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

Buildings 40-32,40-33, and 40-34. The building would be constructed upon a fill pad extending north of a portion of the current Perimeter Road alignment and eastward to near Building 40-82. Buildings 40-60, 40-83, 40-84, 40-097, and a portion of Building 40-85 all reside within the proposed Building 40-58 footprint; these existing buildings will be demolished prior to construction. A number of utilities will need to be abandoned and/or relocated prior to construction. A significant amount of fill will be necessary to raise site grades within the fill pad area to match the floor elevation of adjoining buildings. Existing grades around the south and west perimeter of the site are within a few feet of the established Building 40-58 FFE of 545.5 ft; along the north and east sides of the fill pad, up to 15 ft of fill will be necessary for level construction. Retaining walls are planned along the west and east portions of the fill pad perimeter. Site topography generally slopes towards the north and east. However, existing fill pads around buildings 40-83 and 40-84 interrupt a uniform downward site gradient. Steep slopes are not present in the immediate vicinity of the project area. 2.3 SUBSURFACE SOIL CONDITIONS Subsurface conditions at the project site were explored by advancing and sampling 29 exploratory borings (B-1-14 through B-29-14) on April 10 through April 12, 2014. The exploratory borings were advanced to depths ranging from about 11'/2 to 60'/2 ft below the ground surface(BGS). The approximate locations of the soil borings are shown on Figure 3. A discussion of field exploration and laboratory test procedures, together with logs of the exploratory borings is presented in Appendix A. The results of the geotechnical laboratory testing and a description of the lab test procedures are contained in Appendix B. Most of the borings were terminated a depths less than originally planned due to very dense, difficult drilling conditions. Deeper exploration of was not warranted for foundation design considerations. Subsurface conditions at the project site were generally observed to consist of a layer of fill soil that is underlain by native glacial soils. The depths to the glacial till unit is variable. Around the southwest corner of the building footprint, glacial till is present at relatively shallow depths below the existing ground surface. Elsewhere, glacial till was encountered extending as deep as 53 ft below the ground surface. Past site grading records indicate that the general project area included a ravine that was filled during a major earthwork project in the 1960s. This is consistent with the highly variable top-of-till surface observed in current explorations and in previous explorations. Sub-surface profiles A-A', B-B, C-C',and D-D' are presented on Figures 5 through 8. The majority of fill soil encountered during exploration appears to derive from glacial till re-used as fill during major grading operations in the late 1960s and is similar to the composition of native soils 5/16/14 P:\1423\002\O10\PileRm\R\Draft Bldg 40-58 Report\Bldg 40-58_draft rpt.docx INTERIM DRAFT 2-2