2001 ASD/LRFD Wind/Seismic Supplement - American Wood Council

20 LATERAL FORCE-RESISTING SYSTEMSν s2ν sc= Nominal unit shear capacity for side 2, lbs./ft.(from Column A, Table 4.3)= Combined nominal unit shear capacity of twosidedshear wall for seismic design, lbs./ft.Nominal unit shear capacities for shear walls sheathedwith dissimilar materials on the same side of the wall arenot cumulative. For shear walls sheathed with dissimilarmaterials on opposite sides, the combined nominal unitshear capacity, ν sc or ν wc , shall be either two times thesmaller nominal unit shear capacity or the larger nominalunit shear capacity, whichever is greater.4.3.3.3 Summing Shear Wall Lines: The nominalshear capacity for shear walls in a line utilizing shear wallssheathed with the same construction and materials, shallbe permitted to be combined.4.3.3.4 Shear Capacity of Perforated Shear Walls: Thenominal shear capacity of a perforated shear wall shall betaken as the nominal unit shear capacity multiplied by thesum of the shear wall segment lengths, ∑L i , and the appropriateshear capacity adjustment factor, C o , from Table4.3.3.4.Exception: For wind design, the combined nominalunit shear capacity ν wc , of shear walls sheathedwith a combination of wood structural panels andgypsum wall-board on opposite sides shall equalthe sum of the sheathing capacities of each sideseparately.Table 4.3.3.4 Shear Capacity Adjustment Factor, C oWALL HEIGHT, hMAXIMUM OPENING HEIGHT 1h/3 h/2 2h/3 5h/6 h8' Wall 2'-8" 4'-0" 5'-4" 6'-8" 8'-0"10' Wall 3'-4" 5'-0" 6'-8" 8'-4" 10'-0"Percent Full-Height Sheathing 2Effective Shear Capacity Ratio10%20%30%40%50%60%70%80%90%100%1.001.001.001.001.001.001.001.001.001.001The maximum opening height shall be taken as the maximum opening clear height in a perforated shear wall. Where areas above and belowan opening remain unsheathed, the height of the opening shall be defined as the height of the wall.2The sum of the lengths of the perforated shear wall segments divided by the total length of the perforated shear wall.0.690.710.740.770.800.830.870.910.951.000.530.560.590.630.670.710.770.830.911.00o0.430.450.490.530.570.630.690.770.871.000.360.380.420.450.500.560.630.710.831.00AMERICAN WOOD COUNCIL