(中南大学 资源与安全工程学院，长沙 410083)
摘 要: 利用改进的岩石动静组合加载SHPB试验系统，开展矽卡岩在不同静力轴压水平上以不同卸载速率的卸载过程中受频繁动力扰动作用的动力学试验，研究矽卡岩在高静应力卸载过程中受频繁动力扰动作用下的动力学特性，重点讨论静力轴压大小和卸载速率对岩石受频繁动力扰动时的动力学特性的影响。结果表明：当卸载轴压一定时，累计扰动冲击次数与卸载速率成线性正相关关系；而当卸载速率一定时，累计扰动冲击次数与轴压成线性负相关关系；随着轴压卸载速率的增大，当卸载轴压较小时，动态变形模量先增大后减小；而当轴压较大时，动态变形模量持续减小；岩石动态峰值应力与动力扰动次数呈二次函数关系，但随卸载速率的增加，动态峰值应力与扰动冲击次数关系逐渐过度为线性负相关关系；最大动态应变与扰动冲击次数呈正相关关系。
关键字: 岩石力学；动静组合加载；高静应力；轴压卸载速率；动力学特性；频繁动力扰动
（School of Resources and Safety Engineering, Central South University, Changsha 410083, China）
Abstract:Dynamic experiments on skarn were conducted with a modified one-dimensional coupled static and dynamic loads based on SHPB device, in which rock samples were frequently dynamically disturbed in the process of static unloading with different static unloading rates on different levels of high static axial compression, in order to research the dynamic properties of skarn in the process of high static stress unloading and frequent dynamic disturbance, and focus on the influence of level of axial compression and axial compression unloading rate on the dynamic properties. The results show that there is a positive correlation between accumulated number of dynamic disturbance and axial compression unloading rate when level of unloading axial compression is constant. But when axial compression unloading rate is constant, the accumulated number of dynamic disturbance is negatively related with unloading axial compression. When static axial compression is small, the dynamic deformation modulus firstly increases with the increase of axial compression unloading rate and then it decreases, and when static axial compression is large, the dynamic deformation modulus decreases steadily. The relationship between dynamic peak stress and the dynamic disturbance times is a quadratic function, but with the increase of axial compression unloading rate, it gradually becomes a linear negative correlation. And maximum dynamic strain is positive correlated with the dynamic disturbance times.
Key words: rock mechanics; coupled static and dynamic load; high static stress; axial compression unloading rate; frequent dynamic disturbance
