6300 MERRILL CREEK PKY BASE FILE 2018-01-01 MF Import

Quadrant JN 97092 . August 13, 1997 Page 5 We recommend proof-roiling slab areas with a heavy� truck or a large piece of construction equipment prior to slab construction. Any soft areas encountered during proof-rolling shouid be excavated and replaced with select, imported, structurai fill. Permanent Foundation and Retainina Walls Retaining walls backfilled on only one side should be designed to resist the lateral earth pressures imposed by the soil they retain. The foilowing recommended design parameters are for walls that restrain level backfill: Paremeter Design Value .Active'Earth.Pressure.• I 35 pcf .........._.........._..................._._....._P_....._....... Passive Earth Pressure � 300 cf ........................................_...................._._............_.............._................................ 'Coefficient oF Friction � 0.50 . ......._....._................_......__....._._.....__.............._ . Soil Unit Weight � 135 pcf Where: (I) pcf Is pounde per eubic foot, and (II) aellve and passlve earth pressures are computed using the equlvalent flu�d pressums. •For a restralned wall that cannot deflect at least 0.002 tlmes Its helght,a unllortn Iaterai preasure equal to 10 psf times lhe helght of the wall should be added to the above aetive equivalent 11u1d prussure. The values given above are to be used to design permanent foundation and retaining walls only. The passive pressure given is appropriate for the depth of level, structural fill placed in front of a retaining or foundation wall only. We recommend a safety factor of at ieast 1.5 for overturning and sliding, when using the above values to design the 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, wili be placed behind the walls. If these conditions exist, those pressures should be added to the above lateral soil pressures. Aiso, 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. 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. lieavy construction equipment should not be operated behind retaining and foundation walls within a distance equal to the height of a wall, unless the walis are designed for the additional lateral pressures resulting from the equipment. The wall design criteria assume that the backfill will be well-compacted in lifts no thicker than 12 inches. The compaction of backfill near the walls should be accomplished with hand-operated equipment to prevent the walls from being overloaded by the higher soil forces that occur during compaction. GEOTECH CONSULTANTS,INC.