Hairpin Anchorage for Pre-Eng Metal Building

[Baffled Engineer]

Hello,

I have encountered this atypical hairpin detail for anchoring pre-engineered metal building frames...

I just wanted to get your thoughts on this, if this would be effective at all?

The hairpin will be cast in the slab, but it's wrapped around another U-bar that is anchored into the pilaster.

I always detail the hairpins to wrap around the anchor rods and it's my first time seeing this detail in the picture.
Would the U-bar open up? and is there a direct bearing steel-to-steel check for the rebar?



Thanks!

 

[KootK]

In some ways I like this better than wrapping around the anchor bolts as that's always felt a little sketchy to me.

You're right though in that the connection between the hairpins and the U-bar lack a commonly available design method. I doubt bearing is a problem so long as the bits are kept in contact. You could check the U-bar for bending as a curved beam but I'd not be hopeful that would work out.

And that still leaves the anchorage connection between the U-bar and the pier.

This is the first time that I've seen this as well.

 

[johnwow]

I can see this being beneficial when you are leaving out the slab for a shell building and can temporarily use cable between opposite columns to tame thrust.