1910 MERRILL CREEK PKY 2018-11-15

Mr. Darren Peugh January 19, 2004 Where moisture by vapor transmission is undesirable, we suggest placing a durable plastic membrane over the capillary break material. The membrane should be sealed at the building perimeter with joints overlapped a minimum of six inches and taped or glued. To protect the membrane from damage during constnYction and to aid in uniform curing of the floor slab, we suggest covering the membrane with two inches of capillary break material. For thickness design of the slab subjected to point loading from storage racks and forklift ve]Zicle traffic, we recommend using a subgrade modulus (kS) of 300 pounds per cubic inch (pci). Retainin� Walls Based on review of proposed construction grades, building walls along the east perimeter and portions of the north and south perimeters will support an unbalanced soil loading and; therefore, will need to be designed as retaining walls. The magnitude of earth pressure development on the walls will partly depend on the quality of the wall backfill. We recommend placing and compacting wall backfill as structural fill, as described in the Site Grading and Preparation section of this report. Because the unbalanced soil load will occur from the interior covered portion of the structure, we do not believe installation of wall drainage to prevent hydrostatic loading will be necessary. However, if there is a potential for water to travel towards the wall from within the interior portion of the structure, such as from a water line leak, installation of the wall drainage should be considered. With wall backfill placed and compacted as recommended, we recommend designing unrestrained walls for an active earth pressure equivalent to a fluid weighing 35 pc£ Tf the walls are restrained at the top, an additional uniform lateral pressure of 100 psf should be included in the wall design. If surcharge loading from equipment or product storage occurs within five feet of the walls, the imposed loading should also be considered in the wall design. Friction at the base of foundations and passive earth pressure will provide resistance to these lateral loads. Values for these parameters are provided in the Foundations section of this report. Rockeries As noted earlier, rockery construction will be used to face near-vertical grade transitions created by the planned site grading. The wall locations are shown on Figure 2. The west wall will have a maximum height of 7.5 feet and will be constructed against a native soil cut. Rockeries at the north and east perimeter wi11 be constructed against structural fill with heights ranging from 2.0 feet to a maximum of 9.5 feet. In our opinion, soil conditions observed at the site will be suitable far support of rockery construction. Rockeries that face fill material and exceed a height of four feet should be constructed with a reinforced structural backfill zone. Recommended construction details for rockery construction are attached as Figures 5, 6, and 7. The rockeries must be constructed by a qualified rockery contractor following guidelines established by the Associated Rockery Contractars (ARC). All rock used in the rockery construction should meet �Vashington State Department of Transportation (WSDOT) requirements presented in their Standard Specifications 9-13.7, Rock for Rock Wall. The rockery contractor should provide you with the appropriate documentation verifying rock quality prior to bringing any rock onto the site. Project No. T-5471 Page No. 7