Spiral Staircase

[stevenspm]

Hello,
I have recently been asked to provide lateral bracing for a couple of spiral staircases. They are interior staircases for access to a theater catwalk some 20 to 34' above the base of the stair. The architect is using a proprietary staircase by a manufacturer. My question is how would one go about laterally bracing such a staircase? I am use to connecting spiral stairs at each floor but have not yet done one for 34'. Or should I just worry about the connection to the catwalk and make sure the catwalk at the connection is braced and let the actual staircase design be handled by the manufacturer for span.
Thanks
Phil S

 

[KootK]

Let the manufacturer deal with the need for intermediate bracing if they're willing. At minimum, I'd think that they should be telling you how often the system requires lateral bracing. Maybe it doesn't need lateral bracing at all.

If intermediate lateral bracing is required, I'd run two splayed, level-ish struts from each brace point back to whatever you plan to brace the staircase to. I imagine that you'd need to grab the stair stringers rather than central pole for spatial reasons.

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.