3003 W CASINO RD BLDG 40-56 Geotech Report 2018-01-02 MF Import

beyond the boundary of the organic rich soil as indicated on Plate 9. We estimate that the surcharge w` l induce settlement magnitudes of approximately 2 to 4 inches. The settlement rate is difficult to assess due to the random nature of the subsoils. The estimated surcharge time varies over a wide range. Considering the degree of uncertainty, a wont case scenario may require a surcharge time as much IS 5 months. However, we believe that a period of 2 to 3 months is a more realistic estimate. The settlement of the surcharged soils should be monitored to mist in evaluating the time at which surcharging may be terminated. Hydraulic settlement measuring devices should be used. These devices are easily read and are less susceptible to damage by construction equipment. Measurements should be taken initially prior to the placement of the fill, daily until fill placement is complete and twice weekly thereafter during the surcharge period. Settlement data should be transmitted to Dames A Moore on a timely basis so that we an assess the progress of settlement resulting from the surcharge program. 5.5 PEDESTRIAN TUNNELS/PRESS PITS/UTILIDORS 5.5.1 Foundation Sunoort And ¢ettlement We anticipate that the tunnel walls will be supported on wall footings constructed on fill soil. Alternatively, the tunnel could be designed as a rigid member which would then act as a mat foundation. In either case, the allowable bearing capacity of the fill should be 2,500 psf if prepared according to the following recommendations. The tunnel subgrade should be overexavated by at loot 2 feet and backfilled with select fill. The criteria for the fill material and compaction method rue presented in a later section titled "SITE PREPARATION". Prior to the placement of any compacted fill, the exposed subgrade should be thoroughly proof -rolled, and any soft zones overexavated. a-005.00695.016\ssos0l00.wV 00695.509.0% 17