1. Ph.D. Candidate, School of Civil and Transportation Engineering, Hebei Univ. of Technology, 5340 Xiping Rd., Beichen District, Tianjin 300401, China.
2. Professor, School of Civil and Transportation Engineering, Hebei Univ. of Technology, 5340 Xiping Rd., Beichen District, Tianjin 300401, China (corresponding author).