A comparative study between large deformation finite element and limit equilibrium methods of slope stability analysis

Saha, Biswajit Kumar (2017) A comparative study between large deformation finite element and limit equilibrium methods of slope stability analysis. Masters thesis, Memorial University of Newfoundland.

[English] PDF - Accepted Version Available under License - The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. Download (7MB)

Abstract

Limit equilibrium (LE) methods are widely used to analyze the stability of earthen slopes. In the LE methods, resistance along the critical failure plane is compared against the sum of the driving forces resulted from different sources such as gravity and earthquake. The ratio between the resistance and driving force is expressed as factor of safety (Fs). The Fs does not provide any information about deformation behaviour although it could be a design criteria. The mechanism of failure and deformation behaviour can be better modeled using recently advanced numerical techniques such as finite element (FE) methods. Although FE modeling techniques have been improved significantly over the last few decades, most of the current FE methods have been developed for small strain analysis in Lagrangian framework. However, in large-scale landslides, significant shear displacement occurs along the failure plane that cannot be modeled using the conventional Lagrangian-based FE techniques because of numerical issues resulting from significant mesh distortion. In the present study, the Coupled Eulerian-Lagrangian (CEL) approach in Abaqus is used to simulate large deformation behaviour of slope failure. Analyses are also performed using the limit equilibrium methods in SLOPE/W software. The present study focuses on two critical factors: earthquake loading and retrogression in sensitive clay slopes. Comparison of different methods of analysis shows that Abaqus CEL can successfully simulate the failure process from small- to large-deformation levels. Based on a comprehensive parametric study, different types of failure as reported in the literature from post-failure investigations could be simulated, which cannot be done using the LE method or Lagrangian-based FE technique.

Actions (login required)

View Item