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

O'Donnell, ❑rigl�am & Cartners, N. W. E-].54U May 19, 1901 Paye 8 5tructures may be s�pported on cronventional continuous and indi- �idual spread footings bearing directly on the dense to very dense native till s�ils or on at least two and one-half (2-1/2) feet oE ctructural fill placed in accordance with the Site Prepa- ration section of tliis report. �he structural fill, where used� sliould extend for a lzteral distancc on eitlier side of the footing for a distance equal to tl�p deplh of Eill used. In areas where Eooting elevations will not allow for placement of the tninimum depth oE Cill, the Eootings should be extended down into the dense native till sotls. Perimeter Eootin9s sliould extend to a minimum deptl� of eighteen (10) inchas below the lowest adjacert final grade whlle interior footings may be bottomed twelve (12) inches below grade. Footinqs on the naCive till soils may be decigned for an� allowable .,oil bearing pressure of Cive thousand (5000) psf dea�� plus live loads, and twenty-five hundred (2500) psf on struc- � tural fille. Cantinuous tootings should have a minimum width of Eourteen (]4) inches, and individual column Eooting should ha.e a minimum ]� ''.eral dimension oC twenty-f:our ( 24 ) inches. A r ie- third incre�.se in allowable soil bearing prescure is permissible when consic,ering stiort term lateral loads due to wind :�nd earthquake:+. Where continuous footings extend across the native till soils and the e•tructural fills we recommend that additional steel be placed in the footing. This additional steel should extend a dlstance oE nut less tlian ten (10) feet on either side of tlie transition from natural till soil to structural fill. Individual spread footin9s sliould not under any circumstances be located in a zone oE transition. Should a Eooting be located in such a zone it should be exlended down into firm native bearing material. We recommerd that all footing excavations be examined by a representati•�r from Eartli Consultants, Inc., prior to the place- ment of any iormwork, reinforcing sleel or concrete, to observe compliance Hitli tlie destgn concfepts presented in I:t�is report. Floor Slabs Floor slabs may be supported on native till soils or on structural fill placed in accordance with the Site Preparation section of tliis report. Tlie upper six (6) inches of cut sub- grade area: should be recompacted to at least 95 percent of maximum density. Tlie top four (A) inches oE the supporting media shoild be a free draining sand or gravel to act as a capil- lary brea'.. This requirement may be waived if the supporting media is [cee draining or motsture infiltration will not be a _ problem. Gartli Consullanls, Inc.