1. Assistant Professor, School of Civil Engineering, Southwest Jiaotong Univ., Highway Engineering Key Laboratory of Sichuan Province, Chengdu, Sichuan 610031, China.
2. Professor, School of Civil and Environmental Engineering, Oklahoma State Univ., Stillwater, OK 74078; Adjunct Professor, School of Civil Engineering, Southwest Jiaotong Univ., Highway Engineering Key Laboratory of Sichuan Province, Chengdu, Sichuan 610031, China (corresponding author).
3. Professor, School of Civil Engineering, Southwest Jiaotong Univ., Highway Engineering Key Laboratory of Sichuan Province, Chengdu, Sichuan 610031, China.
4. Professor, School of Civil Engineering, Southwest Jiaotong Univ., Key Laboratory of High-speed Railway Engineering, Chengdu, Sichuan 610031, China.