单轴压缩下含断层带花岗岩声发射、微震和电荷感应实验

发布时间：2018-03-14 21:24

本文选题：断层带　切入点：失稳破坏　出处：《地震地质》2017年05期 　论文类型：期刊论文

【摘要】：针对岩样在外载荷作用下失稳破坏前有声发射、微震和电荷等信号的异常变化特性,运用声发射、微震和电荷感应等全波形综合监测设备对含断层带花岗岩在单轴压缩下变形破裂过程的信号进行同步监测。结果表明:含断层带花岗岩在弹性变形阶段有明显的声发射、微震和电荷感应同步前兆信号,在试样失稳破坏阶段有同步的声发射、微震和电荷感应大幅值前兆信号。断层带对花岗岩试件强度的影响是显著的,含断层带试件的单轴抗压强度大大降低。随着断层带倾角的减小,试样的单轴抗压强度降低,岩样更容易失稳,失稳破坏的能量也更大。随着断层带倾角的减小,试样变形破裂过程的声发射、微震和电荷感应信号都增多,试样出现同步的前兆信号时的应力降低,在试样失稳破坏阶段声发射、微震和电荷感应前兆信号事件的持续时间都增大。断层带倾角30°时,声发射、微震和电荷感应信号突变性增加,进入危险阶段大大提前,大震级事件也显著增多,在矿井大倾角断层处更为危险。在试样失稳破坏阶段前同步产生密集且大幅值的声发射、微震和电荷感应信号,持续时间较短;在试样失稳破坏阶段同步产生密集且最强的声发射、微震和电荷感应信号,持续时间较长。声发射监测数据能较好地反映岩石的微小破裂情况,对声发射、微震和电荷感应前兆信号相结合分析,可以更准确地获得岩石失稳破坏的前兆信息。
[Abstract]:In view of the abnormal characteristics of acoustic emission, microshock and charge signals before instability failure of rock samples under external load, acoustic emission is used. The signal of deformation and fracture process of granite with fault zone under uniaxial compression is monitored synchronously by means of microseismic and charge-induced comprehensive monitoring equipment. The results show that there is obvious acoustic emission in elastic deformation stage of granite with fault zone. The synchronous precursor signals of microshock and charge induction have synchronous acoustic emission during the failure stage of specimen instability. The effect of fault zone on the strength of granite specimen is significant. The uniaxial compressive strength of the specimen with fault zone decreases greatly. With the decrease of the dip angle of fault zone, the uniaxial compressive strength of the specimen decreases, the rock sample is more vulnerable to instability and the energy of failure is also greater. With the decrease of dip angle of fault zone, The acoustic emission, microshock and charge induction signal of the specimen during deformation and fracture increase, the stress decreases when the sample appears synchronous precursor signal, and the acoustic emission occurs at the stage of instability and failure of the specimen. The duration of microseismic and charge-induced precursory signal events increases. When the dip angle of fault zone is 30 掳, the sudden changes of acoustic emission, microshock and charge-induced signal increase, and the danger stage is greatly advanced, and the large magnitude events also increase significantly. It is more dangerous at the fault of large dip angle of mine. Before the failure stage of specimen instability, dense and large amplitude acoustic emission, microshock and charge induction signal are produced synchronously, and the duration is short. Dense and strongest acoustic emission, microseismic and charge-induced signals are produced simultaneously in the instability failure stage of the specimen. The acoustic emission monitoring data can well reflect the tiny rupture of rock and the acoustic emission. Combining microseismic analysis with charge-induced precursor signal, the precursor information of rock instability and failure can be obtained more accurately.
【作者单位】：辽宁工程技术大学力学与工程学院;中国地震局地质研究所地震动力学国家重点实验室;
【基金】：国家自然科学基金(51274114) 中国博士后基金特别资助(2014T70103) 中国地震局地质研究所基本科研业务专项(IGCEA1415)共同资助
【分类号】：TU45

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