17 E MARINE VIEW DR 2019 Geotech Report 2025-10-01

Excavation Considerations We understand that the site grade will not be significantly altered within the project area, and that the majority of earthwork will be limited to the excavation for shallow foundations and shallow underground utilities.Surficial soils consisting of loose to medium dense granular fill were observed in the explorations. We anticipate that these materials can be excavated with conventional excavation equipment, such as excavator or dozers. Because of the past industrial development at the site and presence of extensive fill, some construction debris or obstructions could be encountered during excavation at the site. Clearing and Grubbing The majority of the site is currently gravel surfaced driveway, parking and stockpile areas. We understand that existing improvements will be demolished prior to constructing the planned facility. Any remaining foundations or other below-grade elements from previous site development should be removed, if encountered. Debris and rubble present in the surficial fill soils should be removed from below the planned structures, where present. Subgrade Preparation Subgrade soils will consist of uncontrolled fill. Prior to placement of structural fill, we recommend that the subgrade soils below paved areas and structures be uniformly compacted to at least 95 percent of the MDD per ASTM D 1557. Any soft or organic existing fill or fill that cannot be compacted to a firm and unyielding condition should be removed and replaced with structural fill as directed by the filed geotechnical engineer. Structural fill placed below footings should extend 2 feet beyond the edges of the footings or a minimum lateral distance equivalent to the depth below the footings, whichever is greater. We recommend that a member of our firm observe the building subgrades to confirm that they are consistent with our assumptions for this report. The structural fill should then be placed over the prepared subgrade and compacted in accordance with the earthwork recommendations in this report. Structural Fill All fill that will support foundations,floor slabs, or pavement areas, or be placed against retaining walls or in utility trenches should generally meet the criteria for structural fill presented below.The suitability of soil for use as structural fill depends on its gradation and moisture content. Materials Materials used to provide foundation support and to construct pavement areas backfill utility trenches are classified as structural fill for the purpose of this report. Structural fill material quality varies depending upon its use as described below: 1. Structural fill placed below all building foundations and floor slabs and during wet weather conditions should consist of imported Gravel Borrow,as described in Section 9-03.14(1)of the 2018 Washington State Department of Transportation(WSDOT)Standard Specifications. 2. Structural fill placed to backfill utility trenches may consist of suitable on-site excavated soils provided that the soils are conditioned for the required compaction and placed during dry weather conditions from June through September. If structural fill is placed during wet weather, the structural fill should consist of imported gravel borrow. GEOENGINEERS) August3,2018 Page 13 File No.0643-015-00