为了查明高储能岩体快速卸荷变形破坏机制,设计了锦屏大理岩岩爆试验,对岩爆试件的宏观破坏特征、声发射过程等进行研究。根据以往真三轴岩爆试验特征进行了全程和非全程试验,记录其过程及声发射特征。对比分析两者的宏观破坏特征,解释了岩爆试验的渐进破坏过程。试验结果表明:在大理岩岩爆试验中,岩石试件的宏观破坏是由表及里的;张性裂纹的出现要早于剪切裂纹,剪切裂纹搭接相邻的张性裂纹(或临空面)形成圈闭,圈闭内的岩石碎块出现剥离或以一定初速度弹射;剪切面上岩粉的存在意味着剪切裂纹萌生扩展过程伴随着大量弹性应变能的释放;与其他的岩爆分类和机制相比,岩爆渐进破坏观点能够较好地解释岩爆机制。
In order to identify the deformation and failure mechanism of rock mass with high strain energy under fast unloading condition, Jinping marble rockburst tests are designed, and the macroscopic failure characteristics and acoustic emission(AE) processes are studied. Firstly, based on previous characteristics of true triaxial rockburst tests, true triaxial rockburst tests with entire process and without entire process are done, and a detailed process and AE characteristics are analyzed. Secondly, progressive failure is explained by comparing macroscopic failure characteristics of true triaxial rockburst tests with entire process with that of true triaxial rockburst tests without entire process. Conclusions are drawn as follows:in marble rockburst test, the macroscopic failure of rock specimen varies from outside to inside;tensile cracks appear earlier than shear cracks, and isolated rock fragment, which is confined by tensile cracks (or free face) and lapping shear cracks, peels off with or without a initial speed;the phenomenon that rock powder only exists on the shear crack planes demonstrates that a considerable strain energy dissipates, accompanying expansion of shear cracks;compared with other classification and mechanism of rockburst, a progressive failure view of rockburst in this article explains rockburst mechanism reasonably.