Structural, Material, and Geotechnical Solutions to Levee and Floodwall Construction and Retrofitting - Physical Modeling

This report presents the evaluations of two retrofitting methods for levees and floodwalls. Physical modeling in a centrifuge was used in testing the effectiveness of floodwall panel joint caps or clips and a gap filler. The clip connectors were U-shaped reinforced polymers with various thicknesses and strengths, mounted over the joints between I-wall panels. The expectation was that the clips would improve the overall performance of the wall if the panels were connected and behaved as a single unit. The second retrofit method evaluated what was called the gap filler, which was a mixture of sand and bentonite. The mixture was entrenched along the levee along the riverside of a sheet wall. The belief was that as water pressure on the wall caused the wall to move or rotate toward the landside of the levee the filler would drop down into the gap and expand, thus reducing seepage under the wall. All test models were constructed, then placed on the centrifuge platform and subjected to various flood conditions representing those experienced during Hurricane Katrina.