Particle flow analysis of crack propagation characteristics of cross jointed rock under uniaxial compression

In order to study the influence of cross joints on rock strength and fracture characteristics，the simulation of specimens containing cross joints under uniaxial compression was carried out to explore the influence of cross angle and cross way of cross joints on the mechanics characteristics and crack coalescence behavior. A simulation model of sample was established in particle flow code PFC2D，based on the experimental results of intact specimens，a set of microscopic parameters that can reflect the mechanical properties of sample were obtained. Then，the uniaxial compression tests of the specimens with X-type，L-type and T-type cross joints. The results are as follows：(1) The uniaxial compressive strength，peak strain and elastic modulus of three cross-type specimens show a good linear negative correlation with the cross angle，especially the L-type. (2) The crack coalescence behavior of three cross-type specimens is similar，and the failure mode is basically tensile failure. The number of microcracks and the damage degree of three cross-type specimens are significantly affected by the cross angle. (3) The proportion of each microcrack is basically stable when the specimens containing cross joints are failure. The failure modes of meso-structure of the specimens containing cross joints under uniaxial compression are mainly tensile failure and shear failure. The results provide a certain theoretical basis for the penetration of the Xianglushan tunnel in Central Yunnan Water Diversion Project，and can also provide reference for similar projects. © 2024 Academia Sinica. All rights reserved.