2721 WETMORE AVE MARQUEE APARTMENTS Geotech Report 2023-06-22

Subsurface Exploration, Geologic Hazard, and 2721 Wetmore Preliminary Geotechnical Engineering Report Everett, Washington Project and Site Conditions If variations are observed at that time, it may be necessary to re-evaluate specific recommendations in this report and make appropriate changes. 3.1 Exploration Borings The borings were advanced with a truck-mounted drill rig using 4.25-inch inner-diameter (8-inch outer-diameter) hollow-stem auger tooling. During the drilling process, samples were generally obtained at 2.5- to 5-foot-depth intervals using the Standard Penetration Test (SPT) procedure in accordance with American Society for Testing and Materials (ASTM) D-1586. This test and sampling method consists of driving a standard 2-inch, outside-diameter, split-barrel sampler a distance of 18 inches into the soil with a 140-pound hammer free-falling a distance of 30 inches. The number of blows for each 6-inch interval is recorded, and the number of blows required to drive the sampler the final 12 inches is known as the Standard Penetration Resistance ("N") or blow count. If a total of 50 is recorded within one 6-inch interval, the blow count is recorded as the number of blows for the corresponding number of inches of penetration. The resistance, or N-value, provides a measure of the relative density of granular soils or the relative consistency of cohesive soils; these values are plotted on the exploration boring logs included in the Appendix. The samples collected from the borings were classified in the field and representative portions placed in watertight containers. The samples were then transported to our laboratory for further visual classification. 4.0 SUBSURFACE CONDITIONS Subsurface conditions at the project site were inferred from the field explorations accomplished for this study, visual reconnaissance of the site, and review of applicable geologic literature. As shown on the boring logs, the exploration borings generally encountered up to 5 feet of loose fill soils underlain by glacially consolidated natural sediments interpreted as Vashon lodgement till and Vashon advance outwash. Detailed descriptions of the sediments encountered in our explorations are provided on the exploration logs included in the Appendix. The following section presents more detailed subsurface information organized from the shallowest (youngest) to the deepest (oldest) sediment types. 4.1 Stratigraphy Fill Fill soils were encountered directly beneath-2 to 3 inches of asphalt pavement at the locations of our borings. The fill generally consisted of very loose to loose, moist, light brown to May 28,2019 ASSOCIATED EARTH SCIENCES,INC. FSM/Id-190168E001-2-Projects\20190168\KE\WP Page 3