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Appendix D_Geo Report
GREEN Geotechnical Engineering Exploration and Analysis Proposed Public Storage Facility 17173 Valley Boulevard Fontana, California Prepared for: Public Storage Glendale, California April 1, 2022 Project No. 2G-2202002-R _________________________________________________________________________ GILES ENGINEERING ASSOCIATES, INC. TABLE OF CONTENTS GEOTECHNICAL ENGINEERING EXPLORATION AND ANALYSIS PROPOSED PUBLIC STORAGE FACILITY 17173 VALLEY BOULEVARD FONTANA, CALIFORNIA PROJECT NO. 2G-2202002-R Description Page No. EXECUTIVE SUMMARY OUTLINE ........................................................................................... 1 1.0 SCOPE OF SERVICES .................................................................................................. 3 2.0 SITES AND PROJECT DESCRIPTION .......................................................................... 3 2.1 Site Description ................................................................................................... 3 2.2 Proposed Project Description .............................................................................. 3 3.0 SUBSURFACE EXPLORATION .................................................................................... 4 3.1 Subsurface Exploration ....................................................................................... 4 3.2 Subsurface Conditions ........................................................................................ 5 3.3 Percolation Testing ............................................................................................. 6 4.0 LABORATORY TESTING ............................................................................................... 7 5.0 GEOLOGIC AND SEISMIC HAZARDS .......................................................................... 9 6.0 CONCLUSIONS AND RECOMMENDATIONS ............................................................... 9 6.1 Seismic Design Considerations ......................................................................... 10 6.2 Site Development and Construction Considerations ......................................... 11 6.3 Foundation Recommendations ......................................................................... 14 6.4 Floor Slab Recommendations ........................................................................... 16 6.5 Elevator Pit Recommendations ......................................................................... 17 6.6 New Pavement ................................................................................................. 18 6.7 Recommended Construction Materials Testing Services .................................. 20 6.8 Basis of Report ................................................................................................. 20 APPENDICES Appendix A – Figures (1) and Boring Logs (7) Appendix B – Field Procedures Appendix C – Laboratory Testing and Classification Appendix D – General Information (Modified Guideline Specifications) and Important Information About Your Geotechnical Report _________________________________________________________________________ GILES ENGINEERING ASSOCIATES, INC. GEOTECHNICAL ENGINEERING EXPLORATION AND ANALSYSIS PROPOSED PUBLIC STORAGE FACILITY 17173 VALLEY BOULEVARD FONTANA, CALIFORNIA PROJECT NO. 2G-2202002-R EXECUTIVE SUMMARY OUTLINE The executive summary is provided solely for purposes of overview. Any party who relies on this report must read the full report. The executive summary omits a number of details, any one of which could be crucial to the proper application of this report. This document is a feasibility report and is not, therefore, intended for submission for building purposes. Subsurface Conditions • A Site Class D is recommended for this site based upon the mapped geological features of the site also verified by test borings. • Based upon available geological maps, the site is located at the northern portion of the Peninsular Ranges Geomorphic Provinces of California. Locally, the surficial sediments consisting of young alluvial-fan deposits of Lytle Creek (Holocene and late Pleistocene, Qyfl, consisting of unconsolidated, gray, cobbly and bouldery alluvium of Lyttle Creek fan. • Fill to possible fill soils were encountered within our test borings to depths up to about 5 feet. The fill soils were generally silty sand and poorly-graded sand with silt, medium dense, damp to moist, fine to medium grained, various amount of gravel. • Native soils encountered beneath the fill and possible fill consist of silty sand and poorly-graded sand with silt, which are medium dense to very dense, damp to moist, fine to medium grained, various amount of gravel, and more gravelly with depth and few cobble fragments. • Groundwater was not encountered during our subsurface exploration to the maximum depth explored of 26½ feet. Based on nearby groundwater wells, groundwater level was encountered deeper than 300 feet. Site Development • It is our understanding that the Public Storage will be developing the site to include the construction of a 3-story building at or near existing grade. A parking area will be within the proposed building and a proposed fire lane easement area to the west of the proposed building. See Figure 1, Test Boring Location Plan for location of proposed building and site development. • Due to the presence of variable strength onsite soils, including fill and possible fill, and the existing of structures at the site, it is likely disturbance of the subgrade soils will take place during demolition operations; therefore, it is recommended that the soils within the proposed building area and an appropriate distance beyond (5 feet minimum where possible) be over-excavated to a depth of at least 1 foot below bottom of foundations and floor slab, and to the depth required to remove soil disturbed during demolition and grading, whichever is deeper. The soils exposed at the base of this recommended over-excavation should be examined by the geotechnical engineer to document that the soils are suitable for building support. Geotechnical Engineering Exploration and Analysis Proposed Public Storage Facility 17173 Valley Boulevard Fontana, California Project No. 2G-2202002-R Page 2 _________________________________________________________________________ GILES ENGINEERING ASSOCIATES, INC. Building Foundation • Spread footings that will support the bearing walls and isolated columns may be designed for a maximum, net, allowable soil-bearing pressure of 4,000 pounds per square foot (psf) for the 3-story building. Structural loads supported by a mat/slab may be designed for a maximum modulus of subgrade reaction (ks) of 84 pounds per square inch per inch (psi/in.) Building Floor Slab • The slab should be underlain by a minimum 4-inch-thick granular base supported on a properly prepared subgrade consisting of newly placed structural compacted fill. • The ground floor of the new building may be designed as load-bearing mat/slab, or conventional slab-on-grade with spread footings. • A minimum 15-mil vapor retarder is recommended below the floor slab or base course to protect moisture sensitive floor coverings. Pavement Improvement • Asphaltic Concrete: 3 inches of asphaltic concrete underlain by 5 or 7 inches of base course in parking stall and drive lane areas, respectively. • Portland Cement Concrete: 6 inches in thickness in high stress areas such as entrance/exit aprons lane and in trash enclosure loading zone with a 4-inch granular base. Construction Considerations • All excavations must be performed in accordance with OSHA requirements, which is the responsibility of the contractor. • Loose or disturbed soil resulting from the demolishing and removal of the existing structures, pavement, and foundations should be expected, and monitored by Giles during demo and grading to determine if supplemental recommendations are warranted. GREEN – This site has been given a green designation as no significant cost increases or geotechnical issues are expected. Geotechnical Engineering Exploration and Analysis Proposed Public Storage Facility 17173 Valley Boulevard Fontana, California Project No. 2G-2202002-R Page 3 _________________________________________________________________________ GILES ENGINEERING ASSOCIATES, INC. 1.0 SCOPE OF SERVICES This report provides the results of our Geotechnical Feasibility Study that Giles Engineering Associates, Inc. (“Giles”) conducted regarding the proposed development. This report included several separate, but related, service areas referenced hereafter as the Geotechnical Subsurface Exploration Program, Geotechnical Laboratory Services, and Geotechnical Engineering Services. The scope of each service area was narrow and limited, as directed by our client and in consideration of the proposed project. The scope of each service area is briefly explained in this report. The scope of work performed for this report was consistent with the scope of work outlined within Proposal No. 2GP-2202010. Geotechnical-related services for the proposed development consisted of determining the feasibility of site development. 2.0 SITE AND PROJECT DESCRIPTION 2.1 Site Description The subject site is located at 17173 Valley Boulevard, in the City of Fontana, California. At the time of the exploration, the site was occupied by an asphalt paved parking lot use for trailers parking area and some grass area. The site is approximately 5.33 acres in gross lot area. The site is bounded on the north by a hotel structure with parking lot and Valley Boulevard, on the east by an existing Public Storage facility, on the south by the San Bernardino Freeway (I-10), and on the east by more commercial structures and paved parking lot areas. The neighboring development consists mainly of commercial structures and a concrete channel toward the south, next to the I-10 freeway. Elevations at the site are approximately within elevations 1112 and 1115 feet with the highest elevation point at the northwest area of the site, based on an Alta Survey Plan prepared by DRC Engineering, Inc., dated February 28, 2019. Site slopes down toward the south, with no signs of slope instability. Other existing features consist of trees and shrubs at the southern perimeter of the site and a grassy, unpaved field area at the northeast area of the site. 2.2 Proposed Project Description It is our understanding that Public Storage will be developing this site by constructing a three-story building with a parking area. Additionally, it is proposed Fire Access Easement at the west side of the proposed building and a semi-trailer parking stalls at the north portion of the building. A Conceptual Site Plan prepared by KSP Studio, plan dated February 17, 2021 was provided. The proposed structure will have no basement. At the time of this geotechnical investigation, structural loads were not available, but we have estimated maximum building loads, based on a 10-foot by 10-foot column spacing, to be about 50 to 60 kips for interior columns and 3 to 4 kips Geotechnical Engineering Exploration and Analysis Proposed Public Storage Facility 17173 Valley Boulevard Fontana, California Project No. 2G-2202002-R Page 4 _________________________________________________________________________ GILES ENGINEERING ASSOCIATES, INC. per foot for walls. When design loading conditions are final, we should be notified to re-evaluate the conclusions and recommendations contained in this report. The structure is anticipated to be concrete, masonry, and steel. It is anticipated that the finish floor elevation of the new building will be near or at existing grades (assumed at El. 1115). Therefore, site grading is anticipated to include minor cut and fill in order to establish the necessary site grade to accommodate the assumed floor elevation, exclusive of site preparation or over-excavation requirements necessary to create a stable site suited for the proposed development. 3.0 SUBSURFACE EXPLORATION 3.1 Subsurface Exploration Our subsurface exploration consisted of drilling six (6) exploratory Test Borings, between depths of 6½ to 26½ feet and two percolation test holes at depths of 5 feet each. The borings were drilled with an 8-inch diameter, hollow-stem auger rig. The approximate Test Boring locations are included on the attached Figure 1, Test Boring Location Plan enclosed in Appendix A. Field and laboratory test procedures are enclosed in Appendix B and C, respectively. The terms and symbols used on the Test Boring Logs are defined on the General Notes in Appendix D. Our subsurface exploration included the collection of relatively undisturbed soil samples of subsurface soil materials at selected depth intervals from the test borings for laboratory testing purposes. A representative bulk sample consisted of composite soil materials obtained from the upper soils from the test borings was also obtained. Relatively undisturbed samples were collected (per ASTM D 3550) using a 3-inch outside diameter, modified California split-spoon soil sampler (CS) lined with 1-inch-high brass rings. The sampler was driven with successive 30-inch drops of a hydraulically operated, 140-pound automatic trip hammer. Blow counts for each 6-inch driving increment were recorded on the field exploration logs. The central portions of the driven core samples were placed in sealed containers and transported to our laboratory for testing. Standard split-spoon tests (SS), also called Standard Penetration Test (SPT), were also performed at selected depth intervals in accordance with the American Society for Testing Materials (ASTM) Standard Procedure D 1586. This method consists of mechanically driving an unlined standard split-barrel sampler 18 inches into the soil with successive 30-inch drops of the 140-pound automatic trip hammer. Blow counts for each 6-inch driving increment were recorded on the exploration logs. The number of blows required to drive the standard split-spoon sampler for the last 12 of the 18 inches was identified as the uncorrected standard penetration resistance (N). Disturbed soil samples from the unlined standard split-spoon sampler were placed in plastic bags and transported to our laboratory for testing. Samples were transported to our laboratory for further testing. Geotechnical Engineering Exploration and Analysis Proposed Public Storage Facility 17173 Valley Boulevard Fontana, California Project No. 2G-2202002-R Page 5 _________________________________________________________________________ GILES ENGINEERING ASSOCIATES, INC. At the conclusion of drilling activities, each borehole was backfilled (and patched, where drilled on asphalt pavement). Even with this service, however, it is important to note that some borehole backfill settlement or expansion can and will occur over time. This settlement/expansion can create a hazard and should be carefully monitored by the client and/or property owner. The settlement/expansion can lead to the formation of a “trip joint” representing a threat of injury to persons or animals utilizing or accessing the subject property. Giles has not included a cost for monitoring borehole settlement/expansion after the initial drilling activities and will not be performing this service. 3.2 Subsurface Conditions The subsurface conditions as subsequently described have been simplified somewhat for ease of report interpretation. A more detailed description of the subsurface conditions at the test boring locations is provided by the logs of the test borings enclosed in Appendix A of this report. Pavement Most of the subject site area within our test borings was developed with asphaltic pavement consisted of approximately between 2 to 3 inches thick asphaltic concrete with none to up to 7 inches thick aggregate base, except for Test Boring B-7 consisting of 5 inches thick asphalt pavement over 7 inches of base coarse. Based on our visual observation, the existing pavement is in fair condition. Only Test Boring B-2 was located within an unpaved, soil surface area. Geology Based upon available geological maps, the site is located at the northern portion of the Peninsular Ranges Geomorphic Provinces of California. The Peninsular Ranges are characterized by northwest-trending blocks of mountain ridges and sediment-floored valleys. Locally, the site is underlain by surficial sediments consisting of young alluvial-fan deposits of Lytle Creek (Holocene and late Pleistocene, Qyfl, consisting of unconsolidated, gray, cobbly and bouldery alluvium of Lyttle Creek fan, according to Preliminary Geologic Map of Fontana 7.5 Minute Quadrangle, San Bernardino and Riverside Counties (Morton, 1999). Soil Fill and possible fill materials were encountered in the exploratory borings to depths up to 5 feet. Fill material consists of silty sand and poorly-graded sand with silt, medium dense, damp to moist, fine to medium grained, with various amount of gravel. The fill and possible fill soils are underlain by native soils, consisting of silty sand and poorly-graded sand with silt, which are medium dense to very dense, damp to moist, fine to medium grained, various amount of gravel, more gravelly with depth, and some cobble fragments. Geotechnical Engineering Exploration and Analysis Proposed Public Storage Facility 17173 Valley Boulevard Fontana, California Project No. 2G-2202002-R Page 6 _________________________________________________________________________ GILES ENGINEERING ASSOCIATES, INC. Groundwater Groundwater was not encountered during our field exploration, drilled to a maximum depth of 26½ feet below ground surface (bgs). This area has not been evaluated by the California Geological Survey (CGS); however, based on a nearby well found by researching GeoTracker of the California Department of Water Resources, distance from ground surface to water surface is deeper than 300 feet at this site. Fluctuations of the groundwater table, localized zones of perched water, and rise in soil moisture content should be anticipated during and after the rainy season. 3.3 Percolation Testing It is our understanding that on-site below grade storm water infiltration systems on the north and south sides of the proposed new building are being considered for the subject site. Therefore, percolation tests were performed, at those proposed locations to assess the infiltration characteristics of the on-site soils. The percolation testing consisted of drilling a borehole at a depth of 5 feet bgs, using 8-inch-diameter hollow-stem auger rig, installing a 2-inch-diameter slotted pvc casing with a solid end cap and then surrounding the casing with a granular filter pack. The test zone was determined at depth of ground surface to 5 feet bgs, by using a slotted pvc pipe in that area. The test holes, P-1 and P-2, were then pre-soaked for at least one hour to a minimum depth of 12 inches above the bottom of the boring. After pre-soaking, water was added to the casing and refilled after each consecutive percolation test reading. The drop in water level over time is the percolation rate at the test location. The pre-adjusted percolation rate is generally reduced to account for the discharge of water from both the sides and bottom of the boring. Percolation test procedures and calculated rate were based on Onsite Wastewater Treatment System Soil Percolation (PERC) Test Report Standards: Suitability of Lots and Soils for Use of Leachlines or Seepage Pit (Revised 2017) from the Public Health Environmental Health Services of the San Bernardino and the cited Appendix D of the document “Appendix VII, Infiltration Rate Evaluation Protocol and Factor of Safety Recommendations.” A series of readings were taking by using the falling head method until water reached steady conditions, a minimum of eight readings at 10 minutes intervals were performed. Porchet formula was used to estimate the infiltration rate as follows: Design Infiltration Rate = ∆H (60*r)/ ∆t*(r + 2*HAVE) Where: ∆H = Ho - Hf (inches) Ho = Initial water level; Hf = Final water level r = radius of hole (inch) ∆t = time interval (mins) HAVE = (Ho + Hf)/ 2 Geotechnical Engineering Exploration and Analysis Proposed Public Storage Facility 17173 Valley Boulevard Fontana, California Project No. 2G-2202002-R Page 7 _________________________________________________________________________ GILES ENGINEERING ASSOCIATES, INC. The results obtained from our percolation testing are summarized below. The infiltration rate noted below has not been reduced to account for a factor of safety. Table 1 – Percolation Test Results Test Hole Test Depth1 (feet) Design Infiltration 2 Rate (in/hr) Soil Type P-1 0 - 5 11.3 SM/SP-SM P-2 0 - 5 17.1 SP Notes: 1) Depth is referenced to the existing surface grade at the test location. 2) By applying Porchet formula. The test-specific correction factors should be determined by the civil engineer based on County guidelines, type of infiltration facility to be installed, and the planned maintenance program for the facility. It should be noted that the recommended infiltration rate is based on testing at a particular location and depth, and the overall infiltration rate of the system could vary considerably. All stormwater infiltration facilities should be set back at least 20 feet horizontally from the proposed building and other settlement-sensitive project features. 4.0 LABORATORY TESTING Laboratory tests were performed on selected samples considered representative of those encountered in order to evaluate the engineering properties of the on-site soils. The following is a brief description of our laboratory test results. In Situ Moisture and Density Tests were performed on select samples from the test borings to determine the subsoils dry density and natural moisture contents in accordance with Test Method ASTM 2216 and D2237. The results of these tests are included in the Test Boring Logs enclosed in Appendix A. Sieve Analysis Sieve Analyses, in particularly passing No. 200 Sieve, were performed on selected samples from the Test Borings to assist in soil classification. These tests were performed in accordance with Test Method ASTM D 1140. The results of the Passing No. 200 Sieve are presented included on the Test Boring Logs and shown in Figure 2 included in Appendix A. Geotechnical Engineering Exploration and Analysis Proposed Public Storage Facility 17173 Valley Boulevard Fontana, California Project No. 2G-2202002-R Page 8 _________________________________________________________________________ GILES ENGINEERING ASSOCIATES, INC. Boring No and Depth (ft) Percent Passing No. 200 Sieve B-1 at 7 6% B-2 at 3 14% B-6 at 3 11% B-6 at 5 7% B-7 at 3 4% Comb. Bulk at 1 - 5 8% Expansion Index To evaluate the expansive potential of the near surface soils encountered during our subsurface exploration, a representative soil sample collected from the test borings was subjected to Expansive Index (EI) testing in accordance with Test Method ASTM D 4829. The result of our expansion index (EI) test indicates that the near surface sample has a very low expansion potential (EI = 0). Soluble Sulfate Analysis and Soil Corrosivity A representative bulk sample of the near surface soils which may be in contact with shallow buried utilities and structural concrete was performed to determine the corrosion potential for buried ferrous metal conduits and the concentrations present of water-soluble sulfate which could result in chemical attack of cement. The following table presents the results of our laboratory testing. Parameter Bulk Sample at 1 to 5 feet pH 7.4 Chloride 58 ppm Sulfate 0.042 % Resistivity 11,000 ohm-cm The chloride content of the near-surface soils was determined for selected samples in accordance with California Test Method No. 422. The results of this test indicated that tested soil has a Low exposure to chloride. The results of limited in-house testing of soil pH and resistivity were determined in accordance with California test Method No. 643 and indicated that site soil is Mildly Alkaline with respect to pH. These test results have been evaluated in accordance with criteria established by the Cast Iron Pipe Research Association, Ductile Iron Pipe Research Association, the American Concrete Institute and the National Association of Corrosion Engineers. The test results on a near surface Geotechnical Engineering Exploration and Analysis Proposed Public Storage Facility 17173 Valley Boulevard Fontana, California Project No. 2G-2202002-R Page 9 _________________________________________________________________________ GILES ENGINEERING ASSOCIATES, INC. bulk sample from the site generally indicate that tested soils have a low to mildly corrosive potential when in contact with ferrous materials. We recommend that a corrosion engineer review these results in order to provide specific recommendations for corrosion protection as well as appropriate recommendations for other types of buried metal structures. Corrosivity testing also included determination of the concentrations of water-soluble sulfates present in the tested soil samples in accordance with California Test Method No. 417. Our laboratory test data indicated that near surface soils contain less than 0.042 percent of water-soluble sulfates. Based on the applicable California Building Code (CBC), concrete that may be exposed to sulfate containing soils shall comply with the provisions of ACI 318-11, Section 4.3. Therefore, according to Table 4.3.1 of the ACI 318-11, a negligible exposure to sulfate corrosivity can be expected for concrete placed in contact with the tested on-site soils. No special sulfate resistant cement is considered necessary for concrete which will be in contact with the tested on-site soils. 5.0 GEOLOGIC AND SEISMIC HAZARDS Liquefaction According to Map 9: USGS Liquefaction Susceptibility Zones of Appendix E Hazard Screening Maps of the City of Fontana, State of California, the site is not located within an area identified as having a potential for liquefaction. 6.0 CONCLUSIONS AND RECOMMENDATIONS Based on the results of our subsurface exploration and laboratory testing, the planned development for the subject site is considered feasible from a geotechnical point of view provided the following conclusions and recommendations are incorporated in the design and project specifications. Conditions resulting from the proposed development have been evaluated on the engineering characteristics of the subsurface materials encountered during our subsurface investigation and their anticipated behavior both during and after construction. Conclusions and recommendations, along with site preparation recommendations and construction considerations are discussed in the following section of this report. We recommend that Giles Engineering Associates, Inc. be involved in the review of the grading and foundation plans for the site. Based on the results of our review, modifications to our recommendations may be warranted. Geotechnical Engineering Exploration and Analysis Proposed Public Storage Facility 17173 Valley Boulevard Fontana, California Project No. 2G-2202002-R Page 10 _________________________________________________________________________ GILES ENGINEERING ASSOCIATES, INC. Effect of Proposed Grading and Construction on Adjacent Property Based on a review of the soil conditions, site plan, and building setbacks, it is our opinion that the proposed construction and grading will be safe against geotechnical hazards from landslides, settlement, or slippage provided grading and construction are performed in compliance with the state, city, and local codes and in accordance with the recommendations presented herein. 6.1 Seismic Design Considerations Faulting/Seismic Design Parameters Review of Map 1, City of Fontana Earthquake of Appendix E – Hazard Screening Maps, State of California Earthquake, the site is not located within any active fault zone. Evidence for active faulting at the site was not observed during the subsurface investigation. The potential for fault rupture through the site is, therefore, considered to be low. The site may however be subject to strong ground shaking during seismic activity. The distance from the site to the projection of traces of surface rupture along major active earthquake fault zones, that could affect the site are listed in the following Table 2. Table 2 - Distance from the Site to Major Active Faults Fault Name Distance From the Site San Jacinto Fault 6.4 miles Cucamonga Fault 7.3 miles San Andreas Fault 10.9 miles Source: https://earthquake.usgs.gov/cfusion/hazfaults_2008_search/ These faults would probably generate the most severe site ground motions at the site with an anticipated moment magnitude (Mw) of 7.6. Seismic Design Parameters Seismic Parameters are provided for the project site based on the 2019 California Building Code (CBC) and ASCE 7-16 guidance documents using the Structural Engineers Association of California’s U.S. Seismic Design Maps Online Calculator (https://seismicmaps.org/ based on the project site address. The seismic design parameters for the project site are presented in Table 2 below. Geotechnical Engineering Exploration and Analysis Proposed Public Storage Facility 17173 Valley Boulevard Fontana, California Project No. 2G-2202002-R Page 11 _________________________________________________________________________ GILES ENGINEERING ASSOCIATES, INC. Table 3 – Recommended 2019 CBC Seismic Design Parameters 2019 CBC, Earthquake Loads Site Class Definition (Table 20.3-1 from ASCE 7-16) D Mapped Spectral Response Acceleration Parameter, Ss (for 0.2 second) 1.694g Mapped Spectral Response Acceleration Parameter, S1 (for 1.0 second) 0.6g Site Coefficient, Fa short period 1.0 Site Coefficient, Fv 1-second period 1.7 Adjusted Maximum Considered Earthquake Spectral Response Acceleration Parameter, SMS 1.694g Adjusted Maximum Considered Earthquake Spectral Response Acceleration Parameter, SM1 1.02g Design Spectral Response Acceleration Parameter, SDS 1.129g Design Spectral Response Acceleration Parameter, SD1 0.68g MCEG Peak Ground Acceleration adjusted for site class effects, PGAM 0.759g 6.2 Site Development and Construction Considerations The recommendations for site development as subsequently described are based upon the conditions encountered at the test boring locations and our research at the site. Site Clearing Clearing and demolition operations should include the removal of all landscape vegetation and existing structural features such as asphaltic concrete pavement, concrete curbs, existing footings (if encountered) and walls, and concrete walkways within the area of the proposed new building and site improvements. Existing pavement within areas of proposed development should be removed or processed to a maximum 3-inch size and stockpiled for use as compacted fill or stabilizing material for the new development. Processed asphalt may be used as fill, sub-base course material, or subgrade stabilization material beyond the building perimeter. Processed concrete or existing base may be used as fill, sub-base course material, or subgrade stabilization material both within and outside of the building perimeter. All soils disturbed by the demolition of the existing improvements should be removed and/or compacted to provide a competent subgrade, as determined by the project geotechnical engineer. Should any unusual soil conditions or subsurface structures be encountered during clearing/demolition operations or during grading, they should be brought to the immediate attention of the project geotechnical consultant for corrective recommendations. Geotechnical Engineering Exploration and Analysis Proposed Public Storage Facility 17173 Valley Boulevard Fontana, California Project No. 2G-2202002-R Page 12 _________________________________________________________________________ GILES ENGINEERING ASSOCIATES, INC. Existing Utilities All existing utilities crossing the site should be located. Utilities that will be preserved are recommended to be relocated outside the improvement areas. Utilities that are not to be reused should be capped off and removed or properly abandoned in-place in accordance with local codes and ordinances. The excavations made for removed utilities are recommended to be backfilled with structural compacted fill. Underground utilities, which are to be reused or abandoned in-place, are recommended to be evaluated by the structural engineer and utility backfill is recommended to be evaluated by the geotechnical engineer, to determine their potential effect on the new development. If any existing utilities are to be preserved, grading operations must be carefully performed so as not to disturb or damage the existing utility. Reuse of On-site Soil On-site subsurface material was found to be in the very low expansive soils category (EI = 0). Therefore, similar on-site materials may be reused as structural compacted fill within the proposed development provided they do not contain oversized materials and significant quantities of organic matter or other deleterious materials. All subgrade soil compaction as well as the selection, placement and compaction of new fill soils should be performed in accordance with the project specifications under engineering-controlled conditions. Import Structural Fill Any soils imported to the site for use as structural fill should consist of very low expansive soils (EI < 20). Material designated for import should be submitted to the project geotechnical engineer for evaluation no less than three working days prior to import. In addition to expansion criteria, soils imported to the site should exhibit adequate shear strength characteristics for the recommended allowable soil bearing pressure; soluble sulfate content and corrosivity; and pavement support characteristics. Building Area Due to the presence of variable strength onsite soils including existing fill and possible fill to an depths of about 5 feet at the site, and the likely disturbance of the subgrade during demolition operations, it is recommended that the soils within the proposed new building area, and an appropriate horizontal distance beyond (5 feet minimum where possible), be over-excavated to a depth of at least 2 feet below grade, , and 1 foot below bottom of foundations and floor slab, and to the depth required to remove any loose and disturbed soils during demolition or grading operations, and undocumented fill within the building bearing soils, whichever is deeper. The soils exposed at the base of this recommended over-excavation should be examined by the geotechnical engineer to document that the soils are suitable for building support. Prior to placement of fill, the exposed surfaces approved for fill placement should be scarified to an Geotechnical Engineering Exploration and Analysis Proposed Public Storage Facility 17173 Valley Boulevard Fontana, California Project No. 2G-2202002-R Page 13 _________________________________________________________________________ GILES ENGINEERING ASSOCIATES, INC. approximate depth of at least 6 to 8 inches, moisture conditioned to the recommended moisture content and then recompacted to at least 90% of the soil’s maximum dry density as determined by Modified Proctor (ASTM D 1557). A representative of the project geotechnical consultant should be present on-site during grading operations to verify proper placement and adequate compaction of subgrade and all fills. Positive drainage devices such as sloped concrete flatwork, earth swales and sheet flow gradients in landscape area, perimeter flow-through planter, and surface drain system should be designed for the site. The drainage system should drain to a suitable discharge area away from the structures. The purpose of this drainage system is to reduce water infiltration into the subgrade soils and to direct water away from buildings and site improvements. Grading plans should be reviewed by Giles to verify the validity of our recommendations and modify them, if necessary. All utility trench backfill should be placed in lifts no greater than 8 inches in thickness, moisture conditioned and then compacted in-place to a minimum relative compaction of 90 percent of the soil’s maximum dry density. A representative of the project geotechnical engineer should observe and test the backfills to document adequacy of compaction. Proofroll and Compact Subgrade Following over-excavation and lowering of site grades, where necessary, the subgrades within the proposed building pad and pavement areas should be proofrolled in the presence of the geotechnical engineer with appropriate rubber-tire mounted heavy construction equipment or a loaded truck to detect very loose/soft yielding soil which should be removed to a stable subgrade. Following proofrolling and completion of any necessary additional over-excavation, the subgrade should be scarified to a minimum depth of 6 to 8 inches, moisture conditioned or air dried as recommended, and recompacted to at least 90 percent of the Modified Proctor (ASTM D1557) maximum dry density. The upper 1 foot of the pavement subgrade should have minimum in-place density of at least 95% of the maximum dry density. Low areas and excavations may then be backfilled in lifts with suitable very low expansive (EI < 20) structural compacted fill. The selection, placement and compaction of structural fill should be performed in accordance with the project specifications. The Guide Specifications included in Appendix D (Modified Proctor) of this report are recommended to be used, at a minimum, as an aid in developing the project specifications. The floor slab subgrade may need to be recompacted prior to slab construction due to weather and equipment traffic effects on the previously compacted soil. Geotechnical Engineering Exploration and Analysis Proposed Public Storage Facility 17173 Valley Boulevard Fontana, California Project No. 2G-2202002-R Page 14 _________________________________________________________________________ GILES ENGINEERING ASSOCIATES, INC. Fill Placement Material for engineered fill should be select free of organic material, debris, and other deleterious substances, possess a very low expansive potential (EI < 20) and should not contain fragments greater than 3 inches in maximum dimension. On-site excavated soils that meet these requirements may be used to backfill the excavated building pad and pavement areas. All fill should be placed in 8-inch-thick maximum loose lifts, moisture conditioned above the soil’s optimum moisture content, and then compacted in place to at least 90 percent of the Modified Proctor maximum density, and in accordance with the enclosed “Guide Structural Fill Specifications”. The upper 12 inches of subgrade material within pavement areas should be moisture conditioned slightly above the soil’s optimum moisture content, and then compacted in place to at least 95 percent of the Modified Proctor maximum density, and in accordance with the enclosed “Guide Structural Fill Specifications”. A representative of the project geotechnical engineer should be present on-site during grading operations to verify proper placement and compaction of all fill, as well as to verify compliance with the other geotechnical recommendations presented herein. Soil Excavation All excavations must be performed in accordance with CAL-OSHA requirements, which is the responsibility of the contractor. Shallow excavations may be adequately sloped for bank stability while deeper excavations or excavations where adequate back sloping cannot be performed may require some form of external support such as shoring or bracing. Where there is sufficient space, temporary unsurcharge excavations could be sloped back at a uniform 1h:1v slope gradient in its entirety to a maximum height of 5 feet. All other excavations should be shored. If depth of the excavation adjacent to existing footings extends below the bottom of the existing footings or adjacent to property lines, slot-cutting techniques may be used, if necessary. Water should be allowed to pond on top of the excavation nor to flow towards it. The soils exposed in the cut slopes should be inspected during excavation by a representative of this office, so that modifications of the slopes can be made if any variations in the soil conditions occur. 6.3 Foundation Recommendations Upon completion of the recommended building pad preparation, the proposed structure may be supported by a shallow foundation system such as a conventional spread footing and slab-on-grade, or mat/slab, underlain by a minimum 1-foot-thick structural fill layer. Footings that will support the bearing walls and isolated columns may be designed for a maximum, net, allowable Geotechnical Engineering Exploration and Analysis Proposed Public Storage Facility 17173 Valley Boulevard Fontana, California Project No. 2G-2202002-R Page 15 _________________________________________________________________________ GILES ENGINEERING ASSOCIATES, INC. soil-bearing pressure of 4,000 pounds per square foot (psf). Structural loads supported by a mat/slab may be designed for a maximum modulus of subgrade reaction (ks) of 84 pounds per square inch per inch (psi/in.). Minimum footing and grade beam widths are recommended to be 18 and 24 inches for walls and columns, respectively, regardless of the calculated soil bearing pressure. The recommended allowable soil bearing pressure and modulus may be increased by one-third for short term wind and/or seismic loads. Reinforcing The design of the foundations and the determination of the steel reinforcing should be performed by the project structural engineer. Lateral Load Resistance Lateral load resistance will be developed by a combination of friction acting at the base of foundations and slabs and the passive earth pressure developed by footings below grade. Passive pressure and friction may be used in combination, without reduction, in determining the total resistance to lateral loads. A coefficient of friction of 0.40 may be used with dead load forces for footings placed on newly placed compacted fill soil. An allowable passive earth pressure of 300 psf per foot of footing depth (pcf) below the lowest adjacent grade may be used for the sides of footings placed against newly placed compacted fill. The maximum recommended allowable passive pressure is 3,000 psf. Bearing Material Criteria Structural fill placed and compacted under engineering-controlled conditions continuous from suitable native soils are considered to be suitable for direct foundation support. Soil suitable to serve as the subgrade for placement of structural fill within the zone of foundation influence should exhibit at least a loose relative density (average N value of at least 12) for non-cohesive soils or possess a stiff consistency (average unconfined compressive strength of 2.0 tsf) for cohesive soils for the recommended allowable soil bearing pressure. For design and construction estimating purposes, suitable bearing soils are expected to be encountered at the recommended over-excavation depths, following grading. Field testing by the geotechnical engineer within the foundation bearing soils is recommended to document that the foundation support soils possess the minimum strength parameters noted above. Testing may consist of Dynamic Cone Penetration tests (per ASTM Special Publication 399), pocket penetrometer tests, sand cone test, nuclear gauge test, or other tests as deemed suitable by the Geotechnical Engineer. If unsuitable bearing soils are encountered, they should be recompacted in-place, if Geotechnical Engineering Exploration and Analysis Proposed Public Storage Facility 17173 Valley Boulevard Fontana, California Project No. 2G-2202002-R Page 16 _________________________________________________________________________ GILES ENGINEERING ASSOCIATES, INC. feasible, or excavated to a suitable bearing soil subgrade and to a lateral extent as defined by Item No. 3 of the enclosed Guide Specifications, with the excavation backfilled with structural compacted fill to develop a uniform bearing grade. Foundation Embedment The California Building Code (CBC) requires a minimum 12-inch foundation embedment depth. However, it is recommended that exterior foundations extend at least 18 inches below the adjacent exterior grade for bearing capacity and to provide greater protection of the moisture sensitive bearing soils. Interior footings may be supported at nominal depth below the floor. All footings must be protected against weather and water damage during and after construction and must be supported by suitable bearing materials. Estimated Foundation Movement Post-construction total and differential settlement of a shallow foundation system designed and constructed in accordance with the recommendations provided in this report are estimated to be less than 1 and ½ inch, respectively, for static conditions. The estimated differential movement (½ inch) is estimated to occur over a clear span of 20 feet for spread footing foundations and a clear span of 40 feet for a mat foundation. 6.4 Floor Slab Recommendations Subgrade The floor slab subgrade should be prepared in accordance with the appropriate recommendations presented in the Site Development Recommendations, Section 6.2 of this report. Foundation, utility trenches and other below-slab excavations should be backfilled with structural compacted fill in accordance with the project specifications. Design (Conventional Slab-On-Grade) The floor may be designed as a conventional slab-on-grade where the floor is independent of the foundations, or as a mat/slab where the floor also serves as the foundation system. Design parameters for the mat/slab are provided in section 6.3. The ground floor of the proposed structure may be designed and constructed as a conventional slab-on-grade where the floor slab is independent of the foundation system. The at-grade floor may be designed as a “Mat on Elastic Foundation” using a Modulus of Subgrade Reaction (ks) of 175 pounds per cubic inch (pci) where the slab provides no structural support for the interior load bearing walls and/or columns. The design of the slab is recommended to be performed by the project structural engineer to ensure proper reinforcing and thickness. Geotechnical Engineering Exploration and Analysis Proposed Public Storage Facility 17173 Valley Boulevard Fontana, California Project No. 2G-2202002-R Page 17 _________________________________________________________________________ GILES ENGINEERING ASSOCIATES, INC. Conventional Slab-On-Grade and Mat/Slab The floor slab is recommended to be underlain by a 4-inch-thick layer of granular base, which is not included as a portion of the recommended structural fill layer recommended in Section 6.2 Building Pad Preparation. A 15-mil synthetic sheet should be placed below the floor slab to serve as a vapor retarder where required to protect moisture sensitive floor coverings (i.e. tile, or carpet, etc.) and control moisture through the floor slab. It is recommended that a structural engineer or architect specify the vapor retarder location with careful consideration of concrete curing and the effects of moisture. The vapor retarder is recommended to be in accordance with ASTM E 1745-97, which is entitled: Standard Specification for Plastic Water Vapor Retarders Used in Contact with Soil or Granular Fill under Concrete Slabs. If materials underlying the synthetic sheet contain sharp, angular particles, a layer of sand approximately 2 inches thick or a geotextile should be provided to protect it from puncture. An additional 2-inch-thick layer of sand may be needed between the slab and the vapor retarder to promote proper curing. Proper curing techniques are recommended to reduce the potential for shrinkage cracking and slab curling. Estimated Slab-on-Grade Settlement With proper site preparation and construction monitoring, the total and differential settlements of a conventional slab-on-grade, are estimated to be less than ½ and ¼ inches across a 20-foot span, respectively. 6.5 Elevator Pit Recommendations The proposed 3-story building is assumed to include elevator pits within the building. Additional details regarding the elevator pit were not provided; however, it is assumed that the pit will be a reinforced cast-in-place concrete structure. It is also assumed that elevator-pit floor will be 4 feet below the first-floor level. Giles must be notified if elevator-pit floor will be deeper; this report might need to be revised. Geotechnical-related for an elevator-pit that is 4 feet deep are provided below. The elevator-pit must be designed based on the appropriate codes. This report assumes that floor of the elevator-pit will be at or above El. 1111 (assuming FFE 1115). Therefore, it is assumed that the floor of the elevator-pit will be above the water table and will be supported by suitable bearing native soils or compacted fill material. The elevator-pit foundation is recommended to be designed based on the Foundation Recommendations Section of this report. It is assumed that elevator-pit walls will be cast near existing soil, and that engineered fill between the walls and surrounding soil will consist of properly compacted soils approved by the geotechnical engineer. Based on that assumption, elevator-pit walls are recommended to be designed for an equivalent “at-rest” fluid pressure of 50 psf/foot. Horizontal pressures caused by surface and subsurface surcharge loads (such as first-floor loads and traffic loads within 10 feet measured horizontally) must be added to the “at-rest” fluid pressure. Giles could provide supplemental recommendations regarding surface and subsurface surcharge loads on a case-by-case basis, but would require specific structural loads. Geotechnical Engineering Exploration and Analysis Proposed Public Storage Facility 17173 Valley Boulevard Fontana, California Project No. 2G-2202002-R Page 18 _________________________________________________________________________ GILES ENGINEERING ASSOCIATES, INC. 6.6 New Pavement The following recommendations for the new pavement (if needed) are intended for vehicular traffic associated with the new development within the subject property. New Pavement Subgrades Following completion of the recommended subgrade preparation procedures, the subgrade in areas of new pavement construction is expected to consist of existing on-site soil that exhibit a very low expansion potential and based on a USCS designation of SM. An R-value of 30 has been assumed in the preparation of the pavement design. It should, however, be recognized that the City of Fontana may require a specific R-value test to verify the use of the following design. It is recommended that this testing, if required, be conducted following completion of rough grading in the proposed pavement areas so that the R-value test results are indicative of the actual pavement subgrade soils. Alternatively, a minimum code pavement section may be required if a specific R-value test is not performed. To use this R-value, all fill added to the pavement subgrade must have pavement support characteristics at least equivalent to the existing soils and must be placed and compacted in accordance with the project specifications. Asphalt Pavements The following table presents recommended thicknesses for a new flexible pavement structure consisting of asphaltic concrete over a granular base, along with the appropriate CALTRANS specifications for proper materials and placement procedures. An alternate pavement section has been provided for use in parking stall areas due to the anticipated lower traffic intensity in these areas. However, care must be used so that truck traffic is excluded from areas where the thinner pavement section is used, since premature pavement distress may occur. In the event that heavy vehicle traffic cannot be excluded from the specific areas, the pavement section recommended for drive lanes should be used throughout the parking lot. Geotechnical Engineering Exploration and Analysis Proposed Public Storage Facility 17173 Valley Boulevard Fontana, California Project No. 2G-2202002-R Page 19 _________________________________________________________________________ GILES ENGINEERING ASSOCIATES, INC. Pavement recommendations are based upon CALTRANS design parameters for a twenty-year design period and assume proper drainage and construction monitoring. It is, therefore, recommended that the geotechnical engineer monitors and tests subgrade preparation, and that the subgrade be evaluated immediately before pavement construction. Portland Concrete Pavements Portland Cement Concrete pavements are recommended in areas where traffic is concentrated such as the entrance/exit aprons as well as areas subjected to heavy loads such as the trash enclosure loading zone. The preparation of the subgrade soils within concrete pavement areas should be performed as previously described in this report. Portland Cement Concrete pavements in high stress areas are recommended to be at least 6 inches thick containing No. 3 bars at 18-inch on-center both ways placed at mid-height. The pavement should be constructed in accordance with Section 40 of the CALTRANS Standard Specifications. A minimum 4-inch-thick layer of base course (CALTRANS Class 2) is recommended below the concrete pavement. This base course should be compacted to at least 95% of the material’s maximum dry density. The maximum joint spacing within all of the Portland Cement Concrete pavements is recommended to be 15 feet to control shrinkage cracking. Load transfer reinforcing is recommended at construction joints perpendicular to traffic flow if construction joints are not properly keyed. In this event, ¾-inch diameter smooth dowel bars, 18 inches in length placed at 12 inches on-center are recommended where joints are perpendicular to the anticipated traffic flow. Expansion joints are recommended only where the pavement abuts fixed objects such as light standard foundations. Tie bars are recommended at the first joint within the perimeter of the concrete pavement area. Tie bars are recommended to be No. 4 bars at 42-inch on-center spacings and at least 48 inches in length. ASPHALT PAVEMENTS Materials Thickness (inches) CALTRANS Specifications Parking Stalls (TI=4.5) Drive Lanes (TI=5.5) Asphaltic Concrete Surface Course (b) 1 1 Section 39, (a) Asphaltic Concrete Binder Course (b) 2 2 Section 39, (a) Crushed Aggregate Base Course 5 7 Section 26, Class 2 (R-value at least 78) NOTES: (a) Compaction to density between 95 and 100 percent of the 50-Blow Marshall Density (b) The surface and binder course may be combined as a single layer placed in one lift if similar materials are utilized. Geotechnical Engineering Exploration and Analysis Proposed Public Storage Facility 17173 Valley Boulevard Fontana, California Project No. 2G-2202002-R Page 20 _________________________________________________________________________ GILES ENGINEERING ASSOCIATES, INC. General Considerations Pavement recommendations assume proper drainage and construction monitoring and are based on traffic loads as indicated previously. Pavement designs are based on either PCA or CALTRANS design parameters for twenty (20) year design period. However, these designs are also based on a routine pavement maintenance program and significant asphalt concrete pavement rehabilitation after about 8 to 10 years, in order to obtain a reasonable pavement service life. 6.7 Recommended Construction Materials Testing Services The report was prepared assuming that Giles will perform Construction Materials Testing (CMT) services during construction of the proposed development. In general, CMT services are recommended (and expected) to at least include observation and testing of foundation and pavement support soil and other construction materials. It might be necessary for Giles to provide supplemental geotechnical recommendations based on the results of CMT services and specific details of the project not known at this time. 6.8 Basis of Report This report is based on Giles’ proposal, dated February 15, 2022, and is referenced by Giles’ proposal number 2GP-2202010. The actual services for the project varied somewhat from those described in the proposal because of the conditions that were encountered while performing the services and in consideration of the proposed project. This report is strictly based on the project description given earlier in this report. No structural design plans were available at the time this report was prepared. Giles must be notified if any parts of the project description or our assumptions are not accurate so that this report can be amended, if needed. This report is based on the assumption that the development will be designed and constructed according to the codes that govern construction at the site. The conclusions and recommendations in this report are based on estimated subsurface conditions as shown on the Records of Subsurface Exploration. Giles must be notified if the subsurface conditions that are encountered during construction of the proposed development differ from those shown on the Records of Subsurface Exploration because this report will likely need to be revised. General comments and limitations of this report are given in the appendix. © Giles Engineering Associates, Inc. 2022 APPENDIX A FIGURES AND TEST BORING LOGS The Test Boring Location Plan contained herein was prepared based upon information supplied by Giles’ client, or others, along with Giles’ field measurements and observations. The diagram is presented for conceptual purposes only and is intended to assist the reader in report interpretation. The Test Boring Logs and related information enclosed herein depict the subsurface (soil and water) conditions encountered at the specific boring locations on the date that the exploration was performed. Subsurface conditions may differ between boring locations and within areas of the site that were not explored with test borings. The subsurface conditions may also change at the boring locations over the passage of time. INTERSTATE 10 (SAN BERNARDINO FRWY.) DRAINAGE DITCH EXISTING PUBLIC STORAGE FACILITY (17173 VALLEY BLVD.) EA S E M E N T EA S E M E N T E A S E M E N T EA S E M E N T PROPOSED BUILDING INFILTRATION BASIN PROPOSED INFILTRATION BASIN PROPOSED NOTES: 1.) TEST BORING LOCATIONS ARE APPROXIMATE. 2.) PROPOSED FEATURES ARE APPROXIMATE BASED ON THE PREPARED BY DRC ENGINEERING, INC. "CONCEPTUAL GRADING PLAN", DATED 2-24-2022, 0 20'40' APPROXIMATE SCALE 1965 N. MAIN STREET ORANGE, CA 92865 (714)279-0817 DATE CAD No. 03-29-22 2G-2202002 TEST BORING LOCATION PLAN PROJECT NO.: FONTANA, CALIFORNIA DESIGNED WML PROPOSED EXPANSION FIGURE 1 DRAWN SCALE approx. 1"=40' REVISED 2g2202002-blp2 -- 17173 VALLEY BOULEVARD ILES NGINEERING SSOCIATES, INC. www.gilesengr.com PUBLIC STORAGE FACILITY LEGEND: GEOTECHNICAL TEST BORING PROPERTY LINE LIGHT POLE PERCOLATION TEST BORING GEOTECHNICAL TEST BORING / Approximately 2.5 inches of asphaltic concrete over 7 inches of aggregate base Brown, Silty Sand, fine grained - Moist (Fill) Brown, Silty Sand, fine to medium grained - Moist (Possible Fill) Brown, Silty Sand, fine to medium grained, some Gravel - Moist (Native) Gray, poorly-graded Sand, trace Silt, fine tomedium graned, Cobble fragments, some Gravel - Moist Gray, poorly-graded Sand, fine to medium grained, little Gravel - Moist Boring Terminated at about 16.5 feet (EL. 1098.6') 1-SS 2-CS 3-SS 4-SS 5-SS Dd=102.5 pcf P200=6% 14 48 37 51 34 3 3 4 3 3 Water Observation Data GILES ENGINEERING ASSOCIATES, INC. Remarks: TEST BORING LOGB-1 1115.1 feet 03/04/22 De p t h ( f t ) 5 10 15 El e v a t i o n 1110 1105 1100 MATERIAL DESCRIPTION Sa m p l e No . & T y p e CS = California Split SpoonSS = Standard Penetration TestDrilling Equpment: Hollow-stem auger, 8-inch diameter Elevations based on ALTA Survey prepared by DRC Engineering, Inc.,dated February 28, 2019. PROJECT NO: 2G-2202002 PROPOSED PUBLIC STORAGE FACILITY Changes in strata indicated by the lines are approximate boundary between soil types. The actual transition may be gradual and may vary considerably between test borings. Location of test boringis shown on the Boring Location Plan. BORING NO. & LOCATION: Water Level At End of Drilling: Water Level After Drilling: FIELD REP: NOTES F. NOLPHO N 17173 VALLEY BOULEVARD FONTANA, CA Qu (tsf) Qp (tsf) Qs (tsf) W (%)PID SURFACE ELEVATION: COMPLETION DATE: Water Encountered During Drilling: None Cave Depth At End of Drilling: Cave Depth After Drilling:GI L E S L O G R E P O R T 2 G - 2 2 0 2 0 0 2 . G P J G I L E S . G D T 3 / 2 9 / 2 2 Dirt surface Brown, Silty Sand, fine grained, some Gravel - Moist (Fill) Brown, Sand, little Silt, fine grained - Moist (Possible Fill) Brown, Silty Sand, fine to medium grained, some Clay - Moist (Native) Brown, poorly-graded Sand with Silt, fine tomedium grained, few Gravel - Moist Brown, poorly-graded Sand, fine to medium grained, some Gravel, some Silt - Moist Less Silt, some Cobble fragments More Gravel and Cobble fragments, trace Clay Grayish Brown, Silty Sand, fine to medium grained, some Gravel, few Cobble fragments, trace Clay - Moist Boring Terminated at about 26.5 feet (EL.1090') 1-SS 2-SS 3-SS 4-SS 5-SS 6-SS 7-SS P200=14% 11 16 24 33 76 27 5 12 5 5 3 3 6 Water Observation Data GILES ENGINEERING ASSOCIATES, INC. Remarks: TEST BORING LOGB-2 1116.5 feet 03/04/22 De p t h ( f t ) 5 10 15 20 25 El e v a t i o n 1115 1110 1105 1100 1095 1090 MATERIAL DESCRIPTION Sa m p l e No . & T y p e SS = Standard Penetration Test PROJECT NO: 2G-2202002 PROPOSED PUBLIC STORAGE FACILITY Changes in strata indicated by the lines are approximate boundary between soil types. The actual transition may be gradual and may vary considerably between test borings. Location of test boringis shown on the Boring Location Plan. BORING NO. & LOCATION: Water Level At End of Drilling: Water Level After Drilling: FIELD REP: NOTES F. NOLPHO N 17173 VALLEY BOULEVARD FONTANA, CA Qu (tsf) Qp (tsf) Qs (tsf) W (%)PID SURFACE ELEVATION: COMPLETION DATE: Water Encountered During Drilling: None Cave Depth At End of Drilling: Cave Depth After Drilling:GI L E S L O G R E P O R T 2 G - 2 2 0 2 0 0 2 . G P J G I L E S . G D T 3 / 2 9 / 2 2 Approximately 2.5 inches of asphaltic concrete over 7 inches of aggregate base Brown, Silty Sand, fine to medium grained - Moist (Fill) Grayish Brown, poorly-graded Sand with Silt, fine to medium grained, some Gravel - Moist(Native) Grayish Brown, poorly-graded Sand, fine tomedium grained, some Silt, some Gravel - Moist Gray, Silty Gravel with fine to medium Sand, pieces of Cobble - Damp Gray, poorly-graded Sand, fine to medium grained, some Gravel - Damp Boring Terminated at about 21.5 feet (EL. 1091.4') 1-SS 2-CS 3-SS 4-CS 5-SS 6-SS Dd=120.8 pcf Dd=123.1 pcf 16 44 30 50/5" 50/4" 75 4 3 4 4 2 3 Water Observation Data GILES ENGINEERING ASSOCIATES, INC. Remarks: TEST BORING LOGB-3 1112.9 feet 03/04/22 De p t h ( f t ) 5 10 15 20 El e v a t i o n 1110 1105 1100 1095 MATERIAL DESCRIPTION Sa m p l e No . & T y p e CS = California Split Spoon SS = Standard Penetration Test PROJECT NO: 2G-2202002 PROPOSED PUBLIC STORAGE FACILITY Changes in strata indicated by the lines are approximate boundary between soil types. The actual transition may be gradual and may vary considerably between test borings. Location of test boringis shown on the Boring Location Plan. BORING NO. & LOCATION: Water Level At End of Drilling: Water Level After Drilling: FIELD REP: NOTES F. NOLPHO N 17173 VALLEY BOULEVARD FONTANA, CA Qu (tsf) Qp (tsf) Qs (tsf) W (%)PID SURFACE ELEVATION: COMPLETION DATE: Water Encountered During Drilling: None Cave Depth At End of Drilling: Cave Depth After Drilling:GI L E S L O G R E P O R T 2 G - 2 2 0 2 0 0 2 . G P J G I L E S . G D T 3 / 2 9 / 2 2 Approximately 2 inches of asphaltic concrete over 4 inches of aggregate base Brown, Silty Sand, fine to medium grained - Moist (Fill) Brown, Silty Sand, fine to medium grained, trace Gravel - Moist (Native) Trace Clay Gray, poorly-graded Sand with Silt, fine tomedium grained, Cobble fragments, some Gravel - Moist Gray poorly-graded Sand, fine to medium grained, some Silt, some Gravel - Moist Boring Terminated at about 16.5 feet (EL. 1095.8') 1-SS 2-SS 3-SS 4-SS 5-SS 24 18 40 25 53 4 7 3 4 3 Water Observation Data GILES ENGINEERING ASSOCIATES, INC. Remarks: TEST BORING LOGB-4 1112.3 feet 03/04/22 De p t h ( f t ) 5 10 15 El e v a t i o n 1110 1105 1100 MATERIAL DESCRIPTION Sa m p l e No . & T y p e SS = Standard Penetration Test PROJECT NO: 2G-2202002 PROPOSED PUBLIC STORAGE FACILITY Changes in strata indicated by the lines are approximate boundary between soil types. The actual transition may be gradual and may vary considerably between test borings. Location of test boringis shown on the Boring Location Plan. BORING NO. & LOCATION: Water Level At End of Drilling: Water Level After Drilling: FIELD REP: NOTES F. NOLPHO N 17173 VALLEY BOULEVARD FONTANA, CA Qu (tsf) Qp (tsf) Qs (tsf) W (%)PID SURFACE ELEVATION: COMPLETION DATE: Water Encountered During Drilling: None Cave Depth At End of Drilling: Cave Depth After Drilling:GI L E S L O G R E P O R T 2 G - 2 2 0 2 0 0 2 . G P J G I L E S . G D T 3 / 2 9 / 2 2 Approximately 3 inches of asphaltic concrete over 4 inches of aggregate base Brown, Silty Sand, fine to medium grained, some Gravel - Moist (Fill) Brown, Silty Sand, fine to medium grained, Cobble fragmentts, some Gravel - Moist(Native) Gray, poorly-graded Sand, fine to medium grained, Cobble fragments, some fine Gravel- Moist Some Silt Abundant Gravel Refusal at 22 feet Boring Terminated at about 22 feet (EL. 1092.5') 1-SS 2-SS 3-CS 4-SS 5-SS 6-SS Dd=106.2 pcf 18 25 54/6" 65 77 50/4" 5 5 4 4 3 3 Water Observation Data GILES ENGINEERING ASSOCIATES, INC. Remarks: TEST BORING LOGB-5 1114.5 feet 03/04/22 De p t h ( f t ) 5 10 15 20 El e v a t i o n 1110 1105 1100 1095 MATERIAL DESCRIPTION Sa m p l e No . & T y p e CS = California Split Spoon SS = Standard Penetration Test PROJECT NO: 2G-2202002 PROPOSED PUBLIC STORAGE FACILITY Changes in strata indicated by the lines are approximate boundary between soil types. The actual transition may be gradual and may vary considerably between test borings. Location of test boringis shown on the Boring Location Plan. BORING NO. & LOCATION: Water Level At End of Drilling: Water Level After Drilling: FIELD REP: NOTES F. NOLPHO N 17173 VALLEY BOULEVARD FONTANA, CA Qu (tsf) Qp (tsf) Qs (tsf) W (%)PID SURFACE ELEVATION: COMPLETION DATE: Water Encountered During Drilling: None Cave Depth At End of Drilling: Cave Depth After Drilling:GI L E S L O G R E P O R T 2 G - 2 2 0 2 0 0 2 . G P J G I L E S . G D T 3 / 2 9 / 2 2 Approximately 2 inches of asphaltic concrete, no base Brown, Silty Sand, fine grained - Moist (Fill) Brown, poorly-graded Sand little Silt, finegrained, trace Gravel - Moist (Possible Fill) Brown, poorly-graded Sand, trace Silt, fine to medium grained, some Gravel - Moist (Native) Boring Terminated at about 6.5 feet (EL.1109.9') 1-SS 2-SS P200=11% P200=7% 7 18 6 6 Water Observation Data GILES ENGINEERING ASSOCIATES, INC. Remarks: TEST BORING LOGB-6 1116.4 feet 03/04/22 De p t h ( f t ) 2.5 5.0 El e v a t i o n 1115.0 1112.5 1110.0 MATERIAL DESCRIPTION Sa m p l e No . & T y p e SS = Standard Penetration Test PROJECT NO: 2G-2202002 PROPOSED PUBLIC STORAGE FACILITY Changes in strata indicated by the lines are approximate boundary between soil types. The actual transition may be gradual and may vary considerably between test borings. Location of test boringis shown on the Boring Location Plan. BORING NO. & LOCATION: Water Level At End of Drilling: Water Level After Drilling: FIELD REP: NOTES F. NOLPHO N 17173 VALLEY BOULEVARD FONTANA, CA Qu (tsf) Qp (tsf) Qs (tsf) W (%)PID SURFACE ELEVATION: COMPLETION DATE: Water Encountered During Drilling: None Cave Depth At End of Drilling: Cave Depth After Drilling:GI L E S L O G R E P O R T 2 G - 2 2 0 2 0 0 2 . G P J G I L E S . G D T 3 / 2 9 / 2 2 Approximately 5 inches of asphaltic concrete over 7 inches of aggregate base Brown, poorly-graded Sand, fine grained, trace Gravel - Moist (Fill) Brownish-Gray, poorly-graded Sand, fine to medum grained, some coarse, trace Gravel, some Silt - Moist (Native) Boring Terminated at about 6.5 feet (EL.1105.7') 1-SS 2-SS P200=4%11 27 4 3 Water Observation Data GILES ENGINEERING ASSOCIATES, INC. Remarks: TEST BORING LOGB-7 1112.2 feet 03/04/22 De p t h ( f t ) 2.5 5.0 El e v a t i o n 1110.0 1107.5 MATERIAL DESCRIPTION Sa m p l e No . & T y p e SS = Standard Penetration Test PROJECT NO: 2G-2202002 PROPOSED PUBLIC STORAGE FACILITY Changes in strata indicated by the lines are approximate boundary between soil types. The actual transition may be gradual and may vary considerably between test borings. Location of test boringis shown on the Boring Location Plan. BORING NO. & LOCATION: Water Level At End of Drilling: Water Level After Drilling: FIELD REP: NOTES F. NOLPHO N 17173 VALLEY BOULEVARD FONTANA, CA Qu (tsf) Qp (tsf) Qs (tsf) W (%)PID SURFACE ELEVATION: COMPLETION DATE: Water Encountered During Drilling: None Cave Depth At End of Drilling: Cave Depth After Drilling:GI L E S L O G R E P O R T 2 G - 2 2 0 2 0 0 2 . G P J G I L E S . G D T 3 / 2 9 / 2 2 APPENDIX B FIELD PROCEDURES The field operations were conducted in general accordance with the procedures recommended by the American Society for Testing and Materials (ASTM) designation D 420 entitled “Standard Guide for Sampling Rock and Rock” and/or other relevant specifications. Soil samples were preserved and transported to Giles’ laboratory in general accordance with the procedures recommended by ASTM designation D 4220 entitled “Standard Practice for Preserving and Transporting Soil Samples.” Brief descriptions of the sampling, testing and field procedures commonly performed by Giles are provided herein. GILES ENGINEERING ASSOCIATES, INC. GENERAL FIELD PROCEDURES Test Boring Elevations The ground surface elevations reported on the Test Boring Logs are referenced to the assumed benchmark shown on the Boring Location Plan (Figure 1). Unless otherwise noted, the elevations were determined with a conventional hand-level and are accurate to within about 1 foot. Test Boring Locations The test borings were located on-site based on the existing site features and/or apparent property lines. Dimensions illustrating the approximate boring locations are reported on the Boring Location Plan (Figure 1). Water Level Measurement The water levels reported on the Test Boring Logs represent the depth of “free” water encountered during drilling and/or after the drilling tools were removed from the borehole. Water levels measured within a granular (sand and gravel) soil profile are typically indicative of the water table elevation. It is usually not possible to accurately identify the water table elevation with cohesive (clayey) soils, since the rate of seepage is slow. The water table elevation within cohesive soils must therefore be determined over a period of time with groundwater observation wells. It must be recognized that the water table may fluctuate seasonally and during periods of heavy precipitation. Depending on the subsurface conditions, water may also become perched above the water table, especially during wet periods. Borehole Backfilling Procedures Each borehole was backfilled upon completion of the field operations. If potential contamination was encountered, and/or if required by state or local regulations, boreholes were backfilled with an “impervious” material (such as bentonite slurry). Borings that penetrated pavements, sidewalks, etc. were “capped” with Portland Cement concrete, asphaltic concrete, or a similar surface material. It must, however, be recognized that the backfill material may settle, and the surface cap may subside, over a period of time. Further backfilling and/or re-surfacing by Giles’ client or the property owner may be required. GILES ENGINEERING ASSOCIATES, INC. FIELD SAMPLING AND TESTING PROCEDURES Auger Sampling (AU) Soil samples are removed from the auger flights as an auger is withdrawn above the ground surface. Such samples are used to determine general soil types and identify approximate soil stratifications. Auger samples are highly disturbed and are therefore not typically used for geotechnical strength testing. Split-Barrel Sampling (SS) – (ASTM D-1586) A split-barrel sampler with a 2-inch outside diameter is driven into the subsoil with a 140- pound hammer free-falling a vertical distance of 30 inches. The summation of hammer- blows required to drive the sampler the final 12-inches of an 18-inch sample interval is defined as the “Standard Penetration Resistance” or N-value is an index of the relative density of granular soils and the comparative consistency of cohesive soils. A soil sample is collected from each SPT interval. Shelby Tube Sampling (ST) – (ASTM D-1587) A relatively undisturbed soil sample is collected by hydraulically advancing a thin-walled Shelby Tube sampler into a soil mass. Shelby Tubes have a sharp cutting edge and are commonly 2 to 5 inches in diameter. Bulk Sample (BS) A relatively large volume of soils is collected with a shovel or other manually-operated tool. The sample is typically transported to Giles’ materials laboratory in a sealed bag or bucket. Dynamic Cone Penetration Test (DC) – (ASTM STP 399) This test is conducted by driving a 1.5-inch-diameter cone into the subsoil using a 15- pound steel ring (hammer), free-falling a vertical distance of 20 inches. The number of hammer-blows required to drive the cone 1¾ inches is an indication of the soil strength and density, and is defined as “N”. The Dynamic Cone Penetration test is commonly conducted in hand auger borings, test pits and within excavated trenches. - Continued - GILES ENGINEERING ASSOCIATES, INC. Ring-Lined Barrel Sampling – (ASTM D 3550) In this procedure, a ring-lined barrel sampler is used to collect soil samples for classification and laboratory testing. This method provides samples that fit directly into laboratory test instruments without additional handling/disturbance. Sampling and Testing Procedures The field testing and sampling operations were conducted in general accordance with the procedures recommended by the American Society for Testing and Materials (ASTM) and/or other relevant specifications. Results of the field testing (i.e. N-values) are reported on the Test Boring Logs. Explanations of the terms and symbols shown on the logs are provided on the appendix enclosure entitled “General Notes”. APPENDIX C LABORATORY TESTING AND CLASSIFICATION The laboratory testing was conducted under the supervision of a geotechnical engineer in accordance with the procedures recommended by the American Society for Testing and Materials (ASTM) and/or other relevant specifications. Brief descriptions of laboratory tests commonly performed by Giles are provided herein. GILES ENGINEERING ASSOCIATES, INC. LABORATORY TESTING AND CLASSIFICATION Photoionization Detector (PID) In this procedure, soil samples are “scanned” in Giles’ analytical laboratory using a Photoionization Detector (PID). The instrument is equipped with an 11.7 eV lamp calibrated to a Benzene Standard and is capable of detecting a minute concentration of certain Volatile Organic Compound (VOC) vapors, such as those commonly associated with petroleum products and some solvents. Results of the PID analysis are expressed in HNu (manufacturer’s) units rather than actual concentration. Moisture Content (w) (ASTM D 2216) Moisture content is defined as the ratio of the weight of water contained within a soil sample to the weight of the dry solids within the sample. Moisture content is expressed as a percentage. Unconfined Compressive Strength (qu) (ASTM D 2166) An axial load is applied at a uniform rate to a cylindrical soil sample. The unconfined compressive strength is the maximum stress obtained or the stress when 15% axial strain is reached, whichever occurs first. Calibrated Penetrometer Resistance (qp) The small, cylindrical tip of a hand-held penetrometer is pressed into a soil sample to a prescribed depth to measure the soils capacity to resist penetration. This test is used to evaluate unconfined compressive strength. Vane-Shear Strength (qs) The blades of a vane are inserted into the flat surface of a soil sample and the vane is rotated until failure occurs. The maximum shear resistance measured immediately prior to failure is taken as the vane-shear strength. Loss-on-Ignition (ASTM D 2974; Method C) The Loss-on-Ignition (L.O.I.) test is used to determine the organic content of a soil sample. The procedure is conducted by heating a dry soil sample to 440°C in order to burn-off or “ash” organic matter present within the sample. The L.O.I. value is the ratio of the weight loss due to ignition compared to the initial weight of the dry sample. L.O.I. is expressed as a percentage. GILES ENGINEERING ASSOCIATES, INC. Particle Size Distribution (ASTB D 421, D 422, and D 1140) This test is performed to determine the distribution of specific particle sizes (diameters) within a soil sample. The distribution of coarse-grained soil particles (sand and gravel) is determined from a “sieve analysis,” which is conducted by passing the sample through a series of nested sieves. The distribution of fine-grained soil particles (silt and clay) is determined from a “hydrometer analysis” which is based on the sedimentation of particles suspended in water. Consolidation Test (ASTM D 2435) In this procedure, a series of cumulative vertical loads are applied to a small, laterally confined soil sample. During each load increment, vertical compression (consolidation) of the sample is measured over a period of time. Results of this test are used to estimate settlement and time rate of settlement. Classification of Samples Each soil sample was visually-manually classified, based on texture and plasticity, in general accordance with the Unified Soil Classification System (ASTM D-2488-75). The classifications are reported on the Test Boring Logs. Laboratory Testing The laboratory testing operations were conducted in general accordance with the procedures recommended by the American Society for Testing and Materials (ASTM) and/or other relevant specifications. Results of the laboratory tests are provided on the Test Boring Logs or other appendix enclosures. Explanation of the terms and symbols used on the logs is provided on the appendix enclosure entitled “General Notes.” GILES ENGINEERING ASSOCIATES, INC. California Bearing Ratio (CBR) Test ASTM D-1833 The CBR test is used for evaluation of a soil subgrade for pavement design. The test consists of measuring the force required for a 3-square-inch cylindrical piston to penetrate 0.1 or 0.2 inch into a compacted soil sample. The result is expressed as a percent of force required to penetrate a standard compacted crushed stone. Unless a CBR test has been specifically requested by the client, the CBR is estimated from published charts, based on soil classification and strength characteristics. A typical correlation chart is below. APPENDIX D GENERAL INFORMATION GILES ENGINEERING ASSOCIATES, INC. GENERAL COMMENTS The soil samples obtained during the subsurface exploration will be retained for a period of thirty days. If no instructions are received, they will be disposed of at that time. This report has been prepared exclusively for the client in order to aid in the evaluation of this property and to assist the architects and engineers in the design and preparation of the project plans and specifications. Copies of this report may be provided to contractor(s), with contract documents, to disclose information relative to this project. The report, however, has not been prepared to serve as the plans and specifications for actual construction without the appropriate interpretation by the project architect, structural engineer, and/or civil engineer. Reproduction and distribution of this report must be authorized by the client and Giles. This report has been based on assumed conditions/characteristics of the proposed development where specific information was not available. It is recommended that the architect, civil engineer and structural engineer along with any other design professionals involved in this project carefully review these assumptions to ensure they are consistent with the actual planned development. When discrepancies exist, they should be brought to our attention to ensure they do not affect the conclusions and recommendations provided herein. The project plans and specifications may also be submitted to Giles for review to ensure that the geotechnical related conclusions and recommendations provided herein have been correctly interpreted. The analysis of this site was based on a subsoil profile interpolated from a limited subsurface exploration. If the actual conditions encountered during construction vary from those indicated by the borings, Giles must be contacted immediately to determine if the conditions alter the recommendations contained herein. The conclusions and recommendations presented in this report have been promulgated in accordance with generally accepted professional engineering practices in the field of geotechnical engineering. No other warranty is either expressed or implied. With Dust Palliative With Bituminous Treatment GW Good: tractor, rubber-tired, steel wheel or vibratory roller 125-135 Almost none Good drainage, pervious Very stable Excellent Good Fair to poor Excellent GP Good: tractor, rubber-tired, steel wheel or vibratory roller 115-125 Almost none Good drainage, pervious Reasonably stable Excellent to good Poor to fair Poor GM Good: rubber-tired or light sheepsfoot roller 120-135 Slight Poor drainage, semipervious Reasonably stable Excellent to good Fair to poor Poor Poor to fair GC Good to fair: rubber-tired or sheepsfoot roller 115-130 Slight Poor drainage, impervious Reasonably stable Good Good to fair ** Excellent Excellent SW Good: tractor, rubber-tired or vibratory roller 110-130 Almost none Good drainage, pervious Very stable Good Fair to poor Fair to poor Good SP Good: tractor, rubber-tired or vibratory roller 100-120 Almost none Good drainage, pervious Reasonably stable when dense Good to fair Poor Poor Poor to fair SM Good: rubber-tired or sheepsfoot roller 110-125 Slight Poor drainage, impervious Reasonably stable when dense Good to fair Poor Poor Poor to fair SC Good to fair: rubber-tired or sheepsfoot roller 105-125 Slight to medium Poor drainage, impervious Reasonably stable Good to fair Fair to poor Excellent Excellent ML Good to poor: rubber-tired or sheepsfoot roller 95-120 Slight to medium Poor drainage, impervious Poor stability, high density required Fair to poor Not suitable Poor Poor CL Good to fair: sheepsfoot or rubber- tired roller 95-120 Medium No drainage, impervious Good stability Fair to poor Not suitable Poor Poor OL Fair to poor: sheepsfoot or rubber- tired roller 80-100 Medium to high Poor drainage, impervious Unstable, should not be used Poor Not suitable Not suitable Not suitable MH Fair to poor: sheepsfoot or rubber- tired roller 70-95 High Poor drainage, impervious Poor stability, should not be used Poor Not suitable Very poor Not suitable CH Fair to poor: sheepsfoot roller 80-105 Very high No drainage, impervious Fair stability, may soften on expansion Poor to very poor Not suitable Very poor Not suitable OH Fair to poor: sheepsfoot roller 65-100 High No drainage, impervious Unstable, should not be used Very poor Not suitable Not suitable Not suitable Pt Not suitable Very high Fair to poor drainage Should not be used Not suitable Not suitable Not suitable Not suitable * "The Unified Classification: Appendix A - Characteristics of Soil, Groups Pertaining to Roads and Airfields, and Appendix B - Characteristics of Soil Groups Pertaining to Embankments and Foundations," Technical Memorandum 357, U.S. Waterways Ixperiment Station, Vicksburg, 1953. ** Not suitable if subject to frost. GILES ENGINEERING ASSOCIATES, INC. CHARACTERISTICS AND RATINGS OF UNIFIED SOIL SYSTEM CLASSES FOR SOIL CONSTRUCTION * Value as Temporary Pavement Class Compaction Characteristics Max. Dry Density Standard Proctor (pcf) Compressibility and Expansion Drainage and Permeability Value as an Embankment Material Value as Subgrade When Not Subject to Frost Value as Base Course Giles Engineering Associates, Inc. UNIFIED SOIL CLASSIFICATION SYSTEM (ASTM D-2487) Major Divisions Group Symbols Typical Names Laboratory Classifi cation Criteria Co a r s e - g r a i n e d s o i l s (m o r e t h a n h a l f o f m a t e r i a l i s l a r g e r t h a n N o . 2 0 0 s i e v e s i z e ) Gr a v e l s (M o r e t h a n h a l f o f c o a r s e f r a c t i o n i s l a r g e r th a n N o . 4 s i e v e s i z e ) Cl e a n g r a v e l s (l i t t l e o r n o fi n e s ) GW Well-graded gravels, gravel-sand mixtures, little or no fi nes De t e r m i n e p e r c e n t a g e s o f s a n d a n d g r a v e l f r o m g r a i n - s i z e c u r v e . De t e r m i n e p e r c e n t a g e s o f s a n d a n d g r a v e l f r o m g r a i n - s i z e c u r v e . De p e n d i n g o n p e r c e n t a g e o f f i n e s ( f r a c t i o n s m a l l e r t h a n N o . 2 0 0 s i e v e s i z e ) , c o a r s e - De p e n d i n g o n p e r c e n t a g e o f f i n e s ( f r a c t i o n s m a l l e r t h a n N o . 2 0 0 s i e v e s i z e ) , c o a r s e - De p e n d i n g o n p e r c e n t a g e o f f i n e s ( f r a c t i o n s m a l l e r t h a n N o . 2 0 0 s i e v e s i z e ) , c o a r s e - De p e n d i n g o n p e r c e n t a g e o f f i n e s ( f r a c t i o n s m a l l e r t h a n N o . 2 0 0 s i e v e s i z e ) , c o a r s e - De p e n d i n g o n p e r c e n t a g e o f f i n e s ( f r a c t i o n s m a l l e r t h a n N o . 2 0 0 s i e v e s i z e ) , c o a r s e - gr a i n e d s o i l s a r e c l a s s i f i e d a s f o l l o w s : L e s s t h a n 5 p e r c e n t : G W , G P , S W , S P L e s s t h a n 5 p e r c e n t : G W , G P , S W , S P L e s s t h a n 5 p e r c e n t : G W , G P , S W , S P L e s s t h a n 5 p e r c e n t : G W , G P , S W , S P M o r e t h a n 1 2 p e r c e n t : G M , G C , S M , S C M o r e t h a n 1 2 p e r c e n t : G M , G C , S M , S C M o r e t h a n 1 2 p e r c e n t : G M , G C , S M , S C M o r e t h a n 1 2 p e r c e n t : G M , G C , S M , S C 5 t o 1 2 p e r c e n t : 5 t o 1 2 p e r c e n t : Bo r d e r l i n e c a s e s r e q u i r i n g d u a l s y m b o l s b Cu = greater than 4; Cc = between 1 and 3 GP Poorly graded gravels, gravel-sand mixtrues, little or no fi nes Not meeting all gradation requirements for GW Gr a v e l s w i t h f i n e s (a p p r e c i a b l e a m o u n t o f fi n e s ) GMa d Silty gravels, gravel- sand-silt mixtures Atterberg limits below “A” line or P.I. less than 4 Limits plotting within shaded area, above “A” line with P.I. between 4 and 7 are borderline cases requiring use of dual symbols u GC Clayey gravels, gravel- sand-clay mixtures Atterberg limits above “A” line or P.I. greater than 7 Sa n d s (M o r e t h a n h a l f o f c o a r s e f r a c t i o n i s sm a l l e r t h a n N o . 4 s i e v e s i z e ) Cl e a n s a n d s (L i t t l e o r n o fi n e s ) SW Well-graded sands, gravelly sands, little or no fi nes Cu = greater than 4; Cc = between 1 and 3 SP Poorly graded sands, gravelly sands, little or no fi nes Not meeting all gradation requirements for SW Sa n d s w i t h f i n e s (A p p r e c i a b l e a m o u n t of f i n e s ) SMa d Silty sands, sand-silt mixtures Atterberg limits below “A” line or P.I. less than 4 Limits plotting within shaded area, above “A” line with P.I. between 4 and 7 are borderline cases requiring use of dual symbols u SC Clayey sands, sand-clay Clayey sands, sand-clay Clayey sands, sand-clay mixtures Atterberg limits above “A” line or P.I. greater than 7 Fi n e - g r a i n e d s o i l s (M o r e t h a n h a l f m a t e r i a l i s s m a l l e r t h a n N o . 2 0 0 s i e v e s i z e ) Si l t s a n d c l a y s (L i q u i d l i m i t l e s s t h a n 5 0 ) ML Inorganic silts and very fi ne sands, rock fl our, silty or clayey fi ne sands, or clayey silts with slight plasticity CL Inorganic clays of low to medium plasticity, gravelly clays, sandy clays, silty clays OL Organic silts and organic silty clays of low plasticity Si l t s a n d c l a y s (L i q u i d l i m i t g r e a t e r t h a n 5 0 ) MH Inorganic silts, mica- ceous or diatomaceous fi ne sandy or silty soils, elastic silts CH Inorganic clays of high plasticity, fat clays OH Organic clays of medium to high plasticity, organic silts Hi g h l y or g a n i c so i l s Pt Peat and other highly organic soils D = greater than 4; CD = greater than 4; C60 = greater than 4; C60 = greater than 4; CD = greater than 4; CD = greater than 4; C 10 = greater than 4; C (D = between 1 and 3 (D = between 1 and 330 = between 1 and 330 = between 1 and 3) = between 1 and 3) = between 1 and 3 2 D = between 1 and 3D = between 1 and 3 10 x D = between 1 and 3 x D = between 1 and 3 60 = between 1 and 3 D60 = greater than 4; C60 = greater than 4; CD = greater than 4; CD = greater than 4; C 10 = greater than 4; C (D = between 1 and 3 (D = between 1 and 330 = between 1 and 330 = between 1 and 3) = between 1 and 3) = between 1 and 3 2 D = between 1 and 3D = between 1 and 3 10 x D = between 1 and 3 x D = between 1 and 3 60 = between 1 and 3 Plasticity Chart Pla s t i c i t y I n d e x 0 10 50 1000 10 50 10020900 10 50 1000 10 50 100800 10 50 10020900 10 50 100800 10 50 1000 10 50 100700 10 50 10020900 10 50 100700 10 50 1000 10 50 100600 10 50 10020900 10 50 100600 10 50 1000 10 50 100400 10 50 10020900 10 50 100400 10 50 1000 10 50 100300 10 50 10020900 10 50 100300 10 50 1000 10 50 60 40 20 30 CH OH and MHOH and MH CL ML and OLML and OL CL-ML “A” l i n e Liquid Limit a Division of GM and SM groups into subdivisions of d and u are for roads and airfi elds only. Subdivision is based on Atterberg limits, suffi x d used when L.L. is 28 or less and the P.I. is 6 or less; the suffi x u is used when L.L. is greater than 28. b Borderline classifi cations, used for soils possessing characteristics of two groups, are designated by combinations of group sympols. For example GW-GC, well-graded gravel-sand mixture with clay binder. GILES ENGINEERING ASSOCIATES, INC. GENERAL NOTES SAMPLE IDENTIFICATION All samples are visually classified in general accordance with the Unified Soil Classification System (ASTM D-2487-75 or D-2488-75) DESCRIPTIVE TERM (% BY DRY WEIGHT) PARTICLE SIZE (DIAMETER) Trace: 1-10% Boulders: 8 inch and larger Little: 11-20% Cobbles: 3 inch to 8 inch Some: 21-35% Gravel: coarse - ¾ to 3 inch And/Adjective 36-50% fine – No. 4 (4.76 mm) to ¾ inch Sand: coarse – No. 4 (4.76 mm) to No. 10 (2.0 mm) medium – No. 10 (2.0 mm) to No. 40 (0.42 mm) fine – No. 40 (0.42 mm) to No. 200 (0.074 mm) Silt: No. 200 (0.074 mm) and smaller (non-plastic) Clay: No 200 (0.074 mm) and smaller (plastic) SOIL PROPERTY SYMBOLS DRILLING AND SAMPLING SYMBOLS Dd: Dry Density (pcf) SS: Split-Spoon LL: Liquid Limit, percent ST: Shelby Tube – 3 inch O.D. (except where noted) PL: Plastic Limit, percent CS: 3 inch O.D. California Ring Sampler PI: Plasticity Index (LL-PL) DC: Dynamic Cone Penetrometer per ASTM LOI: Loss on Ignition, percent Special Technical Publication No. 399 Gs: Specific Gravity AU: Auger Sample K: Coefficient of Permeability DB: Diamond Bit w: Moisture content, percent CB: Carbide Bit qp: Calibrated Penetrometer Resistance, tsf WS: Wash Sample qs: Vane-Shear Strength, tsf RB: Rock-Roller Bit qu: Unconfined Compressive Strength, tsf BS: Bulk Sample qc: Static Cone Penetrometer Resistance Note: Depth intervals for sampling shown on Record of (correlated to Unconfined Compressive Strength, tsf) Subsurface Exploration are not indicative of sample PID: Results of vapor analysis conducted on representative recovery, but position where sampling initiated samples utilizing a Photoionization Detector calibrated to a benzene standard. Results expressed in HNU-Units. (BDL=Below Detection Limit) N: Penetration Resistance per 12 inch interval, or fraction thereof, for a standard 2 inch O.D. (1⅜ inch I.D.) split spoon sampler driven with a 140 pound weight free-falling 30 inches. Performed in general accordance with Standard Penetration Test Specifications (ASTM D- 1586). N in blows per foot equals sum of N-Values where plus sign (+) is shown. Nc: Penetration Resistance per 1¾ inches of Dynamic Cone Penetrometer. Approximately equivalent to Standard Penetration Test N-Value in blows per foot. Nr: Penetration Resistance per 12 inch interval, or fraction thereof, for California Ring Sampler driven with a 140 pound weight free-falling 30 inches per ASTM D-3550. Not equivalent to Standard Penetration Test N-Value. SOIL STRENGTH CHARACTERISTICS COHESIVE (CLAYEY) SOILS NON-COHESIVE (GRANULAR) SOILS UNCONFINED COMPARATIVE BLOWS PER COMPRESSIVE RELATIVE BLOWS PER CONSISTENCY FOOT (N) STRENGTH (TSF) DENSITY FOOT (N) Very Soft 0 - 2 0 - 0.25 Very Loose 0 - 4 Soft 3 - 4 0.25 - 0.50 Loose 5 - 10 Medium Stiff 5 – 8 0.50 - 1.00 Firm 11 - 30 Stiff 9 – 15 1.00 - 2.00 Dense 31 - 50 Very Stiff 16 – 30 2.00 - 4.00 Very Dense 51+ Hard 31+ 4.00+ DEGREE OF DEGREE OF EXPANSIVE PLASTICITY PI POTENTIAL PI None to Slight 0 - 4 Low 0 - 15 Slight 5 - 10 Medium 15 - 25 Medium 11 - 30 High 25+ High to Very High 31+ Geotechnical-Engineering Report Important Information about This Subsurface problems are a principal cause of construction delays, cost overruns, claims, and disputes. While you cannot eliminate all such risks, you can manage them. The following information is provided to help. The Geoprofessional Business Association (GBA) has prepared this advisory to help you – assumedly a client representative – interpret and apply this geotechnical-engineering report as effectively as possible. In that way, you can benefit from a lowered exposure to problems associated with subsurface conditions at project sites and development of them that, for decades, have been a principal cause of construction delays, cost overruns, claims, and disputes. If you have questions or want more information about any of the issues discussed herein, contact your GBA-member geotechnical engineer. Active engagement in GBA exposes geotechnical engineers to a wide array of risk-confrontation techniques that can be of genuine benefit for everyone involved with a construction project. Understand the Geotechnical-Engineering Services Provided for this ReportGeotechnical-engineering services typically include the planning, collection, interpretation, and analysis of exploratory data from widely spaced borings and/or test pits. Field data are combined with results from laboratory tests of soil and rock samples obtained from field exploration (if applicable), observations made during site reconnaissance, and historical information to form one or more models of the expected subsurface conditions beneath the site. Local geology and alterations of the site surface and subsurface by previous and proposed construction are also important considerations. Geotechnical engineers apply their engineering training, experience, and judgment to adapt the requirements of the prospective project to the subsurface model(s). Estimates are made of the subsurface conditions that will likely be exposed during construction as well as the expected performance of foundations and other structures being planned and/or affected by construction activities. The culmination of these geotechnical-engineering services is typically a geotechnical-engineering report providing the data obtained, a discussion of the subsurface model(s), the engineering and geologic engineering assessments and analyses made, and the recommendations developed to satisfy the given requirements of the project. These reports may be titled investigations, explorations, studies, assessments, or evaluations. Regardless of the title used, the geotechnical-engineering report is an engineering interpretation of the subsurface conditions within the context of the project and does not represent a close examination, systematic inquiry, or thorough investigation of all site and subsurface conditions. Geotechnical-Engineering Services are Performed for Specific Purposes, Persons, and Projects, and At Specific TimesGeotechnical engineers structure their services to meet the specific needs, goals, and risk management preferences of their clients. A geotechnical-engineering study conducted for a given civil engineer will not likely meet the needs of a civil-works constructor or even a different civil engineer. Because each geotechnical-engineering study is unique, each geotechnical-engineering report is unique, prepared solely for the client. Likewise, geotechnical-engineering services are performed for a specific project and purpose. For example, it is unlikely that a geotechnical- engineering study for a refrigerated warehouse will be the same as one prepared for a parking garage; and a few borings drilled during a preliminary study to evaluate site feasibility will not be adequate to develop geotechnical design recommendations for the project. Do not rely on this report if your geotechnical engineer prepared it: • for a different client; • for a different project or purpose; • for a different site (that may or may not include all or a portion of the original site); or • before important events occurred at the site or adjacent to it; e.g., man-made events like construction or environmental remediation, or natural events like floods, droughts, earthquakes, or groundwater fluctuations. Note, too, the reliability of a geotechnical-engineering report can be affected by the passage of time, because of factors like changed subsurface conditions; new or modified codes, standards, or regulations; or new techniques or tools. If you are the least bit uncertain about the continued reliability of this report, contact your geotechnical engineer before applying the recommendations in it. A minor amount of additional testing or analysis after the passage of time – if any is required at all – could prevent major problems. Read this Report in Full Costly problems have occurred because those relying on a geotechnical- engineering report did not read the report in its entirety. Do not rely on an executive summary. Do not read selective elements only. Read and refer to the report in full. You Need to Inform Your Geotechnical Engineer About Change Your geotechnical engineer considered unique, project-specific factors when developing the scope of study behind this report and developing the confirmation-dependent recommendations the report conveys. Typical changes that could erode the reliability of this report include those that affect: • the site’s size or shape; • the elevation, configuration, location, orientation, function or weight of the proposed structure and the desired performance criteria; • the composition of the design team; or • project ownership. As a general rule, always inform your geotechnical engineer of project or site changes – even minor ones – and request an assessment of their impact. The geotechnical engineer who prepared this report cannot accept responsibility or liability for problems that arise because the geotechnical engineer was not informed about developments the engineer otherwise would have considered. Most of the “Findings” Related in This Report Are Professional Opinions Before construction begins, geotechnical engineers explore a site’s subsurface using various sampling and testing procedures. Geotechnical engineers can observe actual subsurface conditions only at those specific locations where sampling and testing is performed. The data derived from that sampling and testing were reviewed by your geotechnical engineer, who then applied professional judgement to form opinions about subsurface conditions throughout the site. Actual sitewide-subsurface conditions may differ – maybe significantly – from those indicated in this report. Confront that risk by retaining your geotechnical engineer to serve on the design team through project completion to obtain informed guidance quickly, whenever needed. This Report’s Recommendations Are Confirmation-Dependent The recommendations included in this report – including any options or alternatives – are confirmation-dependent. In other words, they are not final, because the geotechnical engineer who developed them relied heavily on judgement and opinion to do so. Your geotechnical engineer can finalize the recommendations only after observing actual subsurface conditions exposed during construction. If through observation your geotechnical engineer confirms that the conditions assumed to exist actually do exist, the recommendations can be relied upon, assuming no other changes have occurred. The geotechnical engineer who prepared this report cannot assume responsibility or liability for confirmation-dependent recommendations if you fail to retain that engineer to perform construction observation. This Report Could Be Misinterpreted Other design professionals’ misinterpretation of geotechnical- engineering reports has resulted in costly problems. Confront that risk by having your geotechnical engineer serve as a continuing member of the design team, to: • confer with other design-team members; • help develop specifications; • review pertinent elements of other design professionals’ plans and specifications; and • be available whenever geotechnical-engineering guidance is needed. You should also confront the risk of constructors misinterpreting this report. Do so by retaining your geotechnical engineer to participate in prebid and preconstruction conferences and to perform construction-phase observations. Give Constructors a Complete Report and GuidanceSome owners and design professionals mistakenly believe they can shift unanticipated-subsurface-conditions liability to constructors by limiting the information they provide for bid preparation. To help prevent the costly, contentious problems this practice has caused, include the complete geotechnical-engineering report, along with any attachments or appendices, with your contract documents, but be certain to note conspicuously that you’ve included the material for information purposes only. To avoid misunderstanding, you may also want to note that “informational purposes” means constructors have no right to rely on the interpretations, opinions, conclusions, or recommendations in the report. Be certain that constructors know they may learn about specific project requirements, including options selected from the report, only from the design drawings and specifications. Remind constructors that they may perform their own studies if they want to, and be sure to allow enough time to permit them to do so. Only then might you be in a position to give constructors the information available to you, while requiring them to at least share some of the financial responsibilities stemming from unanticipated conditions. Conducting prebid and preconstruction conferences can also be valuable in this respect. Read Responsibility Provisions Closely Some client representatives, design professionals, and constructors do not realize that geotechnical engineering is far less exact than other engineering disciplines. This happens in part because soil and rock on project sites are typically heterogeneous and not manufactured materials with well-defined engineering properties like steel and concrete. That lack of understanding has nurtured unrealistic expectations that have resulted in disappointments, delays, cost overruns, claims, and disputes. To confront that risk, geotechnical engineers commonly include explanatory provisions in their reports. Sometimes labeled “limitations,” many of these provisions indicate where geotechnical engineers’ responsibilities begin and end, to help others recognize their own responsibilities and risks. Read these provisions closely. Ask questions. Your geotechnical engineer should respond fully and frankly. Geoenvironmental Concerns Are Not Covered The personnel, equipment, and techniques used to perform an environmental study – e.g., a “phase-one” or “phase-two” environmental site assessment – differ significantly from those used to perform a geotechnical-engineering study. For that reason, a geotechnical-engineering report does not usually provide environmental findings, conclusions, or recommendations; e.g., about the likelihood of encountering underground storage tanks or regulated contaminants. Unanticipated subsurface environmental problems have led to project failures. If you have not obtained your own environmental information about the project site, ask your geotechnical consultant for a recommendation on how to find environmental risk-management guidance. Obtain Professional Assistance to Deal with Moisture Infiltration and Mold While your geotechnical engineer may have addressed groundwater, water infiltration, or similar issues in this report, the engineer’s services were not designed, conducted, or intended to prevent migration of moisture – including water vapor – from the soil through building slabs and walls and into the building interior, where it can cause mold growth and material-performance deficiencies. Accordingly, proper implementation of the geotechnical engineer’s recommendations will not of itself be sufficient to prevent moisture infiltration. Confront the risk of moisture infiltration by including building-envelope or mold specialists on the design team. Geotechnical engineers are not building-envelope or mold specialists. 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