In order to explore the interaction between different joints in the pressure-shear condition and the related failure mechanism，the shear resistance performance of double rough joints was studied by using both experimental and numerical simulation methods. The artificial joint samples were generated by pouring concrete into the PLA molds. It is proven that the JRC of the 3D-printed PLA joint surface is seriously reduced，which should be re-calculated before shear tests. The experimental results show that on account of the failure of the interlayer rock during the shear test，the overall shear strength of double rough joints is lower than that of either of the two joints，and even lower than that of the single smooth joint. Moreover，the PFC2D numerical simulation on shear test of double rough joints shows that the stress concentration induced by the joint asperities leads to the failure of the interlayer rock，which further reduces the shear strength. In addition，the influence of joint spacing on shear strength is not so obvious.
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2017, Vol. 36 
