A comparative slope stability analysis of sheet pile supported I-wall in New Orleans, Louisiana with sheet pile penetrating into sand layer

Abstract

Computer modelling and stability analyses of the New Orleans I-walls with and without the consideration of gap formation has drawn significant attention of the engineering community during the post Katrina period. In addition, when the sheet pile penetrates into sand layer, seepage becomes an integral part of the stability analysis. Basic guidelines have been developed for the analysis of this problem by other researchers and documented by the U.S. Army Corps of Engineers (USACE). However, the inherent complexity of the problem and uncertainties associated with the choice of analysis methods warrant for further investigation of this problem in detail so that more useful insights can be gained. In this paper, a comprehensive analysis of this complex coupled problem of seepage and stability of a typical New Orleans I-wall is presented using different limit equilibrium methods of slope stability analysis. Useful comparisons are made between the analyses results and methodologies. The authors believe that the findings of this study will enhance the understanding of the behaviour of the I-wall sheet pile system subjected to seepage forces, when different limit equilibrium methods of analyses are invoked.

Keywords:

• I-wall
• slope stability
• seepage
• gap
• New Orleans
• limit equilibrium

Acknowledgements

The authors would like to express their sincere thanks to the Engineer, Research and Development Center (ERDC) of U.S. Army Corps of Engineers, Vicksburg, Mississippi for making available the computer program ‘Stability with Uplift (2002)’ based on Method of Planes for slope stability analysis. The computing resources provided by Jackson State University are gratefully acknowledged. The support by the Department of Homeland Security (DHS) through the Department of Energy Oak Ridge National Laboratory is also gratefully acknowledged. The conclusions in this paper are solely those of the authors and do not necessarily reflect the opinions or policies of DHS. Endorsement by DHS is not implied and should not be assumed.