1. Lecturer, State Key Laboratory of Mountain Bridge and Tunnel Engineering, Chongqing Jiaotong Univ., Chongqing 400074, China.
2. Professor, School of Civil Engineering, Chongqing Univ., Chongqing 400044, China (corresponding author).
3. Professor, School of Civil Engineering, Chongqing Univ., Chongqing 400044, China.