巨厚煤层开采微震响应特征及地表沉陷演化规律研究

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中图分类号：TD324/325 文献标志码：A

Abstract： The large space formed by the mining of extremely thick coal seams makes the movement process of overlying strataand the manifestation of mine pressure complex，resulting inunclear characteristicsof field microseismic responses and surface subsidence evolution paterns.To address these problems，the extremely thick coal seam of the Zhundong No.2 MineofCHNEnergy Guoyuan Power Co.，Ltd.was selectedas the research object.Basedon field measurementsand analyses，the study investigated the characteristics of microseismic responsesand the evolution patern of surface subsidence under the influence of mining activities in extremely thick coal seams，and revealed their correlation with the mining rate.The results showed that： ① under the influence of mining in extremely thick coal seams，the distribution range of microseismic events was wide.The distribution range ahead of the working face for microseismic events of different energy levels reached up to 20 times the mining thicknessthe concentrated vertical distribution range above the working face was about 5.5 times the mining thicknes，and the concentrated distribution range on both sides of the working face reached 2.8 times the mining thickness. ② Medium-energy microseismic events accounted for the largest proportion among all events，and the microseismic events in diferent key strata showed a distribution patern of "low-energy events at lower horizons and high-energy events at higher horizons". ③ The surface subsidence exhibited a "funnelshaped" distribution along the inclination direction of the working face，with the maximum subsidence being approximately half of the mining thickness During diferent mining stages，the maximum subsidence position was always located in the middle region of the working face and showed a "lagging" feature relative to the working face position. ④ The mining rate was strongly correlated with the evolution of microseismic activity and surface subsidence.As the mining rate increased，the distribution range of microseismic events on both sides of the working face gradually decreased， while that above the coal seam expanded.Meanwhile，the energy and frequency of microseismic events，as wellas the variation rateof surface displacement，all showed nonlinear increasing trends.

Key words： extremely thick coal seam mining; microseismic response; surface subsidence; spatiotemporal evolution of microseismicity; mining rate

0引言

煤炭开采引起的工作面矿压显现等问题与覆岩移动有关，掌握覆岩内部运动规律对防治巷道变形、工作面异常来压等具有重要指导意义[1-2]。（剩余14343字）