1. Assistant Research Scientist, State Key Laboratory for GeoMechanics and Deep Underground Engineering, China Univ. of Mining and Technology, Jiangsu 221116, China; formerly, Research Fellow, Univ. of Nottingham, Nottingham NG7 2RD, U.K. (corresponding author).
2. Associate Professor, Faculty of Engineering, Univ. of Nottingham, Nottingham NG7 2RD, U.K.
3. Professor, Faculty of Engineering, Univ. of Nottingham, Nottingham NG7 2RD, U.K.