Acoustic emission fractal characteristics of different prefabricated fractured sandstone under uniaxial compression tests

To study the strength characteristics, acoustic emission (AE) rules, and fractal characteristics of the single fractured sandstone under uniaxial compression tests, uniaxial compression strength tests were carried out on prefabricated single fractured sandstone samples with different angles and lengths. The results show that the maximum axial bearing capacity of the specimens decreases with the increase of the fracture length. The prefabricated fracture dip angle has a certain influence on the maximum axial bearing capacity of sandstone, but it is less than the influence of the fracture length on the bearing capacity of the sample. The existence of prefabricated fractures has a great influence on the correlation dimension of sandstone samples. When the prefabricated fracture is in the range of 31.6°–74.7°, the correlation dimension tends to decrease with the increase of the length of the prefabricated fracture. When the prefabricated fracture length l₁/l of the sandstone sample is less than 0.26, the correlation dimension tends to increase first and then decrease with the change of the inclination angle of the prefabricated fracture. The experimental results can provide a reference for roadway support with strong joint and fracture development in the surrounding rock.