4920 DOVER ST 2018-01-02 MF Import

CASCADE GEOTECHNICAL July 6, 1987 Job No. 877-3G Shari Barlow and Greg Gabrio Page 2 organic material. The maximum fill thickness found in the test pits was about seven (7) feet 'in the foundation area. Fill was also observed on the slope to the north of the foundation forms. Beneath the fill is a dense sand with a minor amount of silt and gravel. 'Tnis soil unit is probably advance outwash deposited during the last glaciation. No ground water was found in the test pits. CONCLUSIONS The fill found at this site is not suitable for the support of spread footing foundations; the fill should be removed and the footings should bear on the underlying native sand. The fill on the slope on the north side of the house is marginally stable. Some movement of the fill material may occur Ln the future, but we would not expect this movement to affect the house if the fill. is excavated and the foundation is placed on the native, dense sand, at least twenty (20) feet back from the steep slope. More complete recommendations are presented below. RECOMMENDATIONS Spread Footings All uncontrolled fill and topsoil should be excavated from areas where footings will be placed. The native sand soil found below the topsoil and fill is suitable for the support of spread footings meeting local building code requirements. The native sand has an allowable safe bearing capacity of 2000 p.s.f.