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Re: Bridge collapse in Florida

Posted: Thu Mar 15, 2018 11:58 pm
by CrazyIslander
DOB wrote:The only thing that stops a bad guy with a bridge is a good guy with a bridge.
:lol:

Re: Bridge collapse in Florida

Posted: Fri Mar 16, 2018 12:23 am
by Jeff the Bear
spike wrote:According to this eyewitness https://www.youtube.com/watch?v=NKxR7iU9vTo&t=4s a large white and black mobile crane was lifting something that snapped immediately prior to the collapse. The crane was quickly moved away. In the DM article you can see the blue equipment he refers to lying on the top of the rubble. You can also see the crane.
Youtube video is entitled Stress test causes bridge to collapse.
The idea of stress testing a new structure makes absolutely no sense to me. You stress test/proof load test existing structures, where you don't have access to original calcs or other structural information. Something like that would have (or should have) been designed using a finite element software and subsequently checked. It even looks to have been built precast off-site, so would have been built to high tolerance levels...hence, there should be no need for testing something that would surely have not got built had it not been designed correctly in the first place.

Performing stress tests on new buildings is admitting you designed it wrong, and unless it was designed/built wrong which, as noted, is a very slim chance, the question to ask is...who the fudge pays $16 million odd for something that might work, and you'll only know when it's built and proof loaded?

I'd hazard that there is a good chance that a layman has called it a stress test without knowing what the the fudge was going on.

Re: Bridge collapse in Florida

Posted: Fri Mar 16, 2018 12:26 am
by fishfoodie
Jeff the Bear wrote:
spike wrote:According to this eyewitness https://www.youtube.com/watch?v=NKxR7iU9vTo&t=4s a large white and black mobile crane was lifting something that snapped immediately prior to the collapse. The crane was quickly moved away. In the DM article you can see the blue equipment he refers to lying on the top of the rubble. You can also see the crane.
Youtube video is entitled Stress test causes bridge to collapse.
The idea of stress testing a new structure makes absolutely no sense to me. You stress test/proof load test existing structures, where you don't have access to original calcs or other structural information. Something like that would have (or should have) been designed using a finite element software and subsequently checked. It even looks to have been built precast off-site, so would have been built to high tolerance levels...hence, there should be no need for testing something that would surely have not got built had it not been designed correctly in the first place.

Performing stress tests on new buildings is admitting you designed it wrong, and unless it was designed/built wrong which, as noted, is a very slim chance, the question to ask is...who the fudge pays $16 million odd for something that might work, and you'll only know when it's built and proof loaded?

I'd hazard that there is a good chance that a layman has called it a stress test without knowing what the the fudge was going on.
Eye-Witnesses are rarely right.

I wonder if perhaps someone spotted something was wrong, & what he saw was someone scrambling to support the bridge ???

Re: Bridge collapse in Florida

Posted: Fri Mar 16, 2018 1:38 am
by Ewinkum
fishfoodie wrote:
Jeff the Bear wrote:
spike wrote:According to this eyewitness https://www.youtube.com/watch?v=NKxR7iU9vTo&t=4s a large white and black mobile crane was lifting something that snapped immediately prior to the collapse. The crane was quickly moved away. In the DM article you can see the blue equipment he refers to lying on the top of the rubble. You can also see the crane.
Youtube video is entitled Stress test causes bridge to collapse.
The idea of stress testing a new structure makes absolutely no sense to me. You stress test/proof load test existing structures, where you don't have access to original calcs or other structural information. Something like that would have (or should have) been designed using a finite element software and subsequently checked. It even looks to have been built precast off-site, so would have been built to high tolerance levels...hence, there should be no need for testing something that would surely have not got built had it not been designed correctly in the first place.

Performing stress tests on new buildings is admitting you designed it wrong, and unless it was designed/built wrong which, as noted, is a very slim chance, the question to ask is...who the fudge pays $16 million odd for something that might work, and you'll only know when it's built and proof loaded?

I'd hazard that there is a good chance that a layman has called it a stress test without knowing what the the fudge was going on.
Eye-Witnesses are rarely right.

I wonder if perhaps someone spotted something was wrong, & what he saw was someone scrambling to support the bridge ???
The eye witness didn’t say it was a stress test. Presumably that was the journalist’s interpretation.
He said the crane was loaded with a piece of equipment for tightening the cables, which dropped onto one end of the structure causing the other end to lift.

Assuming the cable being tensioned at the time suddenly slacked off it would conceivably have caused the structure to flex just as the tensioning equipment itself landed on it. Perfect storm for the partially supported bridge, and no calculations could have foreseen it.

This might be just an inadequate or improperly maintained, or improperly operated crane situation.

Re: Bridge collapse in Florida

Posted: Fri Mar 16, 2018 3:07 am
by Farva
Jeff the Bear wrote:
spike wrote:According to this eyewitness https://www.youtube.com/watch?v=NKxR7iU9vTo&t=4s a large white and black mobile crane was lifting something that snapped immediately prior to the collapse. The crane was quickly moved away. In the DM article you can see the blue equipment he refers to lying on the top of the rubble. You can also see the crane.
Youtube video is entitled Stress test causes bridge to collapse.
The idea of stress testing a new structure makes absolutely no sense to me. You stress test/proof load test existing structures, where you don't have access to original calcs or other structural information. Something like that would have (or should have) been designed using a finite element software and subsequently checked. It even looks to have been built precast off-site, so would have been built to high tolerance levels...hence, there should be no need for testing something that would surely have not got built had it not been designed correctly in the first place.

Performing stress tests on new buildings is admitting you designed it wrong, and unless it was designed/built wrong which, as noted, is a very slim chance, the question to ask is...who the fudge pays $16 million odd for something that might work, and you'll only know when it's built and proof loaded?

I'd hazard that there is a good chance that a layman has called it a stress test without knowing what the the fudge was going on.
It certainly looks to have been prefabricated, in that second photo.

Image

Re: Bridge collapse in Florida

Posted: Fri Mar 16, 2018 3:15 am
by Enzedder
Gavin Duffy wrote:
fishfoodie wrote:
CM11 wrote:Epic fail if Boobs and cam are correct (and I see no reason to say they're not).

Did they somehow think that it would hold up without a load on it?
Sadly construction is riddled with people making cretinous decisions :((
Is it, now?
Lowest bidder always wins

Re: Bridge collapse in Florida

Posted: Fri Mar 16, 2018 4:10 am
by goeagles

Re: Bridge collapse in Florida

Posted: Fri Mar 16, 2018 12:36 pm
by Flyin Ryan
camroc1 wrote:
fishfoodie wrote:
CM11 wrote:Epic fail if Boobs and cam are correct (and I see no reason to say they're not).

Did they somehow think that it would hold up without a load on it?
Sadly construction is riddled with people making cretinous decisions :((
For an erection like this, there would be several firms of Consulting Engineers checking both the sequence, and the subsequent stresses in the bridge members for each stage; viz. the original design engineers, the contractors engineers for the erection, and possibly an independent firm acting for the client.
And thus starts one massive CYA effort by everyone involved. And lawyers will go after anyone with money.

I have my Professional Engineer license for mostly resume reasons (I'm a mechanical and a P.E. doesn't have much use in my work since we never deal with the government, most mechanical-based P.E. work would be HVAC), but stuff like this just confirms to me I never want to actually use it.

Re: Bridge collapse in Florida

Posted: Fri Mar 16, 2018 12:43 pm
by Flyin Ryan
Jeff the Bear wrote:
spike wrote:According to this eyewitness https://www.youtube.com/watch?v=NKxR7iU9vTo&t=4s a large white and black mobile crane was lifting something that snapped immediately prior to the collapse. The crane was quickly moved away. In the DM article you can see the blue equipment he refers to lying on the top of the rubble. You can also see the crane.
Youtube video is entitled Stress test causes bridge to collapse.
The idea of stress testing a new structure makes absolutely no sense to me. You stress test/proof load test existing structures, where you don't have access to original calcs or other structural information. Something like that would have (or should have) been designed using a finite element software and subsequently checked. It even looks to have been built precast off-site, so would have been built to high tolerance levels...hence, there should be no need for testing something that would surely have not got built had it not been designed correctly in the first place.

Performing stress tests on new buildings is admitting you designed it wrong, and unless it was designed/built wrong which, as noted, is a very slim chance, the question to ask is...who the fudge pays $16 million odd for something that might work, and you'll only know when it's built and proof loaded?

I'd hazard that there is a good chance that a layman has called it a stress test without knowing what the the fudge was going on.
Florida International University is a public university of the State of Florida, so they would be required to put out the specifications necessary for the bridge and it would go out for bid. If they actually did a stress test, it would be because FIU put it in the bid package.

Re: Bridge collapse in Florida

Posted: Fri Mar 16, 2018 1:06 pm
by troglodiet
So the bridge, designed for Yanks (with a reputation for obesity) collapsed even before one of said Yanks actually walked on it.

Some serious design flaw I'd say.


:P

Re: Bridge collapse in Florida

Posted: Fri Mar 16, 2018 1:09 pm
by A5D5E5
troglodiet wrote:So the bridge, designed for Yanks (with a reputation for obesity) collapsed even before one of said Yanks actually walked on it.

Some serious design flaw I'd say.


:P
Not funny enough.

Re: Bridge collapse in Florida

Posted: Fri Mar 16, 2018 1:15 pm
by troglodiet
A5D5E5 wrote:
troglodiet wrote:So the bridge, designed for Yanks (with a reputation for obesity) collapsed even before one of said Yanks actually walked on it.

Some serious design flaw I'd say.


:P
Not funny enough.

Saffas.

Something.

Something.

Humour.


[/yeeb]

Re: Bridge collapse in Florida

Posted: Fri Mar 16, 2018 1:16 pm
by A5D5E5
troglodiet wrote:
A5D5E5 wrote:
troglodiet wrote:So the bridge, designed for Yanks (with a reputation for obesity) collapsed even before one of said Yanks actually walked on it.

Some serious design flaw I'd say.


:P
Not funny enough.

Saffas.

Something.

Something.

Humour.


[/yeeb]
Better :lol:

Re: Bridge collapse in Florida

Posted: Fri Mar 16, 2018 1:34 pm
by Killer Rabbit
Flyin Ryan wrote:
Jeff the Bear wrote:
spike wrote:According to this eyewitness https://www.youtube.com/watch?v=NKxR7iU9vTo&t=4s a large white and black mobile crane was lifting something that snapped immediately prior to the collapse. The crane was quickly moved away. In the DM article you can see the blue equipment he refers to lying on the top of the rubble. You can also see the crane.
Youtube video is entitled Stress test causes bridge to collapse.
The idea of stress testing a new structure makes absolutely no sense to me. You stress test/proof load test existing structures, where you don't have access to original calcs or other structural information. Something like that would have (or should have) been designed using a finite element software and subsequently checked. It even looks to have been built precast off-site, so would have been built to high tolerance levels...hence, there should be no need for testing something that would surely have not got built had it not been designed correctly in the first place.

Performing stress tests on new buildings is admitting you designed it wrong, and unless it was designed/built wrong which, as noted, is a very slim chance, the question to ask is...who the fudge pays $16 million odd for something that might work, and you'll only know when it's built and proof loaded?

I'd hazard that there is a good chance that a layman has called it a stress test without knowing what the the fudge was going on.
Florida International University is a public university of the State of Florida, so they would be required to put out the specifications necessary for the bridge and it would go out for bid. If they actually did a stress test, it would be because FIU put it in the bid package.
The University would have a scope of works at best. Some architect would have “won” a prettiest walkway contest to do the pretty pictures and subsequently an Engineer would be found to do the actual design. Probably the cheapest Engineer as nobody wants to pay for unnecessary costs like proper detailed design or supervision during construction.
A tender to do the build would then be drafted, with the cheapest tenderer winning the job, expected to complete the build in a short time frame due to delays involving the colour of the cables. Pressures at the precast plant lead to the walkway being placed in situ before the concrete strength test results have come back, which will be found to be inadequate as some clown added too much water to the mix, but unfortunately after the fact. There is also an error with the lapping of the reinforcing steel and the surveyor cocked up the placement of the supporting piers by a metre, but no new design was done as someone would have to pay for that.
After 6 years in courts, the whole thing is settled as an act of god and nobody changes anything.


KR.

Re: Bridge collapse in Florida

Posted: Fri Mar 16, 2018 1:39 pm
by Petej
Killer Rabbit wrote:
Flyin Ryan wrote:
Jeff the Bear wrote:
spike wrote:According to this eyewitness https://www.youtube.com/watch?v=NKxR7iU9vTo&t=4s a large white and black mobile crane was lifting something that snapped immediately prior to the collapse. The crane was quickly moved away. In the DM article you can see the blue equipment he refers to lying on the top of the rubble. You can also see the crane.
Youtube video is entitled Stress test causes bridge to collapse.
The idea of stress testing a new structure makes absolutely no sense to me. You stress test/proof load test existing structures, where you don't have access to original calcs or other structural information. Something like that would have (or should have) been designed using a finite element software and subsequently checked. It even looks to have been built precast off-site, so would have been built to high tolerance levels...hence, there should be no need for testing something that would surely have not got built had it not been designed correctly in the first place.

Performing stress tests on new buildings is admitting you designed it wrong, and unless it was designed/built wrong which, as noted, is a very slim chance, the question to ask is...who the fudge pays $16 million odd for something that might work, and you'll only know when it's built and proof loaded?

I'd hazard that there is a good chance that a layman has called it a stress test without knowing what the the fudge was going on.
Florida International University is a public university of the State of Florida, so they would be required to put out the specifications necessary for the bridge and it would go out for bid. If they actually did a stress test, it would be because FIU put it in the bid package.
The University would have a scope of works at best. Some architect would have “won” a prettiest walkway contest to do the pretty pictures and subsequently an Engineer would be found to do the actual design. Probably the cheapest Engineer as nobody wants to pay for unnecessary costs like proper detailed design or supervision during construction.
A tender to do the build would then be drafted, with the cheapest tenderer winning the job, expected to complete the build in a short time frame due to delays involving the colour of the cables. Pressures at the precast plant lead to the walkway being placed in situ before the concrete strength test results have come back, which will be found to be inadequate as some clown added too much water to the mix, but unfortunately after the fact. There is also an error with the lapping of the reinforcing steel and the surveyor cocked up the placement of the supporting piers by a metre, but no new design was done as someone would have to pay for that.
After 6 years in courts, the whole thing is settled as an act of god and nobody changes anything.


KR.
Apart from one engineer who was threatened with job loss /no payrise/told career limiting decision to hold it up by project manager or similar filth and signed something off he or she shouldn't have.