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HomeMy WebLinkAboutAppendix G - Geotechnical Investigationwww.mooretwining.com PH: 559.268.7021 FX : 559.268.7126 2527 Fresno Street Fresno, CA 93721 PRELIMINARY GEOTECHNICAL ENGINEERING INVESTIGATION PROPOSED WAREHOUSE 14970 JURUPA AVENUE FONTANA, CALIFORNIA Project Number: G21403.01 For: Duke Realty 300 Spectrum Center Drive, Suite 1450 Irvine, CA 92618 October 15, 2015 www.mooretwining.com PH: 559.268.7021 FX : 559.268.7126 2527 Fresno Street Fresno, CA 93721 October 15, 2015 G21403.01 Duke Realty 300 Spectrum Center Drive, Suite 1450 Irvine, CA 92618 Attention:Mr. Adam Schmid Subject:Preliminary Geotechnical Engineering Investigation Proposed Warehouse 14970 Jurupa Avenue Fontana, California Dear Mr. Schmid: We are pleased to submit this preliminary geotechnical engineering investigation report prepared for the proposed warehouse building planned at 14970 Jurupa Avenue in Fontana, California. The contents of this report include the purpose of the investigation, scope of services, background information,investigative procedures,our findings,evaluation,and conclusions and recommendations. This investigation should be considered preliminary and did not include a design level geotechnical study. A future geotechnical engineering investigation will be required to prepare final design level recommendations for the project. We appreciate the opportunity to be of service. If you have any questions regarding this report, or if we can be of further assistance, please contact us at your convenience. Sincerely, MOORE TWINING ASSOCIATES, INC. Geotechnical Engineering Division Dean B. Ledgerwood, CEG Certified Engineering Geologist EXECUTIVE SUMMARY Moore Twining Associates,Inc.conducted this geotechnical engineering investigation for the proposed warehouse building and associated site improvements to be located at 14970 Jurupa Avenue in Fontana, California. At the time of preparation of this report,a site plan for the planned development was not available and information regarding the proposed development was not known in detail. It is our understanding that a one story,approximate 500,000 square foot warehouse type building may be planned in the future. It is anticipated that the building will include structural steel framing with perimeter concrete tilt up wall panels. Appurtenant construction is anticipated to include asphaltic concrete pavements,Portland cement concrete pavements,underground utilities,and isolated landscape areas. Structural loads on the order of 100 kips were assumed for isolated columns and wall loads of about7 kips per linear foot were assumed. In addition, it is assumed that the maximum floor slab loads will be about 625 pounds per square foot below racking areas. According to the ALTA Land Title Survey Plan,the site comprises two (2)properties:Lot 971 (APN 0237-122-07),which includes the majority of the site (about 22.3 acres) and Lot 970 (APN 0237- 121-03),which encompasses an approximate 100 foot wide railroad easement with an area of about 2.4 acres. The ALTA plan shows a railroad spur terminating into the site at the northwest corner of the property. At the time of our field investigation,the site was occupied by the Brown -Strauss Steel facility. The majority of the site was covered with stockpiles of steel beam type materials. Asphalt concrete drive areas were located throughout the site, between the piles of steel. Two (2)existing buildings were noted near the southern site boundary. The subject site was relatively flat. An existing CMU screen wall was located along the southern site boundary,and CMU retaining walls were located along the eastern and northern site boundaries. The adjacent grades east of the site were noted to be about 2 to 3 feet higher than the subject site. The adjacent grades north of the site were noted to be about 4 feet higher than the subject site. Undocumented fill piles were pushed against the walls on the eastern and southern sides of the site. The fill soil piles were about 5 feet high. On August 19, 2015, six (6) test borings were drilled to depths ranging from about 20 to 51½ feet BSG. In addition, three (3) test borings (P-1 through P-3) were drilled to depths of about 4½ to 5 feet BSG for installation of percolation tests. The depths and locations of the test borings were selected based on the type of construction, estimated depths of influence of the anticipated foundation loads,and the subsurface soil conditions encountered. The borings were drilled with a truck-mounted CME-75 drill rig equipped with 8 inch outside diameter (O.D.)hollow-stem augers. EXECUTIVE SUMMARY (cont.) The near surface soils encountered comprised silty sands from the surface to depths ranging from 2½to 8½feet BSG. The near surface soils were noted to contain varying amounts of gravel. The near surface silty sands were underlain by interbedded layers of poorly graded sands,poorly graded sands with silt,and well graded gravels with silt and sand to the maximum depth explored of 51½ feet BSG. Relatively thin beds of lean clays with sand, clayey sands, and sandy silts were encountered at depths greater than 35 feet BSG. Due to the granular nature of the soils encountered, and the lack of debris, fill soils were generally not identified in the test borings drilled during this investigation. However, the boring for percolation test P-1 encountered a railroad tie at a depth of about 1 foot, which may be associated with a buried railroad spur. Therefore, it is anticipated that undocumented fill soils may be present within the site and buried improvements (such as the railroad spur, or remnants of previous improvements). The near surface silty sands were considered non-expansive,exhibited low to moderate compressibility characteristics,slight collapse potential,and good support characteristics for paving when compacted as engineered fill. Groundwater was not encountered in the test borings drilled to a maximum depth of 51½feet BSG at the time of our August 2015 field investigation. From a geotechnical and geologic standpoint,the site is suitable for the proposed construction with regard to support of the proposed structure on shallow spread foundations and concrete slabs-on- grade, provided the recommendations contained in the report are followed. Based on the depth of groundwater in the site vicinity, liquefaction would not be considered a concern for the subject site. The results of the dry seismic settlement analysis indicate an estimated total seismic settlement of 1 inch and a differential seismic settlement of ½ inch, as a result of the design earthquake. Based on the three (3)percolation tests performed as part of this investigation,infiltration of storm water appears feasible from a geotechnical engineering standpoint. The site is not located in an Alquist-Priolo Earthquake Fault Zone and the potential for fault rupture on the site is estimated to be low. Chemical testing of soil samples indicated the soils exhibit a “corrosive”to “moderately corrosive” corrosion potential. Chemical analyses indicated a “negligible” potential for sulfate attack on concrete placed in contact with the near surface soils. This executive summary should not be used for design or construction and should be reviewed in conjunction with the attached report. G21403.01 TABLE OF CONTENTS Page 1.0 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 2.0 PURPOSE AND SCOPE OF INVESTIGATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 22.1 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 2.2 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 3.0 BACKGROUND INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 3.1 Site History and Previous Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 3.2 Site Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 3.3 Anticipated Construction and Grading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 4.0 INVESTIGATIVE PROCEDURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 4.1 Field Exploration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 4.1.1 Site Reconnaissance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 4.1.2 Drilling Test Borings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 4.1.3 Percolation testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 4.1.4 Soil Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 4.2 Laboratory Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 5.0 FINDINGS AND RESULTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 5.1 Surface Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 5.2 Soil Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 5.3 Soil Engineering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 5.4 Groundwater Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8 5.5 Results of Percolation Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9 6.0 EVALUATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9 6.1 Existing Surface and Subsurface Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 6.2 Expansive Soils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 6.3 Static Settlement and Bearing Capacity of Shallow Foundations . . . . . . . . . . . .10 6.4 Seismic Ground Rupture and Design Parameters . . . . . . . . . . . . . . . . . . . . . . . .11 6.5 Liquefaction and Seismic Settlement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 6.6 Asphaltic Concrete (AC) Pavements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 6.7 Portland Cement Concrete (PCC) Pavements . . . . . . . . . . . . . . . . . . . . . . . . . . .12 6.8 Soil Corrosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13 6.9 Sulfate Attack of Concrete . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 G21403.01 TABLE OF CONTENTS Page 7.0 CONCLUSIONS AND RECOMMENDATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 8.0 CONSULTATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19 9.0 NOTIFICATION AND LIMITATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19 APPENDICES APPENDIX A - Drawings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-1 Drawing No. 1 -Site Location Map Drawing No. 2 -Site Plan with Test Boring Locations APPENDIX B - Logs of Test Borings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-1 APPENDIX C - Results of Laboratory Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-1 PRELIMINARY GEOTECHNICAL ENGINEERING INVESTIGATION PROPOSED WAREHOUSE 14970 JURUPA AVENUE FONTANA, CALIFORNIA Project Number: G21403.01 1.0 INTRODUCTION This report presents the results of a preliminary geotechnical engineering investigation for the proposed warehouse building to be located at 14970 Jurupa Avenue in Fontana,California. Moore Twining Associates,Inc.(Moore Twining) was authorized by Duke Realty to perform this preliminary geotechnical engineering investigation. The contents of this report include the purpose of the investigation and the scope of services provided. The previous studies, site description, and anticipated construction are discussed. In addition,a description of the investigative procedures used and the subsequent findings obtained are presented. Finally, the report provides an evaluation of the findings, general conclusions, and related recommendations. The report appendices contain the drawings (Appendix A),the logs of borings (Appendix B), and the results of laboratory tests (Appendix C). The Geotechnical Engineering Division of Moore Twining, headquartered in Fresno, California, performed the investigation. 2.0 PURPOSE AND SCOPE OF INVESTIGATION 2.1 Purpose:The purpose of the investigation was to conduct a field exploration and a laboratory testing program,evaluate the data collected during the field and laboratory portions of the investigation, and provide the following: 2.1.1 Preliminary evaluation of the near surface soils within the zone of influence of the proposed foundations, exterior slabs-on-grade, and pavements with regard to the anticipated foundation and traffic loads; 2.1.2 Recommendations for 2013 California Building Code seismic coefficients and earthquake spectral response acceleration values; 2.1.3 Discussion of preliminary geotechnical design recommendations for foundations and slabs-on-grade; 2.1.4 Preliminary assessment of the potential for liquefaction and seismic settlement; 2.1.5 Opinions regarding the geotechnical engineering feasability of shallow spread foundations; Preliminary Geotechnical Engineering Investigation G21403.01 Proposed Warehouse 14970 Jurupa Avenue October 15, 2015 Fontana, California Page No. 2 2.1.6 Preliminary recommendations for the design and construction of new asphaltic concrete (AC) and Portland cement concrete (PCC) pavements; 2.1.7 A summary of the results of percolation tests; and 2.1.8 Preliminary conclusions regarding soil corrosion potential. This report is provided specifically for the proposed warehouse building and associated improvements referenced in the Anticipated Construction section of this report. This investigation should be considered preliminary and did not include a design level geotechnical study. This investigation also did not include a geologic/seismic hazards evaluation,flood plain investigation, compaction tests, environmental investigation, or environmental audit. 2.2 Scope:Our proposal, dated July 24, 2015, outlined the scope of our services. The actions undertaken during the investigation are summarized as follows. 2.2.1 An ALTA Land Title Survey,prepared by Land Surveying,undated,was reviewed. 2.2.2 A visual site reconnaissance and subsurface exploration were conducted. 2.2.3 Aerial images of the site for twelve (12)individual years from 1994 to 2015, from online sources, were reviewed. 2.2.4 The Phase I Environmental Site Assessment Report, prepared by Partner Engineering and Science,Inc.,identified by project number 15-146427.1, dated September 14, 2015, was reviewed. 2.2.5 Mr. Adam Schmid (Duke Realty) was consulted during the investigation. 2.2.6 Laboratory tests were conducted to determine selected physical and engineering properties of selected samples of the subsurface soils encountered. 2.2.7 The data obtained from the investigation were evaluated to develop an understanding of the subsurface soil conditions and the engineering properties of the subsurface soils. 2.2.8 This report was prepared to present the purpose and scope,background information,field exploration procedures, findings, evaluation, and conclusions and recommendations. Preliminary Geotechnical Engineering Investigation G21403.01 Proposed Warehouse 14970 Jurupa Avenue October 15, 2015 Fontana, California Page No. 3 3.0 BACKGROUND INFORMATION The site history and previous studies,site description,and the anticipated construction are summarized in the following subsections. 3.1 Site History and Previous Studies:Based on review of the referenced Phase I report provided,the site was utilized as an orchard from 1938 to 1966. The Phase I report indicates the site was developed for a steel yard in 1966, and the existing structures were constructed in 1966 and 1977. The phase I report also reported the presence of railroad tracks in the western portion of the site from at least 1938 to present. The Phase I report indicated a former 5,000 gallon underground storage tank (UST)was formerly present at the site. The Phase I report also reported that City of Fontana records indicate a former septic system was in operation until at least 2007. The location of the septic system was unknown, however, the Phase I report indicated the current owner believed it was associated with the existing metal building. No other previous geotechnical engineering,geological,or environmental studies conducted for this site were provided for review during this investigation. If available, these reports should be provided for review and consideration for this project. 3.2 Site Description: The subject site is located at 14970 Jurupa Avenue in Fontana, California. The site is bound to the north by an existing commercial distribution center, to the east by Hemlock Avenue with a warehouse building beyond;to the south by Jurupa Avenue with single family homes beyond,and to the east by railroad tracks with Live Oak Avenue beyond. Based on the plan provided,the subject site is approximately 24.7 acres. According to the ALTA Land Title Survey Plan,the site comprises two (2)properties:Lot 971 (APN 0237-122-07),which includes the majority of the site (about 22.3 acres)and Lot 970 (APN 0237-121-03),which encompasses an approximate 100 foot wide railroad easement with an area of about 2.4 acres. It is not known if the railroad easement will be included as part of the overall site development. The ALTA plan shows a railroad spur terminating into the site at the northwest corner of the property. At the time of our field investigation,the site was occupied by the Brown -Strauss Steel facility. The majority of the site was covered with stockpiles of steel beam type materials sitting on bare ground. Asphalt concrete drive areas were located throughout the site,between the piles of steel.Two (2) existing buildings were noted near the southern site boundary. The buildings included a metal sided shop building and an office building with perimeter CMU walls. Overhead site lighting was noted throughout the site. Existing underground utilities were noted near the buildings and underground electrical lines were generally noted throughout the site for the overhead lighting. Preliminary Geotechnical Engineering Investigation G21403.01 Proposed Warehouse 14970 Jurupa Avenue October 15, 2015 Fontana, California Page No. 4 The subject site was relatively flat.An existing CMU screen wall was located along the southern site boundary,and CMU retaining walls were located along the eastern and northern site boundaries. The adjacent grades east of the site were noted to be about 2 to 3 feet higher than the subject site. The adjacent grades north of the site were noted to be about 4 feet higher than the subject site. Undocumented fill piles were pushed against the walls on the eastern and southern sides of the site. The fill soil piles were about 5 feet high. 3.3 Anticipated Construction and Grading:At the time of preparation of this report, a site plan for the planned development was not available and information regarding the proposed development was not known in detail. It is our understanding that a one story, approximate 500,000 square foot warehouse type building may be planned in the future. It is anticipated that the building will include structural steel framing with perimeter concrete tilt up wall panels. Appurtenant construction is anticipated to include asphaltic concrete pavements,Portland cement concrete pavements, underground utilities, and isolated landscape areas. Structural loads on the order of 100 kips were assumed for isolated columns and wall loads of about7 kips per linear foot were assumed. In addition, it is assumed that the maximum floor slab loads will be about 625 pounds per square foot below racking areas. The site was noted to be relatively flat,therefore,cuts and fills on the order of about 1 to 4 feet would be anticipated. 4.0 INVESTIGATIVE PROCEDURES The field exploration and laboratory testing programs conducted for this investigation are summarized in the following subsections. 4.1 Field Exploration:The field exploration consisted of a site reconnaissance,drilling test borings, percolation testing, and soil sampling. 4.1.1 Site Reconnaissance: The site reconnaissance consisted of walking the site and noting visible surface features. The reconnaissance was conducted by Mr. Amer Razaq on August 19,2015. The features noted are described in the background information section of this report. 4.1.2 Drilling Test Borings: On August 19, 2015, six (6) test borings were drilled to depths ranging from about 20 to 51½ feet BSG. In addition, three (3) test borings (P-1 through P-3)were drilled to depths of about 4½ to 5 feet BSG for installation of percolation tests. The depths and locations of the test borings were selected based on the type of construction, estimated depths of influence of the anticipated foundation loads, and the subsurface soil conditions encountered. The borings were drilled with a truck-mounted CME-75 drill rig equipped with 8 inch outside diameter (O.D.) hollow-stem augers. Preliminary Geotechnical Engineering Investigation G21403.01 Proposed Warehouse 14970 Jurupa Avenue October 15, 2015 Fontana, California Page No. 5 During the drilling of the test borings,bulk samples of soil were obtained for laboratory testing. The test borings were drilled under the direction of a Moore Twining project geologist. The soils encountered in the test borings were logged during drilling by a representative of our firm. The field soil classification was in accordance with the Unified Soil Classification System consisted of particle size, color, and other distinguishing features of the soil. The presence and elevation of free water, if any, in the borings were noted and recorded during drilling and immediately following completion of the borings. Test boring locations were determined by pacing with reference to existing site features shown on the referenced ALTA. The test borings were backfilled with cuttings, thus some settlement should be anticipated. 4.1.3 Percolation Testing:Three (3)percolation tests were conducted in borings P-1 through P-3 at the approximate locations shown on Drawing No.2 in Appendix A. The percolation test holes were drilled with an 8 inch outside diameter hollow-stem auger and extended to depths of about 4½ to 5 feet BSG. A 2-inch diameter slotted PVC pipe was placed in the boreholes and used to transmit poured water to the bottom of the holes. Gravel was placed in the annular area of the borehole (around the pipe)to protect the sidewalls of the holes from collapse and washout during refilling. The test holes were pre-soaked with water on the day prior to commencement of percolation testing. The presoak included filling each test hole with about 16 to 18 inches of water. The test holes were noted to be dry the morning of the percolation tests. Percolation testing included adding water to the test holes periodically and measuring the drop in water level over time until the readings stabilized. Measurements of the depth to water and the time of each reading were recorded on the field percolation test logs. The results of the percolation testing are described in section 5.5 of this report. 4.1.4 Soil Sampling: Standard penetration tests were conducted in the test borings, and both disturbed and relatively undisturbed soil samples were obtained. The standard penetration resistance,N-value,is defined as the number of blows required to drive a standard split barrel sampler into the soil. The standard split barrel sampler has a 2-inch O.D. and a 1 d-inch inside diameter (I.D.). The sampler is driven by a 140-pound weight free falling 30 inches. The sampler is lowered to the bottom of the bore hole and set by driving it an initial 6 inches. It is then driven an additional 12 inches and the number of blows required to advance the sampler the additional 12 inches is recorded as the N-value. Preliminary Geotechnical Engineering Investigation G21403.01 Proposed Warehouse 14970 Jurupa Avenue October 15, 2015 Fontana, California Page No. 6 Relatively undisturbed soil samples for laboratory tests were obtained by pushing or driving a California modified split barrel ring sampler into the soil. The soil was retained in brass rings, 2.5 inches O.D.and 1-inch in height. The lower 6-inch portion of the samples were placed in close- fitting,plastic,airtight containers which,in turn,were placed in cushioned boxes for transport to the laboratory. Soil samples obtained were taken to Moore Twining's laboratory for classification and testing. 4.2 Laboratory Testing: The laboratory testing was programmed to determine selected physical and engineering properties of some of the samples obtained. The tests were conducted on disturbed and relatively undisturbed samples considered representative of the subsurface soils encountered. The results of laboratory tests are summarized in Appendix C. These data, along with the field o observations, were used to prepare the final test boring logs in Appendix B. 5.0 FINDINGS AND RESULTS The findings and results of the field exploration and laboratory testing are summarized in the following subsections. 5.1 Surface Conditions:At the time of our investigation,the site was generally covered by asphaltic concrete paved drive aisles, piles of structural steel, and two structures. The asphalt concrete pavements encountered at one (1)test boring location included 3¼ inches of asphaltic concrete over 3 inches of aggregate base. A buried railroad tie was encountered at percolation test location P-1,in the upper 1 foot BSG,near the western side of the property. Based on conversations with Mr. Mike Gilbert (Brown-Strauss Steel),the railroad tie may be associated with a buried railroad spur. Based on review of the ALTA plan provided,it appears the buried railroad tie would align with the railroad spur shown near the northwest corner of the site. Fill piles with heights of about 3 to 5 feet were noted along the northern and eastern site boundary. The fill piles were located adjacent to retaining walls and the fill soils appeared to contain cobbles and debris. Existing underground utilities associated with site lighting and the existing buildings were noted throughout the site. Preliminary Geotechnical Engineering Investigation G21403.01 Proposed Warehouse 14970 Jurupa Avenue October 15, 2015 Fontana, California Page No. 7 5.2 Soil Profile:In general,the near surface soils encountered comprised silty sands from the surface to depths ranging from 2½to 8½feet BSG. The near surface soils were noted to contain varying amounts of gravel. The near surface silty sands were underlain by interbedded layers of poorly graded sands,poorly graded sands with silt,and well graded gravels with silt and sand to the maximum depth explored of 51½ feet BSG. Relatively thin beds of lean clays with sand, clayey sands,and sandy silts were encountered at depths greater than 35 feet BSG. Due to the granular nature of the soils encountered,fill soils were not noted in most of the test borings drilled during this investigation. However, percolation test P-1 encountered a railroad tie around 1 foot BSG. Therefore, undocumented fill soils are anticipated throughout some of the site. Based on review of NRCS Web Soil Survey,the near surface soils are reported to contain up to 2 percent cobble fraction. Therefore, it should be noted that the near surface soils may contain cobbles. The foregoing is a general summary of the soil conditions encountered in the test borings drilled for this investigation. Detailed descriptions of the soils encountered at each test boring location are presented in the logs of borings in Appendix B. The stratification lines in the logs represent the approximate boundary soil types; the actual in-situ transition may be gradual. 5.3 Soil Engineering Properties: The following is a description of the soil engineering properties as determined from our field exploration and laboratory testing program. Silty Sands:The silty sands encountered were described as medium dense to very dense, as determined by standard penetration resistance,N-values,ranging from 11 to greater than 50 blows per foot. Two (2) relatively undisturbed samples revealed in-place dry densities of 109.3 and 121.5 pounds per cubic foot. The moisture contents of the samples tested ranged from 3 to 5 percent. A consolidation test performed on a relatively undisturbed sample resulted in about 5.3 percent consolidation under a load of 8 kips per square foot. When wetted under a load of 2 kips per square foot,these soils exhibited a slight collapse potential (about 0.7 percent collapse). An expansion index test performed on a near surface silty sand sample resulted in an expansion index of 0. Poorly Graded Sands with Silt and Poorly Graded Sands:The poorly graded sands and poorly graded sands with silt encountered were described as medium dense to very dense, as determined by standard penetration resistance,N-values,ranging from 16 to greater than 50 blows per foot. Five (5)relatively undisturbed samples revealed in-place dry densities ranging from 117.4 to 127.6 pounds per cubic foot. The moisture content of the samples tested resulted in moisture contents between 2 and 4 percent. An atterberg limits test indicated these soils are non-plastic and have no liquid limit value. A direct shear test resulted in an internal angle of friction of 41 degrees and no cohesion value. Two (2) consolidation tests performed on these soils resulted in about 2.5 and 4.7 percent consolidation under a load of 8 kips per square foot. When wetted under a load of 2 kips per square foot, these soils exhibited a slight collapse potential (about 0.5 and 0.7 percent collapse). Preliminary Geotechnical Engineering Investigation G21403.01 Proposed Warehouse 14970 Jurupa Avenue October 15, 2015 Fontana, California Page No. 8 Well Graded Gravels with Silt and Sand:The well graded gravels with silt and sand were described as medium dense,based on the results of standard penetration resistance,N-values of 28 each. Two (2) relatively undisturbed samples revealed in-place dry densities of 122.8 and 127.8 pounds per cubic foot. The moisture content of two (2) samples tested resulted in moisture contents of 2 percent each. A consolidation test performed on a relatively undisturbed sample resulted in about 6.2 percent consolidation under a load of 8 kips per square foot. When wetted under a load of 2 kips per square foot,these soils exhibited a slight collapse potential (about 1.4 percent collapse) Lean Clays with Sand:The lean clays with sand were described as stiff,as determined by a standard penetration resistance, N-value, of 11 blows per foot. Sandy Silts:The sandy silts were described as hard, as determined by a standard penetration resistance, N-value, of greater than 50 blows per foot. Clayey Sands: The clayey sands were described as medium dense, as determined by a standard penetration resistance, N-value, of 26 blows per foot. Maximum Density/Optimum Moisture Tests: The results of one (1) maximum density/optimum moisture determination test performed on a near surface sample resulted in a maximum dry density of 125.9 pounds per cubic foot with an optimum moisture content of 8.6 percent. R-value Test:The results of two (2) R-value tests conducted on near surface samples resulted in R-values of 52 and 55. Chemical Tests:Chemical tests were performed on two (2)near surface soil samples. The results indicated pH values of 7.8 and 4.0;minimum resistivity values of 4,400 and 6,100 ohms- centimeter;0.0023 and 0.0085 percent by weight concentration of sulfate; and “not detected” and 0.0040 percent by weight concentration of chloride, respectively. 5.4 Groundwater Conditions:Groundwater was not encountered in the test borings drilled to a maximum depth of 51½feet BSG at the time of our August 2015 field investigation. Based on our review of various wells on the Department of Water Resources On-line Water Well database, groundwater depths in the vicinity of the site between 2000 and 2015 appear to be greater than 200 feet BSG It should be recognized,however,that groundwater elevations fluctuate with time,since they are dependent upon seasonal precipitation,irrigation,land use,and climatic conditions as well as other factors. Therefore, water level observations at the time of the field investigation may vary from those encountered both during the construction phase and the design life of the project. The evaluation of such factors was beyond the scope of this investigation and report. Preliminary Geotechnical Engineering Investigation G21403.01 Proposed Warehouse 14970 Jurupa Avenue October 15, 2015 Fontana, California Page No. 9 5.5 Results of Percolation Testing:The estimated infiltration rates from the percolation testing are summarized in Table No. 1. Table No. 1 Results of Percolation Tests and Estimated Unfactored Infiltration Rates Test Location Depth of Test, Feet BSG Estimated Unfactored Infiltration Rate 1, 2 (Inches/Hour) Soil Type at Depth of Percolation Test P-1 4.5 27.2 Poorly Graded Sand P-2 5 5.4 Silty Sand P-3 4.5 1.1 Silty Sand 1 - Includes no factor of safety 2- These values account for the effect of the gravel and pipe in the boreholes. The unfactored estimated infiltration rates above do not take into account the long term effects of subgrade saturation, silt accumulation, groundwater influence, nor densification as a result of the construction process.The percolation/infiltration rate of the soils will decrease when the soils are saturated and the percolation/infiltration rate is further reduced the longer the soils are saturated. Published studies indicate short term field infiltration rates can significantly overestimate the saturated permeability. In addition, soil bed consolidation, sediment, suspended soils, etc. in the discharge water can result in clogging of the pore spaces in the soil. This clogging effect can also reduce the long term infiltration rate. Numerous other factors, such as variations in soil type and soil density across the entire area of the system can influence the percolation/infiltration rate,both short and long term. 6.0 EVALUATION The data and methodology used to develop conclusions and recommendations for project design and preparation of construction specifications are summarized in the following subsections. The evaluation was based upon the subsurface soil conditions determined from this investigation and our understanding of the proposed construction. The conclusions obtained from the results of our evaluations are described in the Conclusions section of this report. Preliminary Geotechnical Engineering Investigation G21403.01 Proposed Warehouse 14970 Jurupa Avenue October 15, 2015 Fontana, California Page No. 10 6.1 Existing Surface and Subsurface Conditions:At the time of our field exploration, the existing site development included a shop building and a small office building near the southern site boundary. Other site improvements included asphaltic concrete pavements, site lighting, underground utilities,and retaining/screen walls along the northern and eastern site boundaries. In addition,a railroad tie associated with an apparent old railroad spur was encountered in the western portion side of the site. Also, piles of fill soils were noted against the existing retaining walls along the northern and eastern site boundaries. Based on the referenced Phase I report,a former underground storage tank was located at the property which was reportedly removed and the excavation backfilled. The details of the backfill are not known and thus the fill soils are considered to be undocumented. Undocumented fills should be over-excavated and compacted as engineered fill as part of the site preparation. As part of the site preparation,existing improvements, including foundations, floor slabs, subsurface structures,septic systems,paving,underground utilities and associated backfill,old railroad spurs, undocumented fills,etc.will need to be removed.Care should be taken to over-excavate all soils which are disturbed from the demolition activities prior to backfilling the excavations with engineered fill. From a geotechnical engineering standpoint, the existing Portland cement concrete and asphaltic concrete could potentially be recycled for certain uses. Depending on the characteristics of the recycled material,it may be possible to generate an aggregate base or subbase material. Alternatively, recycled materials could be processed for use as general fill; however, recycled asphalt concrete would not be recommended for fill below the building. 6.2 Expansive Soils: One of the potential geotechnical hazards evaluated at this site is the expansion potential of the near surface soils. Over time, expansive soils will experience cyclic drying and wetting as the dry and wet seasons pass. Expansive soils experience volumetric changes (shrink/swell) as the moisture content of the clayey soils fluctuate. The near surface soils encountered are granular and non-plastic. Therefore, expansive soils are not considered a concern for this project and no special recommendations are included in this report to mitigate expansive soil conditions at the site. 6.3 Static Settlement and Bearing Capacity of Shallow Foundations: The potential for excessive total and differential static settlement of foundations and slabs-on-grade is a geotechnical concern that was evaluated for this project. The increases in effective stress to underlying soils which can occur from new foundations and structures,placement of fill,withdrawal Preliminary Geotechnical Engineering Investigation G21403.01 Proposed Warehouse 14970 Jurupa Avenue October 15, 2015 Fontana, California Page No. 11 of groundwater, etc. can cause vertical deformation of the soils, which can result in damage to the overlying structure and improvements. The differential component of the settlement is often the most damaging. In addition, the allowable bearing pressures of the soils supporting the foundations were evaluated for shear and punching type failure of the soils resulting from the imposed foundation loads. In order to limit the potential for excessive static settlement of the building foundations, over- excavation of the near surface soils and compaction of (onsite)engineered fill is recommended for support of new foundations. The recommendations included in this report are intended to limit the static settlement of foundations to 1 inch total and ½inch differential. A net allowable soil bearing pressure of 2,500 pounds per square foot,for dead-plus-live loads,was used for estimating the static settlements. The net allowable soil bearing pressure is the additional contact pressure at the base of the foundations. The weight of the soil backfill and weight of the footing may be neglected. The net allowable soil bearing pressure presented was selected using the Terzaghi bearing capacity equations for foundations considering a minimum factor of safety of 3.0 and based on the anticipated static settlements noted in this report. A structural engineer experienced in foundation and slab-on-grade design should determine the thickness,reinforcement,design details and concrete specifications for the proposed building foundations and slabs-on-grade based on the anticipated settlements estimated in this report. 6.4 Seismic Ground Rupture and Design Parameters:The site is not located in an Alquist-Priolo Earthquake Fault Zone. The nearest known active fault is the San Jacinto Fault Zone, located about 12.8 miles north of the site. Therefore, the potential for fault rupture at the site is considered low. It is our understanding that the 2013 CBC will be used for structural design,and that seismic site coefficients are needed for design. Based on the 2013 CBC,a Site Class D represents the on-site soil conditions with standard penetration resistance,N-values averaging between 15 and 50 blows per foot in the upper 100 feet below site grade. A table providing the recommended seismic coefficients and earthquake spectral response acceleration values for the project site is included in the Conclusions and Recommendations section of this report. A Maximum Considered Earthquake (geometric mean) peak ground acceleration adjusted for site effects (PGAM)of 0.50g was determined for the site using the Ground Motion Preliminary Geotechnical Engineering Investigation G21403.01 Proposed Warehouse 14970 Jurupa Avenue October 15, 2015 Fontana, California Page No. 12 Parameter Calculator provided by the United States Geological Survey (http://earthquake.usgs.gov/designmaps/us/application.php). A Maximum Considered Earthquake magnitude of 7.6 was applied in the analysis based on deaggregation analysis (United States Geological Survey deaggregation website http://geohazards.usgs.gov/deaggint/2008/. 6.5 Liquefaction and Seismic Settlement:Liquefaction and seismic settlement are conditions that can occur under seismic shaking from earthquake events. Liquefaction describes a phenomenon in which a saturated,cohesionless soil loses strength during an earthquake as a result of induced shearing strains. Lateral and vertical movements of the soil mass, combined with loss of bearing usually results. Fine, well sorted, loose sand, shallow groundwater conditions, higher intensity earthquakes,and particularly long duration of ground shaking are the requisite conditions for liquefaction. Liquefaction would not be considered a concern at this site due to the depth to groundwater. However,due to the presence of medium dense granular soils,a dry seismic settlement analyses was conducted based on the soil properties revealed by the test borings and the results of laboratory testing. The evaluation was conducted for the soils encountered in borings B-1 and B-5 using the computer program LiquefyPro,developed by CivilTech Software. A peak horizontal ground acceleration of 0.50g and a design earthquake magnitude of 7.6 were used in the analysis. Based on the analysis,a dry seismic settlement of 1 inch total and ½inch differential was estimated. 6.6 Asphaltic Concrete (AC) Pavements: Recommendations for asphaltic concrete pavement structural sections are presented in the "Conclusions and Recommendations"section of this report. The structural sections were designed using the gravel equivalent method in accordance with the California Department of Transportation Highways Design Manual. The analysis was based on traffic index values ranging from 5.0 to 10.0. The appropriate paving section should be determined by the project civil engineer or applicable design professional based on the actual vehicle loading (traffic index)values. If traffic loading is anticipated to be greater than assumed, the pavement sections should be re-evaluated. Based on the results of the testing and the procedures in the Caltrans Highway Design Manual, an R-value of 50 was used for the pavement design. 6.7 Portland Cement Concrete (PCC)Pavements:Recommendations for Portland cement concrete (PCC)pavement structural sections are presented in the "Conclusions and Recommendations"section of this report. The PCC pavement sections are based upon the amount and type of traffic loads being considered and the modulus of subgrade reaction for the subgrade soils which will support the pavement. The measure of the amount and type of traffic loads are based upon an index of equivalent axle loads (EAL)from the loading of heavy trucks called a traffic index (T.I). Preliminary Geotechnical Engineering Investigation G21403.01 Proposed Warehouse 14970 Jurupa Avenue October 15, 2015 Fontana, California Page No. 13 The recommendations provided in this report for PCC pavements are based on traffic indices ranging between 5.0 and 10.0 and the design procedures contained in the Portland Cement Association "Thickness Design of Highway and Street Pavements.” The PCC pavement sections were designed for a life of 20 years,a load safety factor of 1.1,a single axle weight of 20,000 pounds,and a tandem axle weight of 35,000 pounds. A modulus of subgrade reaction, K-value, for the pavement section,of 200 psi/in was used for the pavement design based on correlations using the R-value test results. 6.8 Soil Corrosion: The risk of corrosion of construction materials relates to the potential for soil-induced chemical reaction. Corrosion is a naturally occurring process whereby the surface of a metallic structure is oxidized or reduced to a corrosion product such as iron oxide (i.e., rust). The metallic surface is attacked through the migration of ions and loses its original strength by the thinning of the member. Soils make up a complex environment for potential metallic corrosion. The corrosion potential of a soil depends on numerous factors including soil resistivity, texture, acidity, field moisture and chemical concentrations. In order to evaluate the potential for corrosion of metallic objects in contact with the onsite soils,chemical testing of soil samples was performed by Moore Twining as part of this report. The test results are included in Appendix C of this report. Conclusions regarding the corrosion potential of the soils tested are included in the Conclusions section of this report based on the National Association of Corrosion Engineers (NACE) corrosion severity ratings listed in Table No. 1, below. Table No. 1 Soil Resistivity (ohm cm)Corrosion Potential Rating >20,000 Essentially non-corrosive 10,000 - 20,000 Mildly corrosive 5,000 - 10,000 Moderately corrosive 3,000 - 5,000 Corrosive 1,000 - 3,000 Highly corrosive <1,000 Extremely corrosive The results of soil sample analyses indicate that the near-surface soils exhibit a “corrosive” to “moderately corrosive” corrosion potential to buried metal objects. Preliminary Geotechnical Engineering Investigation G21403.01 Proposed Warehouse 14970 Jurupa Avenue October 15, 2015 Fontana, California Page No. 14 If the manufacturers or suppliers cannot determine if materials are compatible with the soil corrosion conditions, a professional consultant, i.e., a corrosion engineer, with experience in corrosion protection should be consulted to provide design parameters. 6.9 Sulfate Attack of Concrete: Degradation of concrete in contact with soils due to sulfate attack involves complex physical and chemical processes. When sulfate attack occurs, these processes can reduce the durability of concrete by altering the chemical and microstructural nature of the cement paste. Sulfate attack is dependent on a variety of conditions including concrete quality,exposure to sulfates in soil/groundwater and environmental factors. The standard practice for geotechnical engineers in evaluation of the soils anticipated to be in contact with concrete is to perform testing to determine the sulfates present in the soils. The test results are then compared with the provisions of ACI 318,section 4.3 to provide guidelines for concrete exposed to sulfate- containing solutions. Common methods used to resist the potential for degradation of concrete due to sulfate attack from soils include,but are not limited to the use of sulfate-resisting cements,air- entrainment and reduced water to cement ratios. The soil corrosion data should be provided to the manufacturers or suppliers of materials that will be in contact with soils (pipes or ferrous metal objects, etc.) to provide assistance in selecting the protection and materials for the proposed products or materials. If the manufacturers or suppliers cannot determine if materials are compatible with the soil corrosion conditions, a professional consultant,i.e.,a corrosion engineer,with experience in corrosion protection should be consulted to provide design parameters. 7.0 CONCLUSIONS AND RECOMMENDATIONS Based on the data collected during the field and laboratory investigations,our geotechnical experience in the vicinity of the project site,and our understanding of the anticipated construction, the following general conclusions and recommendations are presented. 7.1 Based on the findings of this preliminary geotechnical investigation, the site is considered suitable for the proposed construction with regard to support of the proposed improvements on conventional shallow spread foundations. Preliminary recommendations have been included below for planning type purposes. A future design level geotechnical investigation report should be prepared when the details of the proposed site development are known. It should be noted that the recommended design consultation and observation of clearing,and earthwork activities by Moore Twining are integral to this conclusion. 7.2 The near surface soils encountered comprised silty sands from the surface to depths ranging from 2½to 8½feet BSG. The near surface soils were noted to contain varying amounts of gravel. The near surface silty sands were underlain by Preliminary Geotechnical Engineering Investigation G21403.01 Proposed Warehouse 14970 Jurupa Avenue October 15, 2015 Fontana, California Page No. 15 interbedded layers of poorly graded sands, poorly graded sands with silt, and well graded gravels with silt and sand to the maximum depth explored of 51½feet BSG. Relatively thin beds of lean clays with sand,clayey sands, and sandy silts were encountered at depths greater than 35 feet BSG. Due to the granular nature of the soils encountered,and the lack of debris,fill soils were generally not identified in the test borings drilled during this investigation. However, the boring for percolation test P-1 encountered a railroad tie at a depth of about 1 foot, which may be associated with a buried railroad spur. Therefore, it is anticipated that undocumented fill soils may be present within the site and buried improvements (such as the railroad spur, or remnants of previous improvements). 7.3 Based on review of the NRCS Web Soil Survey, the near surface soils are reported to contain up to 2 percent cobble fraction. Therefore, although cobbles were not specifically noted during drilling of the small diameter borings for this investigation, it should be noted that some cobbles may be present in the near surface soils. Oversize rock greater than 6 inches, if present, should be removed from the soils prior to use as engineered fill. 7.4 The near surface soils encountered were granular in nature and not considered expansive. 7.5 The near surface soils encountered exhibited varying densities and standard penetration test (SPT) resistances. Thus, in order to limit differential static settlement of the new foundations,the near surface soils should be over-excavated and compacted to support foundations on engineered fill. On a preliminary basis, the soils within the proposed building area and associated foundations should be over- excavated to a depth of 1 foot below the bottom of the foundations, 4 feet below preconstruction site grade,to the depth required to remove existing undocumented fills,and to at least 1 foot below subsurface structures to be removed,whichever is greater. The building pad over-excavation shall extend to a minimum of 5 feet beyond all foundations. Provided the building pad area is over-excavated and prepared in accordance with the preliminary recommendations included herein, an allowable bearing capacity of 2,500 pounds per square feet would be anticipated for foundation design. 7.6 The preliminary seismic design parameters included in the table below were developed using the Ground Motion Parameter Calculator provided by the United States Geological Survey (http://earthquake.usgs.gov/designmaps/us/application.php) in accordance with the 2013 CBC,a site latitude of 34.0492 degrees,and a longitude of -117.4781 degrees. Preliminary Geotechnical Engineering Investigation G21403.01 Proposed Warehouse 14970 Jurupa Avenue October 15, 2015 Fontana, California Page No. 16 Preliminary Seismic Design Parameters Seismic Factor 2013 CBC Value Site Class D Maximum Considered Earthquake (geometric mean) peak ground acceleration adjusted for site effects (PGAM) 0.50 Mapped Maximum Considered Earthquake (geometric mean) peak ground acceleration, ASCE 7-10 (PGA) 0.50 Spectral Response At Short Period (0.2 Second), Ss 1.5 Spectral Response At 1-Second Period, S1 0.600 Site Coefficient (based on Spectral Response At Short Period), Fa 1.000 Site Coefficient (based on spectral response at 1-second period) Fv 1.500 Maximum considered earthquake spectral response acceleration for short period, SMS 1.500 Maximum considered earthquake spectral response acceleration at 1 second, SM1 0.900 Five percent damped design spectral response accelerations for short period, SDs 1.000 Five percent damped design spectral response accelerations at 1-second period, SD1 0.600 7.7 Groundwater was not encountered in the test borings drilled to a maximum depth of 51½ feet BSG at the time of our August 2015 field investigation. 7.8 Based on the depth of groundwater in the site vicinity, liquefaction would not be considered a concern for the subject site. The results of the dry seismic settlement analysis indicate an estimated total seismic settlement of 1 inch and a differential seismic settlement of ½ inch, as a result of the design earthquake. Preliminary Geotechnical Engineering Investigation G21403.01 Proposed Warehouse 14970 Jurupa Avenue October 15, 2015 Fontana, California Page No. 17 7.9 Based on the three (3) percolation tests performed as part of this investigation, infiltration of storm water appears feasible from a geotechnical engineering standpoint. 7.10 The near surface soils generally have good pavement support characteristics (R-values greater than 50). Based on the results of the R-value tests performed, the following preliminary asphaltic concrete pavement sections have been prepared for Traffic Indices between 5 and 10. At a minimum, preparation of subgrade soils below asphaltic concrete pavement areas should be anticipated to include over- excavation to a depth of 1 foot below preconstruction site grade, or to the depth to remove undocumented fills, whichever is greater. Preliminary Asphaltic Concrete Pavement Sections Traffic Index AC thickness, inches AB thickness, inches Compacted Subgrade, inches 5.0 2.5 4.0 12 5.5 3.0 4.0 12 6.0 3.0 4.0 12 6.5 3.5 4.5 12 7.0 4.0 4.5 12 7.5 4.0 5.5 12 8.0 4.5 6.0 12 8.5 5.0 6.0 12 9.0 5.5 6.5 12 9.5 5.5 7.5 12 10.0 6.0 7.5 12 AC -Asphaltic Concrete compacted an average relative compaction of 93 percent, with no single test value being below a relative compaction of 91 percent and no single test value being above a relative compaction of 97 percent of the referenced laboratory density according to ASTM D2041. AB -Class II Aggregate Base, with minimum R-value of 78 and compacted to at least 95 percent relative compaction (ASTM D1557) Subgrade -Subgrade soils compacted to at least 95 percent relative compaction (ASTM D1557) Preliminary Geotechnical Engineering Investigation G21403.01 Proposed Warehouse 14970 Jurupa Avenue October 15, 2015 Fontana, California Page No. 18 7.11 Based on the results of this investigation,the following preliminary Portland cement concrete pavement sections have been prepared for Traffic Indices between 5 and 10. At a minimum,preparation of subgrade soils below the Portland cement concrete pavement areas should be anticipated to include over-excavation to a depth of 1 foot below preconstruction site grade,or to the depth required to remove undocumented fills, whichever is greater. Preliminary Portland Cement Concrete Pavement Sections Traffic Index ADTT (Trucks/day) PCC thickness (inches) Aggregate Base1 (inches) Compacted Subgrade2 (inches) 5.0 0.5 5.0 4.0 12.0 6.0 1.9 5.5 4.0 12.0 7.0 7 5.5 4.0 12.0 8.0 21 6.0 4.0 12.0 9.0 58 7.0 4.0 12.0 10.0 142 7.5 4.0 12.0 PCC -Portland Cement Concrete (minimum Modulus of Rupture=550 psi) AB -Aggregate Base compacted to at least 95 percent relative compaction (ASTM D1557) Subgrade -Minimum depth of compacted subgrade is 12 inches below the aggregate base section. The upper 12 inches of fill placed should be compacted to at least 95 percent relative compaction (ASTM D1557). 7.12 Chemical testing of soil samples indicated the soils exhibit a “corrosive” to “moderately corrosive”corrosion potential. Chemical analyses indicated a “negligible”potential for sulfate attack on concrete placed in contact with the near surface soils. 7.13 The site is not located in an Alquist-Priolo special studies zone and the potential for fault rupture on the site is estimated to be low. Preliminary Geotechnical Engineering Investigation G21403.01 Proposed Warehouse 14970 Jurupa Avenue October 15, 2015 Fontana, California Page No. 19 8.0 CONSULTATION 8.1 This report is preliminary in nature and a future geotechnical engineering investigation will be required to provide final design recommendations for the project. Moore Twining should be notified when a site plan is available and an estimate for the geotechnical engineering design investigation can be provided at that time. 8.2 Moore Twining should be provided the opportunity to review those portions of the contract drawings and specifications that pertain to earthwork operations and foundations prior to finalization to determine whether they are consistent with our recommendations. 9.0 NOTIFICATION AND LIMITATIONS 9.1 The conclusions and recommendations presented in this preliminary report are based on the information provided regarding the proposed construction,and the results of the field and laboratory investigation,combined with interpolation of the subsurface conditions between boring locations. The nature and extent of subsurface variations between borings may not become evident until construction. 9.2 If variations or undesirable conditions are encountered during construction, Moore Twining should be notified promptly so that these conditions can be reviewed and our recommendations reconsidered where necessary. 9.3 If the proposed construction is relocated or redesigned, or if there is a substantial lapse of time between the submission of our report and the start of work (over 12 months)at the site,or if conditions have changed due to natural cause or construction operations at or adjacent to the site,the conclusions and recommendations contained in this report should be considered invalid unless the changes are reviewed and our conclusions and recommendations modified or approved in writing. 9.4 Changed site conditions,or relocation of proposed structure,may require additional field and laboratory investigations to determine if our conclusions and recommendations are applicable considering the changed conditions or time lapse. 9.5 The conclusions and recommendations contained in this report are valid only for the project discussed in the Background Information section of this report. The use of Preliminary Geotechnical Engineering Investigation G21403.01 Proposed Warehouse 14970 Jurupa Avenue October 15, 2015 Fontana, California Page No. 20 the information and recommendations contained in this report for structures on this site not discussed herein or for structures on other sites not discussed in this report is not recommended. The entity or entities that use or cause to use this report or any portion thereof for another structure or site not covered by this report shall hold Moore Twining,its officers and employees harmless from any and all claims and provide Moore Twining’s defense in the event of a claim. 9.6 This report is issued with the understanding that it is the responsibility of the client to transmit the information and recommendations of this report to developers, owners,buyers,architects,engineers,designers,contractors,subcontractors,and other parties having interest in the project so that the steps necessary to carry out these recommendations in the design,construction and maintenance of the project are taken by the appropriate party. 9.7 Our professional services were performed,our findings obtained, and our recommendations prepared in accordance with generally-accepted engineering principles and practices. This warranty is in lieu of all other warranties either expressed or implied. 9.8 Reliance on this report by a third party (i.e., that is not a party to our written agreement)is at the party's sole risk. If the project and/or site are purchased by another party,the purchaser must obtain written authorization and sign an agreement with Moore Twining in order to rely upon the information provided in this report for design or construction of the project. We appreciate the opportunity to be of service. If you have any questions regarding this report, or if we can be of further assistance, please contact us at your convenience. Sincerely, MOORE TWINING ASSOCIATES, INC. Geotechnical Engineering Division Dean B. Ledgerwood, CEG Engineering Geologist Read L. Andersen, RGE Manager A-1 G21403.01 APPENDIX A DRAWINGS Drawing No. 1 -Site Location Map Drawing No. 2 -Test Boring Location Map B-1 G21403.01 APPENDIX B LOGS OF TEST BORINGS This appendix contains the final logs of borings. These logs represent our interpretation of the contents of the field logs and the results of the field and laboratory tests. The logs and related information depict subsurface conditions only at these locations and at the particular time designated on the logs. Soil conditions at other locations may differ from conditions occurring at these test boring and test pit locations. Also, the passage of time may result in changes in the soil conditions at these test boring and test pit locations. In addition,an explanation of the abbreviations used in the preparation of the logs and a description of the Unified Soil Classification System are provided at the end of Appendix B. C-1 G21403.01 APPENDIX C RESULTS OF LABORATORY TESTS This appendix contains the individual results of the following tests. The results of the moisture content and dry density tests are included on the test boring logs in Appendix B. These data, along with the field observations, were used to prepare the final test boring logs in Appendix B. These Included:To Determine: Moisture Content (ASTM D2216) Moisture contents representative of field conditions at the time the sample was taken. Dry Density (ASTM D2216) Dry unit weight of sample representative of in-situ or in-place undisturbed condition. Atterberg Limits (ASTM D4318) Determines the moisture content where the soil behaves as a viscous material (liquid limit)and the moisture content at which the soil reaches a plastic state Consolidation (ASTM D2435) The amount and rate at which a soil sample compresses when loaded,and the influence of saturation on its behavior. Direct Shear (ASTM D3080) Soil shearing strength under varying loads and/or moisture conditions. Moisture-Density Relationship (ASTM D1557) The optimum (best)moisture content for compacting soil and the maximum dry unit weight (density) for a given compactive effort. R-Value (CTM 301) The capacity of a subgrade or subbase to support a pavement section designed to carry a specified traffic load. Sulfate Content (ASTM D4327) Percentage of water-soluble sulfate as (SO4)in soil samples. Used as an indication of the relative degree of sulfate attack on concrete and for selecting the cement type. Chloride Content (ASTM D4327) Percentage of soluble chloride in soil. Used to evaluate the potential attack on encased reinforcing steel. Resistivity (ASTM D1125) The potential of the soil to corrode metal. pH (ASTM D4972) The acidity or alkalinity of subgrade material.