3800 RIVERFRONT BLVD Geotech Report 2023-05-04

March 26, 2019 HWA Project No. 2015-061-21 Task 600-7 I Table 1. Estimated Shear Wave Velocities Soil Thickness Along ReMi Estimated Shear Wave (ft) Velocity(ft/sec) Fill 8 580 I Refuse 14 580 Alluvium (PT-OH) 46 1 530 Alluvium (Sand) 22 1080 Bearing Sand Beyond Depth of Borings 1200 I 2.3 LABORATORY TESTING Laboratory tests were conducted on selected samples obtained from the explorations to characterize relevant engineering and index properties of the soils encountered. Laboratory tests included in-situ moisture content, grain size distribution, Atterberg Limits, and direct shear testing. The tests were conducted in general accordance with appropriate American Society of Testing and Materials (ASTM) standards. The test results and a discussion of laboratory test methodology are presented in Appendix B or displayed on the exploration logs in Appendix A as appropriate. 2.4 EXISTING SUBSURFACE EXPLORATION AND EXPLORATIONS BY OTHERS HWA reviewed all readily available geotechnical information for the project site. This included a review of HWA's project library and a review of geotechnical reports completed by others in support of previous proposed developments at the site. HWA reviewed the existing draft geotechnical report for the Project Evergreen development (HWA, 2017). This report was generated in support of the Project Evergreens due diligence study. In this effort, HWA drilled 35 geotechnical borings designated BH-1 through BH-35, within the approximate northern 1/3rd of the landfill site. These borings were drilled to depths ranging from 40 to 141.5 feet below ground surface to characterize the subsurface conditions across the site. The approximate locations of these borings are indicated on Figure 2 and their logs areprovided in Appendix C. It should be noted that each of the borings were drilled g pp subjectg prior to placement of fill in the summer of 2018. Therefore, the ground surface contact shown in ' these borings are no longer valid. HWA also reviewed the existing geotechnical report from GeoEngineers(GeoEngineers, 2008). ' This report was generated in support of a previously planned development of the site. In this effort, GeoEngineers performed a series of 47 machine drilled borings across the landfill site in 2007. These borings were drilled to depths ranging from 35 to 110 feet below ground surface to Geotechnical Report Revision 3 26 2019.doc 3 HWA GEOSCIENCES INC.