1. Professor, State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan, Hubei 430071, PR China.
2. Professor, Dept. of Civil and Environmental Engineering, Colorado School of Mines, Golden, CO 80401 (corresponding author). ORCID: .
3. Shaw Professor and Head, Dept. of Civil and Environmental Engineering, Pennsylvania State Univ., University Park, PA 16802.