It does not appear to be well constructed for extended decades of use... has me wondering, do they figure on these things getting damaged and destroyed before some future predetermined date of replacement... or are such things built with a "not my problem" attitude about their projected long term useful life?
The freeway in both directions was closed after the collapse, which was caused by a car hauler truck hitting the bridge at some point after 5 a.m
https://www.freep.com/story/news/local/michigan/detroit/2020/03/27/pedestrian-bridge-collapse-detroit-i-94/2923943001/
the freeway was clear by 5 pm
https://twitter.com/MDOT_MetroDet/status/1243567487486132225
https://twitter.com/MDOT_MetroDet?ref_src=twsrc%5Egoogle%7Ctwcamp%5Eserp%7Ctwgr%5Eauthor
If the rust is anything to go by, they certainly weren't maintaining it to last for decades.
ReplyDeleteBut the piers held up. If those are good, then all they have to do is replace the spans.
Don in Oregon
It isn't that bridges fault it's ugly, I blame the roadway below. In the 60s, when most of our initial interstate infrastructure was being laid out, the minimum vertical clearance was only 14' for non-military routes. What used to happened a lot in urban areas was that when a new bridge was being planned They would set their vertical clearance based on just being an inch or so higher than the closest bridge. That bridge looks like it was maybe constructed on the cheap in the late 70s to mid 80s. The floor beam in girder (fracture critical BTW) design was usually only used when trying to achieve a minimum vertical clearance and minimized the amount of right-of-way and earthwork needed to construct. When you consider the passing of 30+ years of nearby bridges being replaced and multiple paving and roadway improvement projects below, that poor little bridge was just left a few inches shorter than its neighbors and waiting for a poorly secured excavator to rub its belly.
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