Old photos show flaws in steel of collapsed Minnesota I-35W bridge

News Type: Event — Seeded on Sun Mar 23, 2008 2:43 PM EDT

Article Source: The Minneapolis Star Tribune

us-news, ntsb, bridge-safety, minnesota-bridge-collapse, state-of-us-infrastructure

Two crucial gusset plate connections on the Interstate 35W bridge were visibly deformed at least four years before the structure collapsed, according to photographs newly released by the National Transportation Safety Board.

The NTSB s Office of Highway Safety confirmed Friday that the bowing of steel gusset plates depicted in the June 2003 photos is part of the investigation into why the bridge collapsed last Aug. 1.

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Dr. Diane Wakat, PhD's Column, All of Newsvine
Groups: Science And Technology
Regions: Minneapolis/Saint Paul

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3.6

{"commentId":1611386,"authorDomain":"drdianewakat"}

Dr. Diane Wakat, PhD

The deformed plates were located in the bridge's U-10 connections -- nodes of connecting beams that federal investigators believe were among the first points of failure.

The photos came to light last week when the NTSB released more than 100 pages of new information from its investigation.

This is distressing news, indicating the NTSB's and inspector's disbelief that any US bridge might fail - until one did with devastating consequences.

{"commentId":1611386,"threadId":"238933","contentId":"1385254","authorDomain":"drdianewakat"}

1 vote

#1 - Sun Mar 23, 2008 2:45 PM EDT

{"commentId":1611720,"authorDomain":"jtrax"}

Grayfox

It is my impression that additional weight was added to this bridge (the one that collapsed in 2007). I am curious as to the margins allowed in the engineering of these structures when originally built and whether or not these margins are re-engineered following the addition of weight in later years. I am concerned that the bridges across this country are not being re-engineered following the addition of significant weight and we can expect future casualties as a result of this oversight.

It seems to me that immediate corrective action is simple. First look at the bridges that have had the greatest weight increases since the last time they were engineered or re-engineered. These bridges should either be closed immediately or have the majority of the un-engineered weight removed pending re-engineering. Then, these un-engineered bridges should be re-engineered and corrective structural changes made before reopening or adding back the additional weight. Finally, there needs to be legislation passed making it a violation of laws to construct or modify any structure for public use without proper engineering.

{"commentId":1611720,"threadId":"238933","contentId":"1385254","authorDomain":"jtrax"}

2 votes

#2 - Sun Mar 23, 2008 4:55 PM EDT

{"commentId":1612004,"authorDomain":"drdianewakat"}

Dr. Diane Wakat, PhD

Grayfox

Your comments and suggestions go straight to the heart of the matter: bridges upon which more weight has been added should be considered unsafe until proven otherwise. Who will make this happen?

{"commentId":1612004,"threadId":"238933","contentId":"1385254","authorDomain":"drdianewakat"}

1 vote

#3 - Sun Mar 23, 2008 6:53 PM EDT

{"commentId":1612436,"authorDomain":"jtrax"}

Grayfox

Criminal charges against those guilty of negligence and civil trials with large penalties brought by those who lost loved ones should get someone's attention for starters. I believe that there is precedence for criminal negligence charges being brought against engineers. Although there does not appear to be any court action at this time plaintiffs are most likely awaiting the final results of investigations.

{"commentId":1612436,"threadId":"238933","contentId":"1385254","authorDomain":"jtrax"}

1 vote

#4 - Sun Mar 23, 2008 9:43 PM EDT

{"commentId":1613809,"authorDomain":"azsky13"}

azsky13

Although there does not appear to be any court action at this time plaintiffs are most likely awaiting the final results of investigations.

There are two separate groups of plaintiffs who are indeed, waiting.

{"commentId":1613809,"threadId":"238933","contentId":"1385254","authorDomain":"azsky13"}

2 votes

#4.1 - Mon Mar 24, 2008 11:22 AM EDT

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Do You Trust the Bridges You Drive Across?	azsky13	Mon Mar 24	13
Pre-Collapse Photos Show Bends on Bridge	Associated Press	Sun Mar 23	0
Minn. Bridge Similar to I-35W Closed	Associated Press	Thu Mar 20	3
Officials Quickly Close Steel Bridge in Minnesota When Problems Found	The New York Times	Sun Mar 23	3

DR. DIANE WAKAT, PHD

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Old photos show flaws in steel of collapsed Minnesota I-35W bridge

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