prior to any fill placement. Depending upon the soil conditions, these materials may be reused as compacted fills. Any materials incorporated as part of the compacted fills should be approved by the geotechnical consultant. Any underground structures such as cesspools, cisterns, mining shafts, tunnels, septic tanks, wells, pipelines, or other structures not located prior to grading, are to be removed Gary Cruse Appendix E File:e:\wp21\8300\8382a.lgi Page 2 GeoSoils, Inc. or treated in a manner recommended by the geotechnical consultant. Soft, dry, spongy, highly fractured, or otherwise unsuitable ground, extending to such a depth that surface processing cannot adequately improve the condition, should be overexcavated down to firm ground and approved by the geotechnical consultant before compaction and filling operations continue. Overexcavated and processed soils, which have been properly mixed and moisture conditioned, should be re-compacted to the minimum relative compaction as specified in these guidelines. Existing ground, which is determined to be satisfactory for support of the fills, should be scarified (ripped) to a minimum depth of 6 to 8 inches, or as directed by the geotechnical consultant. After the scarified ground is brought to optimum moisture content, or greater and mixed, the materials should be compacted as specified herein. If the scarified zone is greater than 6 to 8 inches in depth, it may be necessary to remove the excess and place the material in lifts restricted to about 6 to 8 inches in compacted thickness. Existing ground which is not satisfactory to support compacted fill should be overexcavated as required in the geotechnical report, or by the on-site geotechnical consultant. Scarification, disc harrowing, or other acceptable forms of mixing should continue until the soils are broken down and free of large lumps or clods, until the working surface is reasonably uniform and free from ruts, hollows, hummocks, mounds, or other uneven features, which would inhibit compaction as described previously. Where fills are to be placed on ground with slopes steeper than 5:1 (horizontal to vertical [h:v]), the ground should be stepped or benched. The lowest bench, which will act as a key, should be a minimum of 15 feet wide and should be at least 2 feet deep into firm material, and approved by the geotechnical consultant. In fill-over-cut slope conditions, the recommended minimum width of the lowest bench or key is also 15 feet, with the key founded on firm material, as designated by the geotechnical consultant. As a general rule, unless specifically recommended otherwise by the geotechnical consultant, the minimum width of fill keys should be equal to ½ the height of the slope. Standard benching is generally 4 feet (minimum) vertically, exposing firm, acceptable material. Benching may be used to remove unsuitable materials, although it is understood that the vertical height of the bench may exceed 4 feet. Pre-stripping may be considered for unsuitable materials in excess of 4 feet in thickness. All areas to receive fill, including processed areas, removal areas, and the toes of fill benches, should be observed and approved by the geotechnical consultant prior to placement of fill. Fills may then be properly placed and compacted until design grades (elevations) are attained. COMPACTED FILLS Any earth materials imported or excavated on the property may be utilized in the fill provided that each material has been evaluated to be suitable by the geotechnical Gary Cruse Appendix E File:e:\wp21\8300\8382a.lgi Page 3 GeoSoils, Inc. consultant. These materials should be free of roots, tree branches, other organic matter, or other deleterious materials. All unsuitable materials should be removed from the fill as directed by the geotechnical consultant. Soils of poor gradation, undesirable expansion potential, or substandard strength characteristics may be designated by the consultant as unsuitable and may require blending with other soils to serve as a satisfactory fill material. Fill materials derived from benching operations should be dispersed throughout the fill area and blended with other approved material. Benching operations should not result in the benched material being placed only within a single equipment width away from the fill/bedrock contact. Oversized materials defined as rock, or other irreducible materials, with a maximum dimension greater than 12 inches, should not be buried or placed in fills unless the location of materials and disposal methods are specifically approved by the geotechnical consultant. Oversized material should be taken offsite, or placed in accordance with recommendations of the geotechnical consultant in areas designated as suitable for rock disposal. GSI anticipates that soils to be utilized as fill material for the subject project may contain some rock. Appropriately, the need for rock disposal may be necessary during grading operations on the site. From a geotechnical standpoint, the depth of any rocks, rock fills, or rock blankets, should be a sufficient distance from finish grade. This depth is generally the same as any overexcavation due to cut-fill transitions in hard rock areas, and generally facilitates the excavation of structural footings and substructures. Should deeper excavations be proposed (i.e., deepened footings, utility trenching, swimming pools, spas, etc.), the developer may consider increasing the hold-down depth of any rocky fills to be placed, as appropriate. In addition, some agencies/jurisdictions mandate a specific hold-down depth for oversize materials placed in fills. The hold-down depth, and potential to encounter oversize rock, both within fills, and occurring in cut or natural areas, would need to be disclosed to all interested/affected parties. Once approved by the governing agency, the hold-down depth for oversized rock (i.e., greater than 12 inches) in fills on this project is provided as 10 feet, unless specified differently in the text of this report. The governing agency may require that these materials need to be deeper, crushed, or reduced to less than 12 inches in maximum dimension, at their discretion. To facilitate future trenching, rock (or oversized material), should not be placed within the hold-down depth feet from finish grade, the range of foundation excavations, future utilities, or underground construction unless specifically approved by the governing agency, the geotechnical consultant, and/or the developer’s representative. If import material is required for grading, representative samples of the materials to be utilized as compacted fill should be analyzed in the laboratory by the geotechnical consultant to evaluate it’s physical properties and suitability for use onsite. Such testing should be performed three (3) days prior to importation. If any material other than that previously tested is encountered during grading, an appropriate analysis of this material should be conducted by the geotechnical consultant as soon as possible. Gary Cruse Appendix E File:e:\wp21\8300\8382a.lgi Page 4 GeoSoils, Inc. Approved fill material should be placed in areas prepared to receive fill in near horizontal layers, that when compacted, should not exceed about 6 to 8 inches in thickness. The geotechnical consultant may approve thick lifts if testing indicates the grading procedures are such that adequate compaction is being achieved with lifts of greater thickness. Each layer should be spread evenly and blended to attain uniformity of material and moisture suitable for compaction. Fill layers at a moisture content less than optimum should be watered and mixed, and wet fill layers should be aerated by scarification, or should be blended with drier material. Moisture conditioning, blending, and mixing of the fill layer should continue until the fill materials have a uniform moisture content at, or above, optimum moisture. After each layer has been evenly spread, moisture conditioned, and mixed, it should be uniformly compacted to a minimum of 90 percent of the maximum density as evaluated by ASTM test designation D-1557, or as otherwise recommended by the geotechnical consultant. Compaction equipment should be adequately sized and should be specifically designed for soil compaction, or of proven reliability to efficiently achieve the specified degree of compaction. Where tests indicate that the density of any layer of fill, or portion thereof, is below the required relative compaction, or improper moisture is in evidence, the particular layer or portion shall be re-worked until the required density and/or moisture content has been attained. No additional fill shall be placed in an area until the last placed lift of fill has been tested and found to meet the density and moisture requirements, and is approved by the geotechnical consultant. In general, per the latest adopted version of the California Building Code (CBC), fill slopes should be designed and constructed at a gradient of 2:1 (h:v), or flatter. Compaction of slopes should be accomplished by over-building a minimum of 3 feet horizontally, and subsequently trimming back to the design slope configuration. Testing shall be performed as the fill is elevated to evaluate compaction as the fill core is being developed. Special efforts may be necessary to attain the specified compaction in the fill slope zone. Final slope shaping should be performed by trimming and removing loose materials with appropriate equipment. A final evaluation of fill slope compaction should be based on observation and/or testing of the finished slope face. Where compacted fill slopes are designed steeper than 2:1 (h:v), prior approval from the governing agency, specific material types, a higher minimum relative compaction, special reinforcement, and special grading procedures will be recommended. If an alternative to over-building and cutting back the compacted fill slopes is selected, then special effort should be made to achieve the required compaction in the outer 10 feet of each lift of fill by undertaking the following: 1. An extra piece of equipment consisting of a heavy, short-shanked sheepsfoot should be used to roll (horizontal) parallel to the slopes continuously as fill is placed. The sheepsfoot roller should also be used to roll perpendicular to the Gary Cruse Appendix E File:e:\wp21\8300\8382a.lgi Page 5 GeoSoils, Inc. slopes, and extend out over the slope to provide adequate compaction to the face of the slope. 2. Loose fill should not be spilled out over the face of the slope as each lift is compacted. Any loose fill spilled over a previously completed slope face should be trimmed off or be subject to re-rolling. 3. Field compaction tests will be made in the outer (horizontal) ±2 to ±8 feet of the slope at appropriate vertical intervals, subsequent to compaction operations. 4. After completion of the slope, the slope face should be shaped with a small tractor and then re-rolled with a sheepsfoot to achieve compaction to near the slope face. Subsequent to testing to evaluate compaction, the slopes should be grid-rolled to achieve compaction to the slope face. Final testing should be used to evaluate compaction after grid rolling. 5. Where testing indicates less than adequate compaction, the contractor will be responsible to rip, water, mix, and recompact the slope material as necessary to achieve compaction. Additional testing should be performed to evaluate compaction. SUBDRAIN INSTALLATION Subdrains should be installed in approved ground in accordance with the approximate alignment and details indicated by the geotechnical consultant. Subdrain locations or materials should not be changed or modified without approval of the geotechnical consultant. The geotechnical consultant may recommend and direct changes in subdrain line, grade, and drain material in the field, pending exposed conditions. The location of constructed subdrains, especially the outlets, should be recorded/surveyed by the project civil engineer. Drainage at the subdrain outlets should be provided by the project civil engineer. EXCAVATIONS Excavations and cut slopes should be examined during grading by the geotechnical consultant. If directed by the geotechnical consultant, further excavations or overexcavation and refilling of cut areas should be performed, and/or remedial grading of cut slopes should be performed. When fill-over-cut slopes are to be graded, unless otherwise approved, the cut portion of the slope should be observed by the geotechnical consultant prior to placement of materials for construction of the fill portion of the slope. The geotechnical consultant should observe all cut slopes, and should be notified by the contractor when excavation of cut slopes commence. Gary Cruse Appendix E File:e:\wp21\8300\8382a.lgi Page 6 GeoSoils, Inc. If, during the course of grading, unforeseen adverse or potentially adverse geologic conditions are encountered, the geotechnical consultant should investigate, evaluate, and make appropriate recommendations for mitigation of these conditions. The need for cut slope buttressing or stabilizing should be based on in-grading evaluation by the geotechnical consultant, whether anticipated or not. Unless otherwise specified in geotechnical and geological report(s), no cut slopes should be excavated higher or steeper than that allowed by the ordinances of controlling governmental agencies. Additionally, short-term stability of temporary cut slopes is the contractor’s responsibility. Erosion control and drainage devices should be designed by the project civil engineer and should be constructed in compliance with the ordinances of the controlling governmental agencies, and/or in accordance with the recommendations of the geotechnical consultant. COMPLETION Observation, testing, and consultation by the geotechnical consultant should be conducted during the grading operations in order to state an opinion that all cut and fill areas are graded in accordance with the approved project specifications. After completion of grading, and after the geotechnical consultant has finished observations of the work, final reports should be submitted, and may be subject to review by the controlling governmental agencies. No further excavation or filling should be undertaken without prior notification of the geotechnical consultant or approved plans. All finished cut and fill slopes should be protected from erosion and/or be planted in accordance with the project specifications and/or as recommended by a landscape architect. Such protection and/or planning should be undertaken as soon as practical after completion of grading. JOB SAFETY General At GSI, getting the job done safely is of primary concern. The following is the company's safety considerations for use by all employees on multi-employer construction sites. On-ground personnel are at highest risk of injury, and possible fatality, on grading and construction projects. GSI recognizes that construction activities will vary on each site, and that site safety is the prime responsibility of the contractor; however, everyone must be safety conscious and responsible at all times. To achieve our goal of avoiding accidents, cooperation between the client, the contractor, and GSI personnel must be maintained. In an effort to minimize risks associated with geotechnical testing and observation, the following precautions are to be implemented for the safety of field personnel on grading and construction projects: Gary Cruse Appendix E File:e:\wp21\8300\8382a.lgi Page 7 GeoSoils, Inc. Safety Meetings: GSI field personnel are directed to attend contractor’s regularly scheduled and documented safety meetings. Safety Vests: Safety vests are provided for, and are to be worn by GSI personnel, at all times, when they are working in the field. Safety Flags:Two safety flags are provided to GSI field technicians; one is to be affixed to the vehicle when on site, the other is to be placed atop the spoil pile on all test pits. Flashing Lights:All vehicles stationary in the grading area shall use rotating or flashing amber beacons, or strobe lights, on the vehicle during all field testing. While operating a vehicle in the grading area, the emergency flasher on the vehicle shall be activated. In the event that the contractor's representative observes any of our personnel not following the above, we request that it be brought to the attention of our office. Test Pits Location, Orientation, and Clearance The technician is responsible for selecting test pit locations. A primary concern should be the technician’s safety. Efforts will be made to coordinate locations with the grading contractor’s authorized representative, and to select locations following or behind the established traffic pattern, preferably outside of current traffic. The contractor’s authorized representative (supervisor, grade checker, dump man, operator, etc.) should direct excavation of the pit and safety during the test period. Of paramount concern should be the soil technician’s safety, and obtaining enough tests to represent the fill. Test pits should be excavated so that the spoil pile is placed away from oncoming traffic, whenever possible. The technician's vehicle is to be placed next to the test pit, opposite the spoil pile. This necessitates the fill be maintained in a driveable condition. Alternatively, the contractor may wish to park a piece of equipment in front of the test holes, particularly in small fill areas or those with limited access. A zone of non-encroachment should be established for all test pits. No grading equipment should enter this zone during the testing procedure. The zone should extend approximately 50 feet outward from the center of the test pit. This zone is established for safety and to avoid excessive ground vibration, which typically decreases test results. When taking slope tests, the technician should park the vehicle directly above or below the test location. If this is not possible, a prominent flag should be placed at the top of the slope. The contractor's representative should effectively keep all equipment at a safe operational distance (e.g., 50 feet) away from the slope during this testing. The technician is directed to withdraw from the active portion of the fill as soon as possible following testing. The technician's vehicle should be parked at the perimeter of the fill in Gary Cruse Appendix E File:e:\wp21\8300\8382a.lgi Page 8 GeoSoils, Inc. a highly visible location, well away from the equipment traffic pattern. The contractor should inform our personnel of all changes to haul roads, cut and fill areas or other factors that may affect site access and site safety. In the event that the technician’s safety is jeopardized or compromised as a result of the contractor’s failure to comply with any of the above, the technician is required, by company policy, to immediately withdraw and notify his/her supervisor. The grading contractor’s representative will be contacted in an effort to affect a solution. However, in the interim, no further testing will be performed until the situation is rectified. Any fill placed can be considered unacceptable and subject to reprocessing, recompaction, or removal. In the event that the soil technician does not comply with the above or other established safety guidelines, we request that the contractor bring this to the technician’s attention and notify this office. Effective communication and coordination between the contractor’s representative and the soil technician is strongly encouraged in order to implement the above safety plan. Trench and Vertical Excavation It is the contractor's responsibility to provide safe access into trenches where compaction testing is needed. Our personnel are directed not to enter any excavation or vertical cut which: 1) is 5 feet or deeper unless shored or laid back; 2) displays any evidence of instability, has any loose rock or other debris which could fall into the trench; or 3) displays any other evidence of any unsafe conditions regardless of depth. All trench excavations or vertical cuts in excess of 5 feet deep, which any person enters, should be shored or laid back. Trench access should be provided in accordance with Cal/OSHA and/or state and local standards. Our personnel are directed not to enter any trench by being lowered or “riding down” on the equipment. If the contractor fails to provide safe access to trenches for compaction testing, our company policy requires that the soil technician withdraw and notify his/her supervisor. The contractor’s representative will be contacted in an effort to affect a solution. All backfill not tested due to safety concerns or other reasons could be subject to reprocessing and/or removal. If GSI personnel become aware of anyone working beneath an unsafe trench wall or vertical excavation, we have a legal obligation to put the contractor and owner/developer on notice to immediately correct the situation. If corrective steps are not taken, GSI then has an obligation to notify Cal/OSHA and/or the proper controlling authorities. Gary Cruse Appendix E File:e:\wp21\8300\8382a.lgi Page 9 Toe of slope as shown on grading plan Proposed grade \ / / ~ / Natural slope to be restored with compacted fill Compacted fill Backcut varies NOTES: Subdrain as recommended by geotechnical consultant 1. Where the natural slope approaches or exceeds the design slope ratio, special recommendations would be provided by the geotechnical consultant. 2. The need for and disposition of drains should be evaluated by the geotechnical consultant, based upon exposed conditions. c. FILL OVER NATURAL (SIDEHILL FILL) DETAIL Plate E-7 Natural grade Proposed pad grade _=::::a...-.,::-::-... · .... ··-: ; .. / .. : .-·<: .. =···-._;··~ ·. . ·: ... .-· : . ~ .• ::....::z_..::, • --__ l_ \<U,, y\\ ;((0~t\ y\ \\''\\\~>::::-\ ,,,\ \\~\/4;✓,,,\'\ ;((0u/ y)\ <0,;;,'\ y\ \Y ~ 3-to 7-foot minimum• \' B d k overexcavate and recompact \ ~~1/\ e roe or per text of report ,,\ \ \::--<, approved native material Typical benching CUT LOT OR MATERIAL -TYPE TRANSITION Natural grade . . . . . • •• • .:.....· ...,.-=:m-rFF7-~~~~~~~~~~~~~m-~ .-. •• •• :~ 3-to 7-foot minimum• ... ·.-. • =·· ~ overexcavate and recompact . b\8. ~;~ • • ....,......,.,...,.......,............,..,....,....,.............,..-11 ~ per text of report · ~~ \ \V • Deeper overexcavation may be Typical benching (4-foot minimum) Bedrock or approved native material recommended by the geotechnical consultant in steep cut-fill transition areas, such that the underlying topography is no steeper than 3:1 (H:V) CUT-FILL LOT (DAYLIGHT TRANSITION) c. TRANSITION LOT DETAILS Plate E-12 APROXIMATE LOCATION OF HAND-AUGER BORINGS GSI LEGEND BOING LOCATION MAP Plate 1 W.O 8382-A-SC DATE: 08/22 SCALE: 1/8 = 1'-0" ALL LOCATIONS ARE APROXIMATE This document or efile is not part of the Construction Documents and should not be relied upon as being an accurate depiction of design. Based on site plans by Arlen Roper Inc. ',;:, .... ;c; '9~.>--}.,.... ~q! ~ w ~ ~ > ~ u "' ... ,., 1,"'-'/, a "' i1' ::, .J "' G~"\'El w ill"" IL ~~ ~ ,< n :,:: ,;;& .. ~ ( .,_ ;:;i~ "' r;'',"1> Cl 4 I "\~ t;. \ I l ''il:,1, .,. I~ g; " ;s-f&,, ~-:...i_ 'i I l~~ ·<J>· :30~0 · • M "' ~ ~ \ 1~ '.j: rCN:11£ • 9-J ~ .. ci: I Ffil ~ r -~•-r 0 ~ 0 ~~ ~ ~ .:.,~ C-ONCll£T[ PATIC J. ~- m :a "'· l;XISi ~IOIING!.E 0 LOT I -e!..OC-K L. 1-1'.AI"' 114',r ~ I! ., -2 !;!~ llJi-+ ------- LOT 5' -m.oc~ L M.AP li"14i EXISTING SITE.PLAN ~ OIRT • ~------------------ I HA-3 ¼,, . I I I I I I I I