1415 75TH ST SW BASE FILE 2016-01-01 MF Import

0'Donnell, d�igham 6 Partners, N. W. E-1540 May 19, 1981 Page 7 be most easily accomplished by excavation with a large bacYnoe or dragline. Tlie excavation, sliould be ma�e in relatively sr.�ll sections, and the excavated area backfilied with compactr:d struc- tural fill as rapidly as possible. Providing that the recommen- dations presented in this report are closely adhered to, we expect Cliat settlements under this deep fill will be on the order of about one (1) inch. The above mentioned settlement magnitudes are based on 95 percent relative conpaction of the overlying atructural fill materials. A lesser degree of relative compaction will increase tl�e magnitude of total settlement. We understand tliat present planning does not call Eor a st�rt to constructton on either of the subject sites in the Immedi�ite future. Consequently, providing lhe fills are placed in accordance with the provisions of the Site Preparation sec- tion of tliis report, and are allowed to remain in an undisturbed condition for as long as po�sible, we are ot tlie opinion that post construction settlements should be reduced in half. For tliis reason we suqgest I:tiat the fills be placed during the coming surtu�er and allowed to remain in place undisturbed until building construction can start. We suggest a waiting period of at least tliirty (30) days. We recommer�d tliat deep fills be �� monitored by means of seltlement markers and if significant differences between the anticipated and recorded settlements are noted, or if the expected settlements cannot be tolerated, we suggest I:liat a surcliarge be placed over the proposed structural fills. The presently existing stormwater retenLion pond fn the northeast corner of tlie wesCern site 'sliould be removed and alternative measures taken to retain or cont:ol the runoEf from the adjacent property. Great care should be taken when remov- ing, or relocating, the retention pond Lo make certain that all soft or wet sediments retained within the pon� area are removed from the site. The tollowing sections of thi� report present more detailed recomraendations for various geotecl�nical engineering aspecls of the project which should be incorporated into the project desi9n and cnnstruction. This report has been prepared Eor specific ' �pplication to this project in accordance with generally acce�,t�Kl geutechnical engineering practices for the exclusive use of 0' Donnell, Origliam and FarCners, N. W. and their repre- sentatives. No other warranty, expressed or impliedr is made. Foundations �ased on tlie design parameters outlined in tlie Project Des- cription section of this report, it is our opinion ttie proposed [arlh Consullanls, Inc.