摘要
为探究单轴压缩下缺陷砂岩的能量演化和力学行为,通过离散元法数值模拟,分析了不同岩桥倾角和岩桥距离对缺陷砂岩的影响,结合能量耗散建立了损伤本构方程。结果表明:岩桥倾角和岩桥距离显著影响缺陷砂岩的力学响应和破坏机制,大倾角(60°、90°)促进裂纹沿最大主应力方向扩展,而小倾角(0°、30°)增加剪切裂纹比例,导致不同的破坏形态;弹性模量和抗压强度随岩桥倾角和岩桥距离的变化呈“U”形非线性特征。能量演化规律对岩桥倾角具有依赖性,总能量和耗散能量随岩桥倾角的增加先降低后升高,并在90°时达到最大。岩桥距离对能量的影响随岩桥倾角的变化而变化,当岩桥倾角小于45°时,能量随岩桥距离的增加而减少,当岩桥倾角大于45°时,能量随岩桥距离的增加先增加后减少。弹性能耗比的三阶段特征可作为缺陷砂岩失稳的预测指标。基于耗散能理论构建的能量耗散损伤本构模型能够准确地描述不同岩桥参数下缺陷砂岩的变形和破坏行为。该模型在实际工程中具有重要的应用潜力,但需要针对具体应力条件进行调整以优化预测准确性。研究结果可为岩土工程的灾害防治提供理论参考。
In order to investigate the energy evolution and mechanical behavior of defective sandstone under uniaxial compression,the discrete element method(DEM)is employed.Effects of different rock bridge inclination angles and distances on the mechanical behavior of defective sandstone are systematically studied by DEM,and established a damage constitutive equation based on energy dissipation.The results indicate that the rock bridge inclination angle and distance significantly affect the mechanical response and failure modes of defective sandstone.Large inclination angles(60°,90°)facilitate crack propagation along the direction of maximum principal stress,while small inclination angles(0°,30°)increase the proportion of shear cracks,leading to different failure patterns.Additionally,the elastic modulus and compressive strength exhibit a“U”-shaped nonlinear characteristic with the variation of inclination angle and distance.Moreover,the energy evolution pattern depends on the rock bridge inclination angle.The total energy and dissipated energy first decrease and then increase with increasing rock bridge inclination angle,and peaking at 90°.The influence of rock bridge distance on energy varies with inclination angle.For angles less than 45°,the two types of energy decrease with increasing distance.For angles greater than 45°,the two types of energy first increase and then decrease.The three-stage characteristic of the elastic energy dissipation ratio can serve as a predictive indicator of the instability of defective sandstone.Furthermore,the energy dissipation damage constitutive model constructed based on dissipated energy can accurately describe the deformation and failure behavior of defective sandstone under different rock bridge parameters.This model has significant application potential in practical engineering,but it needs to be adjusted according to specific stress conditions to optimize prediction accuracy.The research results can provide theoretical references for disaster prevention in geotechnical engineering.
作者
郭永成
陈冰
李建林
邓华锋
GUO Yongcheng;CHEN Bing;LI Jianlin;DENG Huafeng(Key Laboratory of Geological Hazards on Three Gorges Reservoir Area of Ministry of Education,China Three Gorges University,Yichang 443002,Hubei,China;Hubei Key Laboratory of Disaster Prevention and Mitigation,China Three Gorges University,Yichang 443002,Hubei,China;College of Civil Engineering and Architecture,China Three Gorges University,Yichang 443002,Hubei,China)
出处
《高压物理学报》
北大核心
2026年第3期61-75,共15页
Chinese Journal of High Pressure Physics
基金
国家自然科学基金(52009069)
国家自然科学基金重点项目(U22A20600)。
关键词
单轴压缩
缺陷砂岩
离散元方法
裂纹演化
能量本构
uniaxial compression
defective sandstone
discrete element method
crack evolution
energy ontology
