1. Ph.D. Candidate, School of Civil Engineering, Dalian Univ. of Technology, No. 2, Linggong Rd., Ganjingzi District, Dalian 116024, China.
2. Professor, School of Transportation and Logistics, Dalian Univ. of Technology, No. 2, Linggong Rd., Ganjingzi District, Dalian 116024, China (corresponding author).