Unbraced Length of Column
Unbraced Length of Column
(OP)
Having an issue analyzing an existing column as part of a moment frame. Eave height is 35 feet. Kicker angles from flange back to wind girts at 8 feet +/-. Can't justify this as bracing for the weak axis...no info on the wind girts. But the column is way off for the full height...design doesn't work for existing conditions, and the owner is wanting to add a jib crane. Plans showed that the column of interest was intended to be added on to in the future.
Any thoughts on that method of bracing the weak axis? I don't regularly design metal buildings, but I haven't noticed that kind of bracing before.
Any thoughts on that method of bracing the weak axis? I don't regularly design metal buildings, but I haven't noticed that kind of bracing before.






RE: Unbraced Length of Column
The paper thin columns of PEMB's can't work without them.
RE: Unbraced Length of Column
You may consider adding bracing between columns or, better yet, a freestanding jib.
RE: Unbraced Length of Column
Thanks for the responses.
RE: Unbraced Length of Column
RE: Unbraced Length of Column
RE: Unbraced Length of Column
RE: Unbraced Length of Column
It would be for bracing the column weak-axis as you were describing in the OP. If you were not confident in the kickers.
I have heard many debates on whether or not to count on those kickers for bracing, but one would assume that is why they are there.
RE: Unbraced Length of Column
RE: Unbraced Length of Column
There are not just the vertical loads to consider, there are allso the accidental loads from sideways movement or out of straightness.
There are also probably deflection criteria.