1. Associate Professor, College of Civil and Transportation Engineering, Hohai Univ., Xikang Rd. 1, Nanjing, Jiangsu 210098, P.R. China.
2. Professor, College of Civil and Transportation Engineering, Hohai Univ., Xikang Rd. 1, Nanjing, Jiangsu 210098, P.R. China (corresponding author).
3. Master Student, College of Civil and Transportation Engineering, Hohai Univ., Xikang Rd. 1, Nanjing, Jiangsu 210098, P.R. China.