GO BOLTS FOR SHEARWALL 1

[rook1]

Greetings...

I would like to ask for an idea on the effects of go-bolts in the shearwall and how the tension in the bolts are computed considering a certain bolt spacing. Is this system allowed by the UBC? thank...

 

[UcfSE]

rook1:

Are you asking how to calculate the tensionload or how the allowable tension load is calculated?

If its the allowable, here are some considerations. The bolt's allowable values will be based on several factors, probably some tested and some calculated. These different failure scenarios may be bolt failure in tension and pullout failure in concrete. That situation will be governed by embedment depth and edge distance, and will have lower numbers if the bolt is embedded in a masonry bond beam instead of a concrete footing. Also, flexure in the top plate will be a consideration and likely be the limiting value. Sometimes additional capacity is given to the top plate through the sheathing nailing in shear, so you have to watch how you consider that (i.e. if your nailing is used for uplift it is no longer available for shear). In addition, bearing failure at the connection to the top plate may govern if you are using a bolt solely for a large uplift load such as that from a girder truss. In that event you would need to specify a larger washer and check for bearing stress in the wood and bending in the washer. I have worked with a similar system to go-bolt and these are some of the things I consider and also that they use for determining their bolt allowable loads at a given spacing. I hope this helps you out.

 

[ThomasL]

May I ask? are you saying that OSB panels cannot be used for uplift AND shear? SSTD 10-99 Table 305S1 shows values for shearwalls and uplift simultaneously. What are your thoughts here?

 

[UcfSE]

I don't think you can use 100% of the design value for shear and 100% of the design value for uplift at the same time. I don't have your document but if it lists values for uplift and shear at the same time, I would assume that they are not the same as if the uplift and shear acted independently of each other. That is to say that some sort of interaction should account for the oblique resultant load whether by tests simulating these loads or some interaction equation perhaps.