Local stress distribution and evolution surrounding flaw and opening within rock block under uniaxial compression

Abstract Tunnel excavation changes the original stress state which directly leads to the surrounding rock fracture, many researches focus on the stress or displacement evaluation surrounding an opening or a tunnel. Flaws and openings dramatically change the state of internal stress within the rock mass, and the internal stress concentrates at some certain positions surrounding the opening. When the flaws and openings simultaneously exist, the internal stress interacts. To discuss about the stress evolution surrounding the flaw and opening, this study used the PFC program to establish numerical models containing one open flaw and two circular openings. Under uniaxial compression, the stress distributions surrounding the flaw and the openings at different loading stages and different flaw orientations were presented and the principal stress evolutions around the flaw and the openings were analyzed. The proposed numerical method in measuring local stress can be useful to evaluate the local stress distribution and evolution surrounding the flaw and opening.