1. Associate Professor, School of Transportation, Southeast Univ., Nanjing 210096, P. R. China.
2. Professor, Key Laboratory of Concrete and Prestressed Concrete Structures, Ministry of Education, Southeast Univ., Nanjing 210096, P. R. China (corresponding author).
3. Postgraduate Researcher, School of Civil Engineering, Southeast Univ., Nanjing 210096, P. R. China.
4. Researcher, CONSTRUCT & Faculty of Engineering, Univ. of Porto, Porto 4200-465, Portugal.
5. Lecturer, College of Civil Engineering, Nanjing Forestry Univ., Nanjing 210037, P. R. China.
6. Professor, Dept. of Civil Engineering and Mechanics, Columbia Univ., New York 10027.