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40 % increase on wood structural panel shearwall
greetings...
i would like to verify my interpretation of section 2304.4.1 of ibc 2002 stating that the capacities in table 2306.4.1 (allowable shear for wood structural panel shearwalls) are permitted to be increased by 40 % for wind design. does it means that sheathing with 15/32 in thk. ,10d nails spaced at 3" at panel edges and appropriate nails for intemediate member will now have a capacity of 931 lbs/ft instead of 665 lbs/ft?(supposing wind load governs in the design)
im a bit confused because it is different on what is written in ubc specifications. thank you...
you are correct in your interpretation. allowable wind load values are 40% higher because the factor of safety for wind loads on shear walls and diaphragms is only 2, while it is 3 for seismic loads.
daveatkins
also, don't forget the seismic force calced is an ultimate force and the wind is an allowable.
to compare apples to apples, the seismic force is multiplied by .7 and then the shear wall tables may be used. no increase for the seismic while wind may be increased by 1.4.
makes a lateral design twice as long sometimes. |
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