基于微震成像的采煤工作面应力异常监测

为了实现对深井采煤工作面的冲击地压灾害预防，采用微震走时成像技术，监测采煤工作面的应力异常.根据系统要求布置传感器台网，实现工作面全覆盖；采用层状模型分析地震波传播路径，计算地震波传播速度，利用子空间分阶段求解的方法进行反演，实现对监测区域的地震波走时层析成像；结合地震波速度和岩石所受应力的关系，达到研究采煤工作面应力异常的动态分布及变化特征的目的.试验结果表明：工作面推进时，煤层顶板高应力异常达到最大，工作面前方的高应力异常区动态变化范围较大，工作面后方存在较稳定的地震波低速异常，利用微震成像技术可以有效地监测地震波速度异常区域的范围及变化特征.
Abstract: The microseismic velocity tomography technique was used to monitor the stress anomaly of coal face in order to achieve the prevention of rock burst hazards in deep coal mining face. Layout of sensors network was conducted according to the system requirements in order to achieve full coverage of the coal face. The seismic wave propagation route was analyzed by layer model, and the seismic wave velocity was calculated. The three-dimensional tomography of the seismic wave travel time in the monitoring area was realized by using the subspace interdependent method. The dynamic distribution and variation characteristics of stress anomaly in coal mining face were analyzed combined with the relationship between the seismic wave velocity and rock stress. Results show that the high abnormal stress of coal roof is maximal when the working face arrived. The dynamic range of high abnormal stress in front of the working face is larger than other areas. There is a relative stable seismic wave low velocity abnormal area at the back of working face. The microseismic tomography technique can be used to effectively monitor the change and influence range of seismic wave velocity anomaly areas.