On the bridge collapse
Yeah, I know I said I'd make an "everything I've been up to" post, but in the wake of something like this, I'm putting that off for a few days to voice a few of my thoughts on this catastrophe.
First off, let me tell you that shocking as this was, I'm probably even more amazed than most people. The reason for that being, although I did decide to quit, I did spend three years studying civil engineering. To be quite honest, this sort of failure is so rare, for all practical purposes, you can truthfully say it almost never occurs. A complete catastrophic failure requires something to go so completely wrong with a structure... I can't even begin to tell you how shocked I am that something like this would actually happen, especially given the fact that there were no overt abnormal conditions. Collapses happen during disasters, like a hurricane, earthquake, a ship hits the bridge... This doesn't just happen.
You see, structures are generally going to be designed to withstand something like 110-150% of whatever sort of stresses the engineer thinks is going to be on it. In addition, the load used in calculating bridge deck strength assumes that there are going to be fully loaded semi-trucks across the entire span, with only a couple of feet between them, a situation for the probability of occurrence is pretty much nil.
Given that... I can't even begin to guess what actually caused the collapse. In all likelihood, there were a number of things contributing (corrosion from salt, undermining of the supports near the river, improper design in the first place, the possibilities go on). What I can say with a fair degree of certainty is that it appears the starting point was in a failure of the steel frame of the bridge, near one of the concrete support pillars. As the steel work around one support failed, the bridge would have crumpled to the side, as can be seen clearly. As that happened, stresses on the opposing end would have increased to a point far beyond the design tolerances, and it would have pretty much ripped in half, as you can tell. The section connected to that then crumpled, nearly flipping over, which caused the damage on the far approach.
Again, like I said, it's pretty clear what happened, but not why.
You know, I feel... I dunno... Maybe guilty because here I am, rambling on about the engineering implications, while people were killed, and many more traumatized. I guess the only reason for that I can think of is because for years my whole mentality about these sorts of disasters is to understand what went wrong so that it didn't happen again. All the people I knew in the CE department, all of us were very aware that if we, going into the field, messed up, people could die, and I think we took that pretty seriously. And so, even if I didn't finish my degree, even if I'm not there anymore, it's like... I'm looking around at all these people I know, and I'm thinking "We blew it," even though we had nothing to do with it. Dunno if that makes any sense.
Anyways, that's about all I can think of to say.
First off, let me tell you that shocking as this was, I'm probably even more amazed than most people. The reason for that being, although I did decide to quit, I did spend three years studying civil engineering. To be quite honest, this sort of failure is so rare, for all practical purposes, you can truthfully say it almost never occurs. A complete catastrophic failure requires something to go so completely wrong with a structure... I can't even begin to tell you how shocked I am that something like this would actually happen, especially given the fact that there were no overt abnormal conditions. Collapses happen during disasters, like a hurricane, earthquake, a ship hits the bridge... This doesn't just happen.
You see, structures are generally going to be designed to withstand something like 110-150% of whatever sort of stresses the engineer thinks is going to be on it. In addition, the load used in calculating bridge deck strength assumes that there are going to be fully loaded semi-trucks across the entire span, with only a couple of feet between them, a situation for the probability of occurrence is pretty much nil.
Given that... I can't even begin to guess what actually caused the collapse. In all likelihood, there were a number of things contributing (corrosion from salt, undermining of the supports near the river, improper design in the first place, the possibilities go on). What I can say with a fair degree of certainty is that it appears the starting point was in a failure of the steel frame of the bridge, near one of the concrete support pillars. As the steel work around one support failed, the bridge would have crumpled to the side, as can be seen clearly. As that happened, stresses on the opposing end would have increased to a point far beyond the design tolerances, and it would have pretty much ripped in half, as you can tell. The section connected to that then crumpled, nearly flipping over, which caused the damage on the far approach.
Again, like I said, it's pretty clear what happened, but not why.
You know, I feel... I dunno... Maybe guilty because here I am, rambling on about the engineering implications, while people were killed, and many more traumatized. I guess the only reason for that I can think of is because for years my whole mentality about these sorts of disasters is to understand what went wrong so that it didn't happen again. All the people I knew in the CE department, all of us were very aware that if we, going into the field, messed up, people could die, and I think we took that pretty seriously. And so, even if I didn't finish my degree, even if I'm not there anymore, it's like... I'm looking around at all these people I know, and I'm thinking "We blew it," even though we had nothing to do with it. Dunno if that makes any sense.
Anyways, that's about all I can think of to say.