1. Professor, School of Traffic and Transportation Engineering, Changsha Univ. of Science and Technology, and Key Laboratory of Rd. Structure and Material of Ministry of Transport (Changsha), Changsha, Hunan 410014, CN, e-mail: yao26402@126.com
2. Professor, School of Civil Engineering and Architecture, Changsha Univ. of Science and Technology, Changsha, Hunan 410014, CN, e-mail: wucosh@163.com
3. Master, School of Traffic and Transportation Engineering, Changsha Univ. of Science and Technology, Changsha, Hunan 410014, CN (Corresponding author), e-mail: 15116267914@163.com
4. Master, School of Traffic and Transportation Engineering, Changsha Univ. of Science and Technology, Changsha, Hunan 410014, CN, e-mail: fkk1042@163.com