7501 HARDESON RD BASE FILE 2018-01-02 MF Import

CASCADE GEOTECHNICAL INC. June 2, 1994 Job No. 9405-02G unsuitable soils in these wet areas. If encountered, these soils should be removed to a suitable bearing surface prior to placement of structural fill, pavement, foundations, or slab -on -grade floors. 8.2 Cut and Pill Requirements We recommend tha., the walls of temporary excavations within the on -site, moist, dense to very dense silty sand (SM) and sand (SP), or very stiff to hard silt (ML) be excavated to a grade of 0.511:1V or flatter. If these soils are wet to saturated, the cutslope angle should be flattened to a grade of IH:1V or flatter. It may be possible to stabilize saturated sand cutslopes at an angle of 0.511:1V if well points are installed so that dewatering strengthens the face of the cut. Caving of the test pit walls excavated within the on -site uncontrolled fill indicates that excavations within this soil that are deeper than four (4) feet should be sloped to an angle of 1H:1V or flatter. We recommend that temporary bracing or shoring of excavation walls be provided for any excavations that are deeper than four (4) feet, if the excavation walls cannot be suitably sloped. Stockpiled fill slopes should not be steeper than 1H:IV. Final excavation slopes or unreinfor+ced fill slopes should be graded to an angle of 2H:1 V or flatter. We recommend that exposed soils be immediately hydrosoeded and/or planted with vegetation after construction. Drainage should be provided in locations where cut slopes or utility excavations intercept ground water. The results of our laboratory sieve analyses indicate the on -site silty sand (SM) may be used as structural fill for raising grades. The on -site sand (SP) may also be used as structural fill material. These soils must be placed at or just below their optimum moisture content. Due to moisture sensitivity, the on -site silt (ML) would be extremely difficult to compact properly. It may be more feasible to import fill as described below than attempting to compact the on -site silt. Based on samples of uncontrolled fill retrieved from DCPT/MSS q6, it appears some of this material may be reused as structural fill. The uncontrolled fill must be removed down to a suitable subgrade, and replaced and compacted in accordance with the recommendations given 10