I think they were also behind schedule and had to have the bridge open by a certain date. So they had to rush finishing the deck figuring they could fix it in the spring.
Must of been built by the low bidder, Bridge Fails
- Thread starter sdw
- Start date
I don't know enough about cable-stayed structures, I do pipelines - but something on CBC is really concerning me. They loaded cement blocks on the end of the bridge to bring the deck back down to the road surface. Do they have no expansion bearings? Is expansion and contraction engineered to be taken up by the cables?
It would seem to me that the design is already proven to be a failure. Bringing the road surface up to the bridge deck may be the better plan. The witness says the deck went flying up into the air and then dropped to where it was resting at 60cm above the road. Two pickups flew off taking a nose dive into the road.
A "fix" that doesn't ensure that the failure can't happen again is just sheer stupidity.
I imagine that the longitudinal camber designed into the bridge deck is the mechanism for taking up the linear expansion displacement.
The abutments for cable stayed being different than a standard bridge deck which is sections just laying on the structure with periodic expansion joint. Mainly that the abutment would have to be fixed and structural bearing torsion, tensile, compression forces as needed.
Now a days there is so many checks and balances when a structure is built. I have been on bridges and the EIT inspector has stopped the pour as a piece of rebar was missing. I really interested in knowing what failed. As convention concrete bridge moves independent of the abutment. There are several bridges that get re profiled in this province as the road settles. Bridge on piles stay the same. An example of this is the still creek bridge in burnaby by Macdonalds.
This province is in catch up on Bridges many need resurfacing and or seismic work.
examples are Oak street is 20 plus years since the deck same with iron workers, alex fraser etc. Patello has full penetration failure
This province is in catch up on Bridges many need resurfacing and or seismic work.
examples are Oak street is 20 plus years since the deck same with iron workers, alex fraser etc. Patello has full penetration failure
There is a bridge in NY built exactly the same way. With some upgrades after this bridge collapsed.
Gallopin' Gertie (Tacoma Narrows Bridge) failed due to high wind conditions and the fact that engineering did not anticipate that the bridge deck would generate lift (like an aircraft wing) in high wind conditions. The wind funnels into that gorge and it can produce some high wind conditions.
The deck would rise up, tilt, stall, then drop down. This repeated until the oscillations kept getting larger and larger and finally failure.
Lions Gate bridge was upgraded not only to widen it but to also deal with this wind factor issue.
Gusty wind is pretty hard to model in a computer simulation situation.
Seems like this incident was a combination of wind and cold weather. Noticed they had a single lane capability within 72 hours which seems to indicate non of the essential structural issues for the bridge deck itself were compromised. Just the attachment to the abutment which no doubt is being re-engineered as we speak.
Cold will likely be a materials issue while the wind issue will be a bit more complex. Probably up the safety factor and study the spot stress risers to determine if energy absorption will be required.
Don't think you can blame contractor on this one or low cost bidder process until all the facts are in. Other than fatigue from aging, most bridges are at their most vulnerable when being constructed not when in use.
The deck would rise up, tilt, stall, then drop down. This repeated until the oscillations kept getting larger and larger and finally failure.
Lions Gate bridge was upgraded not only to widen it but to also deal with this wind factor issue.
Gusty wind is pretty hard to model in a computer simulation situation.
Seems like this incident was a combination of wind and cold weather. Noticed they had a single lane capability within 72 hours which seems to indicate non of the essential structural issues for the bridge deck itself were compromised. Just the attachment to the abutment which no doubt is being re-engineered as we speak.
Cold will likely be a materials issue while the wind issue will be a bit more complex. Probably up the safety factor and study the spot stress risers to determine if energy absorption will be required.
Don't think you can blame contractor on this one or low cost bidder process until all the facts are in. Other than fatigue from aging, most bridges are at their most vulnerable when being constructed not when in use.
I'm damn sure this bridge wasn't build by the lowest bidder..... companies billing these bridges have to satisfy government standards which all employee must be part of a union .....
Therefore any project the government undertakes cost roughly 3 to 4 times more then the same project done in the private sector.....
Example.... steel frame walls and drywall both sides.... private sector ..... $120 Lin. Ft. ....Government ...... $375.00 ...Lin ft
And the reguirements to bid on these jobs ....well you need to have a good bank account to attach to your bid..
Therefore leaving all the smaller or medium contractors out of the bidding chances.....
So this bridge just as our Port Mann bridge cost a shit load of money...... now engineers will be tracked down ....they have their name attached to that project..... I wouldn't want to be them.... just watch the finger pointing that will come out of that...
Therefore any project the government undertakes cost roughly 3 to 4 times more then the same project done in the private sector.....
Example.... steel frame walls and drywall both sides.... private sector ..... $120 Lin. Ft. ....Government ...... $375.00 ...Lin ft
And the reguirements to bid on these jobs ....well you need to have a good bank account to attach to your bid..
Therefore leaving all the smaller or medium contractors out of the bidding chances.....
So this bridge just as our Port Mann bridge cost a shit load of money...... now engineers will be tracked down ....they have their name attached to that project..... I wouldn't want to be them.... just watch the finger pointing that will come out of that...
The engineering company was was based in Spain. Ferrovial.
http://www.torontosun.com/2016/01/11/nipigon-bridge-engineers-based-in-spain
Bridge was built by BOT Construction.
"Sources say municipal politicians in northern Ontario have long been concerned about the material used for the bridge. According to a PowerPoint presentation on the Ontario Good Roads Association website, while the pre-cast deck, towers and structural steel were all sourced in Canada, the cables came from Spain and the expansion joints were manufactured in China."
http://www.torontosun.com/2016/01/11/nipigon-bridge-engineers-based-in-spain
Bridge was built by BOT Construction.
"Sources say municipal politicians in northern Ontario have long been concerned about the material used for the bridge. According to a PowerPoint presentation on the Ontario Good Roads Association website, while the pre-cast deck, towers and structural steel were all sourced in Canada, the cables came from Spain and the expansion joints were manufactured in China."
L
Larry Storch
cables and the termination fittings are a major issue, not many manufacturers around for this type of cable and the fittings have to be attached completely aligned with the center axis of the cable.
when they build the annacis island bridge was build they contemplated attaching the end fitting while hanging the cable in a mile deep mine shaft
lucky they found another way, certain details like this are critical to the long structural life of the bridge
expansion joints don't sound like the issue, sounds like the attachment mechanism failed under high wind load in sub zero conditions
when they build the annacis island bridge was build they contemplated attaching the end fitting while hanging the cable in a mile deep mine shaft
lucky they found another way, certain details like this are critical to the long structural life of the bridge
expansion joints don't sound like the issue, sounds like the attachment mechanism failed under high wind load in sub zero conditions
"when they build the annacis island bridge was build they contemplated attaching the end fitting while hanging the cable in a mile deep mine shaft"
when they built the annacis island bridge they contemplated attaching the end fitting while hanging the cable in a mile deep mine shaft
sorry folks, grammar terrible, trying to do two things at once
when they built the annacis island bridge they contemplated attaching the end fitting while hanging the cable in a mile deep mine shaft
sorry folks, grammar terrible, trying to do two things at once
The Toronto Star has a picture of the "Temporary Solution" That large stack of concrete barriers on one side of the bridge. If I was those traffic guys, I wouldn't be standing there. I'd have my control point about 100 meters off of the bridge.
http://www.thestar.com/news/canada/...a-into-two-may-reopen-two-lanes-by-march.html
http://www.thestar.com/news/canada/...a-into-two-may-reopen-two-lanes-by-march.html
