3019 BURL PL 2016-01-01 MF Import

With thc loosc soils at thc surfacc, exccssivc moisturc impacting thcsc soils would lead to settlement if there wcre suf(icicnt loading on the soil. A structure such ns this resident µ�ould proviJc cnough loading to causc settlemenl of the soil if the placement were loosc nnd wntcr was inlroduccd in sufficicnt quantitics lo achicvc an optimum moisturc content (1hc amount of walcr added to soils that will allow them to compact to their maximum dcnsity givcn cnou6h forcc). If slope failurc were a possibility, a triggcr would need to happen that would cause a «•cakening in thc slopc. Sincc no movcmcnt has bccn recordcd bcforc 2005 (30 ycars of slabilily), only a fc«� incidcnts would changc thc dynamics of thc slopc and causc u «�cakcning. I'otenlial incidcnts could bc: carthquakc, risc in watcr tablc, addcd IoaJing, undcnnining of slopc, othcr dynamic loadings. Since thc lust major carihquakc was in 2002, givcn thc soils conditions, movcmcnt would bc rclativcly instantancous and would not takc 3:'s ycars lo rcvcal itsclf in 2005. Sincc thcrc was no sign of a watcr tablc or cxcessivc moisture during the enJ of the wet period (and a11er a record snow fall), groundwatcr ��ould no1 bc responsiblc. No addcJ loadings havc bcen placcd on the slope sincc construction. "I�hcrc arc no signs i�f widcrniining of thc slopc, and no othcr dynamic loads arc kno�vn to cxist. Additional rescnrch and a long tcrni analysis woulJ nccd to bc conductcd to dctcrniinc for ccrtain whclher slope failure is responsible for the movemcnt of the structure. Givcn the str�ng c��idcncc against slopc t�ailurc and thc long duration nnd cost of furlhcr tcsting, ndditional rescarch is not rccommrndcd. PRIiVIOUS ti'I'UUII'.ti In March 200G, ('asc I�orcnsics perliirmcd an.c�:iluation of thc fuundation and thc slapc to dctcnninc thc causc tiir thc movcmcnL According la thcir report, thc ntovcmcnl was duc to scldcmcid uf Ihc undcrl� ing loosc suils cumhincd ��iih uncantrolled stonn drainagc. Thc Casc 1'orcnsic rrporl is not includcd in this rcport hut is;nailablc upon requcst. I)I�:SI_GN RI•:l'OM.MI?NI)�:I:IONS It is rccommcndcd that thc housc .md li,undation bc stabilizcd utili•r.ing a pin pilc foundation. ; inch diamctrr pin pilcs arc rccommcndcd I'or lhis stnicturc. 1'ilcs shauld bc placed ��crtically to rst.�ni�,i, ,��i�r��. i'ilc scctiuns should bc attachcd ��i:� a stccl couplcr trcaded to thc pilc. "I hc 2 inch pin pilcs should bc dcsignccl ��'ith � maxitnum loadiug of4 hips. Piles should bc �ilaccd lu rctiisal. Rcfusal is dclincJ us Icss than 1 inch ol'pcnciration in I minutc afcontinuous John Vicente, 3019 Uurl Place, Everett, WA 98203 425-353-4517 Page 4 of 5 �/, �i