9205 4TH AVE W 2025-12-03 - Laserfiche WebLink

July 2, 2008 Duplex Buildings L&A Job No. 8AO67 Page 8 SITE PREPARATION AND GENERAL GRADING Vegetation within construction limits should be cleared and grubbed. Loose fill, topsoil and weak weathered soils should be completely stripped down to very -dense fresh till and/or dense advance outwash soils within the building pads of the duplex buildings, while loose fill, topsoil and unsuitable soil in the root zone should be stripped down to the medium -dense weathered soils and/or dense fresh till soils within the paved driveway. The exposed soils should be compacted to a non -yielding state with a compactor and proof -rolled with a piece of heavy earthwork equipment. TEMPORARY EROSION CONTROL The onsite surficial soils contain a high percentage of fines, and are sensitive to moisture and can be easily disturbed by construction traffic when saturated. A layer of clean, 2-to-6-inch, quarry spalls should be placed over excavated areas and areas of frequent traffic, such as the entrance to the site, as required, to protect the subgrade soils from disturbance by construction traffic. ` Silt fences should be erected along the downhill boundaries of the site to prevent sediment being transported onto adjoining properties or the street by storm runoff. The bottom edge of silt fences should be embedded in a trench and ballasted with crushed rock or gravel. Storm runoff and near -surface groundwater seepage should be intercepted by ditches or interceptor trench drains installed on the uphill side of construction areas. Water captured by such ditches or interceptor trench drains should be discharged into the nearby storm inlet. The storm inlet should be covered with a filter sock to prevent sediment from entering the storm sewer. The filter sock should be cleaned frequently during construction to prevent clogging, and should be removed after completion of construction. LIU & ASSOCIATES, INC.