Drainage-weathering damage rule of thick coal seam and micro-blasting control technology of coal wall rib spalling

In order to solve the serious problem of coal wall rib spalling in water-rich thick coal seams in Zhuxianzhuang Coal Mine after being drained and weathered, the methods such as numerical simulation, theoretical analysis and field measurement were used to analyze the damage mechanism of coal-rock mass of being drained and weathered. In this paper, the development process, influencing factors and control mechanism of coal wall rib spalling in drainage thick coal seam were studied, and the micro-blasting technology was put forward to control spalling.The research shows that under the condition of drainage and continuous ventilation, the coal-rock mass undergoes physical and chemical effects, its strength, friction and cohesion decrease, and vertical fissures are abundant. The coal wall rib spalling is affected by the fissures and residual water-conducting channels in the coal mass, the stress of the coal-rock mass, the influence of mining, the mining space and the stop mining time. It is believed that micro-blasting can effectively improve the occurrence of coal wall rib spalling by establishing the network structure of cracks, enhancing the cohesion and friction between blocks, and improving the stress environment of coal wall. The specific technological parameters are put forward and applied to 880 working face, which can effectively control the coal wall rib spalling of thick coal seam with drain.