1. Ph.D. Candidate, Dept. of Civil Engineering, Tsinghua Univ., Beijing 100084, China.
2. Associate Professor, Dept. of Civil Engineering, Tsinghua Univ., Beijing 100084, China (corresponding author).
3. Associate Professor, Griffith School of Engineering, Gold Coast Campus, Griffith Univ., Southport, Queensland 4222, Australia.
4. Master Student, Dept. of Civil Engineering, Tsinghua Univ., Beijing 100084, China.