宋战平, 刘洪珂, 郑方, 程昀, 孙引浩, 宋婉雪. 考虑层理倾角的硬质砂岩力学行为及破裂响应特征[J]. 煤田地质与勘探.
引用本文: 宋战平, 刘洪珂, 郑方, 程昀, 孙引浩, 宋婉雪. 考虑层理倾角的硬质砂岩力学行为及破裂响应特征[J]. 煤田地质与勘探.
SONG Zhanping, LIU Hongke, ZHENG Fang, CHENG Yun, SUN Yinhao, SONG Wanxue. Mechanical behavior and fracture response characteristics of hard sandstone considering bedding dip angle[J]. COAL GEOLOGY & EXPLORATION.
Citation: SONG Zhanping, LIU Hongke, ZHENG Fang, CHENG Yun, SUN Yinhao, SONG Wanxue. Mechanical behavior and fracture response characteristics of hard sandstone considering bedding dip angle[J]. COAL GEOLOGY & EXPLORATION.

考虑层理倾角的硬质砂岩力学行为及破裂响应特征

Mechanical behavior and fracture response characteristics of hard sandstone considering bedding dip angle

  • 摘要: 针对考虑层理倾角的硬质砂岩力学行为及破裂响应特征问题,对不同层理倾角的硬质砂岩进行单轴压缩试验,深入探究层理倾角对硬质砂岩力学行为的影响以及层理倾角与碎块分形特征之间的关系。试验结果表明,层理倾角对硬质砂岩应力-应变曲线的类型特征无显著影响,但倾角较小时(0°、22.5°、45.0°),曲线表现为单峰变化规律,倾角较大时(67.5°、90.0°),曲线表现为多峰变化规律,且曲线波动位置主要位于峰值附近。峰值应力σd和峰值应变εd均在倾角为67.5°(最不利层理结构面)时达到最小值46.25 MPa和9.80×10-3,层理倾角对硬质砂岩应力的影响明显大于应变,受层理倾角的影响,硬质砂岩的各向异性度为1.32~1.64,表现出低各向异性特征。硬质砂岩随着层理倾角的增大呈现出剪切破坏-剪切张拉复合破坏-层理结构面剪切破坏-劈裂破坏的损伤破坏演化规律;单轴压缩下硬质砂岩的碎块质量特征和分形特征明显,硬质砂岩碎块以中块分布为主,层理倾角对细粒碎块的质量分布影响较小,其分形维数值位于1~2,碎块较大比例分布在大尺寸分布区间。研究结果可为含层理结构面岩石的稳定性及地下空间工程灾害防治提供理论参考。

     

    Abstract: Aiming at the mechanical behavior and fracture response characteristics of hard sandstone considering bedding dip angle, uniaxial compression tests of hard sandstone with different bedding dip angle were carried out to explore the influence of bedding dip angle on the mechanical behavior of hard sandstone and the relationship between bedding dip angle and fractal characteristics of fragments. The test results show that the bedding dip angle has no significant effect on the type characteristics of the stress-strain curve of hard sandstone, but when the dip angle is small (0°, 22.5°, 45°), the curve shows the law of single peak. When the dip angle is large (67.5°, 90°), the curve shows the law of multi-peak, and the fluctuation position of the curve is mainly near the peak value. Both peak stress σd and peak strain εd reach the minimum values 46.25 MPa and 9.80×10-3 when the dip angle is 67.5° (the most unfavorable bedding structural plane). The effect of bedding dip angle on the stress of hard sandstone is obviously greater than that of strain. Affected by bedding dip angle, the degree of anisotropy of hard sandstone is 1.32-1.64, showing the characteristics of low anisotropy. The bedding dip angle has a significant influence on the failure mode of hard sandstone. With the increase of bedding dip angle, the hard sandstone shows the damage failure evolution law of shear failure-shear tension compound failure-bedding structural plane shear failure-splitting failure. Under uniaxial compression, the quality and fractal characteristics of hard sandstone are obvious, the hard sandstone fragments are mainly distributed in middle blocks, and the bedding dip angle has little influence on the mass distribution of fine-grained fragments, and the value of fractal dimension is in 1-2. A large proportion of fragments are distributed in the range of large size distribution. The research results can provide theoretical reference for the stability of rock with bedding structural plane and the disaster prevention and control of underground space engineering.

     

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