Failure Characteristics and Control Technology of Surrounding Rock in Deep Coal Seam Roadway with Large Dip Angle under the Influence of Weak Structural Plane

Xueyuan Qi,Wentian Mi,Ruijie Wang

doi:10.1155/2020/6623159

Abstract

In view of the unsymmetrical large deformation and failure phenomenon that often occurs after the excavation and support of the roadway in steep seam with weak structural plane, the numerical simulation analysis and engineering application research on the deformation and failure characteristics of its surrounding rock are carried out. The results show that the key position of asymmetric deformation is near the weak structural plane and the intersection of the roadway section and the inclined direction of the rock. On this basis, the “unsymmetrical high prestress pressure relief coupling control technology” is put forward, and the industrial test is carried out. The practice shows that the unsymmetrical coupling support technology can not only effectively solve the differential deformation of the surrounding rock but also ensure the coordinated deformation of the support structure and the surrounding rock, thus improving the overall stability of the roadway, greatly reducing the repair rate of the roadway, and saving the support cost.

Highlights

In recent decades, with the gradual depletion of China’s shallow coal resources, coal mining has completely transited to the deep mining stage
Some of them have studied the occurrence of rock strata; for example, Wu et al [3] and others established and analyzed the mechanical model of steep seam by means of theoretical analysis, similar simulation, and numerical simulation and pointed out that the difference of rock stratum structure on two sides of roadway in large inclined coal seam is the fundamental reason for asymmetric failure of roadway
Failure Characteristics of Asymmetric Large Deformation e research results of many scholars on deep coal seam roadway with large dip angle show that the lithology of roof, two sides, and floor of such roadway are often different, and the strata are easy to slide and move along the weak structural plane. e main deformation characteristics are as follows [3,4,5,6,7,8]: (1) e influence of the difference of surrounding rock structure: due to the difference of surrounding rock structure on both sides of the roadway, the stress of the whole roadway is asymmetric. e side with weak rock structure is easy to lose stability before the surrounding rock on the other side under high stress, which makes the deformation and failure of the whole roadway have typical asymmetry

Summary

Introduction

With the gradual depletion of China’s shallow coal resources, coal mining has completely transited to the deep mining stage. 2. Failure Characteristics of Asymmetric Large Deformation e research results of many scholars on deep coal seam roadway with large dip angle show that the lithology of roof, two sides, and floor of such roadway are often different, and the strata are easy to slide and move along the weak structural plane. To understand the mechanism of unsymmetrical large deformation and failure of deep and steep seam roadway under the influence of weak structural plane, taking Dayuan coal 1201 working face as an example, the numerical simulation software FLAC3D is used to simulate the deformation and failure of surrounding rock of roadway under the condition of no support and original support, respectively. The staggered sliding interval of the roof strata of the roadway is mainly concentrated near the right shoulder of the roadway

Analysis of the Mechanism of Asymmetric Large Deformation and Failure

Findings

Control Technology of Unsymmetrical Large Deformation Failure