Strength properties of the jointed rock mass medium under dynamic cyclic loading

The dynamic strength properties of the intermittently jointed mediums are studied using model test to investigate the jointed rock mass behavior under dynamic cyclic load. The model test results demonstrate that (i) the dynamic strength of the jointed samples increases with the loading frequency and decreases with the loading loops; (ii) the dynamic residual strength will not be zero like the static residual strength under one-axle loading condition; (iii) the dynamic strength changes greatly with the joint density and joint angle, and it differs from that of the static strength which reaches the lowest at an angle of 45° + (?)/2, while in the dynamic case, the lowest strength is at the angle of 45°.