Experimental study on mechanical behavior of brittle marble samples containing different flaws under uniaxial compression
Experimental study on mechanical behavior of brittle marble samples containing different flaws under uniaxial compression
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DOI：
10.1016/j.engfracmech.2009.04.005
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发表时间：
2009-08
影响因子：
5.4
通讯作者：
Shengqi Yang;Y. Dai;L. Han;Z. Jin
中科院分区：
文献类型：
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作者：
Shengqi Yang;Y. Dai;L. Han;Z. Jin
利用岩石力学伺服控制试验系统，对我国东部地区的大理岩进行了不同几何形状非重叠预存缺陷的单轴压缩试验。根据大理岩轴向应力-轴向应变全曲线的试验结果，详细分析了裂纹几何形状对大理岩强度和变形特性的影响。与完整大理岩试件相比，不同预存缺陷的大理岩试件均表现出局部化变形破坏。含预存缺陷的大理岩单轴抗压强度、弹性模量和峰值轴向应变均低于完整大理岩，且降低程度与预存缺陷的几何形状密切相关。从脆性大理岩试样中不同预存裂纹的内部尖端观察并表征裂纹的贯通。根据裂纹的几何形状和裂纹扩展机制（拉伸、剪切和压缩），识别出8种不同的裂纹类型，用于分析单轴压缩条件下含不同裂纹试样的破坏模式和开裂过程。最后，分析了单轴压缩条件下裂纹贯通对脆性大理岩试件强度和变形破坏行为的影响。目前的研究提供了更多的了解单轴压缩下岩石破坏的基本性质。
Uniaxial compression experiments were carried out for the marble samples (located in the eastern ground of China) with different pre-existing flaws in non-overlapping geometry by the rock mechanics servo-controlled testing system. Based on the experimental results of complete axial stress–axial strain curves, the effect of flaw geometry on the strength and deformation behavior of marble samples is made a detailed analysis. Compared with the intact marble sample, the marble samples with different pre-existing flaws show the localization deformation failure. The uniaxial compressive strength (UCS), elastic modulus and peak axial strain of marble samples with pre-existing flaws are all lower than that of intact marble sample, and the reduction extent is closely related to the geometry of pre-existing flaws. The crack coalescence were observed and characterized from internal tips of different pre-existing flaws in brittle marble sample. Eight different crack types were identified based on their geometry and crack propagation mechanism (tensile, shear and compressive) for two pre-existing flaws, which can be used to analyze the failure mode and cracking process of marble sample containing different flaws in uniaxial compression. In the end, the influence of the crack coalescence on the strength and deformation failure behavior of brittle marble sample is analyzed under uniaxial compression. The present research provides increased understanding of the fundamental nature of rock failure under uniaxial compression.