Scale effect on the shear behaviour of rock joints based on a numerical study

作     者：Bahaaddini, M. Hagan, P. C. Mitra, R. Hebblewhite, B. K. 

作者机构：UNSW Australia Sch Min Engn Sydney NSW Australia Shahid Bahonar Univ Kerman Kerman Iran 

出 版 物：《ENGINEERING GEOLOGY》 (工程地质学)

年 卷 期：2014年第181卷第0期

页      面：212-223页

核心收录：

学科分类：0709[理学-地质学] 081803[工学-地质工程] 07[理学] 08[工学] 0708[理学-地球物理学] 0818[工学-地质资源与地质工程] 

主　　题：Scale effect Rock joint Shear behaviour Joint roughness Particle flow code 

摘      要：A large number of studies have been carried out to investigate the effect of scale on the shear behaviour of rock joints. However, the nature of scale dependency of rock joints is still unknown and remains an ongoing debate. This paper investigates the effect of joint length on the shear behaviour of rough rock joints using PFC2D. In this numerical approach, the intact material is simulated by a dense packing of bonded particles and the joint is represented by micro-scale slip surfaces at contacts between particles. The validity of this numerical approach in reproducing the shear behaviour of rock joints has been studied in previous studies of authors against the physical experiments, analytical and empirical models. In this study, numerical direct shear tests on a natural tensile joint and subdivided joints were carried out and the shear behaviour of these joints at different scale was investigated. Results of this study show that as the joint length increases, the peak shear strength, peak dilation rate and shear stiffness decrease while the peak shear displacement increases. In order to find out the reason of observed scale dependency, the mechanism of asperity degradation at different scales was investigated and it was found that the mobilisation of different sized asperities at different scales resulted in the observed scale effect. (C) 2014 Elsevier B.V. All rights reserved.