A numerical study of the mechanical properties and rock bridge coalescence of discrete distribution jointed rock masses under uniaxial loading.

Fractured rocks, as typical engineering materials, are commonly influenced by the distinct arrangement of joints and the angle of their inclination. In this study, uniaxial compression tests were conducted on three series of marble samples (a-series, b-series, and c-series), each containing a dip angle of 45°. The mechanical properties and crack propagation characteristics were subsequently analyzed. Furthermore, three series of numerical simulations of the fractured rocks were performed using the discrete element method. A comparison was made between the failure patterns and crack distribution observed in the laboratory tests and those obtained from the PFC simulations, including crack distribution, particle displacement magnitude, and displacement distribution maps for each specimen. Additionally, the strength, deformation characteristics, and failure processes of the rock mass were examined. The results demonstrate that the distribution of joints significantly influences the mechanical behavior of marble. The numerical simulations reveal that both the joint dip angle and joint distribution affect the strength and deformation characteristics of the rock mass. The trend of peak strength variation with dip angle is consistent across all three series, with peak strength increasing as the dip angle increases. Both the joint dip angle and joint distribution impact the failure process of the rock samples; however, the influence of joint distribution is found to be more significant than that of joint dip angle.