Understanding the effect of loading rate on the normal deformation characteristics of joints has been an important topic for rock dynamics and rock engineering activities. In this paper, a series of static and quasi-static cyclic compression tests are performed on intact and jointed specimens, to reveal the mechanism of the dynamic normal behaviour of joints. The rate and peak value of the compression loading in each cycle are carefully determined to relate the dynamic normal characteristics of joint to the damage of joint asperities. The effect of loading rate on the normal stress-closure curve in different cycles of loading is analyzed. The results indicate that the loading rate has little or no effect on the normal deformation of joint under compression when the joint behaves in an elastic manner and no damage is caused to joint asperities. And the rate-dependent normal behaviour of joint, on the other hand, is found to be due to the failure of joint asperities, arising from the rate-dependent strength of the material.

了解加载速率对节理正常变形特性的影响一直是岩石动力学和岩石工程活动的重要课题。在本文中，对完整和有节理的试件进行了一系列静态和准静态循环压缩试验，以揭示节理动态正常行为的机制。仔细确定每个循环中压缩载荷的速率和峰值，以将接头的动态正常特性与接头粗糙度的损坏联系起来。分析了加载速率对不同加载周期法向应力闭合曲线的影响。结果表明，当接头处于弹性状态时，加载速率对受压接头的正常变形影响很小或没有影响，并且不会对接头粗糙度造成破坏。