2320 RAILWAY AVE INTERWEST CONSTRUCTION INC Geotech Report 2023-02-17

I Interwest Construction Co.-Railway Avenue Improvements, Everett,WA Feb. 14,2019/Revised Feb. 7,2020 IGeotechnical Engineering Report P1486-T18 Throughout the drilling operation, soil samples were obtained at 21/2 to 5-foot depth intervals by I means of the Standard Penetration Test (SPT) per American Society for Testing and Materials (ASTM:D-1586),or using a large split-spoon sampler. This testing and sampling procedure consists of driving a standard 2-inch-outside-diameter steel split-spoon sampler 18 inches into the soil with a I 140-pound hammer free-falling 30 inches. The number of blows struck during the final 12 inches is recorded on the boring logs. If a total of 50 blows are struck within any 6-inch interval,the driving is stopped, and the blow count is recorded as 50 blows for the actual penetration distance. The I resulting blow count values indicate the relative density of granular soils and the relative consistency of cohesive soils. IThe enclosed boring logs describe the vertical sequence of soils and materials encountered in the boring, based primarily on our field classifications and supported by our subsequent laboratory examination and testing. Where a soil contact was observed to be gradational,our logs indicate the Iaverage 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 I approximate depth of each soil sample obtained from the borings, as well as any laboratory tests performed on these soil samples. If any groundwater was encountered in a borehole, the approximate groundwater depth is depicted on the boring log. Groundwater depth estimates are I typically based on the moisture content of soil samples,the wetted height on the drilling rods,and the water level measured in the borehole after the auger has been extracted. The soils were classified visually in general accordance with the system described in Figure A-1,which includes a key to our exploration logs. Summary logs of the explorations are included as Figures A-2 and A-7. 3.0 SITE CONDITIONS IThe following sections present our observations, measurements, findings, and interpretations regarding, surface, soil, groundwater, and infiltration conditions. I3.1 Surface Conditions As previously indicated, the project site consists of a historical log and timber storage site for the I Kimberly-Clark Corporation,parcels of which are now owned by the City of Everett or previously listed companies. Several abandoned concrete structures remain alongthe length of the proposed p g P P roadway, water line, and storm line extension. Most of these structures appear partially buried I and/or have fallen into disrepair. Multiple large piles of rubble and construction debris are also scattered, concentrated toward the northern end of the project site. The area appears to be used mainly for stockpiling and storage of shipping containers and truck trailers at present. I The length of the project site and the surrounding area is relatively flat,with very gradual elevation gain from the Snohomish River shoreline east of the site to the BNSF Railroad ROW west of the site. I Vegetation onsite consists mainly of various types of grass, which is tall and unkempt in many I portions of the project area. Ornamental trees line the gravel entrances to some of the parcels owned by the City of Everett, and small saplings have begun to grow in neighboring areas. I IMigizi Group, Inc. Page 3 of 13