3606 W MUKILTEO BLVD 2016-01-01 MF Import

Gcotechnic�l Enginccring Evaluation Mukiltco Boulevard Devclopmcnt EvcrMt, Washington March 31, 2003 NGA �ilc No. 366503 Page 1 I not bc allo�vcd to accumulate in footing trenchcs. All loose or disturbcd soil should be removed from tire foundation excavation prior to placing concrcte. Por foundations constructcd as oudincd abovc, wc rccommend an allowable dcsign bearing pressure of no morc than 2,000 pounds per squarc foot (psn bc uscd for dcsigning footings founded on thc mcdium dcnsc to dense till soils. Thc foundation bcaring soil should be evaluated by a rcpresent�iive of our tirm at thc timc of construction. Wc should be consulted if higher benring pressures are necded. Currcnt Uniforn� Quilding Codc (UBC) guidelincs should be used when considering incrcased allowable bcaring pressurc for short-tenn transitory wmd or scismic loads. Potential foundation settlement using thc rccommended allowable bcnring pressurc is cstimatcd ro be Icss than 1 inch total and I/2 inch diffcrcntial bet�veen adjacent fuotings or across a distance of abaut 40 feet, bascd on our experience with similar resideniial projccts. Latcral londs may bc resisted by friction on the basc of the footing and passivc resistancc against thc subsurfacc portions of tl�c foundation. A cocfficicnt of Giction of 033 tnay bc uscd to calculute thc basc friction and should be npplicd to the vertical dead load only. Passive resistance may be calculated as a triangular equivalcnt Iluid pressurc distribution. An equivalent (luiJ dcnsity of 200 pounds per cubic foot (pcQ should be uscd for passivc resistance design for a Icvcl groimd surface adjacent to the footing. This Ievel surfacc shoidd c�tend horizontally � distancc at Icast thrce times the depth of the footing. Thcsc recommendcd valucs incorporatc safcty fnctors of 1.5 and 2.0 applied to thc estimated ultimatc values for Gictional nnd passivc resislancc, rcspcctivcly. To achicvc this valuc of passivc resistancc, thc foundntions should bc poured "ncnt" against N�c nativc medium dcnsc soils or compactcd fill should bc used as backfill against the footing. \Vc rccommend that the upper 1 foot of s.�il he ncelccted whcn calculating thc passivc resistancc. Retaining N:ills The latcral carth prcssurc acting on rctaining �ealls is dcpcndcnt on thc nature and dcnsity of thc soil bchind tl�c �vall, thc amount of latcral wall movemcnt that can occur as backfill is placed, and thc inclination of thc backiill. \Valls that arc frec to yield at Ieast ono-thousandth of the heiglu of the wall are in an "active" condition. Nalls restrnined from mo�•ement by stiffness or bracing are in an "�t rest" NELSON GEOTECHN/CAL ASSOC/ATES, INC.