11611 AIRPORT RD Geotech Report 2018-01-02 MF Import

( � Geotectmical L'ngineenng Report ProposeJ Alm Warehouse May I 1, 2001 CG Tile No. l l21 Pagc 3 estent than thuse that were noi. Part of a typical glacial sequence includes recessional outwash sand unnerlain by glacial till. The 1982 USGS Distribu[ion and Uescription oC Geolo�ic Units in the Mukilteo Ouadran¢le, Washinaton, by James P. Minazd, was reviewed for the geologic and soil conditions at the si[e. The site is mapped as Qvt (glacial till). Glacial till is a dense, unsorted mix[ure of sand, silt, and gravel that is deposited at the bottom of the glacier, which is commonly referred to as"hardpad'. The glacial till has been consolidated under the weight of the continental glaciers, and exhibits both high strength and low permeability. Our site explorations encountered fill. Where our explorations were able to extend through the fill,we encountered the glacial till. Exploratious Subsurface conditions were explored at [he site by excavating five test pits with an extendahoe backhoe on Apnl 27, 2001. The test pits were excavated to depths of 12.0 to 15.5 feet below the ground surface. The explorations were located in the field by a geologist from this firm who also examined the soils and geologic conditions encountered, and maintained logs of the test pits. The approximate locations of the test pits are shown on the Site Plan in Figure 2. The soils were visually classified in general accordance with the Unified Soil Classification System, a copy of which is presented as Pigure 4. The logs of the test pits are presented in Figures 5 and 6. In the following paragraphs we present a brief summary of the subsurface conditions. A more detailed description of the subsurface conditions is shown on the Test Pit Logs. Subsurface Conditions GeneraL• All of our explorations encountered a surficial layer of loose, nonshvctural fill. The explorations were extended to the maximum reach of the backhoe, and native soils were no[ encountered in Test Pits 3 and 5. In general, the fill was shallower at the westem end of the site, and was deeper near the top of slope at the cast end of the site. The upper 4 feet of fill appeared to have received some level of compactive effort The fill below 4 feet was generally very loose to loose,and severe caving of the test pit sidewalls was encountered during excavation. ; � Cornerstone Geotechnical, Inc. �/� I