Coal Engineering ›› 2022, Vol. 54 ›› Issue (8): 84-90.doi: 10.11799/ce202208016

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Analysis of Stress Evolution Law of Un-mined Coal Pillar in Working Face under Superimposed Stress Environment

  

  • Received:2021-12-22 Revised:2022-04-11 Online:2022-08-15 Published:2022-09-06

Abstract: In view of the technical problem that under the action of mining-excavation superposition stress, the catastrophic instability of surrounding rock in the withdrawal channel is frequently caused by unreasonable support timing, which seriously affects the safe and efficient withdrawal of fully mechanized equipment, this paper takes the withdrawal channel of I030901 working face in Qipanjing Coal Mine as the research background, establishes the mechanical model of residual pillar in the five stages of stress evolution of residual pillar, and puts the measured parameters into the formula to determine the initial disturbance range of superposition stress in theory as 102.48m. On this basis, the FLAC3D numerical calculation model is established to invert the stress propagation law in front of the working face and the superposition effect mechanism of the vertical stress above the residual pillars. The results show that the simulation results are consistent with the theoretical results. Taking into account the influence of working procedures and production conditions, the wealth coefficient is 1.5, and it is finally determined that before the width of remaining pillars is less than 150m, the withdrawal channel is advanced reinforced in the field. The field test results show that the influence range of advanced stress is about 100 m, and the simulation results are consistent with the theoretical calculation results.

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