Engineering: November 2008 Archives

The final report put forward by the National Transportation Safety Board on the collapse of the I-35W bridge in Minneapolis has concluded that: (1) the steel gusset plates originally designed in the mid-1960s to reinforce the bridge's joints were half an inch too thin; (2) the probable causes for the collapse were additional modifications to the original design, which added substantial weight to the bridge, and the weight added by construction materials placed on the bridge by a contractor just prior to the collapse. But construction expert Barry B. LePatner says there is more to it than that.

"The NTSB is severely neglecting its duty to protect Americans," says LePatner, coauthor of Structural & Foundation Failures (McGraw-Hill, 1982, coauthored with Sidney M. Johnson, P.E.) and author of Broken Buildings, Busted Budgets: How to Fix America's Trillion-Dollar Construction Industry (The University of Chicago Press, October 2007, ISBN-13: 978-0-226-47267-6, ISBN-10: 0-226-47267-1, $25.00). "By placing the sole blame for the bridge collapse on the gusset plates and the added weight factor, the Board has ignored the inefficiency and irresponsibility among the government agencies responsible for the bridge, which also contributed to the disaster."

For more, see AmericanSurveyor.com.

A second Kaua'i grand jury is looking into potential criminal charges against retired car dealer Jimmy Pflueger over the collapse of the Kaloko Reservoir dam which killed seven people in March 2006.  Pflueger has denied that he altered the century-old earthen dam, causing the deadly breach.  The grand jury heard testimony from several experts, including a former Kaua'i County engineer and a worker from the state Department of Land and Natural Resources.  HonoluluAdvertiser.com writes:

Relatives of the seven victims and several Kaua'i residents, including entertainer Bette Midler, have sued Pflueger for damages they allege were caused by the Kaloko dam breach.  Pflueger, in turn, has sued the state and C. Brewer & Co., the former owner of Kaloko Reservoir, alleging they knew about possible problems with the dam.

Government construction engineering expert witnesses told the National Transportation Safety Board last week that the underlying cause of the collapse of the Interstate 35W bridge in Minneapolis on Aug. 1, 2007, was the gusset plates that were supposed to hold together the bridge's steel beams. The disaster that killed 13 people and injured 145 appears to have been caused by an unusual load of construction equipment stockpiled for a repaving project and errors in the original design of the joints called gussett plates. 

Bruce Magladry, the NTSB's director of the Office of Highway Safety stated that "Had the gusset plates been properly sized, this bridge would still be there."
For more see StarTribune.com.