【摘要】 为揭示干湿循环条件下粉砂岩变形破坏行为与能量演化机制，开展了不同干湿循环次数下粉砂岩的单轴压缩试验，分析粉砂岩损伤劣化特性及能量演化特征。研究结果表明，随着干湿循环次数增加，粉砂岩干质量、纵波波速、峰值强度和弹性模量逐渐减小，而饱水质量、饱和吸水率逐渐增大，且变化速率逐渐减小，其破坏模式由脆性张拉破坏向塑性剪切破坏转变。干湿循环作用提高了粉砂岩闭合应力比，但降低了其起裂应力比和扩容应力比。弹性能比率呈现先增大后减小的“凸”型，而耗散能比率呈现先减小后增大的“凹”型。压缩储能系数随干湿循环次数增加而减小，粉砂岩积聚能量效率降低，而耗散能量效果越显著。基于耗散能定义了干湿-受荷损伤变量，建立了粉砂岩峰值强度与弹性模量的损伤方程。更多还原

【Abstract】 To investigate the failure deformation behavior and energy evolution mechanism of siltstone under wetting-dry cycles,uniaxial compression tests were performed on siltstone subjected to varying numbers of wetting-dry cycles. The study analyzed the damage and deterioration characteristics along with the energy evolution of siltstone. The findings indicate that as the number of wetting-dry cycles increases,the dry mass,longitudinal wave velocity,peak strength,and modulus of elasticity of siltstone gradually decrease,while the saturated water mass and saturated water absorption increase. Meanwhile,with the rate of change diminishes over time,the failure mode transitions from brittle tensile failure to plastic shear failure. Furthermore,the wetting-dry cycles lead to an increase in the closure stress ratio of siltstone,while the initiation stress ratio and expansion stress ratio decrease. The elastic energy ratio exhibits a “convex” curve that initially rises and then falls,whereas the dissipated energy ratio displays a “concave” curve that first declines and subsequently rises.Additionally,the compression energy storage coefficient decreases with an increasing number of wetting-dry cycles,indicating a reduction in the energy accumulation efficiency of siltstone,while the effects of energy dissipation become more pronounced. A wetting-dry load damage variable was defined based on the dissipated energy,and a damage equation was established for the peak strength and modulus of elasticity of siltstone.更多还原