Research on modelling of spatial dynamic structural mechanics and spatio-temporal evolution of coal mine stopes

Zhi-Jie Wen

doi:10.17559/tv-20150427175109

Abstract

Original scientific paper Major hazardous accidents in coal mines are basically attributable to a lack of understanding of or the failure to establish a complete spatial structural mechanical model of the stope during the course of exploitation, as well as of the spatial movement over time caused by the mining itself, mining at the wrong time, as well as improper roadway maintenance and advance of the work face. To efficiently study and analyze the mechanism behind major stope disasters, a method based on monitoring the stress and displacement of stopes was adopted to deduce the process whereby the overlying strata fracture, and a method of ascertaining stope stability based on qualitative identification of the dynamics was further proposed. The study found that the stability of stopes during the process of mining the face can be divided into two stages: (1) Unstable stage: i.e. the distance the work face has advanced Lx width of work face L0. These research results provide a basis for reasonable determination of a space-time relationship for the mining process.

Highlights

It is necessary to establish scientifically and accurately the relationship between the spatial fracture forms of surrounding rocks and the stress field of the rocks surrounding coal mine stopes in engineering practice based on specific situation of coal seams and mining conditions, and propose a corresponding motionspatiotemporal effect, laying a basis for mitigating accidents and environmental disasters during the process of advancing the face and tunnelling, and during preparation for tunnel stoping in adjacent stopes and the process of stopping
The results of investigations into several major accidents in China show that the range of strata movement connected with accidents exceeds the range of what would generally be considered the "basic roof" (6 to 8 times the stope height) in the direction of thickness, and exceeds the range adjacent to the upper and lower tunnels of the work surface in the level direction, namely, strata movement should be the focus for controlling the inner roof panels of the stope, while the timing of strata movement should be considered for controlling disasters around the stope
Given the engineering characteristics of continual advance of coal stopes, it is necessary to correctly point out that with the advancing of the stope, both the spatial structure and the stress field of the coal stope undergo constant development and change, which are wellregulated and governed by the stratum movement

Summary

Introduction

It is necessary to establish scientifically and accurately the relationship between the spatial fracture forms of surrounding rocks and the stress field of the rocks surrounding coal mine stopes in engineering practice based on specific situation of coal seams and mining conditions, and propose a corresponding motionspatiotemporal effect, laying a basis for mitigating accidents and environmental disasters during the process of advancing the face and tunnelling, and during preparation for tunnel stoping in adjacent stopes and the process of stopping. Based on spatial structural mechanical modelling of stopes, the relevance of characteristic fracture movements of overlying strata and the evolution of mining stress fields in stopes was studied, and a feasible mining space-time relationship for coal mines was proposed, providing new approaches and methods for quantitative research into coal mines.

Results

Conclusion