Hernando Desoto Bridge closed I-40 Memphis

[TennesseeCamper]

22 minutes ago, Ski said:

If this isn't an elaborate hoax, it would appear the crack has been noticeable since before the last inspection.

 

https://www.fox13memphis.com/news/local/2019-photo-appears-show-crack-i-40-bridge-then/3JL6WK5FRVET7OOFTPL7WMC4YI/

I don’t know. To me that  looks like the the edge of the plate that is riveted. It’s not a real clear photo.  

[leroy]

1 hour ago, kentmck said:

I don’t know. To me that  looks like the the edge of the plate that is riveted. It’s not a real clear photo.  

Ya are seein it right ken... The joint is bolted.  This bridge is fairly " new " by big bridge standards.  Fabricated by Bethlehem Steel Corp in the late sixties and early seventies.  They may also have erected it as well, as they did that sort of work too.  This bridge is what is known as a " tied arch " design, and the fractured member is like a bowstring that keeps the arch from straightening out and falling. The connection ya see appears ta be the main one at the end of the arch.

There is a complete fracture to the right of the connection.  Im guessin its 12 inches to 24 inches away from the joint.  Im guessin a fatigue fracture brought on by cyclic loading that started at a notch or inclusion somewhere in the plate.  This is, indeed, bad because the fractured member holds the arch above it in tension.  If its broken, the loads are migrating thru the bridge floor beams and the deck slab, and that aint good.  Thats why they are wringing their hands and keepin traffic off the bridge. 

Concrete aint good in tension, and the floor beam system aint supposed ta carry this load.  If the deck breaks or a floor beam turns loose, they know the arch and bridge is headed for the drink. 

My guess is that they dont want ta take any chances with an errant tow bumping a pier anywhere until they get this bottom chord ( ... the beam with the fracture .. ) stabilized some way.  Watch for em to weld xtra coverplates or rig some big iron some way to carry these loads in the next while.   I spent some time designin and doin some of this when i had to work for a livin... Believe me, the TDOT and the ARKDOT is scared ta death right now...

structural engineerin leroy

Edited May 14, 2021 by leroy

[Grayfox54]

Local news just announced that the Coast Guard has re-opened river traffic. About 1000 barges are now moving again. Good news as the Mississippi river is a major agricultural product pathway.
There is also talk of a temporary repair to re-open road traffic until a permanent repair can be planed and scheduled. But nothing solid as of yet.  

Edited May 14, 2021 by Grayfox54

[Garufa]

6 minutes ago, Grayfox54 said:

There is also talk of a temporary repair to re-open road traffic until a permanent repair can be planed and scheduled. But nothing solid as of yet.  

[Grayfox54]

Not as far fetched as you think. In my career I have repaired large booms on various pieces of equipment by welding and plating the damaged areas. Same principal on a bigger scale. 

[Grunt67]

Don't forget Flex Seal.

[TennesseeCamper]

2 hours ago, Garufa said:

I ain’t volunteering to drive over first!

But hey, I saw them interview an “expert” today, they said this kind of damage wouldn’t cause a bridge collapse.  

[Garufa]

2 hours ago, Grayfox54 said:

Not as far fetched as you think. In my career I have repaired large booms on various pieces of equipment by welding and plating the damaged areas. Same principal on a bigger scale. 

The meme is a joke of course but I could totally believe it considering how Memphis does things and how many of those steel plates hold the streets together, sometimes for an eternity.

I sometimes think that the steel plate street cover was invented there.

Edited May 15, 2021 by Garufa

[leroy]

2 hours ago, Grayfox54 said:

Not as far fetched as you think. In my career I have repaired large booms on various pieces of equipment by welding and plating the damaged areas. Same principal on a bigger scale. 

Gray is most likely right...

I'm guessin they will plate n weld if they have the room... They musta done some quick number crunchin and believe the loads are low enough now with no traffic to get some things movin again. 

My concern would be wind loading now.  The wind bracing under the roadway deck must be helpin alot to carry the dead load of the bridge. They dont want ta see any big thunderstorms roll thru now im thinkin.

Watch for a big bridge contractor ta show up and fix this one for a handsome fee...

leroy...

 

[Grayfox54]

37 minutes ago, leroy said:

They dont want ta see any big thunderstorms roll thru now im thinkin.

Rain and thunderstorms predicted for all next week. 

[leroy]

1 hour ago, kentmck said:

I ain’t volunteering to drive over first!

But hey, I saw them interview an “expert” today, they said this kind of damage wouldn’t cause a bridge collapse.  

Dont hire this guy or gal for your next bridge or hi rise project structural design project.    He ( ..  or she .. ) failed structural analysis. 

leroy.  

[Ronald_55]

I am amazed we do not have morw bridge collapses in general. Lots of them are way past their prime and have much more traffic than they were designed for. Even newly build ones probably suffer from the same corner cutting I saw in construction. 10% less rebar is more prifi6t

 

[Daniel]

So yesterday I drove out to San Antonio and went through Memphis before lunch.  I took the detour over I-55 or whatever it was south of the bridge that is out of service.  Not too much delay for me.  Can't say the same for the people headed into Memphis from Arkansas.  That traffic looked backed up all the way back to I-40 practically.  

[Chris]

4 hours ago, Daniel said:

So yesterday I drove out to San Antonio and went through Memphis before lunch.  I took the detour over I-55 or whatever it was south of the bridge that is out of service.  Not too much delay for me.  Can't say the same for the people headed into Memphis from Arkansas.  That traffic looked backed up all the way back to I-40 practically.  

Thanks for the update. I’ll be making that same run tomorrow. 

[TennesseeCamper]

9 hours ago, Daniel said:

So yesterday I drove out to San Antonio and went through Memphis before lunch.  I took the detour over I-55 or whatever it was south of the bridge that is out of service.  Not too much delay for me.  Can't say the same for the people headed into Memphis from Arkansas.  That traffic looked backed up all the way back to I-40 practically.  

Good to know! I haven’t made that trip west in a long time. I wondered how bad the back up was. I hope to head that way this year.

[TennesseeCamper]

On 5/13/2021 at 7:47 PM, Ski said:

If this isn't an elaborate hoax, it would appear the crack has been noticeable since before the last inspection.

 

https://www.fox13memphis.com/news/local/2019-photo-appears-show-crack-i-40-bridge-then/3JL6WK5FRVET7OOFTPL7WMC4YI/

Arkansas bridge inspector fired!!!

 

Well, what you know that guy was right!

https://wreg.com/news/watch-arkansas-officials-hold-briefing-on-i-40-bridge-situation/?fbclid=IwAR3Q1RTqwUY9qPbsgMhDKOior3a7k2hKRWaWWc5fo4r2udtWX-93nD7bz1s

[gregintenn]

26 minutes ago, kentmck said:

Arkansas bridge inspector fired!!!

 

Well, what you know that guy was right!

https://wreg.com/news/watch-arkansas-officials-hold-briefing-on-i-40-bridge-situation/?fbclid=IwAR3Q1RTqwUY9qPbsgMhDKOior3a7k2hKRWaWWc5fo4r2udtWX-93nD7bz1s

I reckon that would do it.

[deerslayer]

1 hour ago, kentmck said:

Arkansas bridge inspector fired!!!

 

Well, what you know that guy was right!

https://wreg.com/news/watch-arkansas-officials-hold-briefing-on-i-40-bridge-situation/?fbclid=IwAR3Q1RTqwUY9qPbsgMhDKOior3a7k2hKRWaWWc5fo4r2udtWX-93nD7bz1s

Wow, so now they are going to re-inspect the I-55 bridge.  If they find something, we will have a genuine catastrophe.  
 

I shot a match in AR this weekend and Friday afternoon, eastbound traffic into Memphis was a total disaster.  I had planned to come back via Helena, AR after seeing the melee, but was pleasantly surprised that Saturday night traffic was light and we sailed right through I-55 like nothing was even wrong.  The phone traffic app didn’t lie.  

Edited May 17, 2021 by deerslayer

[leroy]

For those interested:  TDOT has a Hernando Desoto Bridge update page... https://www.tn.gov/tdot/projects/region-4/i-40-hernando-desoto-bridge.html  

I lifted these details RE: " The crack " from it a few minutes ago.

"... The arch truss spans are above the roadway and connected with steel box beams. A steel box beam is comprised of two side plates, measuring 32” x 1-3/8” (inboard and outboard), and tow cover plates, measuring 25” x 1/2” (top and bottom). A mechanical fracture, or crack, was discovered within the elements of a steel box beam on May 11, 2021. The fracture impacts 100% of the outboard plate, 100% of the top plate, and approximately 20% of the bottom plate.

The bridge is undergoing intense analysis, including bridge modeling, to determine the extent of the damage. As of May 14, 2021, there is no indication that the bridge is continuing to deteriorate. Additional modeling and analytical tools will be used to ensure quality control before making a final determination on structural stability. Design teams are working on short- and long-term solutions that would allow traffic to safely resume on the bridge ..."

It looks like they have hired the old Peter Kewit Construction company to do the repairs.  They are talkin about reinforcing this area.  Code words for cover plating.  Notice how big the box beam is... 32"x25"...

leroy.

Edited May 18, 2021 by leroy

[Erik88]

I guess my question is, if this crack has been there since 2019 and nothing has happened, is it really as dangerous as they claim? I get that it's bad, but I'm wondering if a temporary fix might be ok. I understand they have to be overly cautious at this point. 

We probably drive over other damaged bridges every day considering out horrible our infrastructure is right now. 

[gregintenn]

15 minutes ago, Erik88 said:

I guess my question is, if this crack has been there since 2019 and nothing has happened, is it really as dangerous as they claim? I get that it's bad, but I'm wondering if a temporary fix might be ok. I understand they have to be overly cautious at this point. 

We probably drive over other damaged bridges every day considering out horrible our infrastructure is right now. 

I don’t believe the bridge is in danger of falling because of what we’ve seen in the pictures. I do believe it is imperative to find the cause of this damage. Whatever caused it may or may not be serious enough to cause a collapse.

Were you making the call, would you take a chance on it, or shut it down intil the cause is determined? 

[FUJIMO]

10 minutes ago, Erik88 said:

I guess my question is, if this crack has been there since 2019 and nothing has happened, is it really as dangerous as they claim? I get that it's bad, but I'm wondering if a temporary fix might be ok. I understand they have to be overly cautious at this point. 

We probably drive over other damaged bridges every day considering out horrible our infrastructure is right now. 

That was my question as soon as it was discovered that there was rust in the break.

As far as our infrastructure it's an all too convenient target anytime politicians want money for something else. For those in TN when "dapper" Don Sundquist was in charge you'll remember we had an explosion of terrible bridges that needed repairs when he wanted to allocate a chit ton of tax dollars toward infrastructure. Sounds like the same old song and dance.

[Chucktshoes]

Just now, gregintenn said:

I don’t believe the bridge is in danger of falling because of what we’ve seen in the pictures. I do believe it is imperative to find the cause of this damage. Whatever caused it may or may not be serious enough to cause a collapse.

Were you making the call, would you take a chance on it, or shut it down intil the cause is determined? 

I don’t wanna take my truck over it until I’m sure that they’ve figured out what the issue is. 

[gregintenn]

Just now, Chucktshoes said:

I don’t wanna take my truck over it until I’m sure that they’ve figured out what the issue is. 

Thankfully, you won’t get a chance to. No one will open that bridge until it is absolutely safe.

[leroy]

It aint unusual to " monitor defects " in structures and even piping systems ( .. we did it on steam lines in fossil plants.. ), which, in the case of cracks, is " let's monitor it and see if it is growin "... This one did pretty fast.  Some defects are worse than others. This is in a main structural member, meaning if you cut it, the structure will fall.

This one is really bad.  Thats why they are doin what they are doin.  Bridge failures are often catastrophic and involve loss of life... This aint a " no.. nevermind " thing.

leroy...