1. Ph.D. Student, School of Civil Engineering, Central South Univ., Changsha 410075, China.
2. Professor, School of Civil Engineering, Central South Univ., Changsha 410075, China (corresponding author).
3. Professorate Senior Engineer, China Railway Southwest Research Institute Co., Ltd., Chengdu 611731, China.
4. Professor, School of Civil Engineering, Central South Univ., Changsha 410075, China.
5. Lecturer, School of Civil Engineering, Central South Univ. of Forestry and Technology, Changsha 410004, China.