Quote:
Originally Posted by Snuffleupagus
Senator Rubio stated the cables were being tightened at the time of the collapse. how this road wasn't closed until the bridge was completed and safety checked is beyond comprehension.
Edit:
update. at least 6 dead now
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If a post-tension cable snapped while they were re-tensioning it, that could explain a mid-span collapse. There was mention of tension jacks being visible in some of the pictures and Rubio's tweet about the cables slackening also supports it.
As for leaving the road open with an unfinished bridge in place. It's not abnormal, that's exactly what is going on with the BRT bridge over Deerfoot. The girders are placed on their bearing plates and braced off to the pier and the permanent braces placed between the girders. Deck is poured (partial or full road closure) and then the whole thing will be post-tensioned with Deerfoot open. In the Florida case, with aesthetic cable stays only, the whole span would have been designed to be supported by the piers and would have been fine to leave installed with bracing.