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Concrete moment frame hit with lift

Concrete moment frame hit with lift

Concrete moment frame hit with lift

(OP)
I have an issue where a lift hit a steel beam, and caused some cracking of a moment connection the beam frames into. I have been asked to say if ok or not, but I first want to know what to really look for? Should I ask for Xrays? Its clearly a big crack, and i suspect the rebar on the weld plates might be compromised.

the moment connection is a embed angle with Dowel bars developed into the concrete. it looks like it rotated and sheared below those bars.

RE: Concrete moment frame hit with lift

Do you have any photos from further away? I'm having trouble understanding what the framing is.

RE: Concrete moment frame hit with lift

How sure are you that this is a moment frame connection? It looks like a corbel detail to me in the second photo. Are you able to post a sketch of the connection detail showing the rebar etc? If the intent of the connection is clear and it was detailed correctly to begin with, it might not be a big deal other than, perhaps, some minor remediation for corrosion control.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

RE: Concrete moment frame hit with lift

(OP)
Here is the elevation, and then a pic of the steel beam they hit. The steel beam is perpendicular to the taller column on the frame. The corbel damage is the opposite side of the steel beam, the weld plate is same side as the steel beam.
my thoughts are this thing racked and twisted as the steel beam was moved upward. No damage to the base plates, or the steel beam attachment.

I hate to have to have them remake the columns, but there also is alot of DL and LL on the lower beam. With the negative moment is the beams at the ends, I am worried about the corbel connection the most.

RE: Concrete moment frame hit with lift

Maybe it's just me but I don't understand where the photos are related to the elevation.

RE: Concrete moment frame hit with lift

(OP)
The steel beam is at the top of the concrete column, the top concrete beam is not installed, the lower one is, and where the cracks are.

RE: Concrete moment frame hit with lift

Jrisebo:
Your building section certainly doesn’t show the corbels, the steel beam or where this all really exists, and most of us are probably not going to spend hours trying to figure that out. Are these really moment connections or do they just induce some moment by the nature of the way they are made? Your bldg. section does say that the design of these connections are the responsibility of the precast supplier. I wonder why you wouldn’t ask them what they think should be done, since they’re on the hook for these connections and their adequacy?

RE: Concrete moment frame hit with lift

(OP)
I designed the connections for the precaster. The frame is just what the EOR showed, I was showing it for the general layout.

I think what happened is the impact caused the column to rotate away, and then come back. this induced a torsion into the connection greater than the design. Final design has minimal torsion, but this i am sure (since it cracked) exceeded any resistance.

I was inquiring if I should get some Xrays for the connections.

Some updated pictures show the lower non corbel side.

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