Slope Stability Analysis under Complex Stress State with Saturated and Unsaturated Seepage Flow

Zongyuan Ma,Faning Dang,Xiaoliang Yao,Caihui Zhu,Guanglei Zhang

doi:10.1155/2021/6637098

Zongyuan Ma, Faning Dang + Show 3 more

Open Access

https://doi.org/10.1155/2021/6637098

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Abstract

Seepage flow is one of the primary factors that trigger slopes and landslides’ failure. In this study, the slope stability under saturated or unsaturated conditions is analyzed. The influence of a complex stress state on the slope stability with the saturated or unsaturated seepage flow is proposed in this paper. Firstly, an elastoplastic constituted model for the soil under a complex stress state is established and as a user subroutine of the finite element method code of FLAC. Secondly, the 2D and 3D problems of slope stability influenced by the saturated or unsaturated seepage flow are analyzed via the finite difference method with the influence of the complex stress state. Finally, the influence of the intermediate principal stress and the saturated or unsaturated seepage flow on the slope stability is analyzed in this study.

Highlights

Soil is a typical polyporous and multiphase material on our planet
Many true triaxial tests have verified that the intermediate principal stress has specific influences on mechanical behavior and strength characteristics of soil, and this problem was summarized by Ma et al [4,5,6]
strength reduction method (SRM) is a method that the original shear strength parameters of soil mass are divided by the strength reduction factor (SRF) to bring the slope to the point of failure

Summary

Introduction

Soil is a typical polyporous and multiphase material on our planet. soils usually contain soil particles, pore water, and pore air. The variation of the water content in soil (due to underground water, seepage flow, or rainfall) is a vital influence factor for soil slope safety and stability. SRM is a method that the original shear strength parameters (e.g., cohesion c and friction angle φ) of soil mass are divided by the strength reduction factor (SRF) to bring the slope to the point of failure. A model test for soil slope failure due to the seepage flow is proposed by Jia et al [3]. According to the model test and field investigation, the stability analyses of an embankment slope and a high loess slope are performed with FLAC, where the complex stress state, groundwater level variation, and seepage flow are taken into account. The problems of fractured wells in a reservoir of hydrogen and carbon based on a dual-porosity medium model were discussed by Xue et al and Liu et al, respectively [20, 21]

Theory and Method

Nψ sin 2 φ α2

A Direction of sliding

Findings

Conclusion