607 RIVERSIDE RD Geotech Report 2022-10-25 (2)

I I IAPPENDIX A FIELD EXPLORATION AND LABORATORY TESTING I Riverside Business Park—Lots 5 and 6 Everett,Washington I On March 7, 2016, we explored subsurface conditions at the site by excavating 12 test pits to a maximum depth of 11 feet below existing surface grades using an excavator. In addition, on March 8,2016, six cone penetration tests (CPTs) were completed at the site. The test pit and CPT locations were approximately determined in the field using by sighting and using a distance measuring wheel from existing site features and adjacent explorations. The test pit and CPT locations are shown on Figure 2. IA geotechnical engineer from our office conducted the field exploration, classified the soils observed in the test pits, maintained a written log of each test pit, collected representative soil samples, and performed a visual site I reconnaissance. All soil samples were visually classified in accordance with the Unified Soil Classification System(USCS)described on Figure A-1. The Test Pit Logs are presented as Figures A-2 through A-13. I Representative soil samples collected from the test pits were placed in closed containers and taken to our laboratory for further examination and testing. Laboratory testing consisted of determining the soil moisture content of all samples, grain size analysis of seven samples,and Atterberg Limits on two samples. The moisture a contents and Atterberg Limits are reported on the Test Pit Logs. The results of the grain size analysis are 111 presented on Figures A-14 through A-16. I In Situ Engineering, Inc., under subcontract to Terra Associates,Inc.performed the CPTs at locations selected by Terra Associates, Inc. The CPTs were each advanced to a depth of 60 feet below the surface. The CPT consists of pushing an instrumented,approximately 1 1/2-inch diameter cone into the ground at a constant rate. During I advancement, continuous measurements are made of the resistance to penetration of the cone and the friction of the outer surface of a sleeve. The cone is also equipped with a porous filter and a pressure transducer for measuring groundwater or pore water pressure generated. Pore pressure dissipation tests were completed at four I of the CPT locations to determine groundwater depths. Measurements of tip and sleeve frictional resistance,pore pressure, and interpreted soil conditions and groundwater depths are summarized in graphical form on the CPT Logs attached in Appendix A. I 1 I I I Project No. T-7388 I