Particle flow analysis of the influences of joints on rock mechanical properties

The failure of natural rock mainly forms along the joint planes; therefore, the existence of joints heavily affects the rock strength. The influences of joints with a different dip angle and cross double joints on rock mass strength were analyzed using theoretical calculation and particle flow PFC2D software to explore the mechanical properties of joints on rock failure. Results show that the strength of a jointed rock has obvious angle-range effects in the uniaxial compression text, and the peak strength of rock specimens is typical of the "U" type with the increase of the joint dip angle. For the rock mass of cross double joints, the rock mass strength is determined by the strength of joints when the joint dip angle of either joint is between 45° and 75°. The rock mass strength is determined by the superposition of the effects of these two joints when the joint dip angles of the two joints are both between 45° and 75° the influences of joints on the rock mass strength are not obvious when neither of the joint dip angles of the two joints is between 45° and 75°. The conclusions obtained in the study have significant implications for understanding the laws of joint rock strength. © 2016 Eastern Macedonia and Thrace Institute of Technology.