Repairing RC Column Base Plastic Hinges

[mes7a]

When RC Column bases in a special moment frame developed plastic hinges from seismic activity.. are they still repairable.. how are they repaired? or do you have to demolish and rebuild the building?

Can anyone show pictures of plastic hinges formed in an RC column?

BTW.. for steel columns.. I guess it's simpler to repair by simply welding those bended anchors or plates after they are hammered back to straight by jacking up the floors.. isn't it..

 

[mike20793]

Here is a picture after a major event. In major seismic events, they cannot be repaired. The goal is to design for life safety, not to keep the building usable after an event.

 

[jayrod12]

What a picture!

 

[mike20793]

That's actually from the Federal Highway Administration, so I imagine that's under a bridge.

 

[mes7a]

Here is a picture after a major event. In major seismic events, they cannot be repaired. The goal is to design for life safety, not to keep the building usable after an event.

Which earthquake produced it? There seems to be some lack of ties.. is it not caused by increased gravity loads in the bridge?

Plastic hinges occur when the column bases rotates and the rebars yielded.

 

[mike20793]

Yes, I am aware what a plastic hinge is and that's what this is showing. Ideally, the plastic hinge forms at the column base. This clearly occurred because of poor detailing. I just googled "plastic hinge in concrete column." There's a lot of pictures available. It's probably from the Northridge Earthquake if I had to guess.

 

[mes7a]

Can plastic hinges occur in column bases without first appearing in the beams above during a parade of shaking ?