基于微地震监测的近水平厚煤层上覆岩层运动规律研究

Research on microseismic monitoring and movement law of overlying strata in near horizontal thick coal seam

为了研究煤矿井下工作面采动对上覆岩层运动规律的影响,以察哈素煤矿近水平厚煤层31313工作面为工程背景,分别从微震事件整体分布范围、岩层中的不同高度分布、微震频次与周期来压关系等方面对岩层移动规律,以及采动影响下煤体破裂范围进行研究,并运用数值模拟软件3DEC进行验证。研究结果表明:发生在不同高度层位的破裂事件具有不同的周期性,一般高位岩层的周期包含若干个中位岩层的周期;采场上方岩层18 m内为直接顶,18~60 m内为基本顶;由微震事件分析得到的周期来压步距是实际来压步距的2倍;采用微地震监测技术可真实有效反演采场上覆岩层的运动规律。研究结果能为微地震技术判识岩层运动规律提供参考。

In order to study the influence of mining on the movement law of overlying strata in underground coal mine,taking the near horizontal thick coal seam 31313 working face of Chahasu Coal Mine as the engineering background,the stratum movement law and coal rock rupture range under the influence of mining have been studied from the aspects of the overall distribution range of microseismic events,the distribution of varied heights in the stratum,and the relationship between microseismic frequency and periodic weighting,numerical simulation software 3DEC was used to verify the results.The results show that the fracture events at different altitude have different periodicity,the high-level period is composed of several midlevel periods;the direct roof is located within 18 m above the stope,and the basic roof is located within from 18 m to 60 m;the periodical weighting step obtained by the analysis of microseismic event is twice the actual periodical weighting step;the movement of overlying rock stratum in stope can be truly and effectively inverted with the help of microseismic monitoring technology.The research results can provide a reference for microseismic technology to identify the law of rock strata movement.