1202 SHUKSAN WAY 2018-01-01 MF Import

!� � ( 3.3 PREVIOUS EAR7HWORK ON LOTS 1 AND 2 Previousl�t GcoEnginccrs has ohzervcd and tcs�cd struciural fill thal ��as placed and crnnpacicd � on the original pit iloor in 1998. Grading at the site also occurred in the summcrs of 1999 :md 2000. We have numerous field rcports documcnting our obscrvalions and thc condition of thc fill lhat we obsen�ed. Strucwral fill placcd in the pit N•as generally compacted to :.1 Icast 92 percenl r MDD per AS'tM D 1557. Une boring(I3-I) was drillcd through the siniclural fill thal was placcd � in 1998. Tlic boring was locatcd near thc southcast comcr of ihc proposcd JanSport building as I sho��i in Figure 2, and the loe of the boring is shmvn in Fieure A-I I in Appcndis A. No rnhcr documents or specific geotechnical reports�+�ere prcpared by our finn for Lots I and '_'. � 3.4 SUBSURFACE CONDITIONS The following subsections describe the gcneral subsurface conditirnis encountcred at the sitc. � The crplorations werc perfomied in arcas where undocmnenicd fill is known to czist. Sir e�plorations werc perfomied in Ihe northem portion of the proposed buiic'ing fnotprint whcre escavated glacial [ill was stockpiled during mining operations prior to 1998, which wcrc thcn I panially rcmovzd during grading activities during and afler the summer of 1998. Two c�plorations , were performed along ihe southwestem side of lhe proposcd building footprint wherc mining j occurred during and after 1998. ?iie area was subsequently backfilled with about G fect of I � undocumented on-sitc soil. No eaplorations(other than B-I i;i 1998) were performed in the south i central or southeastem portions of the proposed building footprint because we generally obscrved � the placement of sWcturel fill in these areas. E�ploration locations refercnced below are shown in Fieure 2 and summap�logs for the eaplorations are included in Appendix A. 3.4.1 SubsurFace Soils . In general, the subsurface soil conditions across the site consist of elacial till fill overl�ing � native advanced ouh+�ash sand. The thickness of the fill increases from west to east across the site. Undocumenled till fill exists along the west and nonhem sides of the building footprint,as sho�cn in Fieure 2. � 71ie undocumenied fill along the northern one-third of tlte building footprint is the bottom remnant of a large o��erburden stockpile that was placed in the former pi[ by CSR Associated. The overburden fill is[he unusable till soils that��erc sVipped from above the sand and gravel deposits. ' The till fill was generally placed and stockpiled using scrapers and it was not engineercd • ` monitored during placement. Borings B-1 through B-6 were drilled in the northern overburden fill I soils. The till fill is typically in a loose to medium dense state and generally consists of gray and bro��n silty fine to medium sand with varying amounu of gravel. Scattered organic matter was cbserveA i�i [he fill in B-1 and B-4. The undocumented fill ranges from about 4.5 to 5 fcet deep � along the northwestem comer(B-5 and B-6)of the building footprint to about 16 to 18.5 feet thick in the northeasc comer (B-1 and B-2) of the building footprint. The underlying native advancc outw�ash sand is typically dense to very dense. lUndocumented fill soils also exist along the westem edge of the proposed building footprint. We observed some swctural fill tltat was placcd last year in the northwest portion of the building � � G c u G n g i n c c r s $ filcNo. 7Sg4-002-00-11301050101 9/J� 7Q