Soil tests indicate that a soft, spongy layer of swamp peat underneath the 17th Street canal floodwall was the weak point that caused soil to move and the wall to breach during Hurricane Katrina, an engineer who has studied the data says.What effect will this have on insurance claims? On possible litigation against the Corps or the contractor? Blageur speculates that these questions will be in the courts for years.
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The contractor who built the 17th Street Canal reported problems drilling the sheet pilings in the soil. Segments of the wall leaned slightly when the concrete was poured, according to a legal ruling in a contract dispute over the matter. An administrative law judge ruled that was due to the unusual bracing system used to build the structure rather than unexpected soil conditions.
Bea said that while the investigators have theorized the Corps missed the peat layer in soil tests before the wall was built, that data they now have shows the peat would be hard to miss.