711 112TH ST SE 7 ELEVEN Geotech Report 2018-01-02 MF Import

Subsurfan Ezplormion nnd Proposcd 7-Eleven Propertv Geotechnica! Engineering Report Everett Washingron DesiRn Recommendarions during site preparation and excavatioii operations so that these underlying soils are not sokened. If disturbance occurs, the softened soils should be removed and the area should bc brought to grade with structural fill compacted to at least 90 percent of its maximum dry densiry as determined by ASTM:D 1557. Site preparation for Floor support should consist of recompacting the exposed ground surface to at least 90 percent of the modified Proctor maximum dry density, proofroiling thc exposed subgrade, and replacing any soft ar..� with structural 611. 7.0 EROSION CONTROL To mitigate the erosion hazard and potential for off-sire sediment vansport, we recommend the following: 1. Since the on-si[e fill soils are moisture-sensitive, construction should proceed during the drier periods of the year. 2. 3ilt fences should be erected around the grading areas and erosion control measures should remain in place until permanent vegetation is established or the impermeable asphalt/concrete surfaces completed. 3. A construction entrance consisting of a quarry rock mat should be installed per Ciry of Evemtt guidelines. 4. Temporary stockpiles of soil should be protected from erosion by covering with plastic sheeting. 5. All storm water from impermeable surfaces, induding roadways, driveways, and roofs should be directed into an approved storm water conveyance system. S.0 S'IRUCTURAL PILL As shown on the Site and Bxploration Plan (Figure 2), building, parking lot, and sidewalk grades will require strucmral fll up to 3 feet thick ro establish the desired grades, especially near the existing slopes. We anticipate that the surface of the existing fill slopes will contain relatively loose soil containing some construction debris and will require some overexcavation to provide a suitable base for fill placement. Further recommendations are provided below. ;ti/nrch !9, 200/ ASSOGA7ED FaRTFi SGENCES SH!l�np � RflMA9f,9d1 � U�.ICI''ryrJ111 - R.R P`�ge 7 �