1. Associate Professor, College of Civil Engineering, Hohai Univ., Nanjing, Jiangsu 210098, P. R. China; Associate Professor, College of Hydraulic & Civil Engineering, Shandong Agriculture Univ., Tai’an, Shandong 271018, P. R. China. E-mail: cmszhy@163.com
2. Professor, College of Civil Engineering, Hohai Univ., Nanjing, Jiangsu 210098, P. R. China (corresponding author). E-mail: qingwenren@163.com
3. Associate Professor, Dept. of Civil and Environmental Engineering, Washington State Univ., Pullman, WA 99164-2910. E-mail: qiao@wsu.edu