8417 EVERGREEN WAY Geotech Report 2022-10-25

Geotechnical Engineering Report- Revised l��rracon Proposed CFT Retail Everett,Washington February 1, 2018 Terracon Project No. 81185002 4.4 Floor Slabs We recommend complete removal of existing fill encountered below the proposed building floor slab, as described above for the foundation subgrades. Removed soil should be replaced with structural fill placed and compacted in accordance with the Earthwork section of this report. A subgrade prepared and tested as recommended in this report should provide adequate support for lightly loaded floor slabs. 4.4.1 Design Recommendations DESCRIPTION RECOMMENDATION Interior floor system Slab-on-grade concrete.' Minimum 4 inches of capillary break 2 above at least medium Floor slab support dense native soil or structural fill placed and compacted in accordance with the Earthwork section of this report. 1. Floor slabs should be structurally independent of any building footings or walls to reduce floor slab cracking caused by differential movements between the slab and foundation. Narrower, turned- down slab-on-grade foundations may be utilized at the approval of the structural engineer. The slabs should be appropriately reinforced to support the proposed loads. 2. Capillary break material placed below floor slabs should meet the general requirements shown in the table below and L.A. Wear and % Fracture requirements of WSDOT Section 9-03.9(3). This layer serves as a capillary break layer, a drainage layer, a leveling layer, and a bearing layer. Gradation Requirements for Capillary Break Sieve Size or Diameter Percent Passing 11/2 inch 100 '/z inch 20 to 100 No. 4 10to70 No. 10 0 to 30 No. 100 0 to 5 No. 200 0 to 3 We recommend subgrades be maintained at the proper moisture condition until floor slabs are constructed. If the subgrade should become desiccated prior to construction of floor slabs, the affected material should be removed or the materials scarified, moistened, and recompacted. Upon completion of grading operations in the building areas, care should be taken to maintain the recommended subgrade moisture content and density prior to construction of the building floor slabs. Where appropriate, saw-cut control joints should be placed in the slab to help control the location and extent of cracking. For additional recommendations refer to the ACI Design Manual. Responsive Resourceful Reliable 12