Pedestrian bridge collaps

STUPIDITY Why would anyone do major work on the bridge without stopping all traffic from moving under the bridge while moving heavy load over the bridge. As a licensed offshore crane operator I would never move heavy loads over people.
 
From what I read the bridge was built along side the road and swung into place and set on its permanent foundation last Saturday 3/10.
The road was closed and it was night time to reduce traffic problems.
Once it was securely in place the road was opened.

Then today; days later the bridge collapsed under its own weight.
A structural defect.

Construction workers were on the bridge and cars were passing under it at the time of collapse.
 
Appears to have been a pre-stressed concrete structure.
Perhaps the tensioning cables inside were compromised during the lift and set.
Or the tensioning cables were not properly anchored?

Eight vehicles waiting for a traffic signal were under it when it collapsed.
 

I watched coverage of it for an hour on the news. Nothing about any heavy load on it. Yes, they were working on it, just as thousands of bridges are worked on every day with traffic going under. Did they fail to consult with you Glen?
 
The center tower and suspension cables were not built and installed yet. You can see the cable support points on the top of the structure as it lies on the ground. What has not been reported yet is what was used for shoring or cribbing to hold this section up until the support column and suspension cables were installed. What you are seeing on the ground is an incomplete structure, incapable of supporting itself as it existed.
 
(quoted from post at 20:40:13 03/15/18) The center tower and suspension cables were not built and installed yet. You can see the cable support points on the top of the structure as it lies on the ground. What has not been reported yet is what was used for shoring or cribbing to hold this section up until the support column and suspension cables were installed. What you are seeing on the ground is an incomplete structure, incapable of supporting itself as it existed.

How did they crane it into position with two cranes if it could not at least support itself?
 

Some before, after and what it would have looked like when done pictures.


mvphoto12950.jpg


mvphoto12951.jpg


mvphoto12952.jpg
 
Agree appears to be a construction issue.
The installation jacks appear to be gone and no reshoring or cribbing is seen.
The bridge completion photo indicates suspension cables to support the bridge.
 
(quoted from post at 21:49:13 03/15/18) The center support is not there either.
The center support [u:229dca5be5]under[/u:229dca5be5] it is there but not the upper with the five stays or cables or whatever per side from center column.
 
From what I'm seeing in those pictures the center support is there. What collapsed was 1/2 of the entire span.

But now my questions range with simple "if the span that collapsed had to be supported about 1/3 the width to move the span into place what made anyone think the span would be self supporting without the tower and suspension cables shown in the what it will look like picture"? Did the desire to make the bridge pleasing to the eye contribute to the failure? If you question that idea think. A suspension pedestrian bridge? Really? Just how much extra was that going to cost?

Rick
 
(quoted from post at 17:40:13 03/15/18) The center tower and suspension cables were not built and installed yet. You can see the cable support points on the top of the structure as it lies on the ground. What has not been reported yet is what was used for shoring or cribbing to hold this section up until the support column and suspension cables were installed. What you are seeing on the ground is an incomplete structure, incapable of supporting itself as it existed.

Did they fail to consult with you Scott?
 
(quoted from post at 05:03:30 03/16/18) No, but they should have consulted with someone. First report on Fox said something dropped from a crane.

Glen, you need to get involved and advise the AHD about who they should have been consulting .
 
It was set Saturday. Then they bragged about what a great job they did raising a one piece bridge. Then Thursday it falls.
 
Dollars to donuts there was a calculation mistake by an engineer. Maybe a decimal point in the wrong place. They apparently thought it was strong enough to support it's own weight before the center support and cables were built and added to the structure.
 
This webpage is by FIU toting the bridge project.
https://news.fiu.edu/wp-content/uploads/17703_EXT_FIU_Bridge_Move_Fact_Sheet_030918_DIGITAL.pdf


The part that collapsed was assembled/constructed next to the street. Then was lifted from below by motorized and steerable mobile platforms.
Cranes were not involved.

There is chatter that they had just done some sort of stress test before the collapse. And that they were in the prossess of tightening some tensioning cables.

Not clear if those were the internal cables or the cables going from the walkway up to the roof.
 
OK according to what I have found so far the design of the bridge is supposed to be OK with the exception that until the tower and suspension cables are in place the span needed to be supported. I suspect that supports were not in place so as not to disrupt traffic.

Rick
 
(quoted from post at 11:19:46 03/16/18) OK according to what I have found so far the design of the bridge is supposed to be OK with the exception that until the tower and suspension cables are in place the span needed to be supported. I suspect that supports were not in place so as not to disrupt traffic.

Rick

Rick you should probably get in touch with the governor of FL and share that information with him.
 

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