Pedestrian bridge collapses at FIU

[CtownCyclone]

http://www.miamiherald.com/news/local/community/miami-dade/article210449384.html

A key concrete support truss in the doomed Florida International University pedestrian bridge developed worrisome cracks 10 days before the structure was lifted into place over the Tamiami Trail, photographs and an internal email unintentionally released by the school show.

Still lots of assumptions and questions in the article. One thing that may have exacerbated the issue was that the installation plan changed to accommodate a potential new lane of traffic.

The rods were apparently a modification to the plans, added to the bridge design after FDOT asked FIU to move the entire bridge 11 feet north to accommodate a future lane for transit.

The move forced a change in the carefully calibrated plan for moving the bridge into place. It put the north end of the main span well off the edge of the roadway on a canal bank. Because a transport machine could not traverse that roadway edge, the point where it would lift the structure was moved toward the center of the bridge. That means the end would sag when lifted. To prevent that, the rods were added to provide extra compressive support.

 

[g4ce]

AvE on YouTube has a really good video where he talks about what may have caused the collapse. The is a Part 1 and Part 2. Part 1 is his initial speculation and Part 2 is after he gets some more information. You could really just watch Part 2.

 

[Cyclones_R_GR8]

A key concrete support truss in the doomed Florida International University pedestrian bridge developed worrisome cracks 10 days before the structure was lifted into place over the Tamiami Trail, photographs and an internal email unintentionally released by the school show.

That's not good at all.