1. Postdoctor, Faculty of Engineering, China Univ. of Geosciences, Wuhan, Hubei 430074, China.
2. Professor, Dept. of Civil, Environmental and Geomatic Engineering, Univ. College London, Gower St., London WC1E 6BT, U.K.; formerly, Univ. of Hong Kong, Pok Fu Lam Hong Kong, China (corresponding author).
3. Professor, College of Civil Engineering and Mechanics, Huazhong Univ. of Science and Technology, Wuhan, Hubei 430074, China.