Researchers Study Structure of NO Levees

Researchers studying the effects of Hurricane Katrina on the levees of New Orleans used a 150 g-ton centrifuge to model one of New Orleans”s levee sections and the hurricane forces that led to its failure. The goal of the test was to learn how layers of peat and clay beneath the levees might have contributed to the failure.

The centrifuge is part of the National Science Foundation (NSF, www.nsf.gov) George E. Brown, Jr. Network for Earthquake Engineering Simulation (NEES, www.nsf.gov/news/special_reports/nees/index.jsp), an interconnected, nationally distributed system of 15 facilities for studying the effects of full-scale earthquake forces on structures and materials.

Tarek Abdoun of Rensselaer Polytechnic Institute (RPI), who led the levee test as part of the U.S. Army Corps of Engineers Hurricane Katrina Interagency Performance Evaluation Task Force, presented the team”s preliminary findings in New Orleans on March 20 at a public meeting of a National Academies committee that is reviewing the study.

During the experiment, the researchers subjected a scaled-down model of the 17th Street Canal levee in New Orleans —complete with local-source peat — to extreme conditions like those experienced during the hurricane on Aug. 29, 2005. The experiment suggested earth sliding along a weak clay layer that underlies a bed of peat directly beneath the levee helped to bring down the 17th Street structure.

The researchers consider the results to be preliminary and will conduct additional tests in the coming weeks.

In addition to supporting experiments like the RPI centrifuge test, NSF has granted numerous awards to researchers studying the effects of Hurricane Katrina and gathering information that can help prepare for future national disasters.

More information about the RPI study is available in the university press release at news.rpi.edu/update.do?artcenterkey=1418&setappvar=page(1).