采动微地震波传播与衰减特性研究

Research on propagation and attenuation characteristics of mining micro-seismic wave

为分析采动地震波煤岩响应及其波场特性,构建顶板岩层和煤层2种传播介质接收采动地震波的多通道微震监测系统,研究2种介质采动地震波的传播和衰减特征。研究结果表明:顶板岩层接收到采动地震波的平均波速、加速度均高于煤层,2种介质中的地震波加速度均与爆破装药量成正相关,与传播距离、介质密度负相关。采动微地震波能量、信号时长随传播距离分别呈指数、线性衰减,近爆心处煤层传播微地震波能量、信号时长均高于顶板,超过一定距离后顶板高于煤层;采动微地震波传播距离有限,顶板的有效传播距离高于煤层,地震波有效传播距离与爆破装药量线性正相关。采动地震波低频部分的品质因子高于高频部分,顶板岩层的品质因子高于煤层。研究成果有助于地震波传播介质选取、检波器布设优化。

This study is aimed to analyze the seismic wave response of coal and rock induced by the mining and the corresponding characteristics of wave field.Multi-channel microseismic monitoring system was installed for monitoring the propagation of the mining seismic wave in the rock roof and coal seam.Then the propagation and attenuation characteristics of mining seismic waves in two propagation media were further analyzed.Research results indicate the average velocity and acceleration of the mining seismic wave received by the rock roof are higher than those received by the coal seam.The accelerations of mining seismic waves in two media were both proportional to the explosive charge,but negatively correlated with propagation distance and medium density.The energy and signal duration of the mining micro-seismic wave showed exponential and linear attenuations with the propagation distance,respectively.The energy and signal duration in the coal seam near the explosive center were higher than those in the roof,while the energy and signal duration in the roof were higher than those in the coal seam after a certain propagation distance.The propagation distance of mining micro-seismic wave was limited,and the effective propagation distance in the roof was higher than that in the coal seam.Meanwhile,the effective seismic wave propagation distance was linearly and positively correlated with the explosive charge.The quality factors of the low frequency part of the mining seismic waves were higher than those of the high frequency part,and quality factors of the rock roof were higher than those of the coal seam.The research results contribute to the selection of the seismic wave propagation medium and optimization of the detector layout.