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Rural Bridge Collapse Immediately After Opening 16
- Thread starter Shotzie
- Start date
There was something done to it: From the picture in the OP's link, I would guess they replaced the original pilings, but keep the roadway. The entire job took barely a month.
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I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
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ACtrafficengr
Civil/Environmental
"it wasn't structurally faulty." So was it sub-structurally faulty?
My glass has a v/c ratio of 0.5
Maybe the tyranny of Murphy is the penalty for hubris. -
My glass has a v/c ratio of 0.5
Maybe the tyranny of Murphy is the penalty for hubris. -
It would appear that the visible piling shifted away from the joint it was supporting.
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I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
TTFN (ta ta for now)
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1
- #7
BridgeSmith
Structural
>>>Hicks called it an “act of God,” insisting the bridge was built to standard.
“Something underneath the riverbed just gave way,<<<
“It wasn’t structurally faulty. The fault is in what God did under the river.”
I don't think God had anything to do with it. Sounds like someone didn't bother with drilling any boreholes to find out what they were founding the piles on...
"It would appear that the visible piling shifted away from the joint it was supporting."
The pier seems to have sunk several feet, so the center span wasn't long enough to reach the pier cap anymore.
“Something underneath the riverbed just gave way,<<<
“It wasn’t structurally faulty. The fault is in what God did under the river.”
I don't think God had anything to do with it. Sounds like someone didn't bother with drilling any boreholes to find out what they were founding the piles on...
"It would appear that the visible piling shifted away from the joint it was supporting."
The pier seems to have sunk several feet, so the center span wasn't long enough to reach the pier cap anymore.
charliealphabravo
Structural
You can almost see them Duke boys coming down the road 
Seriously though. Those steel girders look a bit narrow. Should an old multi-span bridge like that rely on the shear strength and integrity of the beams at the supports?
Seriously though. Those steel girders look a bit narrow. Should an old multi-span bridge like that rely on the shear strength and integrity of the beams at the supports?
BridgeSmith
Structural
Those look like concrete box beams to me.
Edit: Sorry, were you referring to the pier caps? Those do look a bit narrow as a seat for the beams.
Edit: Sorry, were you referring to the pier caps? Those do look a bit narrow as a seat for the beams.
LionelHutz
Electrical
I was sure it's not April yet.
That sure looks like the old bridge. "Timber substructure with concrete girders" is how the old structure is described on the demolition site and that description fits the picture.
That sure looks like the old bridge. "Timber substructure with concrete girders" is how the old structure is described on the demolition site and that description fits the picture.
msquared48
Structural
Article says a 15 foot span?
BS. The writer's dyslexic!
I see what l;ooks like wood framing, but can't be sure... and would not make sense. Must be the coloring.
Mike McCann, PE, SE (WA)
BS. The writer's dyslexic!
I see what l;ooks like wood framing, but can't be sure... and would not make sense. Must be the coloring.
Mike McCann, PE, SE (WA)
The RFP stipulates that the roadway could potentially be reused, while the main objective was to replace the wooden pilings
In any case, sounds like there's at least one PE about to lose their license.
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In any case, sounds like there's at least one PE about to lose their license.
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"How do you drive a pile from under an existing bridge?"
Maybe that is the problem; if they left the roadway in place, they couldn't have driven any new pilings and everything might possibly be sitting on the original, wooden pilings, and the new ones slid off the old ones. That would a bankrupt-inducing suit in the making. If they removed the roadbed and drove new pilings, that would be different.
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Maybe that is the problem; if they left the roadway in place, they couldn't have driven any new pilings and everything might possibly be sitting on the original, wooden pilings, and the new ones slid off the old ones. That would a bankrupt-inducing suit in the making. If they removed the roadbed and drove new pilings, that would be different.
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It sure looks like something shifted the bottoms of the steel pilings out farther into the stream - they don't look vertical anymore, as if they were set on a single submerged block that rotated. I am impressed that the diagonals held them all together and they remained in one plane.
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- #17
SlideRuleEra
Structural
The photo shows a ridiculously undersized pile cap. Not saying it isn't "strong" enough... it is too small, specifically the flange width of steel section. A (concrete) pile cap for a bridge of that size should be double or triple the width of that flange. The end of the span that fell is likely the expansion end and was not anchored (by design) to the pile cap. Probably slipped off, perhaps bending the flange, got wedged in place, slowly "pushed" the pile bent out of the way, then collapsed.
Steel section was probably used for the pile cap, instead of concrete, to lower costs.
![[idea]](/data/assets/smilies/idea.gif "[idea] [idea]")
![[r2d2]](/data/assets/smilies/r2d2.gif "[r2d2] [r2d2]")
It looks to me like the remaining section of roadway on the far side of the creek is hanging out over the pilings cap (toward the middle of the creek, where did the piece that fell sit) on the down stream side. ???
Although the second pilling from the left looks as if the concrete roadway beam slide down the pilling possible pushing it outward toward the creek bank. Same for the far left one.
Although the second pilling from the left looks as if the concrete roadway beam slide down the pilling possible pushing it outward toward the creek bank. Same for the far left one.
BridgeSmith
Structural
It seems to me that both piers shifted sideways, but that could have been the result of the collapse of the center span, rather than the cause of it. Extrapolate the line of the top of the deck for the near span in the picture, and it becomes obvious that the near-side pier is a few feet lower than where it should be, as was stated in the story (granted, that may be the only thing they got right). When it sunk, the distance between the pier caps increased, and the beams slid off the seats.
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