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SMNET STL Project No. 0010771 7zwdng Labs Page 8 Grade the site to prevent water/runoff flow over the face of cut and fill slopes. To accomplish this, use asphalt berms, brow ditches or other measures to intercept and slowly redirect flow. Plant all disturbed r areas with erosion resistant vegetation suited to the area. As an alternative, jute netting or geotextile erosion control mats may be considered for control of erosion. Utility Trench Backfill Utility trenches should be excavated according to accepted engineering practice following OSHA (Occupational Safety and Health Administration) standards by a contractor experienced in such work. The responsibility for the safety of open trenches should be borne by the contractor. Traffic and vibration adjacent to trench walls should be minimized and cyclic wetting and drying of excavation side slopes should be avoided. Depending upon the location and depth of some utility trenches, groundwater flow into open excavations could be experienced, especially during or shortly following periods of precipitation. Sandy soil conditions were encountered throughout the site. At some locations, clean sands were encountered 4 to 5 feet below the surface. These cohesionless soils have a tendency to cave in trench wall excavations. Shoring or sloping back trench sidewalls may be required within these sandy soils. Utility trench backfill placed in or adjacent to buildings and exterior slabs should be compacted to at least 90% of the maximum dry density (ASTM D1557). The upper two feet of the utility trench _ backfill placed in pavement areas should be compacted to at least 90 percent of the maximum dry density (ASTM D1557). Pipe bedding should be in accordance with pipe manufacturer's recommendations. The contractor is responsible for removing all water sensitive settlement from the trench regardless of the backfill location and compaction requirements. The contractor should use appropriate equipment and methods to avoid damage to the utilities and/or structures during fill placement and compaction. Foundations Spread and continuous footings can be designed for the following allowable soil bearing pressures: Dead Load Only 1875 psf Dead-Plus-Live Load 2500 psf Total Load, including wind or seismic loads 3325 psf The footings should have a minimum depth of 12 inches below pad subgrade (soil grade) or adjacent exterior grade, whichever is lower. Footings should have a minimum width of 12 inches regardless of load. " 1417 No.Market Blvd.,Suite 1 . Sacramento,CA 95834 . (916)568-5858 • Fax: (916)568-5813