1130 RAINIER AVE WHOLE SITE DOCUMENTS 2016-01-01 MF Import

� Evarett Housing Aufhority May 16, 2012 � JN 12080 Page 6 the top of the pile during driving If the piles are installed by alternative methods, such as a vibratory hammer or a hammer that is hard-mounted to the instaliation machine, numerous load tests to 200 percent of the design capacity vdould be necessary to substanliate the alloevable pile load. The appropriate number of load tesls �vould need to be determined al the time the conlractor and installation method are chosen. r�ithough it is dif(icult to determine lhe final depths of lhe piles, we anlicipate zpproximately 10 feet of pile embedment inb the corr�pelent native soils to achieve the noled capacities. As a minimum, Schedcle 40 pipe should be used. Due to Ihe exislence of peat soils, which can corrode metal, we recommend the ptles be galvanized. Pile caps and grade �eams should be used to transmit loads to ihe piles. Isolated pile caps shouid include a minimum of h�io piles to reduce the potential for eccenhic Ioads beino 2pplied to the piles. Subsequent sections of pipe can be connected �vilh slip or lhreaded couplers, or ihey can be welded tcgether. Ii slip coupiers are used, lhey should fit snugly into the pipe sections. This may require that shims be used or th2t beads of welding flux be applied lo the outside of lfie coupler. Lateral loads due to wind or seismic forces may be resisted by passive earth pressure acting on the vertical, embedded porlions of the foundation. For this condition, ihe foundation must be either poured direclly against relatively level, undisturbed soil or be surrounded by level compacted fill. We recommend using a passive earth pressure of 300 pounds per cubic foot (pcf) for this resistance. IF the ground in front of a foundation is loose or sloping, the passive earth pressure given above will not be appropriate. We recommend a safety factor o( at leasl 1.5 for ihe foundation's resistance to lateral loading, when using the above ultimate passive value. Due to their small diameter, the lateral capacity of vertical plpe piles is relatively small. Ho�vever, if lateral resistance in addilion to passive soil resistance is required, �ve recommend driving battered piles in the same direction as the applied lateral load. The lateral capacity of a battered pile is equal to one-hai( of the lateral componenl of the allowable compressive load. The allotivable vertical capacily of ballered piles does not need to be reduced i( the piles are battered steeper than 1:5 (Horizontal:Vertical). PERMANENT FOUNDATION AND RETAIN/NG WALLS Retaining walls backfilled on oniy one side should be designed to resist the laleral earth pressures imposed by lhe soii ihey retain. The following recommended parameters are for walls tha; reslrain level backfill: Aclive Earth Pressure ' � 35 pc( Passive Earth Pressure � 300 pcf Soil Unit Weiqht � 130 pcf Wlinro: (I) pcf Is pounds per cublc foot, and (II) activo and passivo earlh pressures are computad using lhe equivalent Iluld prassures. ' For a restrclned wall that eannol deflect al Icast 0.002 timos tls helght, a uniform laterel pressure equal l0 10 psI timos lhe haiphl ol tho wall should 6o addod to ll�o above aclive equlvalent Iluid prossuro. GCOTECH CONSULil�NTS, INC.