特厚煤层下山煤柱区巷道冲击危险性实时监测预警研究

Real-time monitoring and early warning of rock burst risk in dip coal pillar area of extra-thick coal seam

通过理论研究和现场实测,研究了特厚煤层煤巷下山发生冲击地压的原因和冲击危险性实时监测预警方法。研究结果表明,下山煤柱区地层结构与开采形成的"不对称工字形"覆岩空间结构是造成异常应力集中的根本原因。通过建立下山煤柱区上覆岩层空间结构模型和走向支承压力估算模型,得到了煤柱区域支承压力分布规律,该支承压力分布区域的移动和量值的变化是导致下山煤柱区巷道发生冲击地压的主要原因。提出了震动场-应力场一体化监测预警下山煤柱区巷道冲击地压方法,应用微地震系统监测覆岩断裂运动,通过微震冲量快速预测"冲击危险区",通过钻孔应力动态预警"冲击危险程度",实现了下山煤柱区巷道"区域与局部相结合"和"冲击危险区与冲击危险程度相结合"的冲击地压实时监测预警。经千秋煤矿21采区下山煤柱区现场应用,效果良好。

By means of theoretical analysis and field observation, the occurrence cause of rock burst in dip coal pillar area of extra-thick coal seam, and the real-time monitoring and early warning technology were studied in this paper. The results show that the strata structure of dip pillar area and the asymmetric I-shaped spatial strata structure formed by excavation are primary causes of abnormal stress concentration. By establishing spatial strata structure model and strike abutment pressure calculation model in the dip pillar area, the stress distribution law of the overlying strata in the pillar area was obtained. It is revealed that the stress distribution area movement and value variation are the main causes of rock burst in the dip roadway near the coal pillar. In addition, the integrated monitoring and early warning of rock burst in dip coal pillar area were proposed, that is, the strata fracturing and movement were monitored by microseismic system, and the risk region of rock burst was predicted by index of microseismic momentum, while the risk level of rock burst was further predicted by borehole stress maters. Thus, the monitoring and pre-warning system of ＂regional monitoring and prediction and local monitoring and early warning＂ were established. The research achievements were applied to the dip coal pillar area of No.21 mining district, Qianqiu coal mine successfully.