1. Associate Professor, State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan, Hubei 430071, P.R. China; formerly, Dept. of Civil and Environmental Engineering, Colorado School of Mines, Golden, CO 80401 (corresponding author). ORCID: .
2. Professor, Dept. of Civil and Environmental Engineering, Colorado School of Mines, 1012 14th St., Golden, CO 80401.
3. Associate Professor, Dept. of Structural Engineering, Univ. of California San Diego, La Jolla, CA 92131.