Bridge collapse in Minn
 

35 W over the Mississippi collapsed in Minneapolis..:(

Horrifying. That's my usual way home and 9 times out of 10 I'm on that bridge at 6 pm. Because of the construction on the bridge I took the Hennepin Ave. bridge home tonight. It's longer in distance but quicker when I-35 is under construction. A good friend passed over the bridge at about a quarter to 6. We're all calling around to make sure we're ok.

pretty incredible, at least 3 dead last I heard

Wow. I'm out on the West coast now, but have plenty of family members in the Twin Cities area.

I used to take that bridge all the time. Damn!

Have they said how this happened?

Last I heard it was a structural failure that may have been caused by the construction that was happening.

:(
Hope everyone here is o.k. http://forums.pelicanparts.com/uploa...1186027247.jpghttp://forums.pelicanparts.com/uploa...1186027272.jpg

It's just a mind-blowing tragedy, like most people here I have taken that bridge thousands of times. I rode over the 10th ave. bridge, (right next to it), about 1/2 hour before this happened. Unbelievable...

I rode back down there when I heard the news about the bridge, it was a surreal scene w/ what seemed like hundreds of emergency vehicles, many towing rescue boats. There were just droves of cops and emergency personnel + thousands of people just milling around in a state of disbelief. It was a little like 9/11, though not as bad of course. Still, the biggest disaster ever in this state. :(

I spent my early engineering career inspecting bridges. This should be fairly easy for engineers to figure out. From what I can see, the bridge looks to be a somewhat unusual truss design. Many, many bridges in the US are in very poor structural condition - if you crawled under some of these and looked around, you'd be shocked. I'll bet the Federal inspection reports over the years show some significant structural deterioration (i.e. corrosion, fatigue cracks, etc.). All it takes is a failure in one small section to bring the whole thing down with this sort of design. The current construction activity looks to be repaving only. If that's the case, the only potential problem would be unusual loading conditions. Were they stockpiling paving material on the bridge? Did they have heavy equipment concentrated in one area?

I heard one comment to the fact that since there is construction ongoing, the traffic was more concentrated to fewer lanes. Maybe stressing the bridge out more uneven? I don't know.

amazing more people weren't killed. one pic i saw appeared to show a cargo type train crushed under the bridge as well.

Not my comments, but interesting. I cut and pasted this from a bike forum I frequent. Same with the pics.


Thanks Jeff.
Looked it over more carefully and it was actually the girders that were going out of plane. Which would cause allot of undue stress to the main truss. They gave many examples of work they have had to do on the bridge because of the out of plane girders, like drilling holes and refurburshing parts of the on and off ramp to releive stress and re solidify the main truss.

Also it seems like many of the joints were welded, which is not a perferred method compared to rivets or bolts, including in salt heavy enviroments.There where worried about the "high state of corrosiveness" on the joints between the girders and the trusses especially on the east side main truss and south side ramp.

Another telling thing in the report is low grade it got for it's redundancy. Basically all structures have fail safes. If one beam goes the other are able to supoort the new stress. The more fail safes the better the redundacy. This bridge, by definition, had no or little redundacy. Which would mean that if one part of the bridge would fail in any way, not just collapsing, it would shift the new stresses to parts of the brindge that were not able to handle it, those parts would fail and so on and well then the end result would be the bridge would collapse as a whole.

I would be, after reading this report, not a bit surprised that the report will come out about the bridges structure being compromised by shape the bridge was in structurally, mixed with a overload of traffic on one lane and the poor redundacy the design of the bridge portrayed.

Sorry about get into this the way I have. It is part of my job to define structural problems. On a much smaller scale then a bridge, but regardless.

I do not want to take away anything about the seriousness of this event and I do realize all the analyzing of data does not make this any less of a horrible diasaster.

My heart and prayers go out to those people. Keep safe

http://forums.pelicanparts.com/uploa...1186060244.jpg

"out of plane girders" ?? :eek::eek: I'm not sure where he was reading this from - one of the Fed inspection reports maybe?? If that is true and they tried to hold this thing together with bandaids, somebody is in deep, deep *****. There are a lot of bridge types where you can get away with significant deterioration and other problems and still have a reasonable factor of safety - a steel truss type bridge is not one of them!

The blame on this deal will keep lawyers and newspapers in warm mittens for decades to come.

They have I-94 cut down to one lane at night right now. All my contractors (and a lot of other people) have been taking 694 to 35 W to avoid the traffic jams which put them over that bridge.

There are two seasons in MN., winter and road construction. This will be a cluster-fuch of epic proportions.

But hey at least we're getting a $287 million dollar ball park and the light rail fraud on our nickel...nevermind the critical infrastructure. Anybody run 35W N from Hwy 36 out to about Forest Lake (15 mi)? That section of road is so crappy its embarassing...they don't even bother patching the cracks anymore because there's never enough money for it. This whole thing pisses me off because it didn't have to happen.

I really feel and pray for those injured and those who lost there lives in this. What a waste.

/rant
I am furious and I feel terrible for those who have died in this thing.

In my line of work I have been to many places and mpls has the worst roads I have ever driven (inside the USA) I am just furious, we pay the second highest taxes in the nation and it takes months to fix potholes on I-94 or anywhere else. IMO neglect is what caused this.

I mean no disrespect for those that have died I am just angry at this point.

/end rant

Right with ya slak...no disrespect intended here either, but we have a serious "push the problem forward" mentality with the Legislature in this state. Every year its a constant harp on stadiums, K-12, we don't have enough money, blah blah...gettin real old real fast.

I am angry. :mad:

IMO, the higher the taxes, the more "other priorities" a government entity has. Surely you wouldn't argue that crack-addicted illiterate juvenile delinquents don't deserve free room and board more than you deserve decent roads (and other basic services)?

Everytime I hear of a big, new government program, not only will my taxes go up, but it will get the focus over traditional government functions.

Chicago's solution has been to make the rest of the state pay for its infrastructure so that it can focus on "what is really important". :rolleyes:

I have great sympathy for anyone affected by this. It is shocking to think that this structure was inspected and a warning was given which was not acted on, which appears to be the case. If what we are hearing turns out to be true a 'structural collapse due to budget failure' should be listed as the cause and I would want to see the persons responsible for this locked up.

Good questions, but I wouldn't say the "only potential problem" would be unusual loading.

I've heard reports that they were running jack-hammers. I would assume they were breaking up concrete. I wonder how many were being used and the time-frame of their use in relation to the collapse? One cannot ignore the possibility of destructive resonance weakening the structure and contributing to the collapse.

<object width="425" height="350"><param name="movie" value="http://www.youtube.com/v/vTRuWgoEFxo"></param><param name="wmode" value="transparent"></param><embed src="http://www.youtube.com/v/vTRuWgoEFxo" type="application/x-shockwave-flash" wmode="transparent" width="425" height="350"></embed></object>

Here's some video from a security cam of the collapse:

<object type="application/x-shockwave-flash" width="450" height="370" wmode="transparent" data="http://www.liveleak.com/player.swf?autostart=false&token=1ab_1186054443">< param name="movie" value="http://www.liveleak.com/player.swf?autostart=false&token=1ab_1186054443">< param name="wmode" value="transparent"><param name="quality" value="high"></object>

FYI.

Kurt

Wow - just nuts.

My old office had an entire division dedicated to transportation (among other things, they were on the approved designers list for Illinois DOT, not sure about Minnesota, but we had an office there, so maybe...) Anyway the guy who used to sit next to me was a transfer from Chicago - civil engineer. His role back there used to be bridge inspection as well as some roadway design, but he used to tell me horror stories about some of the stuff he'd find on bridge inspections. Apparently the freeze-thaw cycles in the Midwest are very hard on stuff and as usual, the high-$$$ maintenance costs are a political football (most politicians try to push it off onto the next administration or whatever).

Yet another shining example of misappropriation of tax dollars - untold billions to rebuild I-Wreck while our own infrastructure crumbles under us. Very nice.

There is no political glory in maintaining infrastructure. But a government-funded health insurance program for the children? (Think of the CHILDREN.©) That's the kind of thing political legacies are built on.

That is some fantastic footage. It actually looks like the video is edited to start after failure of some of the beams has already occurred. They look twisted at the very beginning of the video. No doubt that video will play a significant roll in determining the exact details of the collapse.

I highly doubt a standard 60 or 90-pound jackhammer on the pavement could have triggered this (unless the deterioration of the steel framing was incredibly severe). Compare that to the resonance from, say, several fully loaded semi-tankers or cement trucks bouncing across this thing at 70MPH day in and day out. But who knows at this point? If there were, indeed, "out-of-plane girders" all normal assumptions can be thrown out the proverbial window.

I don't think that video is going to help much other than verifying that the collapse started on the same side of the river as the camera location which I think is pretty obvious anyway. Unfortunately the steel pier structure that will be the focus of the investigation is just out of view of the camera on the right side.

Yes, one would need to consider all the stresses the bridge has been under, but on "resonant destruction": Consider something like Tesla's oscillator. Or "soldiers marching in unison across a bridge." It's not the "brute force" that is doing the destruction when resonant frequencies destroy something. It is the build-up of wave energy -- the super-imposition of the compressions and rarefactions of the waves moving through a structure -- which fatigues the materials and causes the failure.

It would be a "freak" occurrence if the jack-hammer use did set up resonant frequencies in the structure, but something I wouldn't ignore as a possible factor this early in the investigation.

Appearently, the bridge had a score of 50 out of 120 on it's rating. It was also described as being deficient. And for traffic, it was #12 for traffic over a bridge with a deficient rating. Makes me wonder where the other 11 are...

This will be discussed endlessly, but didn't the legislature pass a transportation bill that included infrastructure repair in '05 that was vetoed by the governor?

Anyone catch Bush's seconds of 'condolences' before he went into a Dem-bashing whine-fest?

Listen guys, I don't drop political crap in your useless post, keep it the hell out of mine. OK?

This is just awful. I hope for the best of the ones left trapped.

I agree. For at least a day or two can we as Pelicanites rise a bit above the average and have enough respect to not twist the tragedy into a political blame game? There will be time enough for that later and plenty to go around.

saw that on a Mythbusters. really interesting theory.

History Channel (or was it Discovery?) recently ran an excellent show on the 'Bridges of New York City'. Amazing what bridges do.

Sadly, this is a problem all over the country. We have neglected vital infrastructure for a very long time. We just have nicer weather here in Cali or the roads would be worse than this one that just collapsed.

What a world we live in that I can call video like that up at the click of a button right after it happens

Watching that video, it strikes me that the first section failed in two places simultaneously. It falls straight down, not hinging down as would result from a single failure, or two failures spaced even a few seconds apart. How strange, and seemingly unlikely.

The second failure point is out of camera view.

Was that the first section that dropped, or is there another section that dropped first out of camera view?