Eliminating torsion design

[jdbpe]

I have a 42 foot long W24 roof beam that needs to support 12 vertical feet of brick with stud backup below. I have C6 channel hangers every 6 feet supported from W24 and a plate in between 6 inch stud backup. The C6 hanger supports an 8x6 tube lintel with angle welded to it to catch brick. The centerline of backup is 17 inches away from the W24 beam. There will be a kicker from tube to W21 that is six feet away. Calculating the torsion along with dead and live load leads to a W24x84. Can I neglect the torsion if I provide a W10 beam on other side of W24 at every plate/C6 hanger location? The W10 beam will connect to the W21x44 six feet away. This location is at the metal deck roof level of a one story building

 

[haynewp]

Have you thought about placing kickers from the bottom flange of the W24 back to the top flange of the W21 at each hanger location to eliminate the dead load torsion from the brick?

 

[JAE]

With wide flanges you have three main choices:

1. Design the Wide Flange for the torsion, checking the strength as well as the stiffness/stability. With WF shapes the stiffness is very very small.

2. Remove the torsion from the supporting WF by providing an alternative load path (Per haynewp). Kickers, etc. are what is typically done.

3. Support the brick in some other way from the ground - you would still have the lateral wind/seismic to path up to the roof, though.

 

[UcfSE]

It sounds like you're proposing to use a W10 beam in flexure to take the torsion from the W24. I suppose that falls under JAE's No. 2 suggestion. I don't see a problem with it as long as you check everything. I've done something similar in the past when I didn't have room for a kicker. I'm almost sure a kicker would be cheaper if you have the clearance for it. Moment connections tend to be pretty expensive.

 

[jike]

Can the W24 be dropped to have the W10's run over the top to pick up the hangers?