Yep, that's an emergency. Good for that city crew which spotted it, but it also raises the question of why this got so bad before inspections identified the problem. Or don't they do inspections in Chicago?
I know this bridge has been there for a long time, but it vividly demonstrates why halving joints should be avoided, IMHO.
Looks like it was already failing in 2018.
Note the difference in the two bottom flanges relative vertical positions...
and the dark "slot"? just off the end of the angle.
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My wife is always making fun of me whenever we walk through or under some structure and my eyes are scanning the framing for "issues".
I've never found one significant but this Chicago failure is just what I'm looking for
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I'm going to show your post to my wife, JAE. Just so she knows that I am not the only one. I have found and acted on some issues over the years, maybe not as important as that one.
I'm struggling to understand why the joint was put in there in the first place, with a pier just a few feet away. Why not just use a double bearing pier?
Second photo shows joint was shimmed to get roadway elevation uniform. Combine impact force/vibrations from roadway elevation difference and gap along with corrosion source and poor upkeep, no wonder the poor design finally "almost" failed.
HotRod - Riveted construction... that bridge screams late 1920's-1930's Great Depression time frame. Top priority... avoid material expense, concrete in this case. Why make an entire pier twice as thick when the spans can be supported as shown on a "thin" pier?
Scheinfeld said the cracks were first noticed by a crew making traffic signal repairs around 10 a.m. Monday. An engineering crew came to the scene and decided to shut down the roadway.
Seven steel girders run north and south along the roadway at that point underneath the viaduct structure near expansion joints, Scheinfeld said. Two of the seven girders have cracks. She said the city plans to install steel plates underneath the roadway as a permanent repair.
Scheinfeld said the bridge is inspected every two years and was due to be inspected again in June. It was deemed in fair condition when last inspected in June 2017, she said.
Section damaged was built in 1986. Kind of confusing, but believe the 'structurally deficient' comment is about the nearby bridge rather than the currently failed section:
The damaged section, built in 1986, is just south of the steel bascule double-decker bridge over the Chicago River, which was built in 1937. It is one of the most heavily traveled structurally deficient bridges in the state, according to the American Road & Transportation Builders Association, a Washington-based trade group that uses Federal Highway Administration figures. The association said that the bridge is “functionally obsolete.”
The term “structurally deficient’’ means that a bridge is in need of repair or rebuilding, according to the association. The Chicago Department of Transportation is planning repairs to this bridge together with the Navy Pier Flyover bike path construction project this year.
They built this when they fixed the infamous S curve. That curve was a traffic engineering disaster. Two sharp curves in an area that would ice up with the lake water spray.
In looking at Google-Maps, they have the same connection on the Southbound side too (a little further south than this one).
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