Shear Studs: Transferring Diaphragm Shear from Comslab Deck into Steel Beam Below
Shear Studs: Transferring Diaphragm Shear from Comslab Deck into Steel Beam Below
(OP)
In my area, we sometimes use a floor system called Comslab. It's basically a ribbed deck system like any other save the fact that the ribs are 8" deep. I have a situation where I need to transfer diaphragm shear down through one of the deck ribs into a steel beam via nelson studs (see attached sketch). Really, it's not a rib so much as a cast block of concrete as deep as a rib.
I'm having a hard time thinking through the checks that need to be done here. Some of my thoughts:
1) Shear friction on a vertical plane at the sides of the rib? We don't do this for ordinary T-beams / joists though.
2) Shear friction on a horizontal plane at the the underside of the slab? Again, not done for ordinary T-beams / joists.
3) Should I design the studs as though they are in a deep rib or as though they are in a solid slab?
4) The diaphragm forces need to strut their way down to the beam. Do the vertical components of these struts tend to pop out the top of the slab? Is this effectively shear in the concrete rib? Should I be thinking stirrups?
5) The code says that, in ribbed deck systems, the stud heads need to be in the topping slab. Would that apply hear? If so, I'll need to get my hands on some rather tall studs.
Thanks for your help.
Kootk
I'm having a hard time thinking through the checks that need to be done here. Some of my thoughts:
1) Shear friction on a vertical plane at the sides of the rib? We don't do this for ordinary T-beams / joists though.
2) Shear friction on a horizontal plane at the the underside of the slab? Again, not done for ordinary T-beams / joists.
3) Should I design the studs as though they are in a deep rib or as though they are in a solid slab?
4) The diaphragm forces need to strut their way down to the beam. Do the vertical components of these struts tend to pop out the top of the slab? Is this effectively shear in the concrete rib? Should I be thinking stirrups?
5) The code says that, in ribbed deck systems, the stud heads need to be in the topping slab. Would that apply hear? If so, I'll need to get my hands on some rather tall studs.
Thanks for your help.
Kootk
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