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bridge collapses in minneapolis (pg. 6)
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| Omega_M |
| quote: | Originally posted by stren
What happened ? were they all sent to Iraq ? |
the contract of rebuilding iraq has been awarded to Haliburton. So the short answer is no. |
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| colonelcrisp |
| quote: | Originally posted by Theresa
Ok, so it is a steel beam supported bridge that is 50 years old, and has only gotten surface repair work done on it recently.
Umm, who is the moron making sure this thing is maintained properly? Hello?! Steel rusts. 50 yrs of usage... of course the damn thing was going to collapse.
They should have replaced the beams!! |
the quebec bridge is a steel riveted cantileverd structure, was completed in 1919 and still stands today.
while steel does rust. rust is not going to cause the failure of structural members. the steel used in the support arch would be well over 1" thick. rust will inhibit itself once it forms meaning that surface rust protects the underlying steel from oxidation. that being said, the greatest risk of failure on a bridge is fatigue cracking. since bridges are subjected to mainly live loads (dynamic loading and unloading) of significant magnitude, they are prone to fatigue cracking. think of a paperclip. if you bend it once, then subsequently bend it back and forth, it provides less resistance to the bending motion each time until eventually it fractures. same goes for structural steel, the bending and movement is minute and almost un detectable, but it happens every day.
over time this bending action more often than not will affect the weld strength on teh members. welds are much more brittle than the virgin steel they hold together. as such they do not take well to fatigue stresses.
50 years is not very old at all for a bridge
especially a steel bridge. many of them last for well over 100 years with propper maintenance.
as for previous bridge collapses, most are during construction as the bridge is designed to carry its loads in a completed configuration. when they are being built, they are horribly unstable structrues. the quebec bridge mentioned above collapsed during construction in 1907 killing 75 workers. it is from this bridge that the iron ring was created....
i am more inclined to suspect taht some part of the rehabilitation of the bridge deck caused a significant load shift to crack a fatigued weld connection at the north support.
my $0.02 |
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| colonelcrisp |
o and wrong....
i have worked on two bridge projects in the US and they were both DOT projects. |
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| chach |
| Why is this still being discussed? |
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| kr00t0n |
| quote: | Originally posted by Yan
YEAH SEAKING!!!! |
that, Magikarp would lay the smackpwn! |
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| stren |
| quote: | Originally posted by chach
Why is this still being discussed? |
why not ? I just heard about it |
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| chach |
| quote: | Originally posted by stren
why not ? |
I don't care :tongue2
The world revolves around me ! :tongue3 |
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| stren |
| quote: | Originally posted by chach
I don't care :tongue2
The world revolves around me ! :tongue3 |
I didn't know you were big and gassy |
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| chach |
| quote: | Originally posted by stren
I didn't know you were big and gassy |
lame nerd joke - 2 cool points |
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| chach |
| quote: | Originally posted by Omega_M
Lame footage.
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Fixed. |
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| Omega_M |
| its a good quality video showing the damage. wft is wrong with you ? |
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