1. Professor, State Key Laboratory of Hydrology, Water Resources and Hydraulic Engineering, Hohai Univ., Nanjing 210098, China. E-mail: weizhu@jlonline.com
2. Postgraduate Student, College of Environmental Science and Engineering, Hohai Univ., Nanjing 210098, China. E-mail: zhangchunlei@mail.edu.cn
3. Associate Professor, Geotechnical Research Institute, Hohai Univ., Nanjing 210098, China. E-mail: acfchiu@yahoo.com.cn