20 SW EVERETT MALL WAY Geotech Report 2018-01-02 MF Import

-- Campbell-Fleury Investments/Mallwest Center 9 April 1986 W-3103-1 Page 3 _ site with a manhole located at itc northern end. The culvert exits at the ground surface at the southern end of the site. Water was seen flowing from the culvert into a drainage stream at the time of our visit. A low, boggy area is present - outside this parcel on the north side of Everett Way. The proje�t site has been cleared and graded in the past. The site may likely be a continuation of the boggy _ area present to the north of Everett Mall Way. _ 3.2 Subsurface Conditions The subsurface exploration program for the study consisted of seven backhoe-excavated test pits. The exploration procedures and interpretive logs are presented in Appendix A of this report. The gross subsurface conditions across the site appeared to be fairly uniform at our test pits consisting of loose fill above a relic topsoil — stratum, underlain by dense native deposits. However, a variable thickness of surficial fill was observed. Generally, a gravelly, silty sand fill was encountered -- below ground surface in the western triangular portion of the site. The fill thickness variPd from 1-1/2 feet in test pi; TP-6 to 4 feet in test pit TP-2 and TP-5. _ The interpreted relative density of the fill soils varied. from louse to medium dense. The fill was general�y variable in color from dark brown to gray with inter- mixed organics, wood fragments and construction debris. This type of soil is generally highly compressible and has low strength characteristics. Basec' on observations made ir� the fie7d and office, it appears that the majority of the fill was placed in the western triangular portion of the site. Beneath the fill soils, native y�ry loose to very dense, silty sands with some -- gravel and gravelly silty sands were disclosed. Addii:ionally, stiff to very stiff - clayey silts were also encountered. At the contact between the fill and native _ soils, a very loose, highly organic and compressible sandy silt occurs. This material may represent a relic oi• buried topsoil horizon. At the eastern third of W the site native soils occurred a;. the surFace. These soils consisted of loose to medium dense, silty sand with some gravel and dense to very dense, gravel�y, silty y sand. The surficial soils contained a 1/2 foot rooty, grass mat. In most cases, contacts between soil ty,r,es k,ere gradational and have been interpreted.