准东二矿巨厚煤层首采面合理推进速度研究

Study on Reasonable Advancing Speed of the First Mining Face ofExtremely Thick Coal Seam in Zhundong No.2 Coal Mine

针对冲击地压矿井回采工作面合理的回采速度问题,以准东二矿巨厚煤层首采工作面为研究背景,通过理论分析与数值模拟软件结合现场微震数据的方法,深入研究了工作面合理的推进速度。研究结果显示:随着工作面的推进,超前支承压力峰值逐步增大,应力集中现象明显,应变能密度随之逐渐增加。随着推进速度的增加,峰值应力呈现出显著的非线性递增趋势。应变能密度峰值与推进速度呈正相关关系。推进速度越快,工作面冲击危险性指数逐步上升,当达到8.0 m/d时,指数异常增加,工作面冲击危险性较强,但速度提升至5.6 m/d时,差异变化并不明显,经过数值模型分析回采速度可提升至5.6 m/d。1101工作面回采阶段实测微震监测数据,分析均速2.45 m/d、3.10 m/d与4.78 m/d相关微震能量,表明在工作面回采过程中,覆岩相对稳定,在最大开采速度4.78 m/d的情况下,可以进行提升开采速度至5.6 m/d。研究结果为提升巨厚煤层首采面冲击地压矿井产能提供了科学依据。

In response to the issue of reasonable mining speed of the mine working face in the case of rockburst,this paper studies deeply into the reasonable advancing speed of the working face,taking the first mining face of extremely thick coal seam in Zhundong No.2 Coal Mine as the background,and by adopting theoretical analysis and numerical simulation software in combination with the field microseismic data.The findings show that:With the advance of the working face,the peak value of the advanced support pressure gradually increases,and the stress concentration is obvious,resulting in a gradual increase in strain energy density.With the increase of the advancing speed,the peak stress presents a significant nonlinear increasing trend.The peak strain energy density is positively correlated with the advancing speed.The higher the advancing speed,the greater the shock hazard index of the working face,especially when it reaches 8.0m/d,the index increases abnormally,and the shock hazard of the working face is strong;but when the speed increases to 5.6m/d,the variation difference is insignificant,and the mining speed can be increased by 5.6m/d through numerical model analysis.According to the microseismic monitoring data measured during the mining stage of the 1101#working face,and the analysis of relevant microseismic energy at the uniform velocity of 2.45 m/d,3.10 m/d and 4.78 m/d,it indicates that the overlying rock is relatively stable during the mining of the working face,and the mining speed can be increased to 5.6 m/d in the case of a maximum mining speed of 4.78 m/d.The findings provide a scientific basis for improving the productivity of the coal mine with rock burst in the first mining face of extremely thick coal seam.