2710 VIEWCREST AVE 2016-01-01 MF Import

Thomas Kelly JN 95192 June 7, 1995 Page 5 depends on the slab shape and the amount of steel placed in it. Reducing the wate; to cement ratio of the concrete and curing the concrete, by preventing the evaporation of free water until cement hydration occurs,will also reduce shrinkage cracking. P@fIR�0QJ1t_EoUpdaLio��d.Retai�ing Wal(s Retaining walls backtilled 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�Ltlmeter _ _- _Desj9n Value Active Earth Pressure* 30 pcf Passive Earth Pressure 350 pcf Coefficient of Friction 0.40 Soil Unit Weight 120 pcf Where: (1) pci Is pounds per cubic foot. (?.) Active and passive earth pressures are computed using the equivalent fluid densities. * For restrained walls that cannot deflect at least 0.002 times their he?yht, a uniform laterr,! pressure of 100 psf �hould 6e added to the above active equivalent fluid pressure. The values given above are to be used to design permanent foundation and ratalning walls only. We recorrmend a safety factor of at least 1.5 for overturning and slfding, when using the above recommended values to design walls. The design values given above do not include the effects of any t�;�drostatic pressures behind the walls and assume tha; no surcharge slopes or loads, such as vehicles, will be placed behind the walls. If these conditions exist, those pressures should be added to !he above lateral soil pressures. Also, if sloping backfill is desired behind the walls, we will need to be given the wall dimensions and the slope of the backfill in order to provide the appropriate design earth pressures. Heavy construction equipment should not be operated behind retaining a7d foundation walls within a distance equal to the height of �� wall, unless the walls are designed for the additional lateral pressures resulting from the equipment. The compactio,i of backfill near GIiOl7iC11 CONSUI:Ii�N9ti,INC