1318 37TH ST Geotech Report 2018-01-02 MF Import

� • � _ JN 97072 James Pirie • . March 18, 1997 Page 6 be placed beneath the slab. Additionally, sand should be used in the ime-grading process to reduce damage to the vapor b��rier, to provide uniform support under the slab, and to reduce shrinkage cra;.king by improving the ccncrete curing process. Permanent Foundation and RetaininG Wa11s Retaining walls back911ed on only one side should be designed fo resist tt e lateral earth pressures imposed by the soil they retain. The following recommended design parameters are for walls that restrain level backfill: . Parameter Desiqn Value �_ � �-a�. S •,� Active Earth Pressure' 35 pcf �c Zi � Passive Earth Pressure 350 pcf _ Coefficient of Friction 0.45 Soil Unit Weight 130 pcf Where: . 1. pcf is pounds per cubic foot. 2. Active and passive earth pressures are computed using the equivalent fluid � densities. .> ' For a restrained wall that cannot deflect i at least 0.002 times its height, a I, uniform lateral pressure equal to 10 psf �v�?? I times the height of the wall should be --' � added to the above active equivalent fluid pressure. • "' � The values given above are to be used to design permanent foundation and retaining walis only. � The passive aressure given is appropriate for the depth of level, structural fill placed in front of a � retaining or fouridation wall only. VVe recommend a safety factor of at least 1.5 for overturning and � sliding, when using the above values to design the walis. The design values given above do not include the effects of any hydrostatic pressures behind the h walis and assume that no surcharge slopes or loads, such as vehicles, will be placed behind the � walls. If these conditions exist, those pressures should be added to the above laterai 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 appr�priate design earth pressures. The surcharge due to traffic loads behind a wall can typically be accounted for by adding a uniform pressure equal to 2 feet multiplied by the above active fluid density. Heavy construction equipment should not be operated behind retaining and foundation walls within a distance equal to the height of a wall, unless the walls are designed for the additional lataral pressures resulting from the equipment. The wall dzsign criteria assume that the backfill will be ��20 ' UGOTECH CONSULTANTS,INC. - - , r�'� '�' � � �%� �i ' � _,,,. �p�'< f ' > ' , ;ta� , ^ y �(� { f f p Y J� � i � I �}�y .ed 5 tt l p i J �� fi f � ,f - i+� �, �Y,^^eY y � r .J,j% i' {r j f � '' � rt•'(il '.i � - a � "k T{V ,�.Y.- . Y :_i{� _ � 1 S i'" c "�,� ` �* J: '� r� t aj { � . . .: t � 4 �S. ��1.'iv.�-�1w%Y...�i' f.1:. . . , . . ,. � _ ... . r.x/?�a'I