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UNIVERSITY OF CALIFORNIA, BERKELEYSpring 2015Department of Civil and Environmental EngineeringInstructor: J. P. MoehleCE 120 - Structural EngineeringSolutions of Assignment No. 5Due:February 27, 2015Solution:!Dead Load from ASCE-7-10 (Table C-3-1):ComponentLoad(psf)Four ply felt and gravel5.5psfMechanical Duct4psf¾” Subflooring (plywood)3psf!Live loads20psf!Material Density: Douglas fir34pcfFig: Schematic Drawing of the Roof.(a)Loads Supported by Plywood:¾in plywood carries weight from everything above it and it’s self weight.Table 1: Loads carried by plywoodDead loadLive loadFour ply felt and gravel=5.5psfRoof Live load =20psf¾” Plywood=3psfTotal=8.5psf[ = 7.9psf]=20psf(b)Loads Supported by Joist:Joist supports loads that are on the plywood (from part a), mechanical ductand its self-weight.•Self-weight of joist:Actual dimensions of 2X10 Douglas Fir roof joist are 1.5”X 9.25”Therefore self-weight= (34pcf)*(1.5/12 ft)*(9.25/12 ft) = 3.27plf[OR:¾” Plywood =0.4psf/(1/8")*(3/4")=2.4psf]