1. Lecturer, College of Water Conservancy and Hydropower Engineering, Hohai Univ., 1 Xikang Rd., Nanjing 210098, China (corresponding author).
2. Professor, College of Water Conservancy and Hydropower Engineering, Hohai Univ., 1 Xikang Rd., Nanjing 210098, China.
3. Professor, Dept. of Civil Engineering, Univ. of Toronto, 35 St. George St. Toronto, ON, Canada M5S 1A4.