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Originally Posted by ASAP
has anyone here seen how construction projects in south florida are handled / maintained?
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Quote:
Originally Posted by RickFLM4
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The unedited version of that AP Story offers MUCH more info, some which I have copied below
https://www.yahoo.com/newsroom/vibes...e-bcd07168f65b
Documents obtained by The Associated Press through a public-records request show that the Florida Department of Transportation in October 2016 advised Florida International University and its contractors to move one of the bridge's main support structures 11 feet (3 meters) north to the edge of a canal, widening the gap between the crossing's end supports and requiring some new structural design.
Videos of the collapse show that the concrete, prefabricated segment of the bridge started crumbling on the same end of the span where the tower redesign occurred, two days after an engineer on the project reported cracks in the same location. The segment that failed had been placed atop the pylon's footing, and the taller tower section was to be installed later.
It is still unclear if the design change contributed to the failure.
Difficulties began in late 2016, when the Florida Department of Transportation emailed project officials saying they wanted more room to allow for future widening of the road, according to the documents. The new position of the tower would be on the north side between the road and the canal.
"This ... places the current location of the pylon in conflict with the extra travel lane and would require bridge design modifications," Alfred Reyna, a transportation department employee working on the bridge project, wrote in an email.
After weeks of back and forth, it was decided to move the pylon 11 feet to the north, sitting near the edge of the canal. According to documents, initial costs for the new design were $204,540, with another $402,723 for construction changes. The final cost was not divulged.
While the NTSB probe has just begun, multiple engineers who reviewed the documents obtained by the AP said moving the tower after the bridge's initial design invited errors.
Henry Petroski, a Duke University civil engineering professor, said even seemingly minor changes in a bridge's design can lead to failures.
"Once a design is completed, subsequent modifications tend to be suggested and approved without the full care that went into the original design. This has happened time and again in bridges and other engineering structures," he said.
The documents show that further time pressures were put on the tower redesign due to a bottleneck at the U.S. Army Corps of Engineers. The Corps was in charge of permitting certain aspects of the new tower's footing and other elements but had stopped due to federal budget cuts. Documents show the contractors wouldn't begin work until the Corp's permits were finished, and FIU worried delays could jeopardize federal funding.
Kenneth Jessell, FIU's senior vice president for financial affairs, in 2017 worried the delays would jeopardize federal TIGER funds for the university's massive transportation redesign, of which the bridge was a key part.
Bridge engineers who reviewed photographs of the collapse said it was ill-advised to move the pylon after completing the initial design, but that more analysis was warranted before it could be known whether this played a role in the collapse.
Robert Bea, a University of California, Berkeley engineering professor, said the tower base may have been more flexible after it was moved closer to the canal. This could have created more stress on the section that collapsed when crews removed temporary supports so traffic could resume, he said.