1. Ph.D. Student, State Key Laboratory of Disaster Reduction on in Civil Engineering, Tongji Univ., Shanghai, P.R. China 200092.
2. Professor, Dept. of Bridge Engineering, College of Civil Engineering, Tongji Univ., Shanghai, P.R. China 200092.
3. Graduate Student, State Key Laboratory of Disaster Reduction in Civil Engineering, Tongji Univ., Shanghai, P.R. China 200092.
4. Professor, State Key Laboratory of Disaster Reduction in Civil Engineering, Tongji Univ., Shanghai, P.R. China 200092 (corresponding author).