Rensselaer engineer joins team to study levee failures in New Orleans


Troy, N.Y. A Rensselaer Polytechnic Institute engineer is headed to New Orleans as part of an expert team investigating levee failures in the aftermath of Hurricane Katrina. The researchers, who are funded by a special exploratory grant from the National Science Foundation (NSF), plan to take lessons from the disaster and apply them to the design of levee systems across the country.

Tom Zimmie, professor and acting chair of civil and environmental engineering at Rensselaer, was recruited for the project by Ray Seed, professor of civil engineering at the University of California, Berkeley. Seed has brought together a group of nationally recognized experts with extensive experience in the field of natural disasters. The team will be collaborating with the U.S. Army Corps of Engineers and the American Society of Civil Engineers.

"Civil engineers have been warning of the possibility that a hurricane might breech the levees in New Orleans for years, with the potential for catastrophic flooding," Zimmie says. "There are hundreds of miles of similar levees across the United States, and we need a better understanding of how to design these systems to protect people from future disasters."

In the coming weeks, the team will investigate a number of aspects of the New Orleans levees, including the damage caused by wind-driven waves and overtopping, the effectiveness of emergency "patches" put in place by responders, and the decision process behind the levee configuration, according to Zimmie. Some levees did not fail, and these provide a further opportunity to gain insight into the design of current and future levee systems.

Zimmie has extensive experience with all types of engineered structures, but most recently his research has focused on how explosions affect dams, pipelines, and other entrenchments -- including levees. He and his colleagues at Rensselaer are specifically interested in understanding how to design levees to withstand a possible terrorist attack.

"The most critical time for embankments and levees is during flood conditions," Zimmie says. "The Mississippi River floods every spring near New Orleans, and the city is obviously not evacuated. Just imagine if there was a terrorist attack during that time."

Using a 150 g-ton centrifuge, Zimmie tests models of structures to simulate their response to different levels of explosions. The goal is to find out how much explosive it would take to breach a dam or levee in a certain location, with certain soil characteristics, to help engineers design structures to withstand such blasts. Zimmie's work at Rensselaer's Geotechnical Centrifuge Research Center is part of NSF's nationwide Network for Earthquake Engineering Simulation (NEES). For more about NEES, including a three-minute video presenting an overview of the centrifuge, visit:

NSF is funding the New Orleans project through its Small Grants for Exploratory Research program, which supports small-scale, exploratory, high-risk research, including rapid-response teams that can investigate areas affected by disasters while evidence and memories are still fresh. For more about NSF's response to the hurricanes, visit:

The team is also funded by UC Berkeley-based Center for Information Technology Research in the Interest of Society, the California Department of Water Resources, and the Sacramento District Army Corps of Engineers.

Source: Eurekalert & others

Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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