摘要
通过27次冻融试验与5级围压(5MPa、10MPa、15MPa、20MPa、25MPa)下三轴压缩试验,结合扫描电镜(SEM)细观观测,系统分析冻融作用下岩石物理力学性质变化与破坏机制。结果表明:冻融循环后纵波波速平均下降11.91%,质量先增后减,内部孔隙与裂隙显著发育;三轴抗压强度随围压升高而增加,但饱和与冻融状态峰值强度较自然状态分别降低约9.4%和39.1%,弹性模量降低、泊松比增大,表明冻融作用显著削弱岩石刚度并增强塑性变形能力;宏观破坏模式由脆性剪切向脆-塑性及多裂纹复杂破坏转变;细观上孔隙增多、微裂隙网络发育,破裂面粗糙伴粉末碎屑,破坏机制以剪切为主。研究揭示了冻融花岗斑岩宏细观损伤协同演化规律,为寒区岩体工程稳定性评价提供理论依据。
This study through 27 freeze-thaw cycles,triaxial compression tests under five confining pressures(5MPa、10MPa、15MPa、20MPa、25MPa),and scanning electron microscope(SEM)observations,the changes in physical and mechanical properties and failure mechanisms were systematically analyzed.Results show that after freeze-thaw cycles,the longitudinal wave velocity decreases by 11.91%on average,mass first increases then decreases,and internal pores and cracks develop significantly.Triaxial compressive strength increases with confining pressure,but peak strengths under saturated and freeze-thaw conditions decrease by approximately 9.4%and 39.1%,respectively,compared to the natural state.The elastic modulus decreases and Poisson’s ratio increases,indicating that freeze-thaw action significantly reduces rock stiffness and enhances plastic deformation capacity.Macroscopically,the failure mode shifts from brittle shear to brittle-plastic transition and complex multi-crack failure.Microscopically,porosity increases,microcrack networks develop,fracture surfaces become rough with powdered debris,and the failure mechanism is predominantly shear.The study reveals the synergistic evolution of macro-micro damage in freeze-thaw granodiorite porphyry,providing a theoretical basis for evaluating rock mass stability in cold regions.
作者
崔子健
刘畅
Cui Zijian;Liu Chang(School of Water Resources and Hydropower,Hebei University of Engineering,Handan 056038,China;Hebei Key Laboratory of Smart Water Conservancy,Handan 056038,China)
出处
《吉林水利》
2026年第3期6-12,共7页
Jilin Water Resources
基金
河北省自然科学基金项目(项目编号:E2020402087)。
关键词
冻融循环
三轴压缩
扫描电镜
弹性模量
Freeze-thaw cycle
Triaxial compression
Scanning electron microscope(SEM)
Elastic modulus
