Embed plate in concrete with headed studs

[ztengguy]

Whats the best way to design a embed plate at a corner of a piece of concrete that has the headed stud coming off the interior of an angle at 45deg into the concrete. A contractor I work with alot likes this detail, I am just not 100% sure what design value to give it. Do you take the edge distance from the end of the stud, or some average value?

 

[a2mfk]

post a sketch of the detail

 

[ztengguy]

Here you go, Thanks!

 

[a2mfk]

I have seen that detail before, but I would be concerned with the weld at the inside radius of the angle.

What forces are being transmitted to the angle? Can you re-pose the sketch with some force vectors? I am guessing horizontal if that is a top of a wall panel?

 

[ztengguy]

Horizontal, max load about 1200lbs. Im not too worried about the connection, just curious about how to put accurate numbers to it.

 

[structSU10]

I have taken the embedment of the anchor as the smaller of the horizontal or vertical projection, then apply appendix D limits. I figure the cone failure should be equivalent to that.

 

[a2mfk]

I may use a bent plate with vertical leg up attached to the right side wall to eliminate that field weld and simplify things.

Headed stud design per StructSU. If there is room in the panel you could go with a vertical stud and place a continuous #4 on the left side of the stud for supplemental reinforcement when the panel reaction is to the left. When the shear is to the right it will simply compress the angle so no worries there. If the headed studs are giving you issues then you can always use a channel with legs down or a bent plate saddle (shaped like an upside down "U") that will give you full shear value of the concrete without needing the studs.

 

[wannabeSE]

I have seen this detail for corner guards at loading docks or trenches. It might be best to contact a stud manufacture for design guidance and availability of special ferrules. Special ferrules are manufactured for this connection (

http://www.nelsonstud.com/portal/portals/0/pdf/catalog/Ferrules/Fillets and Heels.pdf).

I thought this was fairly common. I vaguely remember some company was premanufacturing these embed; but I can not remember the company.

 

[ztengguy]

Thanks. Since its not a huge load, I am comfortable with the min vert or horiz distance. I should have a few test specimens made and pull them to failure.

 

[a2mfk]

zteng- should be pretty straightforward shear cone failure towards a loaded edge per ACI Appendix D. You would likely get push back for doing testing on a fairly common connection you can design.

The more I think about it, the more I like an inverted channel or bent PL saddle to cap the wall. Then you get the full shear of the concrete, and your vertical bars in the panel will also extend through that theoretical shear plane.

 

[ztengguy]

Okay, thanks. This connections would be better with just a embed plate at the top of the wall. No reason for the angle then.