Dr. Zhaofeng Wang is an Associate Research Professor at the State Key Laboratory of Rock Mechanics and Engineering Safety, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, China. He was selected for the Young Elite Scientists Sponsorship Program of the China Association for Science and Technology. He received his BEng degree from Huazhong University of Science and Technology, his MSc degree from China University of Mining and Technology-Beijing, and his PhD degree from the University of Chinese Academy of Sciences. He currently serves as a committee member of the Youth Working Committee of the Chinese Society for Rock Mechanics and Engineering. His research focuses on digital monitoring, mechanical behaviour modelling, and intelligent assessment of geotechnical engineering under extreme environments. He has led five national research projects, published more than 80 SCI/EI-indexed papers, edited one English monograph, been granted 12 invention patents, and contributed to the development of four construction methods and technical specifications. His research achievements have been recognized by several awards, including the First Prize of the Hubei Provincial Technological Invention Award and the First Prize of the Green Mine Natural Science Award. His major contributions have been applied in more than ten major engineering projects, including the Sichuan-Tibet Railway and the China Jinping Underground Laboratory.

Brief Introduction to the Report

With major engineering projects, such as transportation tunnels and underground hydropower caverns, extending to greater depths, deep underground works are increasingly exposed to high in-situ stress, intense excavation disturbance, and complex geological structures. Hazards induced by rock fracturing, including rockbursts, spallings, collapses, and local instabilities, have become critical challenges to safe construction and long-term operation. Hard rocks are typically characterized by high strength, high stiffness, and pronounced brittleness. Their intact matrix generally remains approximately elastic before peak strength, whereas macroscopic nonlinearity is mainly governed by the topological evolution of internal crack systems, including crack initiation, propagation, coalescence, and through-going failure. Unlike shallow rock masses or rocks under conventional triaxial conditions, deeply buried hard rocks are controlled by complex three-dimensional stress states, in which the intermediate principal stress, stress path, and local stress redistribution jointly regulate crack orientation, propagation mode, coalescence pattern, and failure path. This report focuses on the multiaxial fracturing of deeply buried hard rocks and addresses key challenges related to process identification, mechanism interpretation, and theoretical unification. It presents recent advances in the full-process quantitative characterization of fracture evolution, strain-energy-driven fracture localization, three-dimensional stress-induced fracture tendency, and stepped tensile-shear failure mechanisms. Furthermore, a nonlinear analysis framework for multiaxial hard rock fracturing is established to support surrounding rock stability assessment, disaster early warning, and digital twin modelling in deep underground engineering.