2710 VIEWCREST AVE 2016-01-01 MF Import

Thomas Kelly June 7, 1995 �N 95192 Page 5 depends on tlie slab shape and the amount of steel placed in it. Reducing the water to cement ratio of the concrete and r,uriny the concrete, by preventing tho evaporation of free water until cement hydration occurs, will aiso reduce shrinkage cracking. PermansnLEqundati9n�r,dRetsining Wal�� Retaining walls backiiiled on only one side should be designed to resist the lateral earth pressures imposed by the soils they retain. The following recommended design parameters are for walls less than 12 feet in height that restrain level backfill: P�[�SQr __ _J2ssi9[�lu€ Active Earth Pressure* 30 pcf Passive Earth Pressure 350 pcf Coetticient of Friction 0.40 Soil Unit Weight 120 pcf Where: (1) pcf is pounds per cubic foot. (2) Active and passive earth pressures are computed using the equivalent iluid densities. ' For restrained walls that cannot deflect at least 0.002 timss their height, a uniform lateral oressure of 100 psf should be added to the above active equivalent fluid pressure. The values given above are to be used to design permanent Toundation and retaining walls only. We recommend a satety factor of at least 1.5 tor overturning and sliding, when using the above recommended values to design walls. The design values given above do not include the effects of any hydrostatic pressures behind the walls and assume that no surcharge slopes or loads, such as vehicles, will be placed behind the walls. If these conditions exist, those prassures should be added to the above laterd! soil pressures. Also, ii sloping backfill is desired behind the walls, we will need to be given the wall dimensions e;�d the slope of the backfill in order to provide the appropriate design earih pressures. Heavy construction equipment should not be operated behind retaining and foundation walis within a distance equal to the height of a wall, unless the walls are designed for the additional lateral pressures resulting from the equipment. The compaction of backfill near GIiOITiCII CONSULTAKIS,�NC j i