A Study on the Distribution and Evolution of Mining Induced Stress under the Condition of Multiple Mining

Abstract

Mining of multiple coal seams and sections is the main method adopted by the vast majority of coal mines in China at present. However, because of multiple mining, the damage and deformation of surrounding rock increases a lot when comparing with single coal seam mining. Moreover, the normal production and safety of coal mine may also get affected. In multiple coal seam mining, the distribution and alteration of mining induced stress are the main reasons of the above problems. In this study, based on the geological conditions and mining design of Weijiagou Coal Mine, the mining induced stress under multiple mining conditions were studied. According to the failure state, the surrounding rock was divided into the damaged zone, plastic zone and elastic zone. The distribution and range of mining stress in different areas were calculated by utilizing Strain Softening Model. Based on FLAC3D numerical simulation, the distribution and change of mining induced stress along the strike and dip direction of coal seam were obtained. By using the Logarithmic function and the Fourier function, the empirical formula of the relationship between the maximum mining stress in front of the working face and the advancing distance of the working face is obtained. This study provides a reference for the design of roadway support and mining face under multiple mining conditions.