Laserfiche WebLink
Geotechnical Engineering I ptort Irerracon <br /> SN4924—Silver Lake North Cell Tower Everett, Washington <br /> October 24, 2014 Terracon Project No. 81145043 <br /> For the equipment shelter subgrades, we recommend that the subgrades be stripped of <br /> unsuitable materials, and overexcavated to allow at least 4 inches of granular fill to be placed <br /> beneath the slab. To provide a capillary break, the granular fill should consist of clean, free- <br /> draining, uniformly graded gravel, containing less than 5 percent fines, based on that soil <br /> fraction passing the US No. 4 sieve. In addition, the subgrades for the equipment shelter should <br /> be evaluated by a qualified geotechnical engineer to identify any unsuitable areas. Unsuitable <br /> areas identified by visual observation and/or probing should be removed and replaced with <br /> compacted structural fill. <br /> 4.2.3 Fill Material Requirements <br /> All fill materials should be inorganic soils free of vegetation, debris, and particles larger than <br /> three inches in size. Pea gravel or other similar non-cementitious, poorly-graded materials <br /> should not be used as fill or backfill without the prior approval of the geotechnical engineer. <br /> Approved imported materials or onsite fill materials may be used as fill material for the following: <br /> general site grading foundation backfill <br /> foundation and slab areas trench backfill <br /> Fill Type Specification Acceptable for Placement <br /> All locations across the site,with the exception <br /> Common Fill z WSDOT3 Section orro 4(3)for of foundation base materials <br /> Common Borrow <br /> Dry Weather only. <br /> z WSDOT3 Section 9-03.14(1)for Gravel All locations across the site, <br /> Select Fill Borrow Wet Weather and Dry Weather acceptable. <br /> Crushed WSDOT3 Section 9-03.9(3)for Crushed All locations across the site. Recommended for <br /> Aggregate Surfacing (Base Course and Top Course finished base course materials for foundations <br /> Base(CAB) sizes) and slabs. <br /> 1. Controlled, compacted fill should consist of approved materials that are free (free = less than 3% by weight) of <br /> organic matter and debris (i.e. wood sticks greater than '/Anch in diameter). Frozen material should not be used, <br /> and fill should not be placed on a frozen subgrade. A sample of each material type should be submitted to the <br /> geotechnical engineer for evaluation. <br /> 2. Materials within 1-foot of footings should have a maximum particle size of 3 inches. <br /> 3. 2014 version of the Washington State Department of Transportation (WSDOT)Standard Specifications. <br /> Responsive■ Resourceful■ Reliable 4 <br />