Dongqiao Liu is a professor at China University of Mining and Technology-Beijing (CUMTB). He currently serves as Vice Director of the State Key Laboratory of Tunnel Engineering (TESKL), and Vice Dean of the School of Mechanics and Civil Engineering, CUMTB. He is a member of ISRM Commission on Rockburst, Deputy Secretary-General of the Soft Rock Engineering and Deep Disaster Control Branch of Chinese Society for Rock Mechanics & Engineering. He received his Bachelor and Master Degree in Mathematics from CUMTB in 2008 and 2011 respectively, and obtained his Ph.D. in Geotechnical Engineering from CUMTB in 2014. He has mainly engaged in deep geotechnical engineering and tunnel engineering, including rockburst mechanism and control, rock constitutive theory , etc. He has leaded 2 projects of the National Natural Science Foundation of China and 2 international cooperation projects, published more than 110 technical papers, and won 10 provincial and ministerial-level awards.

Brief Introduction to the Report

Rockburst is a highly destructive dynamic disaster in mining and tunnel engineering, with documented occurrences in over 115 countries and regions worldwide. It causes heavy casualties and severe engineering losses, and its complex mechanism makes it a long-standing tough issue restricting the safe development of deep underground engineering. To reveal its intrinsic mechanism and identify reliable early warning precursors, this report demonstrates the systematic experimental research achievement on rockburst mechanism and its precursor characteristics. Based on the self-developed strainburst and impact rockburst experimental systems by TESKL, rockbursts under different engineering conditions were simulated successfully in the laboratory. Combined with acoustic emission, force-deformation acquisition and high-speed photography monitoring, this report analyzes rockburst stress evolution and energy mechanism, establishes an excess energy calculation method, and explores acoustic emission big data characteristics during rockburst. By classifying crack types via support vector machine, the decreasing proportion of tensile cracks was founded as a key precursor characteristic of rockburst. The results confirm that rockburst is an excavation-dependent engineering behavior rather than an inherent brittle failure property of rock under conventional compression tests. The revealed mechanism and precursor characteristic provide important theoretical and experimental support for rockburst prediction and control, and lay a foundation for the safe and sustainable development of deep underground engineering.