3003 W CASINO RD BLDG 45-06 Geotech Report 2025-03-03

Geotechnical Engineering Report lierracon Proposed Flight Line Steam Line Project Boeing Everett Facility • Everett, Washington January 17, 2012 • Terracon Project No.: 81115085 Field Exploration Description Our field exploration for this project included 4 borings completed on November 15, 2011. The approximate exploration locations are shown on the Boring Location Diagram, Exhibit A-2. The exploration locations were determined by measuring distances from existing site features with a fiberglass tape relative to an undated preliminary base map provided by Davido Consulting Group, Inc. Ground surface elevations at the exploration locations were inferred from topographic information presented on the site plan. The locations and elevations of the borings should be considered accurate only to the degree implied by the means and methods used to define them. ' The borings were advanced by an independent drilling company working under subcontract to Terracon. The borings were advanced with a hollow stem auger using a truck-mounted drill rig. A engineering geologist from our firm continuously observed the borings, logged the subsurface conditions encountered, and obtained representative soil samples. All samples were stored in moisture-tight containers and transported to our laboratory for testing. Throughout the drilling operation, soil samples were obtained at 2.5- to 5-foot depth intervals by means of the Standard Penetration Test (ASTM: D-1586). This testing and sampling procedure consists of using a cathead to drive a standard 2-inch outside diameter steel split spoon sampler 18 inches into the soil with a 140-pound hammer free falling 30 inches. The number of blows required to drive the sampler through each 6-inch interval is recorded, and the total number of blows struck during the final 12 inches is reported as the Standard Penetration 111, Resistance, or "blow count" (N value). If a total of 50 blows is struck within any 6-inch interval, the driving is stopped and the blow count is reported as 50 blows for the actual penetration 'i distance. The resulting Standard Penetration Resistance values indicate the relative density of granular soils and the relative consistency of cohesive soils. The enclosed boring logs describe the vertical sequence of soils and materials encountered in each boring, based primarily upon our field classifications. Where a soil contact was observed to be gradational, our logs indicate the average contact depth. Where a soil type changed between sample intervals, we inferred the contact depth. Our logs also graphically indicate the blow count, sample type, sample number, and approximate depth of each soil sample obtained ' from the boring. If groundwater was encountered in a borehole, the approximate groundwater depth, and date of observation, are depicted on the log. 'I' Exhibit A-3 I I