A comparative slope stability analysis of New Orleans I-wall subjected to hurricane loading

Abstract

There has been a relatively long history of interest in comparing the various methods of slope stability analyses in geotechnical engineering. In the past two years, mainly as a result of the damages to the Hurricane Protection System in the New Orleans, LA area and vicinity due to Hurricane Katrina, the interest in comparing a particular method of slope stability analysis with others has intensified. The Method of Planes (MOP) slope stability analysis was utilized in designing hurricane protection measures in New Orleans and vicinity. Due to unsatisfactory performance of some of the measures during Hurricane Katrina, questions were raised regarding the accuracy and suitability of the MOP slope stability analysis, which is not a total equilibrium method of analysis. Following Hurricane Katrina, an extensive investigation of the performance of floodwalls in the New Orleans area that did not perform satisfactorily, has been undertaken by the U.S. Army Corps of Engineers and others. Extensive studies have also been undertaken to assess the stability of the existing floodwalls for possible future hurricane loading. These studies included the stability investigation of cantilevered sheet pile I-walls during hurricane loading. This paper focuses on the assessment of the MOP stability analysis results for a typical New Orleans I-wall subjected to hurricane loading by comparing these results with those of other popular slope stability analysis based on a limit equilibrium approach. Comparisons between different methods of stability analyses have also been presented by considering the gap formed between the I-wall and the levee fill.