1. Postdoctoral Fellow, School of Civil and Transportation Engineering, Guangdong Univ. of Technology, Guangzhou 510006, China.
2. Professer, School of Civil and Transportation Engineering, Guangdong Univ. of Technology, Guangzhou 510006, China (corresponding author).
3. Professer, School of Civil Engineering and Transportation, South China Univ. of Technology, Guangzhou 510641, China.