Design of Nelson Studs

[EngDM]

Hello!

I am curious to what methods can be used to reinforce a nelson stud (acting in shear from a weld plate) so that we can preclude any failure due to pry-out? I'm currently running in the Simpson anchor designer, however there is no setting to ignore it. I'd imagine if the ties are spaced close enough to intercept the pry-out cone, and the anchors are within the vertical steel cage, that it would transfer into those bars and we can develop those for the shear capacity required.

 

[BridgeSmith]

If you want to evaluate the studs for tension and prying action, as well as shear, you'd have to consider combined tension and shear with the appropriate limits in the governing code or specifications, and the tension portion would have to be increased by calculated factor for prying action. Checks for tension failure would be similar to what you would do for a headed anchor bolt, again per the governing specifications.

 

[structSU10]

if you are using ACI code there is no provision to reinforce for pryout. There is a paper 'design of anchor reinforcement in concrete pedestals' that states if the embedment depth is 12 diameters or more it will not govern but no hard backup on that.