3121 8TH ST AB 2016-01-01 MF Import

Junc l, 200R Duplex Iiuilding L&A Job No. 8A055 Page 3 The tcrrain within the sitc gencrally slopes down eastward at grades from A.5 to 22 perccnt lo or just bcyond its east boundary where it is Ilanked by a stcep slope. This steep slope drops off easterly about 8 to 10 feet ai about 100 percent grade down to the railroad ya�d below. The sitc has reccntly been parlially cicared ti�ith scattcred ta(1 maturc trccs dotting thc norihern portion ��,f the sitc. GI:OLOGIC SI'sl'TING f;eolosic Man of the Gverett 7.�-Minutc Quadranele, Snohomish Countv, Washin�ton, by James P. Minard, published by U. S. Geological Survey in 1985, was relercnced for thc geologic and soil conditions at thc site. According to this nublication, thc surlicial soil unit at and in thc vicinity of the subject site is mapped as Vashon "l�ill (Q��)• fhc gcology of thc Pugct Sound Lowland has bcen modificd by thc advancc and retrcat of several glaciers in the past and subsequent deposits and erosion. The latcst glacier advanced to the Puget Sa md Lowland is rcferred to as the Vashon Stade of the rraser Glaciation, which has occurced duria�; thc latcr stagcs of the Plcistoccnc l�poch :md retreatcd from the region some 14,500 years ago. The Vashon lill soil unit was plowed under by glacial ice Juring the most recent glaci�l period as it advanced over an eroded, irregular surl'ace of older formations and sedimcnts. It is a mixture of unsorted clay, silt, sand, gravci, and sc�ttcred cobbles and boulders. 7'he Vashon till soils over the top two to (our feet are normally wcathered to a medium-dense state, and is moderately penneable and compressible. Thc undedying fresh till soils are very dcnse a��d �veakly cemented, and are commonly retcrred to as "hard pan". The underlying fresh till soil� possess a shear strength comparable to that of low-grade concrete and can stand in steep natural slones or man- make cuts Ibr u long period. �l�he frcsh till soils are szlso of extremely low pemieability and are L[U & ASSOCIATES, INC.