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posted by Fnord666 on Thursday June 13 2019, @02:27AM   Printer-friendly
from the a-bridge-too-far dept.

Florida International University ("FIU") needed a foot bridge to cross a canal and busy street. An FIU committee selected a design without redundant structural support because they were wanting a dramatic landmark (the bridge looked like it was a cable stayed design, but it wasn't -- the faux cables were almost entirely aesthetic). The original specs had called for structural redundancy so that the failure of one structural member would not cause a collapse -- the committee ignored this requirement in favor of visual appeal.

The engineering firm selected for the bridge (FIGG) made an error in calculation for a critical member at the end of the span. The engineering firm providing peer review of the design (Louis Berger) has refused to turn over to OSHA, certain documentation regarding what it was supposed to evaluate and what it actually did. When the bridge section which had been built on the side of the road was moved into place, experienced workers became extremely worried about cracks that started appearing and made their worries known to those up the chain. A FIGG engineer examined the cracks but determined they "did not present a safety concern even though its engineers did not know what caused them — and despite clear evidence that they were growing daily." Apparently, the guidelines are that cracks deeper than a half inch are to be taken seriously and these were much deeper and growing daily -- one photo shows a crack 4" deep.

The final bridge would have two sections -- the long section over the roadway and a short section over the canal. The canal section was to be built in place and tied into the long section. Had the canal section been built first, the risk of collapse for the section over the roadway would have been reduced because it would have shored up the longer road section.

The bridge collapsed killing six and permanently disabling another.

Article regarding the OSHA report: https://www.miamiherald.com/news/local/community/miami-dade/article231428938.html
Article regarding independent engineering review with some good explanations which I, as a non-engineer, found informative: https://www.miamiherald.com/news/local/community/miami-dade/article212571434.html
Time Lapse Video of Bridge Collapse (released by FIU): https://www.youtube.com/watch?v=vrBOF2jugFM
Original Soylent item: https://soylentnews.org/article.pl?sid=18/03/19/1746219
Link to the OSHA report itself: https://www.osha.gov/doc/engineering/pdf/2019_r_03.pdf


Original Submission

 
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  • (Score: 2, Interesting) by Anonymous Coward on Thursday June 13 2019, @06:47AM (1 child)

    by Anonymous Coward on Thursday June 13 2019, @06:47AM (#855020)

    The tl;dr seems to be that FIGG basically failed at every level, starting with a botched design, failing to get the required external design reviews, and finally failing to notice that collapse was imminent when inspecting the bridge hours before its failure.

    Then a bunch of other players failed to exercise their independent professional judgement regarding the bridge which clearly was having issues and tragedy results.

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  • (Score: 2, Interesting) by Anonymous Coward on Thursday June 13 2019, @10:53AM

    by Anonymous Coward on Thursday June 13 2019, @10:53AM (#855071)

    Agreed. And they seem to know it. I'm particularly put off by these comments (emphasis mine):

    construction documents prepared by FIGG did not specify that the construction joints be “intentionally roughened” with an amplitude of ¼” to provide higher value of shear friction at the junction of the diagonals and the deck, as required by AASHTO. During interview with OSHA, FIGG presented the argument that the standard FDOT specification already covered this requirement, and therefore it was not indicated on the construction plans. [..] If the structural engineer relies on higher friction value, then the engineer must specify it on the contract plans, as was done in the case of the pylon and the back truss, and not rely on FDOT. Field observation indicated that the construction joints were not intentionally roughened with an amplitude of ¼”.

    Oops. busted.

    During interviews with OSHA following the incident, FIGG engineers stated that because there were multiple PT bars and tendons in the structure, it could be classified as a redundant structure. This statement does not lend itself to the non-redundancy of the structure.

    This is a bad-faith argument suitable for a lawyer, not an engineer.

    At [the morning preceding the collapse], a meeting was held in MCM’s trailer with the attendees from FIGG, FIU, MCM, FDOT and BPA. [..] BPA prepared the minutes a couple of days after the meeting based on handwritten notes taken by BPA during the meeting. BPA also told OSHA that BPA sent the minutes to all participants of the meeting on March 20, 2018, for any comments or edits. BPA said that they received no comments from any of the participants, and therefore the minutes prepared by BPA became final. However after an interview with OSHA, FIGG provided its own version of the meeting, labeled as “corrected”.

    Yep, sure. Believable.