Bridge collapses in Washington state

[George Jones]

A bridge along Interstate-5 in Washington State collapsed on Thursday evening, leaving at least two cars and some people submerged in water, according to Washington State Patrol.
It was unclear how many people were in the Skagit River, the waterway in northern Washington that the four-lane bridge crossed.

http://usnews.nbcnews.com/_news/201...in-washington-state-cars-people-in-water?lite

 

[Greg Bernhardt]

I remember when that bridge collapsed in Minneapolis. How scary!

 

[George Jones]

I remember when that bridge collapsed in Minneapolis.

Yes, I remember that, and I remember the 2006 overpass collapse in Montreal.

How scary!

Yes, very scary. It is unclear if all the people in the vehicles got out alive.

 

[DrDu]

Reminds me of a poem by Theodor Fontane:
http://johnmaynard.net/TayEnglish.pdf

 

[Monique]

What is the maintenance state of bridges in the US? I've heard they are neglected due to the economic situation?

 

[jim mcnamara]

A large number of US bridges are in poor shape and have been that way for a long time -- years.

http://www.businessinsider.com/american-bridges-in-need-of-repair-2012-6?op=1

As far as I can see it is not the current economy that is the root cause, just local governance issues.

 

[jtbell]

One fundamental problem is that highway and bridge maintenance in the US is mostly paid via funds from gasoline taxes, which are assessed at a certain dollar value (which varies between states) per gallon. This leads to two problems:

First, the tax rate is not indexed to inflation, and raising it is politically very unpopular, both at the state and federal levels. The federal gasoline tax has not increased in about twenty years, and states rarely increase theirs.

Second, as cars and trucks become more gasoline-efficient, the amount of gasoline tax collected per vehicle decreases.

This situation has been building up for many years.

 

[Astronuc]

From the article

A witnesses told KING5 that an oversized truck hit the upper right side of the bridge before the collapse.

The minimum vertical clearance on the bridge (distance from the road to something a truck can bump into) is 14.5 feet. The standard height is 16 feet.

. . . .

So damage due to collision as well as the design/condition of the bridge may be factors.

It is true that many bridges across the US are in poor condition. The ASCE frequently gives a C or lesser grade for the infrastructure in the US.

 

[russ_watters]

Dale Ogden told CNN affiliate KING that he was driving near the tractor-trailer's pilot car when he saw a device on that car designed to indicate whether a truck can clear an obstacle hit the top of the bridge.
He then watched in his rear-view mirror as the truck struck the bridge, he told KING.

http://www.cnn.com/2013/05/24/us/washington-bridge-collapse/index.html

I've heard they are neglected due to the economic situation?

Locally it may be true, but it is tough to really say. When the economy tanks, infrastructure spending is one of the easiest way to stimulate it, so there was a huge injection of cash by the federal government into infrastructure in 2009 ($105 Billion).

Major collapses strictly due to deterioration are pretty rare, but certainly age can play a factor even if not the proximate cause. A new bridge could probably better handle getting rammed by a truck than an old bridge. The Minneapolis bridge collapse was caused by a design flaw that was never found, a road surface that had gotten thicker (and heavier) over time and heavy construction equipment sitting on a particularly vulnerable spot. Deterioration probably added a little to that trifecta of faults.
http://en.wikipedia.org/wiki/I-35W_Mississippi_River_bridge#Investigation

Bridges are so overdesigned that it would be tough for deterioration alone to cause a collapse. I do however remember an I95 overpass shutdown for emergency repairs in Philly a few years ago when an off-duty inspector happened by and noticed a crack that he had inspected previously had widened considerably.

 

[lisab]

This particular bridge was not structurally insufficient, but it had been classified as "functionally obsolete". In this case, that means was not wide or tall enough for the amount of traffic it's now being required to take. Of course it was adequate when it was built nearly 60 years ago, in 1955.

Ultimately that truck driver is at fault, IMO. When trucks move over-size loads, they are required to know ahead of time what route they need to take. In this case, according to a truck driver witness, if he had been in the next lane over the truck would have cleared easily. Route information is readily available, it looks like this was just negligence.

Unfortunately this bridge is not designed to take a hit like this:

The bridge was of a "fracture critical" design, as are 18,000 bridges nationwide, meaning it could collapse if even one part failed.

http://usnews.nbcnews.com/_news/201...nto-river-after-wash-i-5-bridge-collapse?lite

Btw, for those who aren't familiar with the local geography: that freeway is the main link between Seattle and Vancouver, BC.

 

[Monique]

A large number of US bridges are in poor shape and have been that way for a long time -- years.

http://www.businessinsider.com/american-bridges-in-need-of-repair-2012-6?op=1

As far as I can see it is not the current economy that is the root cause, just local governance issues.

http://www.cnn.com/2013/05/24/us/washington-bridge-collapse/index.html
Locally it may be true, but it is tough to really say. When the economy tanks, infrastructure spending is one of the easiest way to stimulate it, so there was a huge injection of cash by the federal government into infrastructure in 2009 ($105 Billion).

Thanks for the clarification!

 

[256bits]

Everything you wanted to know about bridge / inspection
http://www.in.gov/dot/div/contracts/standards/bridge/inspector_manual/

Fracture critical means that the bridge design is such that it lacks redundancy for members and its connections in tension. Tension members could develop fatigue cracks over years of traffic use, and on failure the path load is not taken up by another member.

I would be surprised that a hit from a vehicle would be enough to bring the bridge down, without some member already having become deficient through age and not having being noticed by inspection because of inaccessability for a thorough examination.

 

[OCR]

When trucks move over-size loads, they are required to know ahead of time what route they need to take. Route information is readily available, [STRIKE]it looks like this was just negligence.[/STRIKE]

http://en.wikipedia.org/wiki/I-5_Skagit_River_Bridge_collapse

The company's vice-president, Ed Sherbinski, said permits were issued from Washington State that included clearance for all bridge crossings on the route. The truck had been led over the bridge by a pilot escort vehicle.

http://www.washingtonpost.com/national/state-patrol-i-5-bridge-over-skagit-river-collapses-in-nw-wash-vehicles-people-in-water/2013/05/23/ef618aaa-c41c-11e2-9642-a56177f1cdf7_story_1.html

State officials approved the trucking company to carry a load as high as 15 feet, 9 inches, according to the permit released by the state.

The permit specifically describes the route the truck would take, though it includes a qualification that the state “Does Not Guarantee Height Clearance.”

Negligence?

How about diminished...

http://en.wikipedia.org/wiki/Situation_awareness#Situation_awareness_in_team_operations

Ultimately that truck driver is at fault, IMO.

Usually plays out that way, IMO.



OCR

 

[OCR]

Negligence...

Loss of SA...

Transcendent moments...

OCR... lol

 

[lisab]

Negligence?

How about diminished...

http://en.wikipedia.org/wiki/Situation_awareness#Situation_awareness_in_team_operations

Usually plays out that way, IMO.

OCR

Definitely a loss of SA played into this. But there were contributing factors, too.

I heard a live interview of another truck driver who was on the bridge - I can't find a transcript of it, I heard it live on local TV over the net. But that driver said he was one lane over, behind the pilot car, but ahead of the oversize truck. He saw the pilot car safety antenna hit the bridge, but he realized the oversize truck was following too close to his pilot car to stop or change course. He watched the collision in his rear view, then saw the girders fall...then he drove like hell to get off the bridge.

So if that driver's story was accurate, the oversize truck was following too close to his pilot car.

 

[morrobay]

What is the maintenance state of bridges in the US? I've heard they are neglected due to the economic situation?

According to a TV news report 25% of bridges in the U.S. are structurally deficient . Regarding
the economic situation : It seems the roads and bridges in Afghanistan are the priority.
Remember it was Bush who diverted funds for levy upgrades by the army corps of engineers in Louisiana, for Iraq war funding. Which resulted in excess hurricane Katrina damage.

 

[Astronuc]

. . . .
Locally it may be true, but it is tough to really say. When the economy tanks, infrastructure spending is one of the easiest way to stimulate it, so there was a huge injection of cash by the federal government into infrastructure in 2009 ($105 Billion). . . . .

http://www.nytimes.com/video/2013/05/24/us/100000002245042/ailing-bridges-budget-woes.html?nl=todaysheadlines&emc=edit_th_20130525#100000002245042

According to the video from NYTimes, in some states, the stimulus funds were used to replace funds already allocated for projects.

Also in the video, it is mentioned that 10 years ago, the ASCE indicated the cost to fix infrastructure in the US would be ~$1.3 trillion, and now it would be ~$3.6 trillion. It would appear that $105 billion would be inadequate.

In our area, we saw some road work (e.g., paving or repaving of roads), and the replacements of some old bridges. But that is a drop in the bucket compared to the work that needs to be done.

 

[jim hardy]

My most vivid memory of the Minneapolis bridge it the striking difference in design between it and the one just behind it, presumably older.

That concrete bridge is in compression, that is all its parts are trying to push themselves together. A trussed steel bridge is largely in tension, that is its parts are trying trying to separate from one another.

courtesy http://www.freep.com/article/20130523/NEWS07/305230167/I-5-bridge-collapses-NW-Washington-people-water

I like designs where rather than hold Mother Nature at bay, the engineers enlist her aid.

 

[russ_watters]

Understood, yes, the stimulus funds for infrastructure were in general not used for heavy infrastructure projects. One reason is that the money was supposed to be spent quickly, and there really aren't many unfunded "shovel ready" projects. It takes years and costs millions of dollars to design a bridge and it isn't like there are a stack of designed and approved bridge plans laying around ready to execute.

So much of the funding was spent on easy to execute maintenance things such as re-paving roads that didn't really need to be repaved (I saw several in my area).

That wasn't really my point though; my point was just that are issues aren't because of the recent economic issues, they are because of long-term "neglect". (I put "neglect" in quotes because I think the problems while worthy of attention are somewhat overblown.)

 

[256bits]

Definitely a loss of SA played into this. But there were contributing factors, too.

I heard a live interview of another truck driver who was on the bridge - I can't find a transcript of it, I heard it live on local TV over the net. But that driver said he was one lane over, behind the pilot car, but ahead of the oversize truck. He saw the pilot car safety antenna hit the bridge, but he realized the oversize truck was following too close to his pilot car to stop or change course. He watched the collision in his rear view, then saw the girders fall...then he drove like hell to get off the bridge.

So if that driver's story was accurate, the oversize truck was following too close to his pilot car.

Pilot vehicles can be no closer than 100 metres , and no farther than 300 metres.
To witness the antenna hit the bridge and then in a rear view mirror see the truck hit the bridge one lane over and conclude that the distance was too close ... and still keep himself in a straight line...

 

[turbo]

In our area, we saw some road work (e.g., paving or repaving of roads), and the replacements of some old bridges. But that is a drop in the bucket compared to the work that needs to be done.

In this area, we have had no investment in bridges and other infrastructure for years. The only work that has been done on this road was patching cracks in the pavement with hot asphalt, and that was a couple of years ago. The patching is a good idea, hopefully keeping frost damage down, but more cracks are forming because law enforcement fail to keep truckers honest. This road is posted for a GVW of 65K lbs, though I routinely see fully loaded log trucks that are easily 100-110K. This road is a handy short-cut for truckers and they are beating the crap out of the pavement.

 

[Evo]

The past couple of years bridge repair finally started to take precedence here after voters got angry, so, many of the older heavy traffic bridges were replaced or extensively repaired, it was a pain getting around the detours, but better to detour for new construction than for a bridge failing.

http://www.modot.org/safeandsound/

 

[edward]

The truck was southbound and hit the (first) northern most span. Then it continued to cross the bridge?? The arched spans were higher in the center lane than the outside lane.

So now I am wondering if the local escort vehicles had a GPS that showed bridge clearances? Many do and there are units available for commercial truckers.

http://www.komonews.com/news/local/I-5-Skagit-River-bridge-collapse-caused-by-oversize-load-208813861.html?tab=gallery&c=y&img=1

Could the truck simply have been in the wrong lane on the approach?

Could the incline of the approach cause the front of the trucks load to be higher from the bridge roadbed than when measured with the entire rig on flat surface?

http://www.nytimes.com/2013/05/25/u...pse-highlights-infrastructure-needs.html?_r=0

Stick around I may have more questions.

 

[Evo]

The truck was southbound and hit the (first) northern most span. Then it continued to cross the bridge?? The arched spans were higher in the center lane than the outside lane.

So now I am wondering if the local escort vehicles had a GPS that showed bridge clearances? Many do and there are units available for commercial truckers.

http://www.komonews.com/news/local/I-5-Skagit-River-bridge-collapse-caused-by-oversize-load-208813861.html?tab=gallery&c=y&img=1

Could the truck simply have been in the wrong lane on the approach?

Ah, the bridge had no clearance signs, so how is a trucker carrying an oversized load supposed to know for certain? The clearance on the outside lanes is only 14'9", but the middle is 17". You've got to go by the lowest clearance. He could have been under the assumption this was verified. Luckily no one was killed.

 

[edward]

Were there clearance signs? I mean just reading the clearance and knowing the size of your truck should be enough. It sounds to me like either the trucker had no idea how high his load was, or wasn't paying attention.

Even then the clearance was higher in the center lane that in the outside lane. The trucking company had paid for a local escort. Who knew what and when did they know it. :)

PS I made a late edit on my previous post.

 

[Evo]

Even then the clearance was higher in the center lane that in the outside lane. The trucking company had paid for a local escort. Who knew what and when did they know it. :)

PS I made a late edit on my previous post.

I made a late edit on my post.

Aren't local escorts usually for wider than normal loads? Perhaps his load was both, an escort car won't help if no one verified bridge height. Doesn't sound like it's the trucker's fault.

 

[OCR]

Ah, the bridge had no clearance signs, so how is a trucker carrying an oversized load supposed to know for certain?

Only overcrossings of less than 14 feet (the normal legal height limit) require advance postings of height restrictions.[13]

[13] www.wsdot.wa.gov/NR/rdonlyres/337A7006-8808-4790-85EA-167C8AC39F2E/0/OverheightLoads.pdf




OCR

 

[Evo]

[13] www.wsdot.wa.gov/NR/rdonlyres/337A7006-8808-4790-85EA-167C8AC39F2E/0/OverheightLoads.pdf




OCR

Well, he had a local escort with a pole for height that cleared, according to WSDOT, the pole had to be 5" higher than the truck's load. His company had clearance in WA for loads up to 15'9". Apparently he had authorization for the load height to clear this bridge. So, how was he to know he wasn't going to clear? Somewhere someone messed up on what should be attempting to go through this bridge. Large companies have routing software that do this, I'm curious where the mistake lies.

 

[edward]

This picture gives a better idea of just how big that loaded rig was.

http://www.komonews.com/news/local/I-5-Skagit-River-bridge-collapse-caused-by-oversize-load-208813861.html?tab=gallery&c=y&img=5

 

[lisab]

Well, he had a local escort with a pole for height that cleared, according to WSDOT, the pole had to be 5" higher than the truck's load. His company had clearance in WA for loads up to 15'9". Apparently he had authorization for the load height to clear this bridge. So, how was he to know he wasn't going to clear? Somewhere someone messed up on what should be attempting to go through this bridge. Large companies have routing software that do this, I'm curious where the mistake lies.

According to local radio, when the state gives clearance it just means "You have permission to drive that oversize vehicle on our roads." It's ultimately the driver's responsibility to determine a safe route. As I pointed out in an earlier post, he was too close to his pilot car to do anything after he (presumably) saw the safety antenna hit the girder. A simple lane change would have avoided the hazard.

The company is a Canadian company, and it has a long excellent safety record in Washington State. I can only guess they were familiar with the road and any hazards along the route.