Ugly wicked Disaster

[RedRockinMonkeyBoy]

Scour is the process by which water begins to erode away the riverbed at the foundation of the piers (the piers are the vertical supports that go from the water up to the bridge). Overtime, the force of the water can erode away enough material that the foundation weakens and becomes lose, if you will. Worst case secenario is that the piers topple over, of course causing the supported structure to collapse. Scouring is a very slow process and is much more difficult to assess and keep track of because since the foundation is under water, in most cases one must ucs a SCUBA diver to check it out. Scour is not much of a problem in slow-flowing streams but tends to occur in steams where the water moves very rapidly and with great force. Given that the Mississippi flows very gently I doubt scour is the culprit in this case. But only time will tell.

Actually, on the surface the Mississippi "looks" gentle; but it has one heck of an under-current because of the Lock & Dam system from Minneapolis to the Gulf. On top of all of that, a lot of cities have added regular dredgingand high floodwalls to protect themselves when "Ol' man Miss'decideds to throw of hissy-fit. I live on the Mississippi, down river where it joins Illinois and Iowa at the Quad Cities (Where you cross I-80, 74 or 280).

Our section of the river from just north of us at Princeton, IL to just south of us, below Muscatine, IA, actually runs East/West, instead of North/South. The reason is because of all the Lock systems along our portion.

In '05, the FDOT gave this a passing grade, BUT MnDot gave it a failing grade. The crux of the investigation is going to be on the under-girders; the girders that the surface is laid on. That's where the stress-fatigue was prominently noted in the MNDOT report.

The base pillars near both shore lines will be looked at too. The reason for this is that Lock & Dam 1 of the Army Corps of Engineers isn't too far up river from this. It causes a lot of churning and along with the undercurrent, it actually could've caused the scour you mentioned.

The Mississippi is like the old duck parable: Calm and peaceful on the top, but paddling and churning like the dickens underneath.

[Useless]

RockeyMountain:

(Or, anyone Else With Knowledge Pertaining to This!!)

I have not really been following the weather on a national scale, but I do know that a number of different parts of the country have experienced torrential rains and very sever flooding.

Could flooding have palyed any part in this??

[Mr. Ford95]

Hearing witness', it fell like a domino effect, which sounds very intentional. The concrete piers look fine, the steel beams appear to have simply folded unto themselves as if someone had taken a torch to a section and cut them. Obviously that wouldn't happen because it would take too long to cut every section so they all fall together.

First things they will look at are the anchor bolts in the piers and the piers themselves to see if they somehow moved at all. The deck resurfacing had nothing to do with this tragedy. A few bolts had to have given way, whether they were helped or not for this to happen.

[yoopr]

RockeyMountain:

(Or, anyone Else With Knowledge Pertaining to This!!)

I have not really been following the weather on a national scale, but I do know that a number of different parts of the country have experienced torrential rains and very sever flooding.

Could flooding have palyed any part in this??

No-we haven't had rain all summer long

t fell like a domino effect, which sounds very intentional.

[Malaki86]

From the surveilance camera video that's out, it looked like the center section (the main span) fell straight down. It didn't look like it buckled whatsoever.

All I know is that I hate bridges even more now. I've never been a fan of any bridge that has any real height to it. I just hope I don't have to cross the New River Gorge bridge on US19 in WV anytime soon.

[blackchromefan]

With underground utilities (water, sewer, steam, electric), roads and bridges, flood control management, and other major parts of our country's infrastructure failing at an increasing rate, affecting the lives of thousands of Americans and our very economy, it would be interesting to see how much we have spent rebuilding the infrastructure of Iraq over the past five years, wouldn't it?

[yoopr]

From the surveilance camera video that's out, it looked like the center section (the main span) fell straight down. It didn't look like it buckled whatsoever.

All I know is that I hate bridges even more now. I've never been a fan of any bridge that has any real height to it. I just hope I don't have to cross the New River Gorge bridge on US19 in WV anytime soon.

You'd LOVE our Mackinac Bridge up here-It used to be the worlds longest Suspension bridge. You're Waaaaaaaay over the water with this one.

, it would be interesting to see how much we have spent rebuilding the infrastructure of Iraq over the past five years, wouldn't it?


_________________

[Useless]

All I know is that I hate bridges even more now. I've never been a fan of any bridge that has any real height to it. I just hope I don't have to cross the New River Gorge bridge on US19 in WV anytime soon.

Yooper:
You'd LOVE our Mackinac Bridge up here-It used to be the worlds longest Suspension bridge. You're Waaaaaaaay over the water with this one.

Useless:
Bridges never bothered me; they do bug the hell out of my wife though; just a serious phobia, but she does handle it better than she used to!!

Not sure who said this:
....... it would be interesting to see how much we have spent rebuilding the infrastructure of Iraq over the past five years, wouldn't it?

Useless:
I'm no advocate or fan of the current administration, but speaking as a rather liberal Democrat, I would ask that we focus out attentions upon the tragedy at hand on this thread, the lives that have been lost, and the families, friends, andd loved oned who are hurting and in need of our prayers at this time.

Please, there are plenty of other threads to debate politics; this is not one of them.

Please, let's keep it that way!!

Peace,
Useless
_________________

[Malaki86]

I don't think he's trying to stir up something in the politics of the war, but rather focusing on the issue of how much money is being spent on other countries while our own country is starting to literally fall apart (infrastructure).

[Malaki86]

From the surveilance camera video that's out, it looked like the center section (the main span) fell straight down. It didn't look like it buckled whatsoever.

All I know is that I hate bridges even more now. I've never been a fan of any bridge that has any real height to it. I just hope I don't have to cross the New River Gorge bridge on US19 in WV anytime soon.

You'd LOVE our Mackinac Bridge up here-It used to be the worlds longest Suspension bridge. You're Waaaaaaaay over the water with this one.

I can go across the bridges, but I tend to have a "slowdown" effect on them. I'll sometimes go a lot slower than I need to. I also have trouble staying in the right lane going across high bridges. No matter how hard I try, I always seem to be in the left lane (or in the center) of the bridge. I just don't want to see over the sides of the bridge.

I can cross them, but I'm not happy about it. At least I'm not at a point that I freeze up or anything.

[Mr. Ford95]

Malaki, what about the New River Valley bridge on I-64??

I hate bridges with a passion but I cross them anyways because I have no choice in getting to work. I have to cross a river to get there. I always fear it will fall while I'm on it. We have one here that is about 60 feet up from the river and you always end up sitting on it due to a traffic light at either end of it. It will constantly be moving about and you will not feel that unless your sitting still on it. Yes, it has to move some or the bridge would surely fall from being too stiff but this thing dances about like your on a trampoline especially when a semi rolls onto the bridge deck.

What I'm hearing from a local up there, the bridge supports were made so that the entire bridge relied on each section supporting the other. If one section fell, the other 2 would also fall because they were not self supported.

[blackchromefan]

I posted the infrastructure comment...

yes, useless, it is no time or place to debate politics. As a retired Fire Chief/EMT of 20+ years, I have seen tragedy and death first hand, and on many occasions was the first to notify the family members. I am a Christian, and everyone involved has been in my prayers.

But, malaki is right, I wasn't trying to stir anything...sorry if my post implied that.

[Jackrabbit379]

Yeah, I was listening to the Fox Report on Sirius Wednesday evening. Shepard Smith was talking about the news, and all of a sudden, he went on about the bridge falling. I was like, :shock: what?? I cant believe it. That's crazy. Sad.

I cant stand being under water for any length of time, like in a pool for an example. I cant imagine what it would be like to be under that mess. :shock:

[silvan]

I can go across the bridges, but I tend to have a "slowdown" effect on them. I'll sometimes go a lot slower than I need to. I also have trouble staying in the right lane going across high bridges.

That damn bridge on US 301, I think, coming out of Maryland into Virginia... Only two lanes, no shoulder, nothing but a little jersey wall between you and oblivion. I despise that bridge. I used to have to run across it every week.

I run across some long, high bridges now, but nothing that long, or that high.

Somebody said he used to be a bridge inspector. What's the statistic for how many of our bridges are "Structurally Deficient?" I seem to remember some news piece from years back that talked about how tens of thousands of bridges everywhere are getting incredibly low grades, but we keep using them because we have to. It makes me wonder if this big bridge up yonder didn't fall into that same category. They knew it was shot, but it would have taken years and billions to replace it, so they kept trying to put bandaids on it. All of this is purest idle speculation, understand, but I do wonder.

I guess we'll all be wondering a long time until the NTSB publishes its findings six months to a year from now.

[madii'swife]

[quote="silvan"]


Somebody said he used to be a bridge inspector. What's the statistic for how many of our bridges are "Structurally Deficient?" I seem to remember some news piece from years back that talked about how tens of thousands of bridges everywhere are getting incredibly low grades, but we keep using them because we have to. [\quote]

I'm not the bridge inspector..but the piece in yahoo news says there are 77,000 bridges listed as "structurally deficient", 1100 or so in Minnesota alone (I think its Minnesota:?). That is one heck of a scary number if you think about it too hard.

[driver67373]

[quote="madii'swife"]

Somebody said he used to be a bridge inspector. What's the statistic for how many of our bridges are "Structurally Deficient?" I seem to remember some news piece from years back that talked about how tens of thousands of bridges everywhere are getting incredibly low grades, but we keep using them because we have to. [\quote]

I'm not the bridge inspector..but the piece in yahoo news says there are 77,000 bridges listed as "structurally deficient", 1100 or so in Minnesota alone (I think its Minnesota:?). That is one heck of a scary number if you think about it too hard.

I was the bridge inspector (not an engineer mind you, I don't have as much expertise as an engineer might have). I really don't know the national data first hand as I only dealt with a division of FHWA that inspected bridges in US National Parks and associated properties (ie GW Parkway, blue ridge pkwy, natchez trace etc) and military bases. The vast majority of bridges I inspecte were in remote parts of parks and bases and not all that heavily traveled. I do know that in Arkansas where I now live they said we have something like 1700 bridges that are structurally deficient. That is probably on par with most other states. I do think it is a travesty that we are the richest country in the world and enjoy such a high standard of living, yet our infrastructure is decaying at an exponential rate, and is in worse shape than some third world counties. I wonder how many more of these failues have to occur before our politiians wake up and put the money where it should be.

[Orangetxguy]

Just to pose a thought on this bridge collapse...How many of you have ever paid attention to the manner in which your truck respond's, when you hit the approaches to a bridge, at highway speeds?

How many bridges have a large bump right at the joint where the land portion ends and the bridge spans begins?

I can think of a dozen right here in the area I live in, where it feels like the front-end of the truck is getting knocked out from under it, when hitting the bridge decks. How much damage does an 80,000 pound truck do, to a bridge, when it hits a bump at 60 mph? How much damge can be done if 100 80,000# trucks hit that same bump at 60 mph, each and every day? How much more damge can be done, if there are large bumps at each expansion joint in a brdige, as the span is traversed?

Something to think about huh?


I am to young to have seen "Galloping Gerty" but I have seen the film clip of her dance numerous times.
I had the pleasure of crossing the replacement bridge at "Tacoma Narrows" a few times every week. Great bridge to be on during a bright sunny day. A total bit@h to be on when the wind is blowing at 30 mph or higher, loaded or empty. The new "Twin-span" opened to traffic at the "Narrows" just 2 weeks ago...I might see my way clear to get up there and check it out in the near future. It's about 450 feet from the bridge deck of the "Narrows Bridge" to water surface....and the Narrows are 3 miles wide, with a 15 to 30 knot current at any given moment.

Now..want a real adventure? Cross the 520 floating bridge, which spans Lake Washington, from Seattle on the west to Bellevue on the east, when the winds are blowing across the deck at 25 to 30 mph, and waves from the lake are breaking over the side rail of the bridge. Joy Joy Fun Fun.

[driver67373]

Just to pose a thought on this bridge collapse...How many of you have ever paid attention to the manner in which your truck respond's, when you hit the approaches to a bridge, at highway speeds?

How many bridges have a large bump right at the joint where the land portion ends and the bridge spans begins?

I can think of a dozen right here in the area I live in, where it feels like the front-end of the truck is getting knocked out from under it, when hitting the bridge decks. How much damage does an 80,000 pound truck do, to a bridge, when it hits a bump at 60 mph? How much damge can be done if 100 80,000# trucks hit that same bump at 60 mph, each and every day? How much more damge can be done, if there are large bumps at each expansion joint in a brdige, as the span is traversed?

Something to think about huh?
Now..want a real adventure? Cross the 520 floating bridge, which spans Lake Washington, from Seattle on the west to Bellevue on the east, when the winds are blowing across the deck at 25 to 30 mph, and waves from the lake are breaking over the side rail of the bridge. Joy Joy Fun Fun.

There's no damage at all, since the only thing being impacted is the surface of the bridge. That has little to do with the support of it.

Imagine this adventure: I was in Washington earlier this year on 90, it had been a very windy day, well I get to the I-90 bridge over the Columbia River. Ive always found that bridge creepy, its so close to the water. On that particular day the wind must have been blowing 40-50 mph across the gorge. That was a terrifying experience. The waves were surging so high and the river was in turmoil. I was so sure the winds were just going to blow me right over. Good thing I was heavy. My instinct was to slow down almost to a stand still, but fortunately my trainer was with me, and he told me to keep it going steady, whatever i do, dont slow down too much. He said doing that gives the wind a chance to catch you, and you could surely flip over. :shock:

[Orangetxguy]

Imagine this adventure: I was in Washington earlier this year on 90, it had been a very windy day, well I get to the I-90 bridge over the Columbia River. Ive always found that bridge creepy, its so close to the water. On that particular day the wind must have been blowing 40-50 mph across the gorge. That was a terrifying experience. The waves were surging so high and the river was in turmoil. I was so sure the winds were just going to blow me right over. Good thing I was heavy. My instinct was to slow down almost to a stand still, but fortunately my trainer was with me, and he told me to keep it going steady, whatever i do, dont slow down too much. He said doing that gives the wind a chance to catch you, and you could surely flip over. :shock:

Have seen many a truck flipped on that bridge :shock: :shock: ...and at the west end of the curve, as you drop of the hill to the river westbound. I was never concerned about wind flipping my truck ever. Gotta love those round sides on tanks!! :twisted: :twisted: :wink: