采用本质安全型微震监测系统,在煤矿深部采场布置了微震监测台网,对测区内的爆破波信号进行了原位采集试验。提出了地震波“穿层”和“顺层”传播的概念,得到了地震波振幅的衰减曲线和回归方程。试验结果表明,振幅随传播距离的增大呈幂级衰减;“穿层”传播的衰减速率远大于“顺层”传播;地震波“穿层”传播200m后,振幅损失严重,初始到时点开始模糊,需对到时进行补偿后方可参与震源定位。该结果进一步证实了该监测台网布置的合理性(测点平均问距60m)。微震监测和音频电透视结果证明,岩体破裂区和富集水区的存在加速了波的衰减。这些定性和定量的研究结论将为进一步研究微震监测台网布置的优化方案提供理论依据,也可为其他地球物理监测或探测手段提供实测的基础参数。
Based on a microseismic monitoring system, a field monitoring experiment on the wave propagation from an explosive source was conducted in a deep coal mine. The results show that seismic attenuation is exponentially related to the propagation distance. After about 200 m of oblique propagation crosses the rock beddings, the amplitude of the seismic wave is significantly reduced; and the first arrival point is not clear at all and there needs to be compensation prior to source location. The experiment also shows that microseismic monitoring with 60 m geophone intervals is good for mine-scale studies. Microseismic monitoring, together with the result of audio perspective drawing indicates that fractured and water-charged regions significantly accelerates seismic attenuation. The results provide an objective theoretical basis for further studying the optimization of seismic monitoring network arrays, which can support other monitoring tools in underground coal mining.