Circular Stair

[courtnvm]

I have a circular stair I am designing that has a sweep angle of 136 degrees. I have quite a bit of torsion at the base and I am wondering if anyone is aware of any typical connections of radiused stair stringers to concrete floor slab-on-grade.

Thank you so much for your time and attention.

Val C.

 

[J1D]

I've never designed this kind of stair. Just wonder if you can release the bending/torsion at the base and make the stringers to take the torsions.

 

[courtnvm]

Yeah, luckily I was able to get 4 columns at the intermediate landing. Therefore, I released the bending and torsion at the base. I am welding an angle at the base of the tube stringer and bolting the angle to the slab with 3 - 3/4" diameter Hilti Kwik Bolt Expansion Anchors with 6" embedment.

With the columns at midspan of the stringer it really takes some of the torsion out of the stringer.

Val

Val Courtney, PE
Optimal Engineering, Inc.