15 ATTACHMENT 9 - Laserfiche WebLink

Project No. 9929.G Geotechnical Investigation/Vineyard Avenue, Pleasanton 8 August 2003 23. Fill slopes must be compacted as the filling operation progresses by (1) using sheepsfoot- type rollers in conjunction with proper moisture conditioning, or (2) over-constructing the fill slopes and cutting back the looser surface soils to a firm and adequately compacted design slope grade. Track-walking of slope surfaces does not provide adequate soil densities and is an unacceptable method of slope compaction. 24. Cut and fill slopes may experience severe erosion when grading is halted during rainy weather. Before work is stopped, a positive gradient away from the slopes must be established to carry the surface runoff water away from the slopes to areas where erosion and sediment can be controlled. 25. After completion of the slope grading, erosion protection must be provided. Slope planting, preferably with deep-rooted native plants, must be completed on all exposed surfaces of cut and fill slopes. Graded slopes should not be left exposed through a winter season without the completion of erosion control measures and slope planting. Surface and Subsurface Drainage 26. The slope gradients are based on strength characteristics of the materials under conditions of normal moisture content that would result from rain water falling directly on the slope but do not take into consideration the additional seepage forces from springs or subsurface water areas. Areas of observed seepage, as discovered during grading operations, should be provided with subsurface drains below the surface of the slope as directed by the Soil Engineer. Subsurface drainage facilities may include gravel blankets, rock-filled trenches, or horizontally-drilled drains. 27. No ponding of storm water is to be permitted on the building pads during prolonged periods of inclement weather. TERRASEARCH, inc. Page 18 of 53