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i , LSI Adapt, Inc.
<br /> Si�e Preparation
<br /> Prcparation of the ccllular cquipment lcasc arca for conswction should involve cicaring, grubbing,
<br /> stripping, cutting, 611ing,dcwatering, and subgradc prcparation. We providc thc following commcnts and
<br /> recommendations relative to site preparation.
<br /> Temnorarv Drainase: Wc rccommcnd intcrcepting and divcrting any potcntial sourccs of surfacc or
<br /> ncar-surface watcr within the consiruction zones bcfore sfipping bcgins. Bccausc thc scicction of an
<br /> appropriatc drainage systcm will dcpend on thc �vatcr quantity, scason, wcathcr conditions, constn�ction
<br /> sequcncc, and contractor's methods, final dccisions rcgarding drainage systems are bcst madc in thc ficld
<br /> at the timc of consWction. Nonethcless, we anticipate that curbs, berms, or ditches placcd along the
<br /> uphill side of the work arcas will adequatcly intcrccpt surfacc watcr runofl:
<br /> Clearin�+ and Stripnine: Ailer surCace and ncar-surface watcr sources have bccn controllcd, thc
<br /> constructior. arcas should be clearcd and strippcd of all pavement, sod, topsoil, organic-ladcn soil, pre-
<br /> existing fill, and debris. Our cxplorations indicatc that an average thickncss of up to 6-inches of grass,
<br /> sod, and topsoil will be encountercd across lhe plunncd foundation arens, but significant variations could
<br /> exist. Furthermore, it sl�ould bc realizcd that if the stripping operation procecds during wet �vcather, a
<br /> gcncrally grcatcr slripping dcpth might be nccessary to rcmovc disturbcd, surficial, moisturc-sensitivc
<br /> soils; thercfore, stripping is best perfortned during a period of dry wcatl�cr.
<br /> Suberadc Preparation: Exposed subgradcs for shallow footings, mat foundatians, slabs-oti-gradc,
<br /> roadway scctions, and othcr sWctures should be compacted to a firm, unyielding state, if required to
<br /> achieve adcquate dcnsity and warrantcd by soil moisturc conditions. Any localized zones of loose,
<br /> granular soils obscrved within a subgradc area shoidd be compactcd to a density wmmensurate with U�e
<br /> surrounding soils. In contrast, a��y wicunlrollcd fill material or organic, sofl, or pumping soils observed
<br /> within a subgrade should be o�•erexcavated and replaccd with a suitablc structural fill matcrial. It sUould
<br /> be notcd that the near surface bcaring soils at d�is site are anticipated to consist of loose to mcdium densc
<br /> sand with gravcl, whicl� is gcncrally considcrcd to exhibit relativcly high moisture scnsitivity. To
<br /> minimize disturbancc and subsequcnt nced for recompaction, wc thercfore rccommcnd that all bcaring
<br /> subgrade arcas are excavated with a smooth-edged bucket.
<br /> Frozen Sub rF ades: If carthwork takes place during f'reczing conditions, wc rccommend tl�at all cxposed
<br /> subgrades be allowed to thaw and be recompacted prior to placing foundations or subscqucnt Iifts of
<br /> swctural fill.
<br /> Eqttipmcrd Plaljorm Drilled Picr Fowrdatious
<br /> Based on Q�e subsurfacc conditions cncountcrcd in our boring, thc cquipment platfonn may bc supported
<br /> on drilleci pier foundations. Thcsc drillcd picrs should be extcndcd to a minimum depth of S-fect bgs and
<br /> should bc foundcd a minimum of 5,0-fcct into the nativc, vcry dcnsc to dcnsc glacial till soils cncouutcrcd
<br /> Uclow the surficial soils in our site cxploration. Tlic following rccommendations and commcnts arc
<br /> providcd for purposes of drilled picr design and constr�ction.
<br /> Ne�el do Tetra Tech June 25,2004
<br /> LSI Adap;Project No.WA04-11499-GEO page7�
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