1. Professor, Dept. of Civil Engineering, Shanghai Jiao Tong Univ., Shanghai 200240, P.R. China; and Invited Professor, State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu Univ. of Technology, Chengdu 610059, P.R. China (corresponding author).
2. Professor, State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu Univ. of Technology, Chengdu 610059, P.R. China.
3. Professor, Dept. of Civil and Environmental Engineering, Univ. of Massachusetts, Amherst, MA 01002.