The influence of working face pitch angle on the bearing characteristics of support and surrounding rock in fold structure area

HUANG Wenbo; GUO Jun; FENG Guorui; BAI Jinwen; NING Ruifeng; WEN Xiaoze; WANG Zi; YANG Longlong; WU Xueyao

doi:10.13247/j.cnki.jcumt.20240609

Abstract：In the mining process of long-wall fully mechanized mining face in coal mine,it is easy to induce rock burst accidents when the positive angle and negative angle of coal seam in the fold structure area change with each other.In order to explore the influence of geological structure transformation on the working face,based on SOLIDWORKS,Rhino-Griddle and FLAC3D software,a model of inclined long-wall mining in fold structure area under the support of hydraulic support with similar basic action and support principle to actual working condi-tions was established.On this basis,the stress and displacement evolution characteristics of hydraulic support and surrounding rock under the continuous change of coal seam dip angle in the fold structure area were studied.The results show that at the same horizontal elevation in the fold structure area,the stress evolution trend of the surrounding rock is opposite during the downward and upward mining.When the inclined direction of the coal seam is constant,the change of the dip angle has little effect on the surrounding rock.In anticline and syncline mining,the peak point of advance stress at the axis is the farthest from the working face,which is 2.01 and 1.90 m respectively.At the same time,the monitoring of coal wall should be strengthened during axis mining.When the anticline-transition-syncline stage changes,the distance between the peak point and the working face will usher in a sudden increase.The change of the inclined direction of the coal seam has a significant influence on the horizontal displacement of the coal wall within a certain range,which is intensified during anticline min-ing and weakened during syncline mining.When the inclined direction of the coal seam is changed,the stress of the top beam is more complicated than that when the inclined direction is unchanged,and the compressive stress of the front top beam is larger during the transition stage.