[First let me express relief that no one was killed in the collapse.]
Yesterday’s collapse of an I-5 bridge North of Seattle will:
1) Scare Washington legislators into funding the CRC out of fear of a similar collapse.
or
2) Make legislators recognize that they have many bridges with problems and they should spend their dollars on a program to begin addressing this broadly rather than putting all the money in one big project.
or
3) Have no impact if it turns out that this collapse was indeed caused by a large truck striking a bridge member.
Place your bets…
42 responses to “How Will Skagit Bridge Collapse Affect CRC Debate?”
I’m sorry, but I call BS on the truck knocking down the bridge story. I understand a truck may have hit the bridge, but if a bridge fell just because of that then there was something SERIOUSLY wrong with the structural integrity of that bridge in the first place.
I’m sorry, but I call BS on the truck knocking down the bridge story. I understand a truck may have hit the bridge, but if a bridge fell just because of that then there was something SERIOUSLY wrong with the structural integrity of that bridge in the first place.
I agree on the truck issue. If our critical infrastructure is not designed to withstand wayward vehicle strikes, then something is seriously wrong. I think WSDOT and ODOT are in denial about the budget realities. The public won’t stomach the gas tax increases necessary to fund retrofit/replacement projects AND capacity expansion, so something has to give.
Safety and earthquake survivability should be the first priority. If we continue down this path, the next Cascadia subduction quake will absolutely destroy the economic viability of this region, and needlessly kill hundreds of people. Oh, but we’ll have a 12-lane bridge and light rail over the Columbia and a shiny new bypass tunnel under Seattle.
Eric,
One thing to remember about truss bridges–all them metal girders aren’t there just to look pretty and iconic; they’re the essential part of the superstructure. The truss is not mounted on the bridge deck; instead, the bridge deck is essentially hanging from the truss. Destroy the truss and the bridge can easily collapse. In this particular bridge, the truss was only 15′ about the roadbed, so a strike by an oversize vehicle was an accident waiting to happen.
Any estimates on how much it will cost to replace this particular bridge–which
Didn’t finish my last sentence: Any estimates on how much it will cost to replace this particular bridge–which likely is now the #1 priority project for WSDOT?
I could see badly rusted places in some of the photos they released. In that area you also have a combination of rain and salt air. Therefore, the maintenance schedule should be stepped up, and bridges which are markedly deficient placed on schedule for replacement. However, I doubt that replacing this bridge will cost very much, since it is similar to many other bridges on the I-5 that cross small rivers. Now that would be an interesting comparison!
I’m not for massive seismic upgrading to Oregon structures—-but that doesn’t mean I am against replacement of defective structures. There’s a difference: One is a game of whack-a-mole and the other intelligently addresses risky structures. The OSU report released last year places the greater seismic risk down near Rogue River to the Kahlifornia border. So lookout, Ashland and Brookings! Nervous nellies in the Portland area and—ahem, Cannon Beach—should relax.
And specifically to the CRC design. It was the concrete structures that experienced the greater failure in Kahlifornia. Sure, new concrete structures today have much better reinforcement. But metal bridges, I think, have even better protection with isolation bearings and padded rubber bearings. The PEER lab in Berkeley is researching a lot of new ideas and implementing them on Silicon Valley buildings and on CalTrans projects.
Google Maps actually shows the bridge down this morning. With the traffic layer showing, it offers a closure notice (which seems overly-optimistic).
Even if the Cascadia Subduction Zone is factored out, there are still seismic hazards aplenty in our region: a magnitude 6.5 quake centered in a densely populated inland area can wreak as much havoc as an 8.5 out at sea.
That said, we’ve already experienced a pretty recent test of the PNW infrastructure’s seismic preparedness: the 2001 Nisqually earthquake. Impressively enough, no elevated structures failed completely as far as I can recall, but it was significant enough to shut down the Alaskan Way Viaduct for months and ultimately hasten its replacement.
The red areas visible on the collapsed structure are undercoat exposed when the topcoat flexed and peeled off. That’s easily seen because the edges of the exposed red zones have no transition (rust typically tapers off), and the exposed areas are “jagged”. Again, rust generally expands from a break in the coating in something of a circular or elliptical pattern.
But the real telling evidence is in the pictures which show parts of the un-collapsed structure as well. There are no, zero, none red areas on them.
It’s undercoat, not rust.
@Everyone,
The first step should be to add height radar like at Chehalis to the entering ends of each bridge with a big STOP sign similar to ones at the lift span. (They could use the southbound life span one).
Local truckers know the limits on the various steel trusses throughout the area, but long-distance speciality truckers like the one who took down the Skagit Bridge don’t necessarily. That bridge has unusually low clearance for an Interstate Highway bridge (lower than the bridges here). I expect the driver or his company didn’t do their homework before shipping the drilling rig.
To Vancouver, interestingly enough. It was probably heading to the fabricator at the old Kaiser shipyard for use on the North Slope.
Then, Washington and Oregon should put big signs at their respective I-205 splits directing traffic higher than one foot lower than the I-5 bridge clearance to I-205.
The whole package should cost less than three or four million dollars and might save dozens of lives. The Columbia is deep enough that it will swallow a collapsed span whole; there wouldn’t be a deck three feet below the water on which for unlucky cars to land.
@Jeff,
A year is “overly-optimistic”? Wow, I sure hope not. This is going to play absolute hell with Canada-US West Coast trade, lots of which is food. Hothouse tomatoes and peppers from BC are going to be lots more expensive next winter if they don’t get it done before that time.
The state does have a conundrum to solve: the Federal emergency replacement monies can only be used to replace in kind; no capacity expansions are allowed. But they don’t require an EIS or public comment periods. They just get the bridge back the way it was on Uncle Sugar’s dime.
Maybe that would mean as little as fabricating an exact replica of the span that failed, perhaps with more robust girders if so doing wouldn’t overload the footings. It’s conceivable that could be done in as little as three or four months by pre-fabbing the trusses offsite.
But that’s really not what Washington needs on this span. It’s only two lanes and it should be three for another mile and a half to SR 20. Unfortunately, to rebuild the bridge as a three-lanes each way facility it has to go through the entire project lifecycle. And that would take a couple of years.
I-5 across the Skagit River cannot be closed for two years.
Two quick points:
1. The bridge which collapsed was a “fracture-critical” design, meaning it’s possible for a single point of failure to collapse a span:
http://seattletimes.com/html/localnews/2021046062_bridgesafetyxml.html
2. Radar and warning signs are terrific, but it’s astonishingly easy to mechanically protect spans from truck impacts … watch this amazing compilation and enjoy:
https://www.youtube.com/watch?v=JsAlzV4qSD8
More details here:
http://11foot8.com/faq/
But that’s really not what Washington needs on this span. It’s only two lanes and it should be three for another mile and a half to SR 20. Unfortunately, to rebuild the bridge as a three-lanes each way facility it has to go through the entire project lifecycle. And that would take a couple of years.
That could be managed by a two-step process: Replace the current bridge ASAP with one of equal size (presumably more modern methods and clearances). Then go through a longer process to design/build a twin bridge right next to it, like exist on many points along I-5.
I expect the driver or his company didn’t do their homework before shipping the drilling rig.
Possible, but the trucking company involves claims they had the necessary oversize load permits from Washington officials and that they had hired a local guide:
http://www.katu.com/news/local/I-5-Skagit-River-bridge-collapse-caused-by-oversize-load-208813861.html
Anandakos, I got tripped up by the year (for the second time in two days as it happens). Must read more carefully.
Temporary bridges (which have lifespans measured in months or years, rather than decades) can be thrown up in a rather short time-span, while a permanent bridge is built.
The P&W trestle in Milwaukie has a few low-clearance undercrossings, and I recall an over-size truck striking that bridge a few years back. Like in the video–the top of the truck was shorn off, and the bridge sustained little damage.
But railroad trestles spanning a few dozen feet are far more easy to stabilize than bridges spanning hundreds or thousands of feet…
Like in the video–the top of the truck was shorn off, and the bridge sustained little damage.
I should have been more clear about that: The bridge itself in the video is not what’s shearing off the roofs of trucks. They have a very secure bar located just a couple of feet in front of the bridge to, well, ensure compliance with the height limits before a vehicle can ever strike the bridge itself. :-)
(And what such a shear bar might mean for vehicles in mixed traffic at highway speeds, I cringe at the thought, but I’m certain the videos would be popular.)
Ever the optimist, I place my bet on option 2. This should be the final piece of evidence that the “mega project” approach to infrastructure renewal is fatally flawed.
Greed for federal money caused this region’s insane fixation on doing the CRC, when there are many other needs with higher priority and lower cost. Is Washington really going to pledge $500 million for the CRC, when much cheaper alternatives are available for improving the safety, capacity, and disaster-resistance of the current I-5 crossing of the Columbia?
Now, after this, will the Federal Government really insist that the only choice is CRC or nothing when it comes to a Federal contribution?
I predict no-change as a result of the collapse. If this were Seattle with a far greater impact or loss of life, maybe. Or if this was in Eastern Washington, it may sway the holdouts on this transportation bill, yes. It will be largely forgotten. And also in light of the fact that the bridge was not structurally deficient you can not make an argument that we need to go around replacing everything. Given that this guy hit the structure with his truck, It would seem to indicate he or his company was at fault. Would have happened the same as if he had driven over it the day it was completed, Pretty simple.
We will find that yesterday’s collapse of the I-5 Skagit River Bridge is an excellent example of why the developers of the CRC should not replace the existing I-5 bridges. They should build a supplemental bridge for I-5 traffic leaving the old ones for local traffic, transit, bikes and pedestrians – as being proposed in the “Common Sense Alternative”.
A local bridge a quarter mile upstream from the collapsed Skagit River Bridge will carry I-5 traffic while the collapsed bridge, built in the 1950s with weaker steel members than the Columbia River Bridges, is being repaired.
Redundancy is a good thing.
Major egg on Jay Inslee’s face: demanding replacement of bridges that have not failed (and are not likely to) instead of crucial ones that are inadequate and failure-prone.
Also,this is purely a WASHDOT issue. CRC opponents cannot be blamed.
Note too that our existing spans of the Columbia are highly redundant: both I-5 and I-205 are separate structures for north and south bound crossings. I-205 has huge shoulders as well. If any of these four structures were incapacitated the remaining three could more than take up the load.
@Jim Lee,
Climb down from your soapbox. It’s not the governor’s responsibility to take notice of every possible bridge in the state which might be damaged by a passing vehicle.
The bridge was evaluated just last year and got a mediocre but passing grade. Sure, it’s old; it was build for Old Highway 99, and the state just re-purposed it for New Highway 99 (e.g. I-5) when the freeway was built. It’s been there waiting to get hit by an over height heavy load through nine past administrations, both Republican and Democratic. In fact, it was built during the administration of Arthur B. Langlie, Republican.
So I’d say there’s egg on his face, too. It was clearly malfeasance — perhaps even misfeasance — that he did not foresee that Canadian truck bringing down his handiwork fifty eight years later. Such a failure as governor!
I bet they do CRC and the bridge falling down has nothing to do with that.
Too much money (free money in the form of tax payers money) involved and government people never say no to that in the end.
Lots of nice posturing and pandering going on though.
I’m sorry that some of you are ignorant on how structural bridges are built. Thats just reality – if you were present in 1955, or whenever this bridge was designed, perhaps you would have understood the fiscal, time, logistical and material constraints that were a reality back then. They didn’t build bridges to be bomb proof – they built them to be cheap and functional!
If you cut through a critical member on any structure – and every single exposed girder and steel member is carrying a load – then you are going to have problems! Engineers design structural systems to be as efficient as possible, using the absolute least amount of material while maintaining safety standards and a healthy margin of safety.
Its kind of amazing when people are so ignorant of basic physics. Please enroll in your local community college physics/engineering course, or read the wiki on static structures, before slinging mud.
http://www.katu.com/politics/local/Columbia-River-Crossing-debate-influenced-by-I-5-bridge-collapse-208897061.html
For those who want to give WashDOT and Inslee a pass on this, news reports are now saying that this span had suffered repeated impacts in recent years by high loads on trucks. As “was carless” points out, this bridge was built at a time when engineers had learned how to build lighter, cheaper structures to carry the design loads, but before much thought was given to concepts like redundancy and robustness.
Oregon has been replacing a slew of reinforced concrete bridges that were not built to handle modern truck weights. WashDOT should have put replacing or reinforcing their most fragile bridges ahead of the CRC.
Regarding Gov. Inslee, if he is going to push so hard for something like the CRC, he should have done his homework.
Interestingly, Tom Hughes told the City Club last week that he thinks that Washington State may come up with their share of the money even if the Washington Legislature doesn’t provide the funding. Does anyone know what plan he was talking about?
The cause of the Skagit River Bridge collapse, besides the over-sized load, is not the structural integrity of the bridge, but rather the competency of Washington’s Department of Transportation. The curved cross member was not designed to withstand a direct hit from a heavy load. It was designed as one of many components in an economically designed truss system.
The fact that it was vulnerable should have been obvious to WADOT bridge engineers because of its low clearance at the ends of the cross-span and should have been protected from collision. The bridge had been hit before.
There are many ways to protect vulnerable but structurally sound structures besides replacing them as being suggested by some. If there weren’t, most parking structures would quickly become piles of rubble.
@Jim Howell,
With respect to a bridge on a freeway in a free-running fairly rural area, how are you going to “protect it from collision”? That truck may not have been going 60 (the legal maximum for trucks), but it was probably cruising at 50 when it hit the structure.
Apparently either the truck was too close behind the pilot car to stop, the pilot didn’t respond to the whips hitting the bridge quickly enough to warn him in time, or the purported “other semi” “pushed the driver over” to the right when he meant to be in the middle lane. Something went wrong after the truck entered the first span, and a structural member within the truss box was hit. It wasn’t the entrance of the box that was crumpled.
Are you suggesting overheight vehicle radar like at Chehalis? I’d certainly support adding it to all such restricted height bridges on I-5.
http://www.oregonlive.com/business/index.ssf/2013/05/skagit_river_i-5_bridge_collap.html#incart_m-rpt-1
@Anadakos:”With respect to a bridge on a freeway in a free-running fairly rural area, how are you going to “protect it from collision”?”
One bridge demolition every five years or so, doesn’t mean that our whole Transportation system needs to be rebuilt. I thought the Oakland Bay Bridge replacement was an example of Pelosi-inspired pork, because the old bridge had only one 50 foot section that was damaged in the Loma Prieta quake. So it needs a several billion replacement, with parts and labor from China?
But back to your question: The Skagit bridge was from a bygone era and should have been on schedule for some type of reconstruction. And normally the way to prevent large vehicle damage to structures is with Jersey barriers, assuming there is enough room. But, even on older bridges the barriers could be placed near the entrance to guide trucks away from the shoulder.
If it is an extra large load they are supposed to have clearances all mapped out. It works except for one time in a hundred thousand. But I agree, there are a lot of bridges that need closer observation and improvements.
@ Anadarkos
You are right!
The I-5 Skagit bridge was not designed and built under the Inslee administration!
But it had been hit in the same manner before, if not within the Inslee administration, recently enough to attract attention from WASHDOT.
WASHDOT, instead of following old Conde McCullough’s book on the economics and choice of building useful bridges where priority dictates, chose, with Jay Inslee as head cheerleader, to prefer the titanic fraud that is the CRC.
Kitzhaber and Inslee prefer the CRC for the same reason that MULTCO and ODOT rejected Bechtel’s $90 million fixed cost offer to replace the Sellwood: insufficient pork for the construction industry.
Good old-fashioned highway-department politically enabled megafraud!
And I have just verified, via my 6th edition of the AISC Steel Construction Manual, that my soapbox is more than adequately fabricated of bolted wide-flange and H-sections to support my arguments. I have no need nor intention to descend.
Worse yet, I am a native Missourian and expect those in the kitchen to be willing and able to take the heat. Jay Inslee now oversees WASHDOT. It is his responsibility. If he chooses not to take it, he is in the wrong position.
@Jim Lee. “….MULTCO and ODOT rejected Bechtel’s $90 million fixed cost offer to replace the Sellwood: insufficient pork for the construction industry. Good old-fashioned highway-department politically enabled megafraud!”
And in construction lingo, called going t–s up!
@Ron,
All correct, except the Pelosi business. CalTrans managed rebuilding that bridge, not Washington. I expect that CalTrans got all it could from Congress and milked the event for all it was worth. However, at that time Nancy Pelosi wasn’t house speaker, and in fact wasn’t even Majority Leader or whip.
I’m sure she did what she could to get funds, but it’s not like she just crooked her little finger and the billions came pouring out.
I remember having ridden on that road during a trip to California in 1958 with my folks, back before it was an Interstate and was the only real “freeway” south of the Bay Bridge in the East Bay; the Macarthur came later.
It (880, not the Macarthur) needed replacement.
So far as your prescription you’re right; trucks are supposed to know the clearances on bridges they intend to cross. Unfortunately “supposed” apparently didn’t work this time.
You’re right. Ahnold was in charge in Kalifornia at the time.
They should build a supplemental bridge for I-5 traffic leaving the old ones for local traffic, transit, bikes and pedestrians – as being proposed in the “Common Sense Alternative”.
A local bridge a quarter mile upstream from the collapsed Skagit River Bridge will carry I-5 traffic while the collapsed bridge, built in the 1950s with weaker steel members than the Columbia River Bridges, is being repaired.
Actually, the Riverside Drive bridge in Mount Vernon was built in 2003. And I bet that for at least the next several months, Riverside Drive is going to be a traffic nightmare as it is the closest alternative route to I-5; it like the I-5 bridge is only four lanes, with a standard bike lane and sidewalk on each side. However it does not have any height restriction as it is of a modern concrete beam and girder construction, like nearly all modern road bridges are (and a significant number of MAX bridges…)
I agree that the Skagit River, and Columbia River, situations are apples and oranges; the Skagit River bridge was brought down by an oversized load clipping an overhead structural support causing the bridge to fail; this was well documented that the bridge did not have redudant structural support and one failure could cause total failure. Which is exactly what happened. The Columbia River’s issues are much more extensive and complex; and only adding to it is the insistence of certain Portland “stakeholders” demanding that their light rail lobbyists get a “return on investment” in favor of election donations. If bridge/user safety is the #1 consideration, then the easiest way to gain nearly 100% support is to drop the light rail, drop the greenways and wind turbines and art and anything OTHER than just a bridge. We have a perfectly good design just six miles to the east of a sleek, slender, effective bridge called the Glenn Jackson Bridge. Just replicate it – and nothing more.
Protecting A bridge superstructure with a radar warning system is a good idea but a less sophisticated but effective solution would be to install better signage and a robust steel portal frame replicating minimum bridge clearances at least a quarter mile prior to reaching the bridge.
“If our critical infrastructure is not designed to withstand wayward vehicle strikes, then something is seriously wrong. ”
I guess the World Trade Center designers were really at fault for not designing the buildings to stand up against an airplane strike, eh?
Seriously, there’s always SOME level of wayward vehicle strike — in this case, a massively overheight, substantially overweight truck plowing through girders at high speed — which will knock down anything. Building bunkers is not the answer.
Regulating truckers *should* be the answer. You don’t see trains going down routes which they don’t have clearance for, because trains are regulated properly. And trucks aren’t.
If our political system is too broken to regulate truckers properly, then Jim Howell’s solution is the right one:
“a robust steel portal frame replicating minimum bridge clearances at least a quarter mile prior to reaching the bridge. “
“This is going to play absolute hell with Canada-US West Coast trade, lots of which is food. Hothouse tomatoes and peppers from BC are going to be lots more expensive next winter if they don’t get it done before that time. ”
Pffft. Ship it by rail like they did in the 1900s. Refrigerator cars are well-developed tech and BNSF’s refrigerator shipping network is actually pretty well developed.
” Hothouse tomatoes and peppers from BC are going to be lots more expensive next winter if they don’t get it done before that time. ”
Now just try to picture how much BC produce there is, in the whole grocery section ;)
Probably there will be a bigger dent in the number of RV drivers from BC.
A couple of notes:
1) There’s plenty of cropland around Vancouver, and elsewhere in BC. The climate is colder, but local produce is available.
2) Canada, like here, is perfectly capable of importing produce from elsewhere–much of which will arrive by ship or rail, not by truck from the US.
@Ron, Scotty, Nathanael,
You can all scorn as you wish, but if you’ll search the attics of your minds you’ll remember that from about October until mid-April the only even slightly ripe tomatoes and peppers in Northwest stores, except cherry and and Campari tomatoes from Mexico, are from BC Hothouse. The rest are those faintly pink baseballs from Florida.
Of course it’s not the end of the world that we may not get to eat reasonably palatable tomatoes next winter, but from BC’s point of view things are much dicier. If the road isn’t serviceable by that time the price of fresh produce from the south will be higher for everyone north of Mount Vernon.
Scotty’s right that BC can import its produce from elsewhere, but right now most comes from California in the summer and Mexico in the winter. On I-5. In trucks. That’s because it’s cheaper from California and Mexico when available than it is from Chile or Australia.
And, “No”, Nathanael, it won’t be arriving in reefers. There aren’t enough in service to make much of a dent in the refrigerated traffic on I-5. Now it’s conceivable that BNSF might do a trailer lift shuttle from South Seattle, but there isn’t a huge amount of capacity north of Everett.
According to WSDOT, service may be restored in a few weeks: http://www.kgw.com/news/Temporary-bridges-planned-for-fallen-I-5-209012141.html