节理岩体在加载与卸荷条件下,力学特性显著不同,现阶段对于节理岩体卸荷条件下的损伤特性研究较少,且未考虑不同卸荷程度对节理岩体力学特性的影响,基于此,本文开展含不同倾角预制节理岩体在不同程度卸荷损伤后重复加载试验,综合分析卸荷程度、节理倾角及围压对岩体变形特性的影响规律。研究结果表明:(1)岩样的峰值强度随着卸荷量的增加有不同程度的降低,卸荷程度较低时,对岩样极限强度影响较小,随着卸荷量逐渐增大,岩样极限强度降低程度增大。(2)围压较低时,岩样脆性跌落特征明显,随着围压的增高,岩样破坏后达到残余强度的变形开始增加,不同卸荷量造成的差异开始逐渐减小。(3)节理及卸荷量对岩样泊松比均有较大影响,节理岩样泊松比大于完整岩样,节理倾角为45°时,岩样泊松比最大;岩样泊松比随卸荷程度增加而增大,卸荷程度越高,泊松比增大速度越快。(4)节理岩体弹性模量与加载围压的大小、节理倾角以及卸荷损伤程度均有关系。随着围压的升高,岩样弹性模量逐渐增大,其增长速度随围压增大而逐渐降低;卸荷程度越高,岩样弹性模量降低程度越大,对于含不同倾角节理的岩体,影响程度又不一样,其中含45°,60°倾角节理所受影响最大。 The mechanical properties of jointed rock mass under loading and unloading conditions are significantly different. At present, there are few studies on the damage characteristics of jointed rock mass under unloading condition, and the influence of different unloading degree on the mechanical properties of jointed rock mass is not considered. In this paper, we carried out the repeated loading tests of prestressed jointed rock mass with different dip angle under different degrees of unloading damage, and analyzed the effects of unloading degree, joint dip angle and confining pressure on the deformation characteristics of rock mass. The results show that: (1) The peak intensity of rock samples decreases with the increase of unloading amount. When the unloading degree is lower, it has less influence on the ultimate strength of rock samples. As the unloading amount increases, The ultimate strength of rock samples decreases. (2) When the confining pressure is low, the characteristics of brittle drop of rock samples are obvious. With the increase of confining pressure, the deformation of residual strength after rock failure begins to increase, and the difference caused by different unloading amount begins to decrease gradually. (3) The jointed and unloaded loads have great influence on the Poisson’s ratio of rock samples. The Poisson’s ratio of jointed rock samples is larger than that of intact rock samples. The Poisson’s ratio of rock samples is the largest when the joint inclination is 45 °. With the degree of unloading increases, the higher the unloading degree, the faster the Poisson’s ratio increases. (4) The elastic modulus of jointed rock mass is related to the size of confining pressure, joint inclination and unloading damage degree. With the increase of confining pressure, the elastic modulus of rock samples gradually increases, and its growth rate decreases with the increase of confining pressure. The higher the unloading degree is, the greater the decrease of elastic modulus of rock samples is. With the increase of confining pressure, Of the rock mass, the impact is not the same, including 45 °, 60 ° dip joints most affected.