1517 132ND ST SE 2024-12-09 - Laserfiche WebLink

Proposal for Geotechnical Engineering Services Proposed Bank: 1515 132nd Street Southeast, Everett, Washington March 15, 2019 3.0 SUBSURFACE EXPLORATIONS 3.1 SITE GEOLOGY General geologic information for the project area was obtained by reviewing the Geologic Map of the Everett 7.5-Minute Quadrangle, Snohomish County, Washington (Minard 1985). Based on our review,the geologic units in the vicinity of the site consist of Vashon Till — Geologic Map Unit Qvt. Vashon Till consists of an unsorted deposit (diamict) of clay, silt, sand and gravel that has been glacially transported and deposited. This soil has been directly deposited by a glacier and overridden by several thousand feet of glacial ice and is typically dense to very dense. 3.2 SUBSURFACE EXPLORATION We drilled three borings at the site on March 6, 2019. The borings were drilled using a trailer-mounted drill rig owned and operated by Geologic Drill, Inc. under subcontract to PanGEO and were logged by a geologist with our firm. The borings were drilled to a maximum depth of 201/2 feet below existing grade. The approximate boring locations were located in the field by measuring from property corners and site features and are shown on Figure 2, Site and Exploration Plan. Standard Penetration Tests (SPT) were performed at 21/2- to 5-foot depth intervals using a standard, 2-inch diameter split-spoon sampler. The sampler was advanced with a 140- pound drop hammer falling a distance of 30 inches for each strike, in general accordance with ASTM D-1586,Standard Test Method for Penetration Test and Split Barrel Sampling of Soils. The soils were logged in general accordance with ASTM D-2487 Standard Practice for Classification of Soils for Engineering Purposes and the system summarized on Figure A- 1, Terms and Symbols for Boring and Test Pit Logs. 3.3 SOIL CONDITIONS For a detailed description of the subsurface conditions encountered at each exploration location,please refer to our boring logs provided in Appendix A. The stratigraphic contacts indicated on the boring logs represent the approximate depth to boundaries between soil units. Actual transitions between soil units may be more gradual or occur at different elevations. The descriptions of groundwater conditions and depths are likewise 19-049 1515 132nd St SE Page 3 PanGEO,Inc.