New shear strength criterion for rough rock joints considering shear velocity

The stability of jointed rock under dynamic loading conditions, which is under different shear velocities, is one of the urgent problems in the current engineering construction. By using JAW-600 coupled shear-flow machine,four groups of rock-like joints with different roughness coefficients are sheared with different shear velocities based on the rock joints from the underground caverns of Huangdao State Oil Reserves. The experimental results show that the shear velocity and joint roughness coefficient obviously affect the shear strength. The shear strength for any rough rock joints decreases with the increasing shear velocity. Meanwhile, the shear strength under any shear velocity shows a linear increase with the joint roughness coefficients. On the basis of the experimental data and Barton’s criterion for shear strength, a new shear strength criterion considering shear velocity for rough rock joints is proposed. Then its correctness is verified by the shear strength of rock joints proposed by Barton with an average estimation error of 10.539% .