Coal Engineering ›› 2022, Vol. 54 ›› Issue (4): 68-73.doi: 10.11799/ce202204013

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Study on spatial structure change of overlying rock in working face under different boundary conditions and its influence on strong mining pressure

  

  • Received:2021-10-22 Revised:2021-11-08 Online:2022-04-15 Published:2022-07-06

Abstract: In the process of deep mining, with the advance of the working face under different mining conditions, the working face will experience different goaf boundary conditions. Based on the theory of overlying rock spatial structure, the overlying rock structure is called "O" type and "S" type under the condition of “one side goaf” and “two sides goaf” boundary condition, and the overlying rock structure is defined as "O-S" type in the process of their transformation. In order to study the spatial structure change of different overlying rocks in working face and its influence on rock burst, based on theoretical calculation, microseismic monitoring and on-line stress monitoring, the different overlying rock structure types formed during mining in 30202 working face of Muduchaideng Coal Mine are analyzed, and the characteristics of mine pressure appearance and the distribution of rock burst risk area under different overburden spatial structures are analyzed. The results show that under the condition of "one side goaf", the risk of impact in the mining process is small, in the process of changing the boundary conditions from "one side goaf" to "two sides goaf", the impact risk of the goaf side and its end coal in the adjacent working face is obviously higher than that in the previous stage, under the condition of “two sides goaf”, the distribution area of the influence range of inclined supporting pressure on the side of return air roadway is the risk area of rock burst. The research results can be used for reference for the analysis of stope pressure characteristics, roof control and roadway support design under different mining conditions.

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