Pipe Hanger in Seismic Zone PEMB 1

[swearingen]

Posted in the Seismic section, but thought I'd get more eyeballs here...


I have a run of industrial duct pipe (12" Sch 10) that will hang from the roof of a PEMB. ASCE 7 doesn't give much guidance on this sort of thing, so I wanted to ask if anyone here can point me in the right direction.

Initially, I supposed I would put a vertical hanger with a diagonal to keep it from swinging wildly in a seismic event.

I can't imagine this hasn't been done before...

Thanks in advance for any pointers.


-5^2 = -25 ;-)

http://www.eng-tips.com/supportus.cfm

 

[FoxSE14]

Typically accomplished with a trapeze which is braced to the diaphragm above using angles/unistrut/cable. Make sure the braces can handle loads in N-S and E-W orthogonal directions (don't forget the loads are reversible). Determine brace forces using Chapter 13 of ASCE 7.

A google search for "pipe trapeze seismic" will yield some helpful images to get your mind headed in the right direction.

This being a PEMB likely without much reserve capacity - you may have to spread the load into the diaphragm with additional reinforcement (horizontal cross-bracing perhaps?) in the plane of the roof/roof framing.

 

[dhase]

On what I think was a similar project I was helping out with at my last job, we used the SMACNA manual to give us guidance on where we might need to provide lateral and transverse bracing for the pipe that we were hanging from the ceiling. But we also had to use our best judgement for some of it as well. I hope this helps.