1. Professor, Dept. of Geotechnical Engineering, Tongji Univ., 1239 Siping Rd., Shanghai 200092, P.R. China (corresponding author).
2. Engineer, Architectural Design and Research Institute of Guangdong Province, 97 Liuhua Rd., Guangzhou 510010, P.R. China.
3. Professor, Dept. of Civil Engineering and State Key Laboratory of Ocean Engineering, Shanghai Jiao Tong Univ., Shanghai 200240, P.R. China.