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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-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。
After the normal operation of the reservoir, the reservoir water level will periodically rise or fall according to the plan. The soaking-drying cycle will lead to the gradual deterioration of the rock mass properties in the bank amplitude of the bank slope, which will affect the stability of bank slope. Based on this, Sandstone immersion-drying cycle experiment considering water pressure rise and fall was designed, and the deformation and failure characteristics of sandstone samples were mainly studied. The results show that water pressure increases, decreases and soaking-drying cycles cause irreversible and progressive damage to rock samples. During the cycling process, the stress-strain curve of sandstone samples gradually becomes slower and the length of the compression section gradually increases The slope of the elastic deformation section decreases gradually, the elastic modulus decreases gradually and the yield stage also gradually becomes longer, and the corresponding axial strain becomes larger gradually when the specimen reaches the peak strength, and the shear failure angle of the specimen gradually changes Small trend. The change of the stress-strain curve shows that there is a clear “soft” tendency of the rock samples. Moreover, the more soaking-drying cycles, the more severe the rock samples are. The research results have great reference value for grasping the deformation and failure of rock mass in reservoir-waterburst zone of bank slope bank, which provides a useful basis for long-term stability analysis of bank slope.