基于弹性波传播理论的微地震技术被用于煤矿水力压裂破裂监测、动力灾害预警等。煤系地层是典型的层状介质，弹性波在层状煤岩中传播受到介质不均匀性和层面反射、折射的影响，其传播规律和衰减特性研究仍需完善。利用脉冲发生器产生稳定的震源激励，通过DS2系列全信息声发射信号分析仪对弹性波在层状煤岩、纯煤、纯砂岩中传播的衰减特性进行了试验研究。结果表明：相同试验条件下，组合煤岩体中弹性波传播的幅值衰减随着传播距离、震源激励频率（FREQ）的增加而减小。层状煤岩中，弹性波传播的幅值衰减先快后慢，煤层中的衰减梯度较岩层大，呈现出阶段性的衰减特征；弹性波信号的质心频率发生频移，峰值频率出现分级现象。煤层与岩层联结面处介质层之间结合的紧密程度是影响弹性波衰减的主要因素，紧密程度越高则幅值衰减越小；煤层硬度越高弹性波信号的初始幅值越大，低频率范围内（FREQ≤4 MHz）层状软煤层中弹性波幅值较层状硬煤层衰减快；层状煤岩中震源激励频率与弹性波传播距离呈负相关依赖，近距离范围内的低频信号的传播距离较高频远，幅值衰减梯度大。层状煤岩中弹性波幅值衰减梯度随品质因子增大逐渐减小，品质因子由小到大依次为软煤、硬煤、砂岩。研究成果可为微地震拾震器布置方法的优化提供理论基础。

The micro-seismic technology based on elastic wave propagation has been applied to the monitoring of hydraulic fracturing in coal mine and the early warning of dynamic disasters. As a typical stratified medium,the propagation of elastic waves in the stratified coal rocks is affected by the heterogeneity of the media and the reflection and refraction of the layers. Therefore,the study on the propagation law and attenuation characteristics of the elastic waves still needs to be improved. The attenuation characteristics of elastic wave propagating in layered coal,pure coal and pure sandstone are studied by using DS2 series full information acoustic emission signal analyzer. The results show that under the same test conditions,the attenuation of amplitude of elastic wave signals generated by different groups of coal rocks decreases with the increase of source distance and source excitation frequency. In layered coal rock,the attenuation of the amplitude of elastic wave signal is first fast and then slow,and the attenuation gradient in the coal seam is larger than that in the rock layer,showing a periodic attenuation characteristic. The centroid frequency of the elastic wave signal is shifted,and the peak frequency is graded. The main factor affecting the attenuation of elastic wave is the degree of tightness between the coal seam and rock layer,the higher the degree of tightness,the smaller the attenuation; secondly,the higher the hardness of the coal seam,the greater the initial amplitude of the elastic wave signal will be. In the low frequency range (FREQ≤4 MHz),the elastic wave amplitude in the layered soft coal seam decayed faster than the hard one; in layered coal rock,the source excitation frequency and elastic wave propagation distance are negatively correlated and dependent,the low-frequency signals in the short range have a farther propagation distance and higher amplitude attenuation gradient than the high-frequency signals; thirdly,the attenuation gradient of the elastic wave amplitude gradually decreases as the quality factor increases,and the quality factor from small to large is soft coal,hard coal,and sandstone. The research results can provide a theoretical basis for the optimization of the arrangement method of the micro-seismic pickup.