4818 BELVEDERE AVE 2016-01-01 MF Import

Novembcr 9, 200G Singlc-Family Rcsidencc - Dcivcdcrc Lot 4 1_8cA Job No. 6A149 1'agc 3 far the geologic and soil cundilions ut the lots. According to this publicntior., the surficial soil units at nnd in the vicinity of the lots are map�:d as ��.shon 7'ill (Q��) underlain by Espe::�nce Sand (Q�). The geology of the Pugct SounJ Lowlund hus been modified by the advance and reVet�t of sevcral glacicrs in the past und subsequcnt dcposits and crosiun. 7'hc latest glncier advanced to the Pugct Sound Lowl:uid is rcferred to as the Vusshon Stadc of the Praser Glaciation, which has occurted during the later stnges of the I'leistocene G�ch nnd retreated from the region some 14,500 ycars ugo. The Vashon Till was deposited dirccUy by glacial ice �iuring the most rccent glacial period as it advunced over an eroded, irtegular surface of older fonnations nnd sediments. It is a very dense mixwre of unsorted clay, silt, snnd, grovel, and scattercd cobbles nnd boulders, often referred to as "hazd pan". 7'he till soils over the top two to four feet nre normally weathered to a medium densc st�te, nnd is moderately permcable anJ compressible. 'fhe undedying fresh till is very dense And is practically impervious to stortnwnter infiltration. The tresh till has the strength of low-grade concrcte und cun stand in a stcep natuml or cut slope foi a long period. If temains undisturbed nnd well-drained, the fmsh till can provide excellent foundntion support with IitUe setdcment es�cted. 7'he Vashon '1'ill, howcvcr, was nol encountcrcd by our test boring drilled on the adjacent l3elvedcre I.ots 32 and 33. Thc 1 sperancc SanJ soils arc advnncc outwatih sand sedimcnts consists of proglacial 1luvial und lacustrine de�wsits laid down by slow-moving meltwater streams from the advancing but distunt Vashon glacicr. It is gencrally composed of li�ht brown to IigM gray, well-sorted, fine-to- medium-grained sand. It may includc lenses of thin silt or conrsc sand und small gravel locnlly. In confined situations, the Isperuncc Sand soils are gencmlly in dense to very dense state. The I:sper�ice tiund deposits, hou�ever, can subject rather eysily to rainwash emsion and gullying, LIU & ASSO�CIATES, INC.