Study On Micro-Seismic Activity Of Floor Failure In Mining Face Under Confined Water

With the depletion of shallow coal resources and the increasing depth of coal mining,the phenomenon of coal seam floor sudden water has become more serious and is one of the main factors threatening the safe recovery of mineral resources in China.In the process of coal seam mining,the activation of the fault in front of the mine is induced by the influence of mining,resulting in the destruction of the bottom slab.Therefore,the analysis of the destruction law of the coal seam bottom slab is the key to determine the risk of sudden water in the bottom slab.The paper summarises the results of research on the detection technology of coal seam floor water burst and water prevention and control at home and abroad,and uses the numerical simulation and analysis software RFPA to reproduce the whole process of fault activation during coal seam excavation by using the engineering geology of the 12123 working face and the actual condition of the retrieved coal seam in Pan Er coal mine.The dynamic development law of fracture generation,breeding development and penetration damage is analysed,and the dynamic damage process of fracture generation~development~deformation~damage is obtained for the coal seam floor during the back mining process,and the deformation of the floor shows the change law of compression~expansion~decrease in expansion~stability.The ESG micro-seismic monitoring system was optimised and commissioned at the Pan II mine to monitor the coal seam retrieval process at the working face.Through continuous monitoring of the whole process of coal seam retrieval,the spatial distribution characteristics of the number,energy and density of micro-seismic events during retrieval were summarised and analysed,and the damage pattern of the bottom slab under the influence of faults was obtained.Combining the numerical simulation results with the micro-seismic monitoring results,the damage depth of the coal seam floor was determined to be 27 m,proving the reliability of the numerical simulation in studying the damage pattern of the coal seam floor under the influence of faults and the accuracy and practicality of the micro-seismic monitoring system.The results show that the combination of numerical simulation and micro-seismic monitoring technology is feasible for studying the damage pattern of the coal seam floor under the influence of faults,and that the monitoring of disasters induced during the coal seam re-mining process in the mine area can be used as an effective analysis method to prevent the damage of the floor during the coal seam re-mining caused by faults,and to reduce the losses caused by the sudden water of the coal seam floor.The research results of the paper are of great reference value to other mines in the prevention and control of water in the coal seam floor.Figure[42] Table[7] Reference[79]...