3313 OAKES AVE 2020-07-14 - Laserfiche WebLink

GeoTest Services,Inc. December 9,2016 3313 Oakes Avenue,Everett,WA Job No. 16-0659 and a parking lot serving a two-story office building borders the subject property to the north. As mentioned previously, the owner of the subject property also owns the adjacent property to the north. The subject property is currently vacant and covered with tall grass, with a large tree situated at the south-central portion of the property. The western portion of the property is only partially covered with grass. We understand that there was an old single-family residence that used to occupy the western portion of the subject property. Based on a review of aerial imagery from Google Earth, it appears that a large portion of the existing house structure was removed in 2007, with the remaining above-grade remnants removed by 2012. From the western property line (approximate elevation 143 feet), the ground generally slopes to the east at a gentle rate, then steepens slightly towards the eastern property line, over approximately 7 feet of vertical relief. A retaining wall runs along the entire length of the southern and eastern property lines. This wall varies in height to a maximum 8 feet along the eastern property line. The foundation for the southern portion of the wall varies from near the surface at its western end to near alley level at its eastern end. Another retaining wall runs parallel to the northern property line adjacent to the neighboring parking lot. This wall steps down to the east and is approximately 5.5 feet in height at its highest point. Subsurface Soil Conditions Subsurface conditions were explored by excavating and sampling five test pits (TP-1 through TP-5) on November 18, 2016. The test pits were advanced to depths of 2.5 to 7.5 feet BGS. All test pits were excavated until the soils were very difficult to excavate, or large obstructions were encountered (TP-3). All of the test pits (except TP-4) encountered a thin layer of loose, organic topsoil directly underlying the surface. The test pits excavated in the eastern half of the site (TP-1 and TP-2) encountered approximately 1 to 3 feet of loose, silty sand fill underlying the near- surface topsoil. Underlying these soils was loose to medium-dense, native, weathered, silty sand that became unweathered and dense to very dense at an approximate depth of 5 to 6 feet BGS. The very dense soils were encountered to the maximum explored depth of the test pits. TP-3, which was excavated near the northeast corner of the proposed western building footprint, encountered loose fill directly underlying the near-surface topsoil. At an approximate depth of 2.5 feet BGS, concrete debris was encountered, including a concrete slab that was still intact and in place. This appeared to be part of the foundation and slab of the old residence that occupied the western half of the subject property. As a result, the next test pit (TP-4) was excavated approximately 10 feet west of TP-3. TP-4 and TP-5 encountered the native, weathered, silty sand at or near the existing ground surface. The unweathered, dense to very dense soils were encountered at approximately 1 to 1.5 feet BGS. These soils were encountered to the maximum explored depth of the test pits. Page 3 of 17