11310 EVERGREEN WAY 2018-01-01 MF Import

\ . .-.� Mr. Sn�ce Vanderwall • Ap�ll 16, 2008 I The contractor may find that it is more expeditlous to remove alt of the fllls from under � ( the pad in the old fill areas if there are too many trenches based on the new foundadon locations. The Individual overexcavated trench margins should be extended laterally beyond the fatlng perimettrs. The trenches should be wide enough to provide an influence line extending dewnward and outward at a 0.5:1 (H:V) betow the base of the fouting. This would mean that where four feet of fill exists below the footlng grade, the -• trench would need to be two feet wider tt�an the inside and outside foodng edge. The variable depth of the flll will determine the varying depth of the fills. Some foundation areas for the new buliding may require over excavatlon due to the .. presence of unforeseen utility trenches, buried topsoil and o:ganic pockets, or other . poorly tompacted old fills. Foundation subgrades in these areas can be brought back bo � � grade with compacted structura� FlII or clean ballast rak. These areas m�y not become evident undl demolidon fs complete and some subgrades are exposed. Foundatlon subgrades should be prepared as recommended in the Site Preparadon and Greding sectlon. Perimeter foundations should extend at least 1.5 feet below final exterior grades for frost protection. Interlor foundations can be constructed at any � convenient depth. All fooUng e�ccavations should be thoroughly recompacted w{th hand equipment following excavation disturbance. For footings bearing on shallow native soils or on compacted structural fill or rock, w2 recommend designing foundations for a net allowable bearing ppacity of 2500 pounds per square foot(ps�. Foundations for the building based at deeper depths on the tlll or for the new storm water vault extended to the tlll may be designed for an allowable bearing capadty of 5,000 psf. All foundations, including interior column footlngs, should be a minimum of 1.5 feet wide. For short-term loads, such as wind and seismic, a 1/3 increase (n this allowable capacity can be used. Based on the soil conditions observed in the borings and the local seismicity, the site fails in Site Class D, in accordance with the 2006 Internadonal Buflding Code. Also, based on our review of the soil conditions, the potential for soil Ifquefaction to occur on this site is low. LaYeralloads For designing foundations to resist lateral loads, a friction coefficient of 0.4 can be used. Passive earth pressures acting �n the sides of the footings and buried portions of the foundatlon stem walls can also be considered. � Project No. 1235- \ Page Nd 7��%