Even things built 100 yrs ago have to pass today's safety regulations. 50 isn't old for a steel structure but I guess that's immaterial since the update said... a truck ran into it.
Scary stuff. Like Walt said.. glad it wasn't higher and the river wasn't deeper.
Thousands of bridges deemed structurally sound are of outdated design...
Thousands of bridges similar to I-5 span at risk of freak accident due to outdated designs
Saturday, May 25,`13 — Thousands of bridges around the U.S. may be one freak accident or mistake away from collapse, even if the spans are deemed structurally sound.
The crossings are kept standing by engineering design, not supported with brute strength or redundant protections like their more modern counterparts. Bridge regulators call the more risky spans “fracture critical,” meaning that if a single, vital component of the bridge is compromised, it can crumple. Those vulnerable crossing carry millions of drivers every day. In Boston, a six-lane highway 1A near Logan airport includes a “fracture critical” bridge over Bennington Street. In northern Chicago, an I-90 pass that goes over Ashland Avenue is in the same category. An I-880 bridge over 5th Avenue in Oakland, Calif., is also on the list. Also in that category is the Interstate 5 bridge over the Skagit River north of Seattle, which collapsed into the water days ago after officials say an oversized truck load clipped the steel truss.
Public officials have focused in recent years on the desperate need for money to repair thousands of bridges deemed structurally deficient, which typically means a major portion of the bridge is in poor condition or worse. But the bridge that collapsed Thursday is not in that deficient category, highlighting another major problem with the nation’s infrastructure: Although it’s rare, some bridges deemed to be fine structurally can still be crippled if they are struck hard enough in the wrong spot. “It probably is a bit of a fluke in that sense,” said Charles Roeder, a professor of civil and environmental engineering at the University of Washington.
While the I-5 truck’s cargo suffered only minimal damage, it left chaos in its wake, with two vehicles catapulting off the edge of the broken bridge into the river below. Three people involved escaped with non-life threatening injuries. The most famous failure of a fracture critical bridge was the collapse of the I-35W bridge in Minneapolis during rush hour on Aug. 1, 2007, killing 13 people and injuring more than 100 others. The National Transportation Safety Board concluded that the cause of the collapse was an error by the bridge’s designers — a gusset plate, a key component of the bridge, was too thin. The plate was only half of the required one-inch thickness. Because the bridge’s key structures lacked redundancy, where if one piece fails, there is another piece to prevent the bridge from falling, when the gusset plate broke, much of the bridge collapsed.
Mark Rosenker, who was chairman of the NTSB during the I-35W bridge investigation, said the board looked into whether other fracture critical bridges were collapsing. They found a few cases, but not many, he said. “Today, they’re still building fracture critical bridges with the belief that they’re not going break,” Rosenker said. Fracture critical bridges, like the I-5 span in Washington, are the result of Congress trying to cut corners to save money rather than a lack of engineering know-how, said Barry B. LePatner, a New York real estate attorney and author of “Too Big to Fall: America’s Failing Infrastructure and the Way Forward.”
Last edited by waltky; 05-25-2013 at 10:48 PM.
Temporary bridges planned for fallen Skagit River bridge...
Temporary bridges planned for fallen I-5 in Wash.
May 26,`13 -- Federal investigators used 3D laser scans Sunday to study what remained of a collapsed Washington state bridge as Gov. Jay Inslee announced temporary spans will be installed across the Skagit River within weeks - if plans go well.
Sunday's announcement comes a day after the chairwoman of the National Transportation Safety Board called last week's Interstate 5 bridge collapse a wake-up call to the state of safety of the nation's infrastructure and the Saturday destruction of a highway overpass in Missouri that was struck by a cargo train. The Washington state collapse, caused by a semi-truck carrying an oversize load striking the bridge, fractured one of the major trade and travel corridors on the West Coast. The interstate connects Washington state with Canada, which is about an hour north of Mount Vernon, where the bridge buckled.
After the collapse, semi-trucks, travel buses and cars clogged local bridges as traffic was diverted through the small cities around the bridge. But overall, traffic was flowing as well as expected during the holiday weekend. "We're going to get this project done as fast as humanly possible," Inslee, a Democrat, said Sunday. "There are no more important issue right now to the economy of the state of Washington than getting this bridge up and running." Inslee said he hopes the temporary spans, each with two lanes for northbound and southbound traffic, will be finished in about three weeks' time or about mid-June. The spans will be pre-built and trucked to Mount Vernon. The state plan also calls for a permanent span to be built and competed by autumn, officials said.
Officials say there are remaining inspections to the spans left standing to make sure they are safe to use. The federal government is expected to cover 100 percent of the costs of the temporary bridge and 90 percent the replacement, said state Transportation Secretary Lynn Peterson. The temporary span would be able to carry regular-sized cargos as well as cars. The speed limit would be lower than the 60 miles per hour allowed previously. Barges arrived this weekend at the river with equipment ready to remove the mangled steel, pavement and cars in the water. On Thursday, a semi-truck carrying an oversize load clipped a steel truss, starting the collapse of the span and sending cars and people into the cold river waters, authorities said. The three people in the cars survived with non-life threatening injuries.
An investigation by The Associated Press suggests similar accidents could happen elsewhere. Thousands of bridges around the U.S. are kept standing by engineering design, rather than sheer size or redundant protections. Such spans may be one freak accident or mistake away from collapse. Bridge regulators call them "fracture critical" bridges, because if a single, vital component is compromised, they can crumple. NTSB Chairwoman Debbie Hersman said such bridges and other kinds of bridges around the nation should be looked at. "The wake-up call is really to focus on how important our infrastructure is to our nation, certainly for our commerce and keeping communities vibrant and connected," she said Sunday, adding that when important decisions are made about infrastructure, safety should have "a seat at the table."
Some bridges, like the ones that are on postcards, end up being FAR better taken care of than some bridge in the middle between 'no' and 'where'.
But we know that unsupervised contractors + 'limitless funds' = at standards, if you're lucky.
The ESB is also a business building, which means they probably built it a hell of a lot better than a public building.
Wasn't in the concrete that got hurt or something?
Bridge Collapse A Wake-Up Call...
NTSB says Wash. bridge collapse is wake-up call
May 26, 2013 - Other over-height vehicles had hit the Skagit River bridge before its collapse Thursday.
The collapse of an Interstate highway bridge in northern Washington state is a wake-up call for the entire nation, the chairman of the National Transportation Safety Board says. Investigators need to find out what happened at the I-5 span 60 miles north of Seattle and if it could be repeated at similar bridges around the country, Debbie Hersman said Saturday. "This is a really significant event and we need to learn from it, not just in Washington but around the country," Hersman said after taking a boat ride on the Skagit River below the dramatic scene where a truck bumped against the steel framework, collapsing the bridge and sending two vehicles and three people falling into the chilly water. "At the end of the day it's about preventing an accident like this," she said.
Her team will spend a week to 10 days looking at the bridge, talking to the truck driver whose vehicle hit it, and examining maintenance documents and previous accident reports. Other over-height vehicles struck the Skagit River bridge before the collapse on Thursday, she noted. Investigators are using a high tech 3-D video camera to review the scene and attempt to pinpoint where the bridge failure began. Hersman does not expect the investigation to delay removal of debris from the river or work on a temporary solution to replace or repair the I-5 span. State and federal officials can, and will, work together on the investigation, she said. They'll be watching for safety issues that could affect other bridges. "The results can be very catastrophic," Hersman said. "We're very fortunate in this situation."
While the National Transportation and Safety Board finishes its inspection, state workers will begin removing debris from the river. Next, temporary spans, each with two lanes for northbound and southbound traffic, will be will be installed across the river. It's expected to be finished in about three weeks' time or about mid-June. "We're going to get this project done as fast as humanly possible," Gov. Jay Inslee said. "There are no more important issue right now to the economy of the state of Washington than getting this bridge up and running." Inspectors are working to find out whether the disintegration on Thursday of the heavily used span over the Skagit River, 60 miles north of Seattle and 40 miles south of the Canadian border, was a fluke or a sign of bigger problems. "These things take time. We want to make sure it's done right, done thoroughly," Washington Transportation Department spokesman Bart Treece said.
A trucker was hauling a load of drilling equipment Thursday evening when his load bumped against the steel framework over the bridge. He looked in his rearview mirror and saw the span collapse into the water behind him. Motorists should not expect to drive on I-5 between Mount Vernon and Burlington for many weeks and possibly months, Treece said. Treece asked people to plan for an extra hour to make their way through detours around the collapsed bridge. There are three detour options northbound and two options southbound. About 71,000 vehicles use that stretch of highway every day. Late Saturday morning, traffic was moving freely through the detours. Inslee said it will cost $15 million to repair the bridge. The federal government has promised $1 million in emergency dollars and more money could come later, according to Washington's congressional delegation.
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