DOI: 10.11799/ce202506003
Floor failure characteristics and downward mining feasibility of bottom coal seam under repeated mining in contiguous coal seams
REN Yuqi
LI Yang
LEI Xinghai
Abstract：In order to reasonably demonstrate the downward mining feasibility of the bottom coal seam under the repeated mining in contiguous coal seams,a study of the failure characteristics and downward mining feasibility was conducted based on such engineering background in Qianjiaying Coal Mine,using theoretical analysis,numerical simulation,and on-site detection.Based on the theory of slip line field in coal seam mining floor,the failure depths of the floor were 7.85 m and 4.18 m after the initial and repeated mining of upper coal seams,by optimizing the stress zone of the abutment pressure in front of the coal wall.The bottom coal seam was not affected and maintained good continuity and integrity.The numerical simulation results showed that the fracture number in the floor increased under the influence of the initial and repeated mining of upper coal seams,but the development of fracture depth remained basically unchanged.The fractures were densely developed to the main roof of the bottom coal seam.The GPR on-site detection results showed that the electromagnetic signal distribution of the floor was relatively uniform after the initial and repeated mining of upper coal seams,and there were no abnormal phenomena such as large-scale fluctuations of electromagnetic signals.The integrity of the No.9 coal seam roof can be maintained,and the mining was feasible.
Keywords：contiguous coal seamsrepeated miningfailure depthmining feasibility
Publication Date：2025-06-30
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：7( 17-23 )