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| 不同围压下砂岩裂纹特征应力演化及破坏模式研究 |
| Evolution of Crack Characteristic Stresses and Failure Modes of Sandstone Under Different Confining Pressures |
| 投稿时间：2026-06-16 修订日期：2026-07-02 |
| DOI： |
| 中文关键词: 砂岩 常规三轴压缩 围压 裂纹特征应力 裂纹体积应变法 破坏模式 |
| 英文关键词: sandstone conventional triaxial compression confining pressure crack characteristic stress crack volumetric strain method failure mode |
| 基金项目:安徽省科研编制计划项目(2025AHGXZK30564),安徽省智能地下探测重点实验室开放基金(APKLIUD25KF05) |
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| 中文摘要: |
| 为探究不同埋深条件下砂岩裂纹特征应力的演化规律及破坏机制,开展不同围压下的常规三轴压缩试验,系统分析围压对砂岩强度特征、裂纹演化过程及宏观破坏模式的影响。结果表明:随着围压由5 MPa增至15 MPa,砂岩峰值强度由109.09 MPa提高至131.01 MPa,弹性模量由4550.19 MPa增至6385.41 MPa。各裂纹特征应力均随围压增加而提高,其中裂纹起裂应力和裂纹损伤应力对围压变化表现出更高敏感性。裂纹起裂应力比(σci/σp)由0.47增至0.71,而稳定裂纹扩展阶段对应的应力区间由0.31减小至0.14,表明围压能够显著延缓裂纹萌生,但促使裂纹在较窄应力区间内快速扩展并趋于失稳。随着围压升高,试样破坏模式由张拉-剪切复合破坏逐渐向单一剪切破坏转变。研究结果揭示了围压对砂岩裂纹萌生、扩展及失稳过程的控制作用,可为地下岩体稳定性评价及相关工程设计提供参考。 |
| 英文摘要: |
| To investigate the evolution of crack characteristic stresses and failure mechanisms of sandstone under various buried depths, a series of conventional triaxial compression tests were conducted under different confining pressures. The influences of confining pressure on the strength characteristics, crack evolution processes, and macroscopic failure modes of sandstone were systematically analyzed. The results indicate that as the confining pressure increases from 5 MPa to 15 MPa, the peak strength of the sandstone increases from 109.09 MPa to 131.01 MPa, and the elastic modulus increases from 4550.19 MPa to 6385.41 MPa. All crack characteristic stresses increase with the elevated confining pressure, with crack initiation stress and crack damage stress exhibiting higher sensitivity. The crack initiation stress ratio（σci/σp）increases from 0.47 to 0.71, while the stress interval corresponding to the stable crack propagation stage decreases from 0.31 to 0.14. These findings demonstrate that confining pressure significantly delays the onset of crack initiation but accelerates crack propagation within a narrower stress range, leading to rapid instability. Furthermore, as the confining pressure rises, the failure mode of the specimens gradually transitions from combined tensile-shear failure to single shear failure. These results reveal the governing role of confining pressure in the processes of crack initiation, propagation, and instability, providing a theoretical basis for the stability evaluation and engineering design of underground rock masses. |
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