A New Closure to Slice Model for Slope Stability Analysis

Tianyun Liu,Chongbin Zhao,Yunling Duan

doi:10.4236/eng.2012.47052

Abstract

This paper presents a new closure to slice models for evaluating slopes. The discussion is based on the minimal inter-slice action (MIA) hypothesis, which results in a new slice model without including artificially adjustable parameters. It has been realized that the new slice model predicts the minimum value of the safety factor, while all other slice models available always overestimate the value of the safety factor. Moreover, the gravity moment of each slice is found to be opposite to the overturning moment, which is different from the existing knowledge. In particular, the new slice model overcomes the situation where different assumptions of the inter-slice force function will give different safety factors to the same slope. The related numerical examples indicate that the new slice model can serve as a reliable tool for investigating geotechnical slope stability.

Highlights

An accurate model for evaluating slope stability can provide considerable help for mitigating slope geological hazards [1]
The discussion is based on the minimal interslice action (MIA) hypothesis, which results in a new slice model without including artificially adjustable parameters
It has been realized that the new slice model predicts the minimum value of the safety factor, while all other slice models available always overestimate the value of the safety factor

Summary

Introduction

An accurate model for evaluating slope stability can provide considerable help for mitigating slope geological hazards [1]. The selection of the inter-slice force function depends heavily on intuition and experience [3,5,8,9,10,11,12] These assumptions are inconsistent with the experimental observations due to the fact that the normal and shear stresses are both non-uniform on the interface of blocks in contact [13]. We propose the minimal inter-slice action (MIA) hypothesis, which embodies an optimal closure to the slice model. With this new closure, the slice model has no artificially adjustable parameters for the selection of inter-slice force functions. The numerical results show that the new slice model predicts the minimum value of the safety factor, while all other existing slice models commonly overestimate the stability of slopes

Existing Slice Models

Minimum Inter-Slice Force

Minimum Moments

Numerical Examples

20 Boundary

Conclusion