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by In what is being called the worst collapse in 25 years, a bridge spanning the Mississippi in Minneapolis collapsed and fell more than 60 feet during rush hour traffic Wednesday night. Rescue efforts following the disaster are reportedly going better than expected with the official estimate missing persons falling today to as few as 8, although a fifth death was recently confirmed. One hundred and ten people were treated at area hospitals with injuries sustained during or after the bridge failure "anomaly."
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Costs and Deficiences
It was just last week that I took I-35E through St. Paul. Now I know accidents happen and I'm as bothered as anyone by my Senator's ridiculous statement that bridges shouldn't collapse in America. But even as her premise is messed up a larger point seems to make sense: Can't we build bridges that don't collapse? or don't collapse all at once?
I mean, I'm no engineer, but if you look at this picture of the collapsed bridge in the background with a newer arched bridge in the foreground http://www.slate.com/id/2171634/ it seems obvious that you're looking at a stronger bridge in the foreground. When I lived in England I spent many a day walking under Roman aqueducts built thousands of years ago that looked none the worse for wear. It seems to me like the arch would always be a better (best?) way to go. (The last graphic shows the design of the bridge that fell and, pardon my complete ignorance, but it looks really cheap to me. Is that true?) Even if that's not the case, what are the major factors that go into bridge design? Surely it can't be only money, as one reader of the NY Times said (see post below). And would they really replace the San Francisco Bay Bridge with one that has no redundancy in a major earthquake zone? Is redundancy always a matter of money? Anyone who can help me out I'd be glad to hear it.
http://news.blogs.nytimes.com/2007/08/02/bridge-collapses-in-minneapolis/#comment-78561
http://www.startribune.com/10072/rich_media/1341492.html
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Stucturally Deficient by markmcb :: NR7 :: Show
It's interesting that there are more than 70,000 structurally deficient bridges in the US (roughly 13%). Anyone seen any cost estimates for repairing bridges like this? I can only assume that these numbers will climb (both costs and deficiencies) as the infrastructure built during the rapid growth of the 1940's and 50's ages.