Failure characteristics of rock-like materials with single flaws under uniaxial compression

A uniaxial compression test was conducted with a servo loading apparatus to study the failure of a rock-like specimen with a pre-existing single flaw. The evolution of cracks was monitored with digital image correlation technology and simulated with the expanded distinct element method based on the strain strength criterion. The concentration and evolution of the principal strain field were found to be consistent with the initiation, propagation, and coalescence of cracks. As the inclination angle increased, the position of the maximum principal strain concentration changed from within the flaw to the flaw tips, and the distribution of the horizontal displacement field changed from symmetric to antisymmetric. The initiation stress and peak strength were affected by the inclination angle; they were minimum when the inclination angle was 60°. As the inclination angle increased, the failure mode of the specimens transformed from mostly tensile failure to mostly shear failure.