There are engineers discussing it here:
Non-engineers cannot join in. I find that forum to generally be extremely educational for things like this. Some of it is far over my head, but, for example, I now understand that they can’t just slap a patch on the beam, because that would not restore the tension that the beam had been carrying. That force has gone somewhere else – perhaps is now a lateral force in the piers, which they may not be designed to take.
I’d call them brave, like anyone who takes on personal risk for the benefit of others.
Thanks for the link; that’s an excellent discussion going on over there.
I wonder if that determines when various members are bolted together.
It’s actually worse than that.
He’s sitting on one part and is tied to the other part. if either side of the failure falls, he’s going swimming.
That picture is interesting in that there appears to be a section of the inboard vertical web that is not disrupted. If that is a box beam (whether built-up or straight from the mill as a box), the crack isn’t across the entire circumference. Or at least the entire circumference hasn’t displaced laterally.
Excellent find there on that engineering forum @eschrodinger. Thanks.
As a side note for us here on SDMB, I have to say that seeing cutesy sig sections on many posts where the multi-line sig is bigger than the post quickly gets very tiresome.
Especially when a couple of folks get into a dialog so at a glance it looks like dueling sigs with some small distracting noise mixed in. That “small distracting noise” being the sole actual meaningful content of the exchange.
Glad we don’t have 'em.
Someone at the engineering forum posted a description saying that 3 sides of the box beam have complete breaks and the fourth side has a 20% break.
Preach it! I sporadically read some forums that are like that, and that is the reason I used “sporadically”. It’s especially bad when the sigs are stupid.
Yeah. I just got down to that post. Thanks.
So what we’re seeing there is the undisplaced inboard portion of the floor plate of the box beam.
A sig that the user would have to manually select “on” to appear in that post and which could not be posted more than once per thread no matter what the user wants would be as far as I’d be willing to permit the things were I the King.
At vBulletin we had the sig-defaults-off-must-be-selected-on feature, but not the once-per-thread-maximum feature. Only a few goofs abused that.
Of course nothing can stop folks willing to type their “clever” repetitive content at the end of every post.
Regards,
Are you trying to get yourself banned?
I figure excerpts for satirical purposes are fair use. You’ll notice I didn’t quote the whole “work”. 
Allow me to float the idea that the harness isn’t to keep him safe if either part of the bridge gives way, but rather in case he slips and falls. Because I would suspect that if either part of the bridge gives way (ie, collapses into the water) both sides of the fracture are liable to come down, and everything above as well, and no amount of “safety harness” is going to save some unlucky inspector who happens to be in that spot from going in with it and probably being crushed/perforated/drawn under by the wreckage.
Aye; I was going to point that out as well as note that the harnass is defintely not so he can save the bridge should it begin to fall.
TDOT is planning a temporary fix. No duck tape is needed. 
Would the steel rods restore tension in that beam? I assume they’re planning heavy threaded rod that can pull the crack together. I hope they monitor the repair with a live camera. Check it daily to confirm it doesn’t break again.
“Interim fix” implies that they’re going to do something more complete in the future. The article doesn’t say what that would be. They could go over the whole bridge and add reinforcement, or they could replace the bridge.
This reminds me of what happened with the San Francisco-Oakland Bay Bridge. A segment of the upper deck of the eastern span collapsed in the 1989 Loma Prieta earthquake. Caltrans (the state agency that builds and maintains state highways) fixed the immediate problem in about a month, but the collapse made it clear that the bridge was not earthquake-safe. A new eastern span was proposed, but design considerations and politics delayed the project. In 2009, twenty years after the quake, two structural problems were discovered. The first was a crack in an eyebar that Caltrans was able to repair pretty quickly. The second was a crossbeam and two tie rods that broke off and fell onto the upper deck, which forced the bridge to be closed for five days.
A new eastern span finally opened in 2013, twenty-four years after the quake.
Mod note: Don’t be such a jerk. No warning.
Mod note: Don’t be such a jerk.
Something I vaguely remember reading was they were thinking of replacing the whole 37 foot long beam which was broken (or whatever length it was)–but this would have to be manufactured and it takes weeks for the manufacture.
I read a description of what the engineers discovered. One crucial girder was really on the point of failing. I suppose some of you might have preferred that the bridge fall as in Minneapolis before closing it, but it really sounded like it was well past the time of pushing the panic button. Notice that river traffic was also halted pending further study.