1. Associate Professor, Dept. of Civil and Transportation Engineering, Hohai Univ., No. 1 Xikang Rd., Nanjing 210098, China (corresponding author).
2. Postgraduate, Dept. of Civil and Transportation Engineering, Hohai Univ., No. 1 Xikang Rd., Nanjing 210098, China.
3. Senior Engineer, Corporation of Jiangsu Transportation Science Institute, No. 223 Shuiximen Rd., Nanjing 210017, China.