花岗岩破裂过程声发射主频多元前兆信息识别  

Identification of multiple precursor information of acoustic emission dominant frequency in the process of granite failure

作　　者：张艳博[1] 于光远[1] 田宝柱[1] 刘祥鑫[1] 梁鹏[1] 

机构地区：[1]华北理工大学矿业工程学院,河北省矿业开发与安全技术重点实验室,河北唐山063009

出　　处：《采矿与安全工程学报》2017年第2期355-362,共8页Journal of Mining & Safety Engineering

基　　金：国家自然科学基金项目(51374088,51174071,51574102);河北省自然科学基金项目(E2012209047)

摘　　要：通过开展自然花岗岩单轴压缩声发射实验,获取岩石变形破裂全过程声发射波形信号,基于频谱分析理论,分析花岗岩破裂过程声发射主频演化规律,研究花岗岩变形破裂的主频多元前兆特征。研究结果表明:最高频、最低频、敏感主频出现率和主频变异系数4个参数能够从不同角度反映岩石破裂过程,适合作为岩石失稳预测的主要参数;岩石破裂前,最高频密集出现接近110 k Hz的主频值,最低频由接近0.4 k Hz低频值密集出现的活跃期转入极少接近0.4 k Hz低频值出现的稳定期;35~45 k Hz频段的主频值对此类花岗岩内部裂纹积聚最为敏感,加载后期此频段主频出现率突现大幅度下降并转入平静;主频变异系数在岩石破裂前密集出现较大幅度上升点。经统计分析,4个参数对岩石破裂前兆的响应时间从早到晚依次为最高频、最低频、敏感主频出现率和主频变异系数。不同参数能够从不同角度反映岩石内部裂纹演化过程,鉴于岩石变形破坏的复杂性,建议对各参数进行联合分析,为岩石破裂灾变提供更可靠的预警信息。The uniaxial compression acoustic emission experiment of natural granite was carried out to receive the waveform signal of acoustic emission in the whole process of granite deformation and fracture. Based on spectrum analysis theory, the evolution law of dominant frequency of acoustic emission was analyzed during granite fracture, and multiple premonitory characteristics of dominant frequency of granite deformation and fracture were studied. The results have shown that the four main parameters of the highest frequency, the lowest frequency, occurrence rate of sensitive dominant frequency, and coef- ficient of variation of dominant frequency can reflect the rock failure process from different angles and are suitable parameters for rock instability prediction; before rock fracture, the highest value of domi- nant frequency intensively approaches 110 kHz, and the lowest frequency is transformed from the active period during which the value of the lowest frequency intensively approaches 0.4 kHz into the stable period during which the value of the low frequency rarely approaches 0.4 kHz; the dominant frequency value at 35-45 kHz is most sensitive to the accumulation of cracks inside the granite, and the occurrence rate of dominant frequency in this band greatly reduces and is transferred to peaceful emergence at late loading; the dominant frequency variation coefficient has significantly rising points before rock failure. Statistical analysis has found that the successive order of the four parameters responding to rock failure are the highest frequency, the lowest frequency, occurrence rate of sensitive dominant frequency, and coefficient of variation of dominant frequency. Different parameters can reflect the internal crack evolution of rock from different angles. In view of the complexity of rock failure, it is recommended that multiple parameters should be jointly analysed to provide more reliable early warning information for the monitoring of rock failure.

关 键 词：花岗岩 声发射 主频 多元前兆 

分 类 号：TD353[矿业工程—矿井建设]