1. Professor, Highway Engineering Key Laboratory of Sichuan Province, School of Civil Engineering, Southwest Jiaotong Univ., Chengdu 610031, China.
2. Research Assistant, Highway Engineering Key Laboratory of Sichuan Province, School of Civil Engineering, Southwest Jiaotong Univ., Chengdu 610031, China (corresponding author).
3. Research Assistant, Highway Engineering Key Laboratory of Sichuan Province, School of Civil Engineering, Southwest Jiaotong Univ., Chengdu 610031, China.