基于AE传播规律监测急倾煤层掘进期动力现象

Monitoring and Measuring Dynamic Phenomenon of Gateway Driving in Steep Inclined Seam Based on AE Transmission Law

为了考察急倾斜煤层巷道掘进过程中动力现象的声发射监测效果,对声发射在煤岩体内的传播规律进行了理论分析,使用AEF-2型便携式声发射仪对东林煤矿井下煤层内的声发射传播规律进行了现场试验,得出了声发射信号的振幅随传播距离的增大呈指数衰减关系,且衰减系数约为0.314 1。据声发射传播规律巷道掘进过程中的动力现象进行了跟踪监测,监测结果表明：当实际监测的振幅衰减系数与回归分析得出的衰减系数差距较大时,AE监测到的振幅衰减曲线上会出现异常点;当监测曲线出现异常点时,即为发生动力现象的位置大多集中在掘进面再向前掘进4~6m。利用声发射传播规律对动力现象进行监测,可实现动力灾害的超前预测。

In order to investigate the acoustic emitting monitoring and measuring effect of the dynamic phenomenon during the inclined seam geteway driving,the paper had a theoretical analysis on the transmission law of the acoustic emitting in the coal and rock mass.The AEF-2 mode portable acoustic emitter was applied to the site trial on the acoustic emitting and transmission law in the coal mass of Donglin Mine.With the transmission distance increased,the amplitude of the acoustic emitting signal would be an attenuation relationship of the index.The attenuation coefficient would be 0.314 1.According to the transmission law,a tracing monitoring and measuring was conducted on the dynamic phenomenon during the gateway driving process.The monitoring and measuring results showed that when there would be a big difference between the attenuation coefficient and the transmission law attenuation coefficient,there would be a abnormal point in the AE amplitude attenuation curve.When the abnormal point appeared in the monitoring and measuring curve,the location of the dynamic phenomenon to be occurred mostly would be at 4~6 m area in front of the gateway driving face.The application of the acoustic emitting and transmission law to the monitoring and measuring of the dynamic phenomenon had obtained good monitoring and measuring effects and could have a advanced prediction of the dynamic phenomenon.