Acoustic Emission and Mechanical Characteristics of Rock-Like Material Containing Single Crack Under Uniaxial Compression

Fissures are generally the weakest part in engineering rock masses. Once it extends, the masses would be in failure mode, which in turn triggers geological disasters. The fracture is one of the most critical factors affecting its mechanical properties. At present, there is a paucity of systematic research on the impact of the dip angles of failures on the mechanical properties of rock masses. In this paper, the influences of single fracture dip on the mechanical properties and acoustic emission parameters of rock-like materials were investigated by the uniaxial compression tests and acoustic emission tests. Then, numerical simulations of the crack extension process were carried out for rock-like materials of different inclination classes. The results show that as the crack dip angle increases, the rock material's peak strength will be V-shaped distribution, with the lowest strength at a dip angle of 45 degrees. The average deterioration degree of the strength by unilateral prefabricated fissures was 43.67%, with almost no effect when the fissure face's width was parallel to the loading direction. The damage modes of the specimen with and without prefabricated fissures are splitting damage and the shear damage, respectively. The stresses are concentrated at the two tips of the prefabricated fractures, and the wing cracks extend symmetrically until it penetrates vertically. The specimens with prefabricated 45 degrees inclined fractures show the highest degree of deterioration, with a single event releasing approximately 1/10 the energy of other rock-like materials.

Automated summary

This study investigates the influence of single fracture dip on the mechanical properties and acoustic emission parameters of rock-like materials through experiments and numerical simulations. The results indicate that as the crack dip angle increases, the rock material's peak strength will be affected, with the lowest strength at a dip angle of 45 degrees. The specimens with prefabricated 45 degrees inclined fractures show the highest degree of deterioration, releasing approximately 1/10 of the energy of other rock-like materials.