1. Associate Professor, Dept. of Civil and Transportation Engineering, Hohai Univ., Nanjing 210098, China (corresponding author).
2. Postgraduate Student, Dept. of Civil and Transportation Engineering, Hohai Univ., Nanjing 210098, China.
3. Professor, Dept. of Civil Engineering, Southeast Univ., Nanjing 210096, China.
4. Assistant Engineer, Anhui Transportation Investment Group Co., 180 Camphor Ave., High-Tech Development Zone, Hefei 230088, China.