冻融环境下红砂岩力学特性试验及损伤分析

摘要

Combining the experiments and the damage mechanical theory analysis,the freeze-thaw cycling experiment was conducted for the red sandstone in the water-saturated state,the mechanical property tests with different number of freeze-thaw cycles were carried out,the rock deterioration process of the freeze-thaw damage was analyzed,then the deformation and failure laws and the damage propagation mechanical characteristics were studied systematically for rock.It is shown that the deterioration modes of the freeze-thaw damage for the red sandstone include the spalling mode and the fracture mode.The greater the number of the freeze-thaw cycles the more intensified the reduction of the strength and the elastic modulus will result,with the increased compaction property,the weakened elasticity and the enhanced plasticity.Through the nonlinear evolution of the rock damage,the initial defect of meso-structure within the rock will lead to the deterioration of the macro mechanical behavior finally.%将实验研究与损伤力学理论分析相结合,对红砂岩进行饱水状态下的冻融循环试验及不同冻融次数下的力学特性试验,分析了岩石的冻融损伤劣化过程,系统研究了岩石的变形破坏规律及损伤扩展力学特性.研究表明:红砂岩呈现出剥落和断裂的冻融损伤劣化模式；随着冻融次数的增加,岩石的强度及弹性模量急剧降低,并表现出压密性增大、弹性减弱、塑性增强的特征；岩石初始细观结构的缺陷经过损伤的非线性演化,表现出宏观力学性能的劣化.