22 ATTACHMENT 02 - Laserfiche WebLink

July 2, 2012 Job No. 1806.101A Page 3 SITE GRADING The on-site soils are generally suitable for engineered fill, provided they are free of debris, significant vegetation, rocks greater than 6 inches in largest dimension and other deleterious matter. In engineered fill and building pad areas, the upper foot of existing ground should be overexcavated, and the exposed grade should be scarified to a depth of about 12 inches,properly moisture conditioned to at least 3 percent above the optimum moisture content and compacted to a minimum of 90 percent relative compaction as determined by ASTM D1557. Cut and fill slopes should be graded at 2H:1 V. Fill slopes should be keyed and benched into the hillside and should include a subdrain. Keyways should slope back into the slope at a 5 percent gradient, extend a minimum of 4 feet into completed soil, and have,a width of 15 feet or half the fill slope height, whichever is greater: All fill should be compacted to a minimum of 90 percent relative compaction (ASTM D1557) at 3 percent above optimum. Horizontal benches should be excavated to key the fill into native material. A keyway subdrain should be located along the upslope side of the keyway and consist of a 6; inch diameter perforated PVC pipe placed holes down surrounded by 6 inches of Class 2 Permeable .Material. ,The subdrain should discharge via a closed pipe to the proposed storm drain system. We recommend that supplemental investigations be performed for each proposed residence when specific house plans become available. Foundation recommendations can be provided upon request. We trust this provides the information needed at this time If you have any questions, please contact us. LIMITATIONS The conclusions and recommendations of this geotechnical investigation report are based on the information provided to us regarding the proposed development, subsurface conditions encountered at the test pit locations, laboratory tests and professional judgment. The study has been conducted in accordance with current professional geotechnical engineering standards; no other warranty is expressed or implied. The locations of the test pits were estimated by pacing from existing features and should be considered approximate only. The test pits show subsurface conditions encountered at the locations and dates indicated; it is not warranted that they are representative of such conditions at other Iocations or times. BERLOGAR STEVENS&ASSOCIATES