MACRO- AND MESO-ANALYSES OF ROCK JOINT DIRECT SHEAR TEST USING PARTICLE FLOW THEORY
ZHOU Yu1,2,MISRA A2,WU Shunchuan1,ZHANG Xiaoping3
(1. Key Laboratory of Ministry of Education for Efficient Mining and Safety of Metal Mine,University of Science and Technology Beijing,Beijing 100083,China;2. School of Engineering,University of Kansas,KS 66045–7609,USA;3. Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China)
Abstract:The numerical simulation of rock joint shear test was successfully performed using the particle flow theory based on particle flow code(PFC),by addressing the implementation issues such as floater elimination,constant normal stress servo mechanism and loading velocity specification. Based on the simulation results,the mechanical evolution law and failure mechanism during the shear test process are deeply discussed from macro- and meso-scale perspectives. The reliability of the simulations method is verified by comparing calculation results and existing data from laboratory joint shear test. The main research results are as follows:(1) With the increase of constant normal stress,the number of failure-bond particles on joint,shear stress and shear displacement at the peak shear stress increase,while the effects of shear resistance and dilatancy on joints decrease. (2) As the shear displacement increases,the number of normal contact between particles on joint decreases and contact vector direction aligns towards the direction of shear load. Furthermore,the contact force on joint continually increases with cracks developing in the joint vicinity;and the rupture frequency is found to be most intense at the peak value of shear stress. (3) The shear resistance obtained from numerical calculation is higher than that of the laboratory test. However,the calculated shear resistance can be decreased effectively by reducing the particle radius. The comparison analysis between laboratory test and calculation results shows that the particle flow calculation method proposed here is suitable for the numerical simulation of rock joint test,and it can function as a beneficial reference for deeply research on the laboratory joint shear test as well as the mesomechanical parameter determination for joint model in PFC.
周 喻1,2,MISRA A2,吴顺川1,张晓平3. 岩石节理直剪试验颗粒流宏细观分析[J]. 岩石力学与工程学报, 2012, 31(6): 1245-1256.
ZHOU Yu1,2,MISRA A2,WU Shunchuan1,ZHANG Xiaoping3. MACRO- AND MESO-ANALYSES OF ROCK JOINT DIRECT SHEAR TEST USING PARTICLE FLOW THEORY. , 2012, 31(6): 1245-1256.
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