单轴加卸荷过程中岩石声学特性及其与损伤因子关系

Relationship between the acoustic characteristics and damage variable in the process of uniaxial loading and unloading

设计了岩石试块的单轴加卸荷实验.利用声发射观测动态检测损伤的扩展,通过超声波检测来定量评价岩石试块的损伤程度.结果表明:岩石在加载和卸载两种过程中都有新的损伤产生;其损伤扩展和演化过程可以通过声发射监测来动态观测,损伤演化的水平则可通过超声波的信号特征进行定量评价.

Underground excavation is an unloading process, which not only results in the change of stress distribution in surrounding rocks, but also gives rise to the change in rock properties. In order to analyze the stability of slope and optimize the design, studies on the change in mechanical properties of rocks, due to unloading process caused by excavation in an open-pit mine, must be carried out. In uniaxial loading and unloading process, the damage process in rocks was tested by ultrasonic wave and acoustic emission, in which the damage development was dynamically measured by acoustic emission and the damage degree was quantitatively estimated based on ultrasonic wave. The result shows that new damage can be induced in both loading and unloading processes. The damage development and its evolution process can be dynamically measured by monitoring of acoustic emission, and the level of damage evolution can be quantitatively estimated by the signal characteristics of ultrasonic wave.