I 35 bridge collaps in Minneapolis

ornryactor · 08-01-2007, 10:06 PM

8man is right- it was the expansion joints that made it look like such clean breaks. However, if those weren't there, I think other sections of the bridge would have gotten dragged down, too.

Fox News had a guy on the line whose apartment is across the street. He ran over and was helping rescue people, and said that out of all the cars that were on the bridge, there were only 6 in the water. Thank goodness- fatalities could have been a lot higher.

This sucks. I'm checking Facebook to make sure all my friends up there are okay...

AirWalke · 08-01-2007, 10:08 PM

My girlfriend's uncle works up in Minneapolis, and crosses that bridge every day after he leaves work at 6.

He had the day off today.

Dave19642006 · 08-01-2007, 10:17 PM

ON MSNBC NOW

Mayor (Minneapolis) states 6 confirmed dead
a website will be up shortly for the injured

It was built in 1967 was inspected last in 2006, no structural deficiencies. decks needed maybe replaced in 2020. Concrete repair was being done on the bridge (concrete replacement, rails, Joints, ect.). It just started that project.

60 children involved, 10 were sent to the hospitalized, 2 with serious, all released

NOT A TERRORIST ATTACK as reported

clone52 · 08-01-2007, 10:57 PM

Originally Posted by ornryactor

8man is right- it was the expansion joints that made it look like such clean breaks. However, if those weren't there, I think other sections of the bridge would have gotten dragged down, too.

Fox News had a guy on the line whose apartment is across the street. He ran over and was helping rescue people, and said that out of all the cars that were on the bridge, there were only 6 in the water. Thank goodness- fatalities could have been a lot higher.

This sucks. I'm checking Facebook to make sure all my friends up there are okay...

Had to be more than 6 in the water. There were only a few on the bridge out of the water and they said traffic was bumber to bumper and stopped. One stations was reporting 50 cars in the water. My fear is that the 6 deaths are only from people that were sent to hospitals. I don't think that would include any that were crushed or cars that could be in the river.

JCloned · 08-01-2007, 11:00 PM

Does this remind anyone of the movie Mothman Prophesies with Richard Gere? Scary and Tragic

ornryactor · 08-01-2007, 11:08 PM

Originally Posted by clone52

One stations was reporting 50 cars in the water.

There's no way that's correct. They just misunderstood the info they got. There were lots of vehicles on the bridge as a whohle, but everyone else is saying "only" 50 were on the section of bridge that collapsed. Of those 50, a lot landed on solid ground. Personally, I think there must have been more than 6 in the water, but I was just repeating what the guy was saying.

throwittoblythe · 08-01-2007, 11:11 PM

Originally Posted by ornryactor

There's no way that's correct. They just misunderstood the info they got. There were lots of vehicles on the bridge as a whohle, but everyone else is saying "only" 50 were on the section of bridge that collapsed. Of those 50, a lot landed on solid ground. Personally, I think there must have been more than 6 in the water, but I was just repeating what the guy was saying.

Every major news station is reporting 30-50 cars in the water. I doubt they all got it wrong. Anderson Cooper just interviewed one of the emergency management people and she confirmed 30-50 cars in the water.

ornryactor · 08-01-2007, 11:15 PM

Originally Posted by throwittoblythe

Every major news station is reporting 30-50 cars in the water. I doubt they all got it wrong. Anderson Cooper just interviewed one of the emergency management people and she confirmed 30-50 cars in the water.

I stopped watching about two hours ago. I didn't think they'd undershoot by that much. Okay, 30-50 cars. It still sucks.

Dave19642006 · 08-01-2007, 11:19 PM

Originally Posted by throwittoblythe

Every major news station is reporting 30-50 cars in the water. I doubt they all got it wrong. Anderson Cooper just interviewed one of the emergency management people and she confirmed 30-50 cars in the water.

It was during rush hour also

Dave19642006 · 08-01-2007, 11:19 PM

Originally Posted by ornryactor

I stopped watching about two hours ago. I didn't think they'd undershoot by that much. Okay, 30-50 cars. It still sucks.

1 car sucks

throwittoblythe · 08-01-2007, 11:29 PM

It will be interesting to see what the final cause of failure was. They said on CNN they have a structural engineering team assessing the situation now, but they are mainly trying to determine if it's safe to send rescue workers back onto the bridge.

They interviewed a Civil Engineering professor from U of Minn. that had experience with this bridge and he made a very good point. The bridge did not fail in just one spot, the whole thing came down at once. To me, that points to a failure in design. There was one other bridge in Ohio that did this and it was a very poor design. One of the upper cable supports snapped and caused a chain reaction which made the entire thing come down in like 10 seconds.

Also, you have to keep in mind that this bridge was designed and built some 40 years ago. So, they designed for what they felt was necessary. How many cars drove over that bridge on average right when it opened is probably far less than what drove over in the passed few years. We use safety factors in civil design which are supposed to account for these things like increased load, partial failure, things like that. For example, we increase car loading by 60%. So, if you estimated 100 cars on the bridge at the maximum load, you would design the members to hold 160 cars. However, you can't design for everything and you can't predict the loads on a bridge some 40 years into the future.

This brings to light the fact that in the US our infrastructure is deteriorating at a much greater rate that we can build it. Cities are growing way too fast to keep roads/bridges/buildings up to standards so that they can be used safely. There simply isn't enough money or time to fix all the problems within the infrastructure at the same pace as is necessary. Look at how big of a headache I-235 has been in Des Moines; it took over 6 years to get that project completed (and it's still not completely done) and it will be over capacity in probably less than 10 years.

No matter how you spin it, this is tragic. Hopefully it wasn't some mundane error which could have easily been prevented which caused the collapsed. Whatever the reason, there will be no excuse.

jdoggivjc · 08-01-2007, 11:52 PM

It makes you wonder if the same thing could happen in the Quad Cities.

The I-74 bridge not only was never designed for the traffic it handles on a daily basis (~75,000 vehicles), it's not designed in spec for interstate code. As a matter of fact, when they built it (1935), it was originally only one of the two spans. They actually had to build the second span in 1959 because the original span couldn't handle U.S. 6 traffic by itself.

Money is earmarked to begin replacing it starting in 2010, but seeing what happened in Minneapolis to a bridge that is much newer handling the same kind of traffic that the I-74 bridge holds makes you wonder if the same could happen here, especially when the bridge doesn't even come close to being designed for the traffic it now holds.

clone52 · 08-02-2007, 12:35 AM

Originally Posted by throwittoblythe

It will be interesting to see what the final cause of failure was. They said on CNN they have a structural engineering team assessing the situation now, but they are mainly trying to determine if it's safe to send rescue workers back onto the bridge.

They interviewed a Civil Engineering professor from U of Minn. that had experience with this bridge and he made a very good point. The bridge did not fail in just one spot, the whole thing came down at once. To me, that points to a failure in design. There was one other bridge in Ohio that did this and it was a very poor design. One of the upper cable supports snapped and caused a chain reaction which made the entire thing come down in like 10 seconds.

Also, you have to keep in mind that this bridge was designed and built some 40 years ago. So, they designed for what they felt was necessary. How many cars drove over that bridge on average right when it opened is probably far less than what drove over in the passed few years. We use safety factors in civil design which are supposed to account for these things like increased load, partial failure, things like that. For example, we increase car loading by 60%. So, if you estimated 100 cars on the bridge at the maximum load, you would design the members to hold 160 cars. However, you can't design for everything and you can't predict the loads on a bridge some 40 years into the future.

This brings to light the fact that in the US our infrastructure is deteriorating at a much greater rate that we can build it. Cities are growing way too fast to keep roads/bridges/buildings up to standards so that they can be used safely. There simply isn't enough money or time to fix all the problems within the infrastructure at the same pace as is necessary. Look at how big of a headache I-235 has been in Des Moines; it took over 6 years to get that project completed (and it's still not completely done) and it will be over capacity in probably less than 10 years.

No matter how you spin it, this is tragic. Hopefully it wasn't some mundane error which could have easily been prevented which caused the collapsed. Whatever the reason, there will be no excuse.

I don't think they could have underestimated the weight of cars on it. Worst case, they would assume bumper to bumper trafic and then add a significant safety factor. I don't know that bumper to bumper trafic could weigh much more now than it did 40 years ago.

throwittoblythe · 08-02-2007, 12:46 AM

Originally Posted by clone52

I don't think they could have underestimated the weight of cars on it. Worst case, they would assume bumper to bumper trafic and then add a significant safety factor. I don't know that bumper to bumper trafic could weigh much more now than it did 40 years ago.

I get your point, but I was referring to the traffic load itself. If a bridge isn't expected to see bumper to bumper traffic on a regular basis, then you wouldn't assume that in design. An example would be a rural bridge; you know that won't ever see bumper to bumper traffic, so you do a traffic study to see what type of loading it needs to handle. Who knows what the traffic was like in that part of the Twin Cities back in the 60s. I know cars haven't changed a whole lot, but the number of people sure have.

Basically, the whole idea is that things are being used today for situations other than what they were designed for. Our interstate system in Iowa will deteriorate at a faster pace now because of the 70 mph speed limits over most of it. When I-35, I-80, etc were designed, they were not designed to take 70+mph at a constant rate. This is just one example.

clone52 · 08-02-2007, 12:53 AM

After looking at some pictures, it appears that the middle section that is in the water had 2 of its lanes of traffic completely submurged. As i understand it, the bridge had 4 lanes each way, with only 2 lanes open each way because of the construction. Going in 1 direction, the two lanes with traffic were left out of the water while the 2 closed lanes were under water. Going in the other direction, the two lanes under construction were out of the water while the two lanes with traffic are completely submerged.

Just looking at the mid-section, there were only 6 cars left on the road and it looks like there were probably 28-32 there if it was bumper to bumper. So, from that mid section, we're probably talking 22-26 cars in the water.

I've also heard that it was a free span bridge with no supports under the middle part. Or at least no anchors. From the look on the pictures, there were supports on either side of the river. Once the middle part dropped, it appears those supports got bent back away from the river under the weight of the road still attached to it.

Looking at some more pictures, the side with the train appears to have its support bent back away from the river. The opposite side is more of a mess. I bet the initial failure was right above the train. When that section fell, it may have pulled the support away from the river. The section over the river would have collapsed and pulled the opposite support towards the river. Then, two sections on the other side of the river collapsed as well because the support couldn't hold it.