|
NTSB: I-35W Gusset Failure Could Have Been 'Catastrophic'
QUESTION:The only thing I can think of is that whatever equipment was up there
was concentrated enough in one area that it caused too much stress in
that area, causing the failure. The failure of whatever in that small
area means bridge falls down.
I'm curious if they've gone ahead and put up any sort of permanent
signing besides the occasoinal 35W-Detour signs on 280? Have they put
anything on the overhead BGS, or are they still relying on the
variable boards planted on the side of the road?
ANSWER: Actually, passenger vehicles are never used to design loading; heavy
trucks are the design vehicle for structures, and each one is assumed
to weigh the maximum allowed amount. Back when this bridge was
designed it was lower than the current allowed amount, though, which
is now 80,000 pounds.
I would be surprised if they determine that the construction equipment
was the sole cause of this collapse. It's still my opinion that the
lack of adequate inspection and maintenance caused the structure to
deteriorate to the point where the loading (vehicles or construction),
caused the collapse. Had it been maintained properly the construction
loading would not have done anything.
|
|
|
|
