Shear behavior of clayey infilled rock joints having triangular and sinusoidal asperities

Rock joints govern an important role in the overall stability of rock slope which may be filled with infill material due to transported materials with water, weathering as well as joint shearing. There are two methods of testing rock joint shear behavior, one is Constant Normal Load (CNL), and another is Constant Normal Stiffness (CNS). The CNL is found suitable in slope stability where sliding mass can move freely without any restriction while CNS is suitable in underground excavation, pile socketed in rock and reinforced rock slope where the stiffness of boundary restricts dilation during the shearing process. This study investigates the shear behavior of clay infilled rock joints with triangular and sinusoidal asperities under CNL conditions. The pair of triangular and sinusoidal asperities is Type 1T, Type 2T and Type 1S, Type 2S respectively where prefix represent asperity height and suffix represent the type of asperity. Joint Roughness Coefficient (JRC) obtained from back-calculation of Barton equation using experimental data is 7, 9, 9 and 12 for Type 1T, Type 2T, Type 1S and Type 2S respectively. The direct shear test was performed on two campaigns, among these, was one of understanding shear behavior of infilled rock joints under various normal loads and another was the shear behavior of infill rock joints under various infill thicknesses. During the first campaign shear behavior of clayey infilled rock joint fewer than three different normal loads were tested. Likewise, in the second campaign shear behavior of clayey infill rock joint under three infill thickness were performed. Overall this study provides better insights into shear behavior clayey infilled rock joints having different joint morphology