2414 BAKER AVE 2017-01-13 - Laserfiche WebLink

Tom Eiden J N 101 i 4 June 21, 2010 Page 4 differential settlements on the order of one-half inch in a distance of 50 feet along a continuous footing with a uniform load. Lateral loads due to wind or seismic forces may be resisted by friction between the foundation and the bearing soil, or by passive earth pressure acting on the vertical, embedded portions of the foundation. For the latter condition, the foundation must be either poured directly against relatively level, undisturbed soil or be surrounded by level structural fill. We recommend using the following ultimate values for the foundation's resistance to tateral loading: ,.. � Coefficient of Friction 0.50 Passive Earth Pressure 350 pcf Where: (i) pcf is pounds per cubic foot, and (ii) passive earth pressure is computed using the equivalent fluid density. PERMANENT FOUNDATION AND RETAIN/NG WALLS Retaining walls backfiiled on only one side should be designed to resist the lateral earih pressures imposed by the soil they retain. i he following recommended parameters are for walls that restrain level backfill: Where: (i} pcf is pounds per cubic foot, and (ii) active and passive earth pressures are computed using the equivalent fluid pressures. * For a restrained wall that cannot deflect at least 0.002 times its height, a uniform lateral pressure equal to 10 psf times the height of the wall shouid be added to the above active equivalent fluid pressure. The values given above are to be used to design permanent foundation and retaining walls only. It is not appropriate to back-calculate soil strength parameters from the earth pressures and soil unit weights presented in the table. The passive pressure given is appropriate for the depth of level structural fill placed in front of a retaining or foundation wall only. The values for friction and passive resistance are ultimate values and do not include a safety factor. We recommend a safety factor of at least 1.5 for overturning and sliding, when using the above values to design the walls. Restrained wall soil parameters should be utilized for a distance of 1.5 times the wall height from corners or bends in the walls. This is intended to reduce the amount of cracking that can occur where a wall is restrained by a corner. GEOTECH CONSULTANTS, INC.