1. School of Civil and Transportation Engineering, Beijing Univ. of Civil Engineering and Architecture, Beijing 100044, China; Fundamental Research Innovation Center, Research Institute of Highway Ministry of Transport, Beijing 100088, China (corresponding author).
2. China Road & Bridge Corporation, Beijing 100011, China.
3. Fundamental Research Innovation Center, Research Institute of Highway Ministry of Transport, Beijing 100088, China.
4. Research Institute of Highway Ministry of Transport, Beijing 100088, China.