Bridge Collapse

[carolyn]

As Im sure many of you have seen on the news there was a major bridge that collapsed in Mpls into the Mississippi. For my friends and acquiantances out there, Im obviously okay and fortunately did not need to use that way to get home tonight.

 

There is not much ability to use cell phones right now and havent been able to get in touch with any of my friends.

 

I dont know what else to say. Its really a horrific scene.

 

Positive vibes to all involved in the accident and recovery.

[rmncwrtr]

It's horrible, Carolyn. I was watching the news and can't even fathom what it must be like there. The mechanical engineer in me has been trying to analyze what I see on the screen. Hugs and prayers to all involved. So glad you're okay!

[wayne]

Sorry Minneapolis.

As a builder, I am sad that our stuff falls down sometimes. I maintain a vigilant saftey and structure regimine constantly. It is like climbing all day every day when it comes to the saftey of me and my crews..

I cant believe it failed with half the lanes closed too.

We have our own viaduct waiting to come down, yikes

[foraker]

That's very near our main mid-western office. :-(

[carolyn]

Im going to try and stop gluing my eyes to the news and go to bed.

Thank you Sobo for the phone call. Thanks for your continued effort to reach me. In some ways Its good to know it took so many tries to get through. Hopefully the people I have been trying to reach are having the same difficulties getting in touch with me to let me know they are okay.

 

This is a MAJOR thruway into/outof the city as well as getting from one side of the city to the other. I was on the bridge yesterday afternoon and Saturday evening. Its about 3 blocks from one of my jobs. There will be a lot more deaths involved in this tragedy than they are currently reporting. Kudos to the media for not speculating. But reality is that it was rush hour on a major highway. There are cars which may not be found in the river for days or weeks. Cars that were smashed by infastructure. Those people have not been accounted for or confirmed dead - because they have not been found.

 

Damn, this is crazy!

 

And - Wayne - indeed it is a good thing it was down to one lane (on one direction). Imagine two more lanes opened during this.

[olyclimber]

Thats horrible news Carolyn. Best wishes to everyone involved.

[Crux]

Heard about it on the radio 30 minutes ago. Report stated over twenty families are reporting missing persons now. Felt disbelief at first, then anger. Curiously, went online to verify...

 

 

 

 

[snugtop]

Apparently that bridge was known to be "structurally deficient"...and apparently there are over 160,000 bridges in the US that are also in this category...very scary.

Edited August 2, 2007 by snugtop

[StreetBoss]

Heard about it on the radio 30 minutes ago. Report stated over twenty families are reporting missing persons now. Felt disbelief at first, then anger. Curiously, went online to verify...

 

 

 

 

Rudy - what's the engineering perspective? Was this your firm's?

 

[RuMR]

go ahead and try to get more money to fix them... or better yet, try tolling them to get them fixed...

 

structurally deficient is an "interesting" term...

 

The FHWA termed it as needing eventual replacement, yet somehow, i didn't see them helping to foot the bill

[RuMR]

Heard about it on the radio 30 minutes ago. Report stated over twenty families are reporting missing persons now. Felt disbelief at first, then anger. Curiously, went online to verify...

 

 

 

 

Rudy - what's the engineering perspective? Was this your firm's?

 

 

actually bob, the industry is taking this very seriously...there are few structural, very few, structural failures...but even a few are a few too many...it makes me sick to my stomach

 

I'm completely speculating, but my money is on a fatigue issue...only way to explain forty years of service with a sudden catastrophic failure.

 

and no, neither this office, nor any other of my firm's offices were involved with the original design or any subsequent retrofit efforts.

[StreetBoss]

Is the fatigue caused by inadequate engineering, maintenance (many cities choose to save money that way), over use or materials?

 

[RuMR]

shitty detailing causes members to be prone to fatigue...notches, certain welding details, etc. are "start" points for cracks...

 

bad steel can be sensitive to fatigue...its a combination of many things...none of which are apparent when the structure is "new"...all newer designs have fairly stringent charpy tests for members that are deemed "fracture critical"...and stress ranges are kept very low in fatigue-sensitve details.

Edited August 2, 2007 by RuMR

[lizard_brain]

From CNN:

 

"In 2005, the U.S. Department of Transportation's National Bridge Inventory database concluded the bridge was "structurally deficient."

 

(The whole article is here.)

[StreetBoss]

Thanks for the insight

 

[RuMR]

From CNN:

 

"In 2005, the U.S. Department of Transportation's National Bridge Inventory database concluded the bridge was "structurally deficient."

 

(The whole article is here.)

Tom Everett of the Federal Highway Administration's National Bridge Inspection Program said the structurally deficient rating was a "programatic classification rather than an indication of safety."

 

"It does not indicate a bridge is dangerous or that that bridge must be replaced,"

 

Edited August 2, 2007 by RuMR

[lizard_brain]

From CNN:

 

"In 2005, the U.S. Department of Transportation's National Bridge Inventory database concluded the bridge was "structurally deficient."

 

(The whole article is here.)

Tom Everett of the Federal Highway Administration's National Bridge Inspection Program said the structurally deficient rating was a "programatic classification rather than an indication of safety."

 

"It does not indicate a bridge is dangerous or that that bridge must be replaced,"

 

Okaaaaaayyyy... This bridge isn't unsafe, it's just 'structurally deficient'. Say that just before it collapses.

 

 

[underworld]

it's like saying 98% of all cars on the highway have a reduced amount of tread on their tires!!! OMG!!!!!

 

 

[RuMR]

From CNN:

 

"In 2005, the U.S. Department of Transportation's National Bridge Inventory database concluded the bridge was "structurally deficient."

 

(The whole article is here.)

Tom Everett of the Federal Highway Administration's National Bridge Inspection Program said the structurally deficient rating was a "programatic classification rather than an indication of safety."

 

"It does not indicate a bridge is dangerous or that that bridge must be replaced,"

 

Okaaaaaayyyy... This bridge isn't unsafe, it's just 'structurally deficient'. Say that just before it collapses.

 

my point is that there are many many bridges out there that carry that "rating". And the general public drives over them willy-nilly, then bitches about every damn tax that is earmarked for transportation to FIX them. Then, when they fall down, they point and say "why the hell wasn't this fixed"...

 

BTW...if you feel this way, don't park under the viaduct, or drive on it, or be anywhere near it...mmmmkay?

Edited August 2, 2007 by RuMR

[RuMR]

it's like saying 98% of all cars on the highway have a reduced amount of tread on their tires!!! OMG!!!!!

 

precisely, and they sometimes blow out...except when a bridge goes, the fatalities are higher...

[carolyn]

So Rudi and other architects, builders, etc...Can the excessive heat we have been receiving more and more over the years, especially this summer, contributed in any way?

 

I have heard from many folks today, which is good news. So, I dont know anyone affected by this - yet. Its difficult not knowing when, how, or if they will ever be able to recover bodies. I cringe everytime I watch the news and they start interviewing someone whose friend or relative is missing, hoping its not someone I know.

 

I have yet to get near the bridge. Part of me wants to see it, but I know it is also going to be a pretty awful and probably emotional site. I work a few blocks from the site this weekend. It is and will be quite a zoo, especially with a visit from Bush on Saturday.

 

 

[Cobra_Commander]

I crossed that sucker a bunch of times when I was in college there, wow.

 

Having been a diver for some research in the Mississippi there, I can say with confidence those recovery divers have probably the worst job in the world right now.

[sk]

So Rudi and other architects, builders, etc...Can the excessive heat we have been receiving more and more over the years, especially this summer, contributed in any way?

 

I have heard from many folks today, which is good news. So, I dont know anyone affected by this - yet. Its difficult not knowing when, how, or if they will ever be able to recover bodies. I cringe everytime I watch the news and they start interviewing someone whose friend or relative is missing, hoping its not someone I know.

 

I have yet to get near the bridge. Part of me wants to see it, but I know it is also going to be a pretty awful and probably emotional site. I work a few blocks from the site this weekend. It is and will be quite a zoo, especially with a visit from Bush on Saturday.

 

 

*HUGS* i hope all your people are okay. i didn't hear about this until this morning. i am slow on the news.

 

lots of good thoughts your way

 

xoxoxoxoox

[sobo]

So Rudi and other architects, builders, etc...Can the excessive heat we have been receiving more and more over the years, especially this summer, contributed in any way?

 

First, let me say that I'm glad that you're OK, Carolyn, and that as of now, you aren't personally connected to anyone in this tradegy. I sincerely hope that fact doesn't change with the passage of time.

 

Secondly, excessive (ambient) heat would have no effect in relation to what Rudy is talking about (the structural detailing: notches, welds, etc.) in this example. I agree with Rudy and also suspect that stress-corrosion cracking will likely emerge as the reason for this failure (is this the Bridge Collapse Speculation Thread??), and as he stated, takes time to manifest itself, and is not apparent when a structure is new. Some engineering students on this site might remember (from their Catastrophic Failures class) the Silver Bridge over the Ohio River between Ohio and West Virginia that collapsed 40 years ago. Stress-corrosion cracking in the link pin connectors of this suspension-style bridge was the ultimate culprit that killed 46 people. Given what I have seen on the videos and the type of superstructure construction, we might very well see this emerge as the culprit once again.

 

my point is that there are many many bridges out there that carry that "rating". And the general public drives over them willy-nilly, then bitches about every damn tax that is earmarked for transportation to FIX them. Then, when they fall down, they point and say "why the hell wasn't this fixed"...

 

My sentiments exactly. For all of you folks who vote down transportation tax packages, take notice. It's not just potholes that need fixin'...

[RuMR]

So Rudi and other architects, builders, etc...Can the excessive heat we have been receiving more and more over the years, especially this summer, contributed in any way?

 

I have heard from many folks today, which is good news. So, I dont know anyone affected by this - yet. Its difficult not knowing when, how, or if they will ever be able to recover bodies. I cringe everytime I watch the news and they start interviewing someone whose friend or relative is missing, hoping its not someone I know.

 

I have yet to get near the bridge. Part of me wants to see it, but I know it is also going to be a pretty awful and probably emotional site. I work a few blocks from the site this weekend. It is and will be quite a zoo, especially with a visit from Bush on Saturday.

 

heat is not usually a problem...the bearings were apparently shot though, so maybe "expansion" was blocked up and inducing more compression causing a buckling...probably not though...extremely unlikely...