Wood Column Design at Bolt Hole

[pioneer09]

I have a multiple ply wood column that is braced at top and bottom. It is connected at the base by way of a steel channel bolted to the wood column. The bolts are close to the edge of the wood column. As the column wants to bend, the wood member will want to separate at the bolt hole location if there is not enough material. I am thinking the stress that must be checked is the shear parallel to grain based on the location of the bolt hole. This would include using the adjusted design shear per the effective depth as outlined in NDS manual for a bolted connection. I have attached a sketch of my description above. Any thoughts would be appreciated.

 

[KootK]

A couple of questions:

1) What are the loads on the column? Is there an applied moment? Transverse load between supports? Or is the bending just anticipated buckling movement?

2) How long is the channel and how long is the column?

At first blush, I don't see a longitudinal shear issue. If there's a real shear force at the joint, I'd think that it would be more tension perpendicular to grain at the bolt holes. And that's accounted for in the bolt design values via edge distances etc.

Is axial load transmitted through the channel? If so, the eccentricity of the channel connection might be worthy of some attention.



I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[pioneer09]

The column is part of a frame that was originally designed as a pinned connection at the base. The customer wants to utilize a 6' steel channel with approximately 4' exposed. I believe the wood column will begin to split if the bolts are to close to the edge. I interpret this applied force acting horizontally to the column at the bolt hole locations coming from the moment arm that develops between the bolt hole spacing in the steel channel.

 

[KootK]

Got it. I stand by my original assessment. Horizontal shear should be checked but that's separate from the bolts and is really just your transverse shear check. The wood splitting issue at the bolts is a real thing but that's a tension perpendicular to grain issue and should be automatically accounted for in a proper bolt design where attention has been paid to edge distances parallel to shear etc.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.