can you ommit a shear wall holddown

huangyhg

can you ommit a shear wall holddown?
if you have a wood shear wall and it's long enough, can you use the sill plate anchorage to replace the typical end-of-wall shearwall holddown?  theres no code requirement for holddowns and i think its more of an analysis decision.
never seen it done, but am looking at a set that has this.
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its all in the load path.  if you can transfer the tension force in the stud(s) to the sill plate, if sill plate can transfer the load to the anchor bolt, and if the anchor can transfer load into foundation, then i say it's good. you might want to make sure the remaining anchors can take the shear/direct uplift load without the one you are using for a hold-down.
j
also, if there is sufficient dead load on the wall to resist the overturning moment, a hold-down is not required.
also, in a special case where a transfer beam is over the top of the shearwall, the holddowns can be omitted on the shearwall, but, depending on the dead load afailable to resist overturning, may have to be applied to the transfer beam and associated column connections.
mike mccann
mccann engineering
typically long shear walls have an opening in them, if this is the case then you must reduce it's capacity, and it would be called a perforated shear wall.  code does require that the end of each perforated wall to have a hold down.
re  
if it's a long wall and has an opening, just make it two sahear walls and put in more hold downs.  forget the complicated analysis, use full values.  
if the h/t ratio comes into play (>2:1) to effectively reduce the allowable shear values, then maybe, depending on the hailing and holddown sizes.
i just try to kiss wherever possible.  
mike mccann
mccann engineering