3003 W CASINO RD BLDG 40-58 Geotech Report 2022-10-25

APPENDIX A FIELD EXPLORATIONS Subsurface conditions within the limits of the project area were explored on April 10, 11, and 12, 2014. The exploration program consisted of advancing and sampling twenty-nine exploratory borings at the approximate locations shown on the Field Explorations Plan(Figure 3 of this report). The exploratory borings were advanced to depths ranging from about 11.5 to 60.5 ft below existing ground surface(BGS) using a truck-mounted drill rigs and the hollow-stem auger drilling method. Several drill rigs and drilling crews were used to accommodate the three-day exploration schedule. Holocene Drilling, Inc. of Puyallup, Washington advanced the borings under subcontract to Landau Associates. The explorations were located in the field by reference to existing features using recent Google Earth imagery and conceptual site sketches developed provided by the design team. Boring positions were determined after drilling by the project surveyor. Field explorations were coordinated and monitored by a geotechnical engineer or geologist from our staff, who also obtained representative soil samples, maintained a detailed record of the observed subsurface soil and groundwater conditions, and described the soil encountered by visual and textural examination. Each representative soil type observed in our exploratory borings was described using the soil classification system shown on Figure A-1, in general accordance with ASTM International(ASTM) D2488, Standard Recommended Practice for Description of Soils (Visual-Manual Procedure). Logs of the exploratory borings are presented on Figures A-2 through A-31. These logs represent our interpretation of subsurface conditions identified during the field exploration program. The stratigraphic contacts shown on the logs represent the approximate boundaries between soil types; actual transitions may be more gradual. The soil and groundwater conditions depicted are only for the specific dates and locations reported and, therefore, are not necessarily representative of other locations and times. A further discussion of the soil and groundwater conditions observed is contained in the text portion of this report. Soil samples were obtained using a 2-inch outside-diameter (O.D.) split-spoon sampler and the Standard Penetration Test (SPT) procedure (ASTM D1586). Split-spoon samplers were driven up to 18 inches using a 140-pound automatic trip hammer falling from a height of 30 inches. The number of blows required to drive the sampler for each 6-inch interval of the 18-inch drive was recorded on the field log. The number of blows required to drive the sampler the last 12 inches (or portion thereof) is termed the Standard Penetration Resistance and is shown on the summary log. Upon completion of drilling and sampling, the boreholes were decommissioned in accordance with the requirements of WAC 173-160. Bentonite chips were used over the full depth of the decommissioned boreholes. The surface of each borehole was sealed with a quick-setting concrete plug. 5/16/14 P:\1423\002\010\FILERM\R\DRAFT BLDG 40-58 REPORT\APPENDICEs'APPENDIX A-BLDG 40-58.00cx LANDAU ASSOCIATES A-1