Deformation and Failure Characteristics of the Undermining Coal Seam Roadway Under Opposite Mining and Tunneling of Close Coal Seam Group
Aiming at the mutual disturbance problem between 10205 working face and its lower 20203 working face during the downward mining process of close coal seam in Longhua coal mine.Theoretical analysis,FLAC3D numerical simulation and other methods were used to study the characteristics of the stress distribution in the mining field of the 10205 working face,the distribution law,the depth of the bottom plate damage,and the support parameters of the 20203 roadway,etc.,and to investigate the influence of the 10205 working face in the 1-2 seam on the stability of the construction of the 20203 roadway of the 20203 working face in the 2-2seam during the process of the mining back.The results show that,at the initial stage of 20203 roadway excavation in the lower coal seam,the roadway is only affected by the stress perturbation brought by its own excavation,and the roadway peripheral rock stress shows a uniform and stable change as a whole.When the length of the upper seam working face is 325 m,the maximum damage depth of the upper seam working face bottom plate is 20 m.The peripheral rock stress of the lower seam back-mining roadway does not change much compared with the period of digging,and the back-mining roadway is kept stable in the process of mining the upper seam.At the same time,the main stresses in 10205 working face are transmitted to the bottom plate in a diffuse manner,the largest main stress diffusion area is in the stress increase area,while the smallest main stress diffusion area is in the stress decrease area,and both of them are similar in the distribution law,and the stress concentration occurs in the stress increase area.According to the theoretical model of slip line,the maximum damage depth of the upper seam bottom plate is 18.6 m,which is close to the numerical simulation results.The results of the study are helpful to ensure the safety of the downstream mining of the close coal seam and the stability of the support of the roadway in back mining.
close seamopposite mining and tunnelingroadway supportfloor failure lawroadway stability
万方数据
维普
