Who Broke The Bridge?

[Streetcar]

Totally unrelated, but how do they set the rivets on a beam like that?

The rivets were heated up and installed from inside the beam. The exterior side was then hammered to form rivet head.
I inspected major bridges for over a decade

 

[ruffdog]

It looks like the broken beam is like a channel that is open to the inside.

I-40 Bridge Over Mississippi Could Be Shut Down For Months; Inspectors Called 911 | The Weather Channel - Articles from The Weather Channel | weather.com

 

[newbury]

Looks like infrastructure repair time.
Barge traffic from the east might divert through the Tenn-Tom. I'm about 2 miles from it. My relative who lives right on the waterway said barge traffic was up yesterday. I often hear their horns as they lock through.

 

[Jstpssng]

I must have a guilty demeanor. When I read his headline the first thing that I thought was "It wasn't ME!!!!"

 

[PILOON]

Tied arch bridge not suspension
Bolted not riveted
Failure appears to be fatigue at weld
Beam looks to have minimal rust and section loss

At WELD?
They used rivets.
Yes, minimal rust from what I saw.

 

[RickB]

Tied arch bridge not suspension
Bolted not riveted
Failure appears to be fatigue at weld
Beam looks to have minimal rust and section loss

At a weld? There's no weld at that break. That bridge must have been one of the ones you "inspected".

 

[s219]

Interesting failure. When a structural member breaks clean right near a major connection like that, it sort of suggests cyclical loading or vibration fatigue. The ability for the member to flex and relax is constrained when you get into short range of a connection.

 

[LS Tractor Owner]

Ahhh, a couple of guys on ropes and a couple mig welders could fix that right up!

......not..... that took some stress.

 

[Streetcar]

At WELD?
They used rivets.
Yes, minimal rust from what I saw.

The box beam is made of four steel plates joined by longitudinal welds. The pieces are bolted together. If you look close you can see the hex head of the bolts at the connection

 

[Streetcar]

At a weld? There's no weld at that break. That bridge must have been one of the ones you "inspected".

Longitudinal weld for length of member.
I have been the lead engineer for inspection of several bridges across Ohio river and numerous other bridges.
Cracks can grow from fraction of an inch to completely through member in hours.