lateral support for steel beam
lateral support for steel beam
(OP)
I am designing a steel beam to support a floor system which is made of 18” deep timber joists and plywood floor. Joists are hung on the top flange of the steel beam with 12” space(30' span ). My question is:
Can I consider this steel beam as fully lateral supported? Does any one know a book or a website discussing about that. Thank you for help.
Can I consider this steel beam as fully lateral supported? Does any one know a book or a website discussing about that. Thank you for help.






RE: lateral support for steel beam
DaveAtkins
RE: lateral support for steel beam
RE: lateral support for steel beam
The beam is continuous. My question is actually how to know “IF there is enough floor system to prevent buckling”
Simpson hangers are welded to steel beam on the top flange to support joist. I am not sure if it is good enough or not. In my case, considering lateral support and not will affect final cost a lot. However, I lack of any data to support my assumption.
RE: lateral support for steel beam
DaveAtkins
RE: lateral support for steel beam
For instance, if your joists beared on the beam on a bearing plate and were toe-nailed, that probably isn't good enough to brace the beam. If on the other hand your floor sheathing was fastened to the beam flange directly with powder-driven fasteners and the floor sheathing attached to shear walls, then you're probably braced pretty well.
As Dave said, it can be very intuitive and is part of the art of engineering as opposed to the science. Given some rational engineering analysis and jugdment you can usually figure it out and be pretty safe. Besides the AISC manual, you can also look in Salmon and Johnson's Steel Strucutures. They have a rational method for designing beam bracing also. Keep in mind it is out dated, but probably works. For my part I assume a larger unbraced length than the joist spacing, say midspan bracing for instance, and things work out fine, but that's what makes me and my boss comfortable. You may be ok with something different. I'd go with the text book, the AISC and some gut feeling and see what you come up with.
RE: lateral support for steel beam
It gives example for this kind of condition, it does not suggest to hange the timber joists to the top flange, you should use timber block fixed on the bottom flange and sit the timber joist onto the block.
Further consideration please see that guide
Meggie