Study on calculation of rock joint JRC value based on forward and #br#
reverse direct shear tests
XIAO Weimin1，2，LIU Weichao1，2，ZHU Zhanyuan1，2
(1. School of Civil Engineering，Sichuan Agricultural University，Dujiangyan，Sichuan 611830，China；2. Sichuan Higher Education Engineering Research Center for Disaster Prevention and Mitigation of Village Construction，Dujiangyan，Sichuan 611830，China)
Abstract：JRC is a key parameter to predict the shear strength of rock joint by using Barton?s JRC-JCS model. Although there are massive researches on methods for calculating JRC of a rock joint profile，few researches had been reported on the calculation of rock joint JRC value by considering shear direction. Herein，based on the 2D coordinate data of Barton?s ten standard profiles derived from fine digitization process，firstly the root mean square of the first derivative of the profile was calculated by consideration of shear direction. Meanwhile，forward and reverses direct shear tests were performed on artificial rock joint specimens which were of the same topography of Barton?s standard profiles. Then non-linear regression analyses were performed between JRC and which were respectively derived from back-calculation of forward and reverses direct shear test results and 2D coordinate data of standard profiles，from which empirical logarithmic and exponential expressions were obtained for determining the JRC value of rock joint profile considering shear direction. Furthermore，the predictions of JRC values derived from the above-mentioned empirical logarithmic and exponential expressions were compared with these back-calculated from forward and reverses direct shear tests. From the comparisons，it showed that the empirical exponential expression was more suitable for calculating the JRC of rock joint profile in forward direct shear tests，while the empirical logarithmic expression was more suitable for reverse direct shear tests condition.
肖维民1，2，刘伟超1，2，朱占元1，2. 基于正反向直剪试验的岩石节理JRC值计算研究[J]. 岩石力学与工程学报, 2021, 40(S2): 3098-3106.
XIAO Weimin1，2，LIU Weichao1，2，ZHU Zhanyuan1，2. Study on calculation of rock joint JRC value based on forward and #br#
reverse direct shear tests. , 2021, 40(S2): 3098-3106.
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2021, Vol. 40 
