2205 BROADWAY 2016-01-01 MF Import

LSI - ADAPT 1 1 recommrnd that continuous a�a11 footings have a minimum width of 24 inches and individual footings a minimum width of 24 inches. All exterior footings exposcd to frost action shall be placed a minimum of 18 inches bel�w finished grede. With sWchual loading as expected, total settlements in the range of 1 inch and dif3eren6al settlements of approximatelV one-half in^.h are possible. As site soils below the footing would consisi of�anular deposi[s or �wctural fill, most of the anticipated settlemenu should occur during construction as dead loads are applied. A one-third incrcase :n allowable bearing capacity may be�tiliud for short-tertn loads, such as in the case of a seismic event or�vind loading. We rccommend that a soils engineer from ADAPT inspect all fboting excavaGons prior Ir, concrete placement to assure adequate bearing capacity conditions have been achicved. If loose or soR suil conditions aze encountered, these soils shall be compacted or removed and replaced with str�ctural fill. Lateral loads can be resisted by friction between the foundation and the supporting nativc soil or compacted fill subgr.+de,or by passivic eanh pressure acting on the buried ponions of the foundations. 'I'he Coundations must be poured"neaC'against the existing soil,or backfilled�+�ith a compacted fill. . Passive pressure = 30D pcf . Coefficient of friction = 0.35 Thc above values include a factor of safety of 1.5. All footing excavations should be cxamincd by a reprc�entative from LSI - ADAPT, prior to placing fotms or rebar,to verify that conditions aze as anticipatcd in this reporl. Setsmtc Design Consideration The Pugct Lowland is classificd as s Srismic Zone 3 by the Unifortn Building Code �'UBC). The largest eanhquakes in the Pugel Lowland are W idespread and have been suUcrustal events,n:nging in depth from 30 to 55 I:ilometers. Such deep events have exhibited no surfacc faulting. Based oct our sudace exploratiott,we interpret the site conditions to corzespond to a Seismic Profile t;�pe Sa, the Still S�il ['rofile, based on the observed range of SPT blow counts. The shallow soil conditions werc assumed to bc reisresentative tor site conditions beyond the depth explore�i. I Structures are subject to damage from earthquakes due to direct and indirect action. Direct action is rcprcsented by shaking. [ndirect action is rcprescnted by foundation soil failures and is typifi:d by ground fTilure or liquefaction. Liquefaction is a phcnomenon in which soils lose all shear strength for shon periods I cf time during an earihquakc. The effccts of liquefaction may Ue large total and/or diffcrential sc[tlement for swcturcs witfi foundations founded in the liquefying soils. Groundshaking of sufTicienl duration results in the loss of grain-to-grain contact due to rapid incrcase in pore water pressure, causing'4:c soil to bchave as a Ifluid for sl�ort periods of time. IL51•ADAPT Job No.WA02-8727 Page 7 August 6,7002 ��