1. Ph.D. Candidate, Key Laboratory of Concrete and Prestressed Concrete Structures, Ministry of Education, 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. Assistant Professor, Charles E. Via Jr. Dept. of Civil & Environmental Engineering, Virginia Tech, Blacksburg, VA 24061.
4. Professor, Highway College, Chang’an Univ., Xi’an, Shaanxi 710064, China.