ASCE Responds to the I-35W Bridge Collapse

In response to the catastrophic I-35W bridge collapse in Minneapolis, ASCE is playing a significant and proactive role in the review and analysis of one of our nation's tragic infrastructure disasters. Shortly after the collapse occurred, ASCE immediately began to provide technical and authoritative information to the media and has developed a dedicated area on the ASCE website to providing further resources and related information. The website will continue to evolve over the coming days and should serve as an excellent resource to keep members up to date and help in answering any general questions that may be received. ASCE members can take pride in knowing that ASCE and the civil engineering profession continue to play such a key role in understanding and responding to natural and man-made disasters and in improving the resilience of our nation’s critical infrastructure.

Thursday, August 2, 2007

I-35W Bridge Collapses During Afternoon Peak Hour

August 1, 2007--You can read about the I-35W bridge collapse at most of the major network websites (See links at right).

Here is an FHWA Press Release dated Aug. 2, 2007:

Here is a security camera video of the collapse:

Here are photos of the collapse:

Diagramming the collapse:

Problems with Minnesota bridge noted twice since 2001:

Here is the MnDOT 2001 Report:

A 2001 study conducted by the Minnesota Department of Transportation found "several fatigue problems" in the bridge's approach spans and "poor fatigue details" on the main truss. The study suggested that the design of bridge's main truss could cause a collapse if one of two support planes were to become cracked, although it allowed that a collapse might not occur in that event. But, the study concluded, "fatigue cracking of the deck truss is not likely" and "replacement of the bridge ... may be deferred."

Two years ago, the U.S. Department of Transportation's National Bridge Inventory database said the bridge was "structurally deficient." The Minneapolis Star Tribune quoted Jeanne Aamodt, a spokeswoman for the Minnesota Department of Transportation, as saying the department was aware of the 2005 assessment of the bridge. The bridge received a rating of 4 on a scale of 1 to 10. A bridge receives a rating of 4 when there is "advanced section loss, deterioration."

About 100,000 cars a day travel over the bridge, according to the Minnesota Department of Transportation. See full story:

FEMA: News Releases

Department of Homeland Security News News & Press Releases

National Weather Service Current Advisories for the US