Experiment study on shear behavior of artificial joint under CNL and CNS boundary conditions
CUI Guojian1，2，ZHANG Chuanqing1，2，HAN Huachao3，ZENG Zhiquan3，ZHOU Hui1，2，LU Jingjing1，2
(1. State Key Laboratory of Geomechanics and Geotechnical Engineering，Institute of Rock and Soil Mechanics，Chinese Academy of Sciences，Wuhan，Hubei 430071，China；2. University of Chinese Academy of Sciences，Beijing 100049，China；
3. PowerChina Huadong Engineering Corporation Limited，Hangzhou，Zhejiang 310014，China)
Abstract：To compare the shear behavior of rough rock joints under the CNL and CNS conditions，a series of direct shear tests of rough artificial joints under both CNL and CNS conditions were conducted. The effects of boundary conditions，initial normal stress and joint roughness on shearing behavior of the artificial joints were analyzed. Test results showed that the effect of normal stiffness is significant under low initial normal stress level. The strain hardening behavior of shear stress-shear displacement curves were observed under the CNS conditions，which is different from the strain softening behavior under the CNL conditions，and the normal displacement was further suppressed in the CNS tests. The peak and residual shear strengths，peak shear and normal displacements were larger under the CNS conditions than that under the CNL conditions. With the increase of initial normal stress，the effect of normal stiffness is gradually weakened. Under the high initial normal stress level，the shear test results under both CNS and CNL conditions are similar. Test results could improve the understanding of the shear behavior of the rough joint under the CNL and CNS conditions.
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2019, Vol. 38 
