Study on strength behaviors of rock joints under different shearing deformation velocities

Strength of rock joints under different shear deformation velocities is the basic information to assess the response and safety of rock structures under earthquake. By using the RMT-150C servo-test system, artificial concrete joint samples with hammered surfaces have been employed to study the strength of rock joints under different shearing velocities. Based on the experimental results, it can be found that the peak shear strength decreases with the increase of shear deformation velocity; and that the decreasing rates decrease with the increment of shearing deformation velocity. It is also indicated that the peak shear strength of rock joints clearly increases with the increase of normal stress and undulation angles at different shear deformation velocities. Based on the experimental results, a model to describe the peak strength of rock joints with shear deformation velocity and undulation angle is presented.