16 ATTACHMENTS - Laserfiche WebLink

r'roject No. JB-569 20 June 2006 Page 8 All import fill must be compacted to a minimum relative compaction of 90 percent of the maximum dry density and moisture-conditioned to a minimum of 2 percent over the optimum moisture content according to ASTM test methods and procedures. The import fill should be non-expansive, free of deleterious materials, and meet the requirements in Table 2. Samples of any proposed import fill planned for use on this project should be submitted to our representative for approval and appropriate testing no less than 4 working days before the expected delivery to the job site. Table 2 IMPORTED MATERIAL REQUIREMENTS Sieve Size Percent Passing 6 inches 1150 mm) 100 4 inches (100 mm) 95 - 100 #200 5-25 Plasticity (PU = 12 or less Liquid Limit ILL) = 30 or less Clay soils should not be allowed to dry out and crack. Any dried clay soils should be wetted until they reach acceptable moisture contents or they can be excavated and replaced with acceptable properly compacted fill. 6.1.5 Cut Slopes Cut slopes should not be steeper than 2H:1 V. We recommend all cut slopes be evaluated by our engineering geologist during earthwork operations. If adverse bedding or other zones of weakness either in the bedrock or soil materials are encountered additional recommendations will be provided. 6.1.6 Fill Slopes Fill slopes should not be steeper than 2H:1 V. For fill placed on native or cut slopes or reconstructing a slope area, we recommend that a keyway be excavated at least 3 feet into the underlying competent bearing soil or bedrock at the toe of the proposed fill as shown on Figure 9. The bottom of the keyway must be a minimum width of 10 feet and be sloped a minimum of 2 percent downward into the hillside. The total depth and width of the keyway and the extent of the fill slope configuration will be determined in the field during grading by our representative. A subdrain system must be installed in the keyway to collect migrating water. The subdrain system should consist of '/Z by 3/<-inch clean drain rock wrapped in ~Korbmacha~rptOgedeelrt~r~ge(O~extlle with a perforated rigid 4-inch-diameter PVC (sch. 80)