Engineers blame shifting barriers, not overtopping
Tags: engineering, levees, floodwallsFrom "Engineers: New cause of New Orleans flood":
Much of the city flooded not because water rushed over the tops of levees, but because two of the storm barriers that ring New Orleans actually shifted and then collapsed, a team of independent engineers said Friday.
The preliminary analysis contradicts initial reports by the U.S. Army Corps of Engineers, which said water may have pushed over the top of the levees, eroding the earthen embankments that support the flood walls.
The independent engineers said the shifting of the barriers was understandable and did not assign blame or speculate about design flaws that the storm surge from Hurricane Katrina may have exposed.
"Levees tend to be built in very difficult situations on poor site conditions because you're essentially turning marshy land into land you can stabilize and do things on," said civil engineering professor Raymond Seed, who led a team from the University of California at Berkeley.
The California team worked with the American Society of Civil Engineers and Army engineers for several days this week before releasing the findings. More research is planned.
And, the Army Corps of Engineers says:
Soil giving way beneath the flood walls, causing the walls to collapse, was "certainly a possibility," said Paul Mlakar, a senior research scientist with the Corps.
See also:
Soil heaves, structural problems caused flooding, not overtopping?
