Evolution law of water-rock interaction on the shear behavior of granite fractures
DOU Zihao1, ZHAO Zhihong1, GAO Tianyang2, LI Jinjin2, YANG Qiang3
1. Department of Civil Engineering, Tsinghua University, Beijing 100084, China; 2. Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China; 3. Department of Hydraulic Engineering, Tsinghua University, Beijing 100084, China
Abstract：To study the influence of water-rock interaction on the shear behavior of granite fractures, direct shear tests were conducted on Beishan granite fracture samples that were dry or immersed in water for different durations. The immersion affected the shear properties of granite fractures in terms of decreasing peak strength, shear stiffness and dilation, and increasing peak shear displacement. The three-dimensional morphologies of fracture surfaces before and after shear were recorded using a three-dimensional blue light scanner, and the volume changes of sheared-off asperities were calculated. With increased immersion duration, the volume of the sheared-off asperities increased significantly, and an empirical expression is proposed to describe this relation. Moreover, a nanoindentation test was conducted on the granite surfaces under dry and immersed for 12 months conditions. The maximum indentation depth and plastic deformation of the immersed granite samples were significantly larger than those of the dry samples. The nanohardness and Young's modulus of the granite samples decreased significantly after the long-duration immersions, which indicated that the fracture asperities were damaged more easily after the immersions.
窦子豪, 赵志宏, 高天阳, 李津津, 杨强. 水岩作用下花岗岩裂隙剪切力学特性演化规律[J]. 清华大学学报（自然科学版）, 2021, 61(8): 792-798.
DOU Zihao, ZHAO Zhihong, GAO Tianyang, LI Jinjin, YANG Qiang. Evolution law of water-rock interaction on the shear behavior of granite fractures. Journal of Tsinghua University(Science and Technology), 2021, 61(8): 792-798.
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2021, Vol. 61 
