About the collapse of minnesota bridge?

Question

i want to ask u, how it could be collapsed?
what standard design and constructing that they use to construct the Minnesota Bridge?
is there any connection between the standard they use to construct the bridge with Load Resistance and Factor Design (LRFD), standard for steel construction design?
I'm so afraid if it happen cause steel constructions design in most Indonesia based on American Standard Design, n it taught in most university in Indonesia....
I hope there is no mistake...

Answer 1

I would have to disagree with one answer regarding the changing and improvement of design standards. In some cases the standards are not made better but rather are less restrictive as various parties seek technical or economic relief from the standards' requirements.

With regard to the failure of the bridge in question. We do no yet know what caused the failure but I would hazard a guess it is not due to compliance with any standard but rather due to maintenance or repair neglect.

I would so say the design from a conceptual standpoint is not a very good one. The truss design with its multitude of connections is a nightmare to inspect and maintain. This is specially true in the environment of Minnesota where chemicals are used each winter to de-ice the roadway.

Answer 2

"the bridge was built to withstand nominal 40,000 pound gross truck loads. Laws have changed over the years to allow for greater truck loads without regard for the original load capacities of these older bridges"

Sorry, I call BS! Every state has a Department of Transportation charged with the legal responsibility of keeping the roads and highways safe. The bridges are designed for a specific weight and no one with an IQ larger than their shoe size, let alone a professional engineer with legal liability would randomly allow the structural capacity to be exceeded. He or she would lose their engineering license and never be able to work in their profession again.

They would also be creating personal liability for damages and injury as the state insurance will only cover them if they follow 'generally accepted principles' in their field.

If there is a capacity limit for the bridge less than the legally allowed truck weight, weight restrictions are posted on the bridge. If a trucker is caught exceeding the weight limit, they are fined. There are weigh stations along the highways where trucks have to check in. If one is found overweight, they know what route was followed and can impound the truck till the fines are paid.

This MN study was completed over a year ago: http://www.dot.state.mn.us/information/truckstudy/

Do you think the citizens on the committee would approve overloading the bridges?

Other info:

http://www.mankatofreepress.com/local/local_story_223005512.html

http://www.hudsonstarobserver.com/articles/index.cfm?id=25330§ion=News

Answer 3

Bridges have fallen for centuries, all of them will be some time, there are many reasons to happen, I will give you just 10.
1 Wrong .Design:
2. Wrong materials
3. Poor workmanship
4. Poor land studies
5. Old and rusted
6. Poor maintenance
7.Poor Inspections
8. Miss use, excessive weight or crossing velocity
9. Surrounded vibrations
10. Natural earth movement

Answer 4

The simple answer to why it fell is corrosion. The Japanese designed a bridge about ten years ago to extremely rigorous standards, but a quake chopped it up. Then they redesigned it using techniques on the micro scale for the welds to reduce all impurities, and it stands to this day.

Answer 5

Most countries copied American designs for bridges. In fact, most anytime we build large resources like telephone, internet, fiber optic or power lines other countries copy our techniques. Usually they improve them and do it after we learn our lessons on our designs, so your bridges might be a bit safer. Plus they probably aren't as old as ours are. The bridge in question was undergoing repairs when it collapsed, so they knew it wasn't in the best shape.

Answer 6

This bridge was built to standards from the late 1940's to the mid-1950's. Standards change, and improve over time (especially safety standards) as our scientific and engineering knowledge increases.

Check with your professors to see which American standards are practiced in your country. They are probably a lot newer (and better) than the standards by which the Minn. I-35W bridge was constructed.

One more note: I have heard tell (but I cannot cite references) that the bridge was built to withstand nominal 40,000 pound gross truck loads. Laws have changed over the years to allow for greater truck loads without regard for the original load capacities of these older bridges (plus truckers will try and overload their trucks, too). Larger truck loads over the years may have contributed to the failure.

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Answer 7

I dont know good question

but i live near where the bridge collapsed

it was scary

my cousin walked under it 10 min before it collapsed