1. Beijing Jiaotong Univ.; Beijing
2. State Key Laboratory of Hydro-science and Engineering; China
3. Dep. of Civil and Environmental Engineering; Hong Kong Univ. of Science and Technology; Hong Kong
4. State Key Laboratory of Geohazard Prevention and Geoenvironment Protection; Chengdu Univ. of Technology; Chengdu 610059 Sichuan
5. College of Civil Engineering and Architecture China Three Gorges Univ.; China