|The storm surge slammed a three-story casino barge into this reinforced concrete building across U.S. 90 in Biloxi, Miss. (Photo by the University at Buffalo, State University of New York)|
The tragedy of Hurricane Katrina is inescapable, but the Multidisciplinary Center for Earthquake Engineering Reasearch, Buffalo, N.Y., is working to ensure that critical lessons are learned from the storm. The center has sent one team to New Orleans, where members found evidence of levees failing before they reached design capacity. Another team investigating post-storm conditions along the Mississippi coast marveled at the destructive power of a wall of water three stories high.
The center team sent engineers with a broad spectrum of expertise to the New Orleans on October 3. Staying in Baton Rouge along with most of the evacuees, the group made the now 2.5-hour, 70-mile commute every day through October 9 to study engineered structures. One notable observation is the lack of hurricane damage. "There was very little damage due to wind, but flooding destroyed the city," says Gilberto Mosqueda, assistant professor in the Dept. of Civil, Structural and Environmental Engineering at the State University of New York at Buffalo. He maintains that failure in long-term planning doomed the city. "This could have been prevented had the proper resources been allocated to the levees," he says. "Its not like were dealing with a 30-ft wall of water like in Mississippi," he says. New evidence points to the levees failing because of intrinsic flaws, not overtopping, he says. "The soil embankments were pushed back 30 ft in some areas," says Mosqueda.
The famous image of high-rise buildings with their windows blown-out that created speculation of tornadoes proved to have a much simpler explanation. "When we looked upwind, we found buildings with gravel roofs that pelted the buildings downwind," say Mesquaeda.
The destruction of the Mississippi and Alabama coasts resulted from the destructive force of a 30-ft storm surge. The center sent personnel on September 6 to investigate the damage and see what lessons could be learned. "Our main objective was to look at structural damage and identify similarities to past earthquake damage," says Mosqueda. The ultimate goal of the research is to find a way to make structures multi-hazard resistant, says Mosqueda.
The researchers immediately noticed similarities between seismic and storm surge damage. Bridge spans below the surge line were unseated. This sheer-induced damage is common in earthquakes. Restraints have been used in quake prone areas to minimize this effect and the center hopes to identify an existing restraint method that would work for both, says Mosqueda.
Instead of shifting bridge spans a few feet, the powerful surge threw members several hundred yards. Mosqueda wants to calculate the force needed to move so much reinforced concrete so far, helping to measure the actual size of the force that leveled much of Gulf Coast.
The centers research will be welcome beyond the academic community. "If there were any sort of prescribed method, we would certainly include it in our designs," says Nick Amerger, division maintenance engineer, Alabama Dept. of Transportation, Mobile Division. The center also will evaluate the sustainability of lifelines during the storm. "We want to see which hospitals were able to stay open and which could hold backup power," says Mosqueda.
The center will make preliminary data available immediately and then will spend the next year modeling the storm and conducting experiments, says Mosqueda.