二长花岗岩三轴加卸载过程中声发射特征分析

发布时间：2018-08-13 19:52

【摘要】：为认识二长花岗岩在不同受载路径条件下破坏过程中声发射特征,通过三轴循环加卸载压缩试验和声发射试验,分析了玲珑金矿二长花岗破坏过程应力应变曲线和声发射特征参数的关系,结果表明:(1)在花岗岩的循环加卸载过程中,声发射信号主要出现在加载期的超过前一循环最大值的阶段和卸载过程的初期,弹性加载和卸载阶段后期基本无声发射现象;(2)岩石声发射活动与岩石变形破坏过程以及能量释放特征规律密切相关,在对二长花岗岩的加卸载试验的过程中,随着加卸载的进行,存在着声发射活动的活跃期和相对平静期;(3)主破裂阶段及峰后相对应力较高的时期所释放的能量要远高于卸荷阶段的初期、塑性变形的中后期这两个活跃期释放的能量,该阶段绝大部分的弹性应变能释放出来;(4)在岩石试样初期的循环加卸载过程中,岩石内部塑性破坏程度较低,Kaiser效应显著,后期的循环加卸载过程中即塑性阶段的中后期,Felicity效应显著;(5)岩石进入塑性变形的中后期,微破裂发展至破坏阶段,裂纹大量扩展、贯穿,形成宏观裂缝,弹性应变能大量释放,AE信号强烈,当达到塑性中后期的标志点时,岩石试件即到了主破裂的前夕。
[Abstract]:In order to understand the characteristics of acoustic emission (AE) in the process of failure of the bifeldite under different loading paths, a triaxial cyclic loading and unloading compression test and an acoustic emission test were carried out. The relationship between stress-strain curve and acoustic emission characteristic parameters during the failure process of Erchang granitic in Linglong Gold Mine is analyzed. The results show that: (1) during the cyclic loading and unloading of granite, Acoustic emission signals mainly occur at the stage of loading which exceeds the maximum value of the previous cycle and at the beginning of the unloading process. (2) Acoustic emission activity of rock is closely related to the process of rock deformation and failure and the characteristics of energy release. With the development of loading and unloading, there are active and relative quiet periods of acoustic emission activities. (3) the energy released from the main rupture stage and the higher corresponding force after the peak stage is much higher than that at the early stage of unloading stage. In the middle and late stage of plastic deformation, most of the elastic strain energy is released from the two active periods. (4) during the initial cycle loading and unloading of rock samples, the degree of plastic failure in rock is lower than that of Kaiser effect. The Felicity effect is significant in the late cycle loading and unloading process, that is, in the plastic stage. (5) when the rock enters the middle and late stage of plastic deformation, the microfracture develops to the failure stage, and the crack propagates and runs through, forming the macroscopic crack. The elastic strain energy releases a large number of strong AE signals. When the mark point of the middle and late stage of plasticity is reached, the rock specimen will arrive on the eve of the main rupture.
【作者单位】：北京科技大学金属矿山高效开采与安全教育部重点实验室;中国五矿集团公司;
【基金】：国家重大基础研究项目(973计划)(2010CB226803) “十二五”科技支撑计划(2012BAK09B07)
【分类号】：TU45

【相似文献】