bhyde@inmet.UUCP (09/19/83)
#N:inmet:7600004:000:928 inmet!bhyde Sep 18 12:30:00 1983 My father recently outlined a pleasing line of reasoning about the bridge in Conn. that collapsed. Consider the shape of the slab: a b ------------/ / / It is somewhat more trapezoidal than this. / / <-- traffic flow -- /-----------/ c d Each time a lone truck would drive over the bridge in one lane or the other it would lift all the wieght off of either b or c. At that point the bolt which failed would drift. A micron everytime? The shape of the slab is important; very few bridges have it. The shape provides leverage. At two in the morning it is easier to get a large number of trucks in the same lane and alone. Of course there was a bolt to be poped off too. Some about of force behind the "drift" is called for. It is a big object to rock back and forth so it would seem easy to obtain that force.