花岗岩破裂过程声发射主频多元前兆信息识别

发布时间：2018-04-19 05:04

本文选题：花岗岩 + 声发射　；参考：《采矿与安全工程学报》2017年02期

【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。
[Abstract]:Through the uniaxial compression acoustic emission experiment of natural granite, the acoustic emission waveform signal of the whole process of rock deformation and rupture is obtained. Based on the spectrum analysis theory, the evolution law of the main frequency of acoustic emission in the process of granite rupture is analyzed.The main frequency multivariate precursor characteristics of granite deformation and fracture are studied.The results show that the four parameters, the highest frequency, the lowest frequency, the sensitive main frequency occurrence rate and the main frequency variation coefficient, can reflect the rock fracture process from different angles and are suitable for the prediction of rock instability.At the highest frequency, the main frequency value is close to 110kHz.The lowest frequency is the most sensitive to the accumulation of internal cracks in this type of granite, from the active period of close to 0.4 kHz concentrated low frequency value to the main frequency value of the stable phase 35 ~ 45 kHz, which rarely approaches 0.4 kHz low frequency value.At the later stage of loading, the frequency of the main frequency suddenly decreased and turned to calm, and the coefficient of variation of the main frequency increased by a large margin before the rock burst.By statistical analysis, the response time of the four parameters to the rock rupture precursor is the highest frequency, the lowest frequency, the sensitive main frequency occurrence rate and the main frequency variation coefficient from early to late.Different parameters can reflect the evolution process of rock internal cracks from different angles. In view of the complexity of rock deformation and failure, it is suggested that the parameters should be analyzed jointly to provide more reliable early warning information for rock rupture and catastrophe.
【作者单位】：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;
【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)
【分类号】：TD311

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