Sandstone Damage Characteristics Based on Triaxial Test and Discrete Element Numerical Simulation

The combination of triaxial test and numerical simulation can provide a more comprehensive understanding of the damage mechanism of rocks and provide reference and guidance for engineering practice. In this paper, the sandstone of a slope in Suzhou was analyzed by the triaxial tests, and the simulation by using discrete element method was carried out. The peak strength with an enclosing pressure of 1 MPa was 111.6 MPa, and the elastic modulus was 19.93 GPa. The simulation results after calibration matched well with the triaxial test results, and the crack initiation stress, the peak stress of crack damage stress can be realized by the stress–strain curve. Due to the pre-compression, the simulation cannot reflect the crack closure. The damage of the specimen was in the form of shear damage, and the angle between the damage surface and the horizontal plane was about 67°. This indicates that the damage of the sandstone is caused by poor shear strength due to insufficient particle bonding.