Why Bridges Fall Down
The Interstate 35W Bridge had no piers in the water. Instead, a single 458-foot long steel truss arch supported the main deck. In a technical report from the University of Minnesota Department of Engineering dated March 2001, inspectors noted that "The bridge's truss deck has not experienced fatigue cracking, but it has many poor fatigue details on the main truss and floor truss system ... the fatigue cracking of the main deck is not likely, which means that the bridge should not have any problems with fatigue cracking in the foreseeable future."
The inspectors concluded that the Department of Transportation "does not need to replace this bridge because of fatigue cracking, avoiding the high costs associated with such a large project."
Update:
More About the Interstate 35W Bridge:- Graphic: Critical Parts of the Structure, from The New York Times
- Learn About Bridge Construction
Comments
Could it possibly have been caused by poor maintainance of the structural integrity caused by poor funding to the D.O.T and infrastructure? If I am wrong forgive me.
i’m thinking that this was a natural occurance due to liquidfaction. people stated that they heard or felt vibrations prior to the collapse and then the bridge fell. please beleive me the mississippi river can not be tamed no matter what man tries to do with it. it is quite possible that water leached into the ground below the footings for the columns on that side of the bridge, liquified and compromised the structure. this does happen in nature during an earthquake when the plates vibrate and the earth above loses it surface tension. will be curious to see what comes of this. the bridge was too young to fall and the adjacent bridge had no problems or at least they are saying that it has none
everyone is quoting the reports but ignoring that the report was reinterpreted by accountant minded persons who were looking more at the cost of replacing the bridge than at the impact of what the report actually meant.
This is the same mentality that NASA had when the technical people reported that the O-rings might fail but were out voted by those worrying about funding and keeping to a schedule.The cost in human lives far outweighs any monetary amount and when you think that these accidents could have been prevented .too mnuch beaurocracy