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� ,nry t�, ��e �` Northern, r��. <br /> Proj�et No.296-004 <br /> 1 <br /> a.3 Foundatlon P/aca�nent • . <br /> � The on-site medium dense to dense sand (SP)and dense sandy gravel(GP)or propaly <br /> piaced and compacted stniccural fiU, aze suitabie for the wpport of building loads designed 6ar <br /> � a maximum aafe bearing capacity of 2,000 pst Concrete continuous strip and apread footiegs <br /> may be placed directly on these bearing soils. 'Lhe in-situ uncontrolied fill, loose soila,and <br /> organic soils found at the site are not suitable for wppoct of foundation loads as unacceptable <br /> rI�vels of diffaential settlement would be expected. <br /> The(ateral resistance of spraad footings is controUed by a wmbination of sliding <br /> ( rosistance betwan the footing and the foundaaon materials and passive earth presaue against <br /> the buried portions of the footings. We rocommend a passive earth pressure in compacted <br /> sand or gravd backfill, and the onsite naave sand and gravel of 225 pcf(pounds per abic <br /> t foot)equivalent fluid. We recommend a coefficia►t of base friction of.35 be uxd bet�veen <br /> cast-in-place concrete(foodng base) and the foundation subgrade soils. <br /> lThe project site is located in seismic zone 3 as deSned in the Uaiform Buildiag Code <br /> (iJBC 199�. Zoae 3 includes the westem portion of Washington aad Oregon. The seisa►ic <br /> � Zone factor(Z)as defined in the UBC code is found to be 03. The"Soil Profile Type"for <br /> the up}xr loose fill aad native fine-grained soils observed at the site is Se, and for the lowa <br /> dense to very dense sand, sandy gravel and silty sand is Sc per the UBC code. The valua of �, <br /> � seismic mne�cient C.and C.for the upper loose layer is calculated to be 0.36 and O.E4 <br /> respectively.The values of seisauc zoae ccefficient C.and C.for the lower dense to very <br /> dense native soils is calculated to be 0.36 and 0.45 respectively. <br /> 1 All underground storage tanks should be supported by the aative very dense sandy <br /> � gravel,or very dease silty sand(Glacial Till). Continuos dewataing will be required during <br /> excavation and placement of the UST's. Specific rocommendatioas rogarding dewatecing are <br /> presented in the Site Dewateriag scction of this report. <br /> lAll Undergound storage tanks should be fastec�ed with straps a�hored in concrete <br /> deadman beams on both sides of the proposed tanks. The deadman snchors should be <br /> designed by a qualified engineer to counteract the buoya�forces aaing upon the UST's <br /> t specially during the periods when the tanks are near empty. Adequate co�sinment should be <br /> provided arouad the proposed UST's and UST intake valves to mitigate spills contributing to <br /> � the contamination of the groundwater. <br /> The founda:ions for the propoud fueling island canopy should be placed directly on <br /> � the on-site, native medium dense to dense sand(SP),the on-site native sandy gravel(GP)or <br /> properly placed and compacted structural fi1UCDF. <br /> � With structural foundation loads up to a maximum of 2,000 psf,we andcipue total <br /> settlement under footings to not exceed three quarten(3/4)of an inch and differentid <br /> settlement not to exceed one haif(U2) inch. We antici�aate that mou of the settlemerrc will <br /> � occur immediately upon imposition of the loads(during consteuction). <br /> 1 7 <br />