Single Web Stiffeners for Bearing?
Single Web Stiffeners for Bearing?
(OP)
Hi folks,
I've been presented with an issue on a job where the erector did not install the stiffeners as specified. Now a beam that is transferring a column can not be accessed to install a stiffener plate on one side (wall is in the way). I've been looking through the SCM and it seems that they are very specific on the word "pairs" for the stiffeners. The commentary does not seem to help either. Does the AISC not allow for use of a single stiffener for a concentrated compressive load? Does a single doubler plate make the most sense in this situation? Thanks
I've been presented with an issue on a job where the erector did not install the stiffeners as specified. Now a beam that is transferring a column can not be accessed to install a stiffener plate on one side (wall is in the way). I've been looking through the SCM and it seems that they are very specific on the word "pairs" for the stiffeners. The commentary does not seem to help either. Does the AISC not allow for use of a single stiffener for a concentrated compressive load? Does a single doubler plate make the most sense in this situation? Thanks






RE: Single Web Stiffeners for Bearing?
If the stiffeners cannot be aligned with the column flanges, I don't think they will do much good. The Contractor may have to remove enough wall to permit placing stiffeners as detailed on the drawings.
BA
RE: Single Web Stiffeners for Bearing?
RE: Single Web Stiffeners for Bearing?
We can do a lot more to help if you provide an answer to this question aknyg.
To my knowledge, there is no prohibition on single stiffeners. The truth, which may not be particularly helpful, is that any connection arrangement is probably viable so long as you can demonstrate that it works by the numbers. The stiffeners may be performing a number of functions:
1) Keeping the beam web from crippling.
2) Keeping the beam web from buckling.
3) Keeping the beam web from sway buckling and, generally, stabilizing the joint.
4) Providing an appropriate bearing surface for the column.
5) Keeping the column web from crippling.
That said, with a web aligned wide flange column to wide flange beam connection, often the detailing is simply a result of a "standard detail" being applied to the connection. In that case, there is usually wiggle room for modifying the connection if you understand the critical failure modes.
Do you know which failure modes are critical here? If so, you may well be able to get away with one sided stiffeners.
Again, it depends which failure modes you're hoping to address by using the web doubler. Web doublers are normally used to address shear capacity and shear buckling, neither of which is likely to be an issue here. I supposed that the doubler could also be used to address ordinary beam web buckling however. No matter what, I'd retain the stiffeners on at least one side. Even one sided, they'll do a lot to stabilize the joint (item #3 above).
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.
RE: Single Web Stiffeners for Bearing?
RE: Single Web Stiffeners for Bearing?
Help us help you. Just type Y or N. Or, if you're feeling sporting, supply a sketch.
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.
RE: Single Web Stiffeners for Bearing?
RE: Single Web Stiffeners for Bearing?
RE: Single Web Stiffeners for Bearing?
RE: Single Web Stiffeners for Bearing?
RE: Single Web Stiffeners for Bearing?
I didn't ask whether or not you were talking about web crippling. I asked on which member is web crippling / web yielding critical? It could be the beam, the column, or both. I'm trying to narrow the scope of the problem in order to help you effectively, that's all.
I'd recommend reviewing this thread for ideas: Link. If a "do-nothing" solution doesn't calc out, consider a detail like the one shown below. It can be accomplished without demolishing any of the existing wall that you're trying to preserve.
I agree with BA's concern. A W10x30 is a small beam and a W14 can potentially be a very large column.
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.
RE: Single Web Stiffeners for Bearing?