4027 4TH ST SE 2018-01-01 MF Import

January l4, 2003 HWA Proiect No. 2002-146-21 There is no structucal need to fiU under the building and fill in this azea will increase settlemrnt The driveways and pazking azeas need to be designed for drainage (before and afta settlement) and to be functional with respect !o the building. We recommend keeping &II to a minimum where practical. Fill will affect the ground immediately unda that fill and the surrounding area for some distance away. Fill placed over the 54" sewer line to the west of the new building will cause settlement of the line. Based on our understanding that the maximum amount of fill to be placed over the pipe will be about 3 feet, the pipe may experience up to 8 inches of settlement. If this settlement is greater than what the pipe can accommodate, lightweight fill may be used to reduce the magnitude of the settlement We do not recommend placing pre-load out-side the footprint of the new building (i.e. over tiie: existing utilities). 4.4.4 Preloading Prcloading would be an optiou to limit post construction settlement of the site fills and d�e need for extreme utility flexibility. It will not eliminate the need for flex'rble coupiings between pile-supported and non-pile-supported features nor will it reduce the need to design the piles for downdrag. If the preload is used it must be placed over the entire building footprint or post construction settlement of the building will be more in the poRion not preloaded. Herein we have used the ter�n preload to be the total weight placed on the site during preloading. It is possible that only part of the preload fill will be removed leaving some site fill. The term surcharge is used for the preload fill that is above the pertnanent site till. We have assumed that the preload will be fill that has a unit weigh 130 pcf in a moist condition. We recommend that the preload be at least rivice the avetage load that will finally be applied to the site and a minimum of G00 psf (i.e. 4.6 feet of 611). We understand the full height of the preload is to be confined to the footprint of the new building due to site constrainLs. Il�c longer thc preload is left in place the less post construction settletnent will be experi�nced. The organic silt is expected to have a lazge primary consolidation component, most of �vhich will occur over a period a few weeks ro months. It is also expected to have a significant secondary component, which will decrease with time but be significant over a period of many years. Settlement should be monitored during the preload period through the use of simple settlement plates. Fills should be placed and compacted in accordance with project specifications within the preload area, to design finish grade plus 6 inches. The additional 6 inches is to allow for 7002146 mpon • final 13 HWA GEOSCIENCES INC.