Determining the Critical Slip Surface of Three-Dimensional Soil Slopes from the Stress Fields Solved Using the Finite Element Method

Yu-Chuan Yang,Hui-Ge Xing,Xing-Guo Yang,Jia-Wen Zhou

doi:10.1155/2016/7895615

Abstract

The slope stability problem is an important issue for the safety of human beings and structures. The stability analysis of the three-dimensional (3D) slope is essential to prevent landslides, but the most important and difficult problem is how to determine the 3D critical slip surface with the minimum factor of safety in earth slopes. Basing on the slope stress field with the finite element method, a stability analysis method is proposed to determine the critical slip surface and the corresponding safety factor of 3D soil slopes. Spherical and ellipsoidal slip surfaces are considered through the analysis. The moment equilibrium is used to compute the safety factor combined with the Mohr-Coulomb criteria and the limit equilibrium principle. Some assumptions are introduced to reduce the search range of center points and the radius of spheres or ellipsoids. The proposed method is validated by a classical 3D benchmark soil slope. Simulated results indicate that the safety factor of the benchmark slope is 2.14 using the spherical slip surface and 2.19 using the ellipsoidal slip surface, which is close to the results of previous methods. The simulated results indicate that the proposed method can be used for the stability analysis of a 3D soil slope.

Highlights

Landsides are a common worldwide geological disaster that can cause heavy casualties and huge economic losses [1,2,3]
Limit equilibrium method is the most popular method in assessing slope stability [8, 9]; this method cannot provide the relationship of internal stress and strain in rock or soil slopes, and they do not always provide unique factors of safety owing to the inherent assumptions of limit equilibrium analyses [10]
The slope stability problem is an important issue for construction safety and long-term operation

Summary

Introduction

Landsides are a common worldwide geological disaster that can cause heavy casualties and huge economic losses [1,2,3]. Limit equilibrium method is the most popular method in assessing slope stability [8, 9]; this method cannot provide the relationship of internal stress and strain in rock or soil slopes, and they do not always provide unique factors of safety owing to the inherent assumptions of limit equilibrium analyses [10]. Finite element method is widely used in slope stability analysis because the method can calculate the stress and strain based on the nonlinear constitutive relation of rock and soil mass [2, 11, 12]. This method cannot consider both the stress and moment equilibrium [13]. The strength reduction method can determine the failure zone and the safety factor [2, 14, 15], it is difficult to link the finite element calculation results with the traditional safety factor of the slope

Methods

Results

Conclusion