Ontario Cable Stay Bridge Failure
Ontario Cable Stay Bridge Failure
(OP)
Some engineers in Spain are going to have an interesting few days of review/discussion ahead of them. 2' of movement seems to suggest something was fundamental was missed. It is posted in the failure section too, but it would be interesting to hear some comments from people that design cable stay bridges.
Link to news story: http://www.cbc.ca/news/canada/thunder-bay/nipigon-...
Link to news story: http://www.cbc.ca/news/canada/thunder-bay/nipigon-...






RE: Ontario Cable Stay Bridge Failure
thermal movement?
RE: Ontario Cable Stay Bridge Failure
Did the other end lift up as well?
At this end, there seems to be one platform segment that did not move up. A different support piece spanning a gap between the dirt-supported roadway and the first cable-suspended roadway section?
RE: Ontario Cable Stay Bridge Failure
RE: Ontario Cable Stay Bridge Failure
The article claims a "gust of wind" but I find that very unlikely.
RE: Ontario Cable Stay Bridge Failure
It looks like one side is longer than the other and the final design is to have three towers and cable systems, but they opened one half while they demolish the old bridge to make way for the second half.
This picture looks like they have just weighted it down with a lot of concrete to get it back in place.... http://topoflakesuperior.ca/north-superior-news/ni... scroll down to the 4th photo
Remember - More details = better answers
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RE: Ontario Cable Stay Bridge Failure
RE: Ontario Cable Stay Bridge Failure
RE: Ontario Cable Stay Bridge Failure
Looking at the stack on concrete, I wonder if one cable system and bridge deck gave out (allowing them to jury rig something to get the other side of the bridge open ?
I'd be surprised if thermal expansion/contraction wasn't considered in the design. It can't be a surprise that it gets cold in Canada in winter !
another day in paradise, or is paradise one day closer ?
RE: Ontario Cable Stay Bridge Failure
http://www.netnewsledger.com/2016/01/10/nipigon-br...
RE: Ontario Cable Stay Bridge Failure
RE: Ontario Cable Stay Bridge Failure
edit: The MoT had some spare blocks to re-open. http://www.cbc.ca/news/canada/thunder-bay/nipigon-...
RE: Ontario Cable Stay Bridge Failure
RE: Ontario Cable Stay Bridge Failure
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Ontario Cable Stay Bridge Failure
Ought to work, right? 8<)
RE: Ontario Cable Stay Bridge Failure
Some eyewitness accounts report that the end of the bridge abruptly uplift then crashed downward, reported like a buffet/burst of wind.
From Link
There is a photo that I saw (but cannot now locate) that shows some acute deflection in the subject span adjacent to the abutment.
RE: Ontario Cable Stay Bridge Failure
Same span AFTER install of concrete barrier kentledge:
RE: Ontario Cable Stay Bridge Failure
RE: Ontario Cable Stay Bridge Failure
There must be some sort of differential loading / response here and maybe they didn't analyse the single deck operation quite as much as the whole bridge?
I'm pretty sure it is the "short" side which has jumped up, which tends to show that the uplift force has not been well anchored down.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Ontario Cable Stay Bridge Failure
So in an unrestrained condition, when the cables shorten due to lower temperatures the bridge deck would go up (most notably at the ends), correct?
Were the bolts that "broke" used to hold the deck at the same elevation as the rest of the roadway as the cables shrank? Essentially taking care of thermal effects by increased stress in the cables and bolts?
RE: Ontario Cable Stay Bridge Failure
another day in paradise, or is paradise one day closer ?
RE: Ontario Cable Stay Bridge Failure
So when they're building one of these bridges - do they have to calibrate the installation stress in the cables to the temperature during installation? The forces induced with the temperature there must be massive.
RE: Ontario Cable Stay Bridge Failure
It is unlikely that the root cause was the opening of the bridge with only two lanes. This is standard procedure (at least in Canada) for replacing bridges which are critical links. This is not a new situation for the design firm.
RE: Ontario Cable Stay Bridge Failure
It does look though like the holding down system / bolts / structure has failed, but the uneven nature of the pull up may have something to do with only half of the bridge being built?
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Ontario Cable Stay Bridge Failure
RE: Ontario Cable Stay Bridge Failure
The pictures shown already demonstrate that; the bridge is split on an expansion joint.
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RE: Ontario Cable Stay Bridge Failure
another day in paradise, or is paradise one day closer ?
RE: Ontario Cable Stay Bridge Failure
RE: Ontario Cable Stay Bridge Failure
another day in paradise, or is paradise one day closer ?
RE: Ontario Cable Stay Bridge Failure
RE: Ontario Cable Stay Bridge Failure
RE: Ontario Cable Stay Bridge Failure
another day in paradise, or is paradise one day closer ?
RE: Ontario Cable Stay Bridge Failure
I'm wondering if someone forgot to check the half built case in the cold and distributed the thermal effects from the centre set of cables into both bridge decks and their anchorage instead of just one. Then it's winter time with only one deck built and suddenly the centre cables aren't facing the resistance that was expected. From the short term fix, it seems like it just needed a bit more weight to get it back to the right elevation, so the .
I can very much see a situation where someone goes "It's extra strong when there's only one deck there" so only does a surface level check of things and then misses the strange case where it's not.
Or maybe the whole thing was designed just fine and there was a construction problem, or some sort of crazy unexpected load action.
RE: Ontario Cable Stay Bridge Failure
http://www.canadianconsultingengineer.com/transpor...
RE: Ontario Cable Stay Bridge Failure
RE: Ontario Cable Stay Bridge Failure
HOWEVER WITH THIS EDIT NEXT POST CORRECTS ME. THANKS
http://www.iegroup.net/about.html
RE: Ontario Cable Stay Bridge Failure
No worries. The news has been plastered with comments about a Spanish firm designing a Canadian bridge, so I am sure a lot of people thought that was the case.
@oldestguy
You have the wrong Infinity Engineering. My understanding is that they were doing the construction engineering, not the bridge design.
http://www.infinity-engineers.com/
http://www.infinity-engineers.com/infinityprojects...
RE: Ontario Cable Stay Bridge Failure