H-Adaptive Updated Lagrangian Approach for Large-Deformation Analysis of Slope Failure

Abstract

This paper presents a novel approach to improving our understanding of complicated slope failure mechanisms that can occur in strain-softening material as well as to evaluating the accompanying postfailure deformation of slopes. Three cutting-edge technologies were integrated into one numerical analysis tool: (1) a large-deformation analysis using the updated Lagrangian formulation, (2) a stable numerical algorithm for the solution of progressive failure in strain-softening materials, and (3) an h-adaptive mesh refinement algorithm. The significance of this study is mainly in the adoption of a proper numerical discretization for cases of slope failure in which large deformations lead to distortion of the finite-element mesh, unreliable results, and lack of convergence. The h-adaptive remeshing technique is used to refine the finite-element mesh around the area of large shear strain, thereby improving the accuracy and convergence of numerical solutions. This study presents a method that can be used to simulate the failure of slopes with highly strain-softening materials that experience large deformations, so that postfailure deformations can be determined. The validity of the method is demonstrated through simulation of the failure and deformation of a highway embankment, and comparing the predicted deformations with the observed record.