2001 ASD Supplements - unprotected PDF - American Wood Council

ASD WOOD STRUCTURAL PANEL SHEAR WALL AND DIAPHRAGM SUPPLEMENTSW-33Step 6.Diaphragm Deflection (N-S Direction)35vLvL( DXc)∆ 0.188Diaphragm= + + Len+ ∑8Eab 4Gt 2bFor N-S direction:v = 61,519 lb ÷ 2 ÷ 110' = 280 lb./ft.L = 240 ft.E = 1,700,000 psiA = 21.75 sp. in.(for Douglas fir-Larch No. 1 2x8s)(cross-sectional area for (2) 2x8s)b = 110 ft.G = 90,000 psit = 0.298 in.(for Sheathing grade)(for 15/32" unsanded panels)∆ Diaphragm N-Sv 8d= 280 ÷ 2 = 140 lb./nail (8d spaced 6" o.c., at interior panel edges near East and West boundary)e n= 0.0338 x 1.2 = 0.041 (Table 3.2; 20% increase for non-Structural I)= ∆ bending+ ∆ shear+ ∆ nail slip+ ∆ chord splice slipA35vLvL( DXc)∆ 0.188Diaphragm= + + Len+ ∑8EAb 4Gt 2b+ + + + += + + 0.188(240) (0.041) +8(1,700, 000) (21.75) (110) 4(90, 000) (0.298) 2(110)35(280)(240) (280)(240) 4(1/32)(20 40 60 80 100) 2(1/32)(120)APPENDICES= 0.595" + 0.626" + 1.832" + 0.204"= 3.257"Note: The average chord splice slip on each side of the splice, is assumed to be 1/32 inch (which is half of the 1/16 inch allowable oversize forthe bolt hole, for both tension and compression chords) and these splices are assumed to be located at 20 feet on center along the North andSouth walls.Since the base of the wall is essentially a pinned connection, the diaphragm deflection causes little, if any, out-of-plane bending of the wall. Thecalculated deflection at the top of the wall should be used to evaluate potential vertical instability caused by horizontal deformation (P∆effects). If necessary, diaphragm deflection can be reduced in a number of ways, such as additional nailing, the use of Structural I panels, etc.APA – The Engineered Wood Association