中文摘要：

水库正常运营后，库水位将按计划周期性的上升或下降，浸泡-风干循环作用将导致库岸边坡变幅带岩体性质逐渐劣化，进而影响库岸边坡的稳定性，基于此，设计了考虑水压力升、降变化的砂岩浸泡-风干循环作用试验，重点研究了砂岩试样的变形及破坏特征。研究结果表明：水压力升、降变化和浸泡-风干循环作用对岩样造成了不可逆的渐进性损伤，在循环作用过程中，砂岩试样的应力-应变曲线逐渐变缓，压密段长度逐渐变长，弹性变形段的斜率逐渐减小，弹性模量逐渐降低，屈服阶段也逐渐变长，试样达到峰值强度时对应的轴向应变逐渐变大，试样的剪切破坏角有逐渐变小的趋势。应力-应变曲线的变化显示岩样有明显的“变软”的趋势，而且，浸泡一风干循环次数越多，岩样的损伤越严重。研究成果对于把握库岸边坡库水消落带岩体变形、破坏规律具有较大的参考价值，为库岸边坡的长期稳定性分析提供了有益的依据。

英文摘要：

In the process of impoundment and normal operation of reservoirs, the water level will rise and fall periodically in a planned way. As a result, the immersion-air dry function will lead to the degeneration of mechanical properties of rock mass in variable amplitude zone with time, and then affect the slope stability. Based on these, the immersion-air dry circulation function tests considering the change of water pressure of sand rock are designed, and the deformation and fracture features of rock samples are studied. The test results indicate that the rise or decline of water pressure and the immersion-air dry circulation function have cumulative and irreversible damage to the samples. In the process of circulation, the stress-strain curves of the sand rock samples become slow gradually, the compaction segment gradually becomes long, the gradient of the elastic deformation section decreases gradually, elastic modulus reduces gradually, yield step gradually becomes long, the axial strain corresponding to the peak intensity increases gradually, and the fracture angle of the samples decreases gradually. The stress-strain curves of the sand rock samples show that the samples have a distinct trend of softening. Moreover, the more the cycle times of the immersion-air dry, the more the serious damage to the rock mass. The results of important reference value in the studies on the deformation and fracture laws of the variable amplitude rock in reservoir banks will provide a favorable evidence for the long-term stability analysis of reservoir bank slopes.