1. Associate Professor, Dept. of Highway and Railway Engineering, Transportation College, Southeast Univ. Nanjing, Jiangsu 210096, China.
2. Postdoctoral Research Associate, Dept. of Civil and Environmental Engineering, Univ. of Tennessee, Knoxville, TN 37996 (corresponding author).
3. Graduate Student, Dept. of Highway and Railway Engineering, Transportation College, Southeast Univ. Nanjing, Jiangsu 210096, China.