Meikuang Anquan (Apr 2023)
Zonal prevention and control technology for rock burst in asymmetrical pressure-relief working face under protective layer
Abstract
In order to effectively prevent and control the rock burst in the asymmetric pressure-relief working face under protective layer, taking the 0291 working face of Tangshan Coal Mine as the engineering background, the theoretical analysis and numerical simulation methods were adopted, and the potential influence factors of rock burst in the working face and the occurrence area were analyzed. The results show that the mining depth, bursting tendency of coal seam and its roof, residual pillars in upper protective layer and goaf of the coal seam and thick and hard roof are the potential influence factors of rock burst. Before mining, under the influence of the residual pillars in the protective layer and goaf, the stress of the two tunnels in the 0291 working face shows an asymmetrical distribution. The high stress area of the return airway is mainly located below the cutting line and stop line of the 0250 goaf, while the high stress area of the transportation roadway is mainly located below the cutting line of the 0251 goaf. The working face had obvious zonal characteristics. In the early stage of mining, the advanced stress in surrounding rock of transportation roadway is higher than that of return airway. It is necessary to strengthen the monitoring of transportation roadway and take pressure-relief measures in time. When the working face enters the lower part of 0251 goaf, the surrounding rock stress of the transport roadway decreases rapidly, and the prevention focus should be transferred from the transport roadway to the return air roadway. According to the results of numerical simulation, the impact zones can be divided and the prevention and control measures of impact zones in the mining were put forward. Field monitoring results show that the measures taken can effectively reduce the occurrence of rock burst.
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