New criterion for rock joints based on three-dimensional roughness parameters
来源期刊：中南大学学报(英文版)2014年第12期
论文作者：TANG Zhi-cheng(唐志成) 刘泉声 HUANG Ji-hui(黄继辉)
文章页码：4653 - 4659
Key words：rock joint；shear behavior；peak shear strength；three-dimensional roughness parameter
Abstract: The shear behavior of rock joints is important in solving practical problems of rock mechanics. Three group rock joints with different morphologies are made by cement mortar material and a series of CNL (constant normal loading) shear tests are performed. The influences of the applied normal stress and joint morphology to its shear strength are analyzed. According to the experimental results, the peak dilatancy angle of rock joint decreases with increasing normal stress, but increases with increasing roughness. The shear strength increases with the increasing normal stress and the roughness of rock joint. It is observed that the modes of failure of asperities are tensile, pure shear, or a combination of both. It is suggested that the three-dimensional roughness parameters and the tensile strength are the appropriate parameter for describing the shear strength criterion. A new peak shear criterion is proposed which can be used to predict peak shear strength of rock joints. All the used parameters can be easily obtained by performing tests.
TANG Zhi-cheng(唐志成)1, 2, LIU Quan-sheng(刘泉声)1, HUANG Ji-hui(黄继辉)2
(1. School of Civil Architectural Engineering, Wuhan University, Wuhan 430072, China;
2. Department of Geotechnical Engineering, Tongji University, Shanghai 200092, China)
Abstract:The shear behavior of rock joints is important in solving practical problems of rock mechanics. Three group rock joints with different morphologies are made by cement mortar material and a series of CNL (constant normal loading) shear tests are performed. The influences of the applied normal stress and joint morphology to its shear strength are analyzed. According to the experimental results, the peak dilatancy angle of rock joint decreases with increasing normal stress, but increases with increasing roughness. The shear strength increases with the increasing normal stress and the roughness of rock joint. It is observed that the modes of failure of asperities are tensile, pure shear, or a combination of both. It is suggested that the three-dimensional roughness parameters and the tensile strength are the appropriate parameter for describing the shear strength criterion. A new peak shear criterion is proposed which can be used to predict peak shear strength of rock joints. All the used parameters can be easily obtained by performing tests.
Key words:rock joint；shear behavior；peak shear strength；three-dimensional roughness parameter
