3003 W CASINO RD BLDG 40-56 2018-01-02 MF Import

- i , � SITE CONDITIONS i Site conditions were established through a combination of visuai inspcctions by Dames & ' Moore steff, information from borings previously drilled by Dames 8c Moore in the vicinity, informetion from caisson installation records for cor.struction of the most recent Building 40-56 extension, and topogrephic informetion from �urveys of pre-construction conditions. � $yrfnce end Subaurfece Conditiona � � , `� The ground surface throughout the site of the proposed extension is flat and paved with r, asphalt. The peved ereas are currendy used as roadways f�r vehicular treffic or as parking or storage ereas. Subsurface conditions consist of a layer of miscellaneous fill soil overlying the very dense glacial till thet typically mantles the Boeing Everett plant site. The fill was reportedly ptaced in � an uncontrolled manner prior to 1970 es pnrt of en extensive grading and construction program. - The fill is a mixture of aend and silt with verying emounts of gravel and wood fregments. The sand component seems to predominate in most borings,but the consistency of the soil seems to be controlled by the silt fraction. Occasional cobbles and orgenic matter were elso -- encountered throughout the layer. Penetration resistence velues uf from 10 to 40 blows per foot measured during sampling indicate that the soil is in e medium to very stiff condition at most locatione sampled. However, soft or loose zones were noted in Boring B-S where penetration resistance values of 2 and 5 blows per foot were recorded in the upper 25 feet. A void was encountered et e depth of 53 feet in Boring B-4,which also exhibited caving from approximately 20 to 45 feet during dritling. 7'he fill layer varies in thickness from I 1 to 65 feet at locations sampled in the vicinity of the proposed extension. The greatest thickness was encountered in the northeast corner of the — proposed extension. The fill thickness generelly increases in a northerly diroction, but the pnttern seems m conform to previous ground surfece contours that contained two northerty trending revines. A better underotending of the verietion of fill thickness can be gained by i - examining Pletes 2 and 3, which present subsurface profiles alung the north end south walis of the proposed eddition. — The glaciel till beneath the fill soils was very dense, with penetrfltion resistances mostly greater than 100 biows per foot. In some borings the tiii was somewhat weathered in the upper 2 •0 4 feet. At these locations the penetretion rcsistances were slighUy lower and the soil color was more brownish. ; Measurements made during previous investigetions in the vicinity indicate that ground water - is not encountered within the range of depths of concern to this project. 3 I n..,� �� ; -. ��,,,,,,