魏继祖, 梁芳敏, 闫石, 李湖滨, 闫自刚. 端部摩擦作用对砂岩尺寸效应影响的试验[J]. 煤矿安全, 2018, 49(9): 73-78.
    引用本文: 魏继祖, 梁芳敏, 闫石, 李湖滨, 闫自刚. 端部摩擦作用对砂岩尺寸效应影响的试验[J]. 煤矿安全, 2018, 49(9): 73-78.
    WEI Jizu, LIANG Fangmin, YAN Shi, LI Hubin, YAN Zigang. Experiment on Influence of End Friction on Size Effect of Sandstone[J]. Safety in Coal Mines, 2018, 49(9): 73-78.
    Citation: WEI Jizu, LIANG Fangmin, YAN Shi, LI Hubin, YAN Zigang. Experiment on Influence of End Friction on Size Effect of Sandstone[J]. Safety in Coal Mines, 2018, 49(9): 73-78.

    端部摩擦作用对砂岩尺寸效应影响的试验

    Experiment on Influence of End Friction on Size Effect of Sandstone

    • 摘要: 为研究端部摩擦作用对砂岩材料尺寸效应的影响,提出了1种采用岩石垫块消除端部摩擦作用的试验方法,对不同高径比的砂岩试样进行了单轴压缩试验,并与传统试验方法进行对比分析。结果表明:采用岩石垫块的方法对端部摩擦具有很好的抑制作用;受端部摩擦作用环向约束的影响,采用传统试验方法加载时,试样的破坏形态随长径比的增大经历劈裂破坏-拉剪混合破坏-剪切破坏的演变过程,消除端部摩擦后试样的破坏形态均为剪切破坏;在端部摩擦作用下,岩石的峰值强度测试值大于其真实强度,试样的测试值是由真实强度和端部摩擦贡献值2部分组成,端部摩擦贡献值随试样尺寸的增大总体逐渐减小。

       

      Abstract: To investigate the influence of the end friction on the size effect of sandstone, a new test method was proposed to reduce the end friction. Uniaxial compression tests were carried out on sandstone samples with different height-diameter ratios. The results show that: the proposed test method in this paper has good inhibiting effect on the end friction. Due to the hoop constraint of end friction, the damage mode of samples experience the evolution from splitting failure to tension-shear hybrid failure and shear failure with the increase of the height-diameter ratio in the traditional uniaxial compression, while the failure patterns are always shear failure when the end friction has been eliminated. Under the influence of end friction, the experimental uniaxial compressive strength is greater than its true strength. The test strength comprises the true strength and the contribution value of end friction, and the contribution value decreases gradually with the increase of the height-diameter ratio.

       

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