基于岩体损伤破坏岩爆启动起电规律研究

A study on electrification mechanism during rock burst start-up based on rock damage and destroy

岩体变形破裂产生自由电荷过程对于岩爆机理研究具有重要的意义。采用理论分析和试验研究相结合的方法,建立了岩体损伤破坏力-电耦合理论模型,为室内岩体电荷感应试验提供了理论基础。选取花岗岩、砂岩、泥岩标准试件进行等围压三轴加载试验,研究了三种岩石岩爆启动过程电荷感应规律。试验结果表明:岩体弹性变形阶段电荷信号稳定,岩爆启动后岩体变形破坏导致损伤局部化,该过程监测到大量脉冲状电荷信号,同种岩体随着围压的升高电荷信号强度增强,不同岩体电荷感应规律明显不同,岩爆启动后三类岩石电荷信号分别表现出不同特征。总结出岩爆启动过程自由电荷产生机理,由此提出了接触剥离、压电、摩擦、破裂四种岩爆过程起电方式。

The process of free charge come from rock deformation fracture which plays an important role in studying rock burst.A theory model of rock damage electro-mechanical coupling was established and which provides the theoretical basis for the indoor rock charge induction test.Based on equal confining pressure triaxial loading test of granite,sandstone and mudstone,the charge induction law in the start-up process of rock burst was studied.The test results show that charge signals keep steady in rock elastic deformation,rock deformation fracture damages localization after rock burst start-up and a great quantity pulse charge signals were monitored in the process.In the same league rocks charge signals were enhanced with confining pressure while there was obvious different in different rocks.The charge signals at such three types are of different forms after rock burst start-up.Finally,the mechanism of free charge emerges in rock burst start-up was concluded and four rock burst electrification patterns of contacting-stripping,piezoelectric,frictional and cracked was presented.