Stress Heterogeneity and Slip Weakening of Faults under Various Stress and Slip

Longjun Dong,Qiaomu Luo

doi:10.1155/2020/8860026

Abstract

The rock mass of deep underground engineering is in the complex geological environment of high stress, high temperature, and high water pressure. In the process of deep mining and underground space development, the fault-slip seismic source may cause engineering accidents with strong destructive capacity. An in-depth study of fault slip characteristics is very important in the engineering disaster prevention and control. In this paper, a slip model was established based on the finite element software ABAQUS. A total of 20 loading ways are set for various stress and slip, which include the possible slip conditions of fast slip, slow slip, and critical state. By comparing the simulation diagrams and collecting the data of representative grid elements on the loading surface and slip surface, the slip characteristics such as stress heterogeneity under different loads are analyzed. The results show that the increase of slip velocity will make the slip unstable, and the local stress and deformation will become irregular. The spatial stress heterogeneity and the resulting local high working rate will lead to the decrease of the friction strength and the slip weakening. These results can provide some useful suggestions for the research of seismic activities caused by fault slip.

Highlights

Nowadays, due to the saturation of the space capacity, the development of underground space has gradually become the focus of the world [1]
In order to study the impact of stress on slip and friction, we conducted a numerical simulation based on the finite element software ABAQUS
On the basis of the 12 loading ways performed in the experiment, 8 new loading ways are set for small slip and large slip

Summary

Introduction

Due to the saturation of the space capacity, the development of underground space has gradually become the focus of the world [1]. It is necessary to analyze the underground rock mass whether it is developing underground space or deep mining [3, 4]. The deep underground engineering rock mass is in a complex geological environment of high geostress, high temperature, and high water pressure. With the increase in depth and ground stress, mining conditions have become more complex and the rock will be unstable [5], leading to frequent engineering accidents. The engineering accidents such as rock bust [6] caused by fault-slip seismic sources due to larger magnitude and stronger destructive capacity, resulting to serious casualties and economic losses [7, 8]. The corresponding source types include cavity collapse type and pillar bursts type [9]

Methods

Results

Conclusion