Numerical Study of the Strength and Characteristics of Sandstone Samples with Combined Double Hole and Double Fissure Defects

To explore the failure mechanism of rock with holes and fissures, uniaxial compression tests sandstone samples combined double hole fissure defects were carried out using Particle Flow Code 2D (PFC2D) numerical simulation software. The behaviour mechanical properties at different angles analysed, evolution results stress field crack propagation studied. show that a decrease in angle, initiation stress, damage elastic modulus peak defective decrease, while strain increases, brittleness is weakened. Rocks lead to modes, positions development directions. After compression, both compressive tensile concentration areas are produced rock, but primary importance. area mainly distributed around fissures defect connecting line, decreases decreasing angle. This study can correctly predict provide reference for actual engineering.