1. Professor, Key Laboratory of Civil Engineering Safety and Durability of China Education Ministry, Department of Civil Engineering, Tsinghua University, Beijing, China 100084 (corresponding author).
2. Ph.D. Candidate, Key Laboratory of Civil Engineering Safety and Durability of China Education Ministry, Department of Civil Engineering, Tsinghua University, Beijing, China 100084.
3. Professor, Department of Civil and Environmental Engineering, Louisiana State University, Baton Rouge, LA 70803, and Adjunct Professor, School of Civil Engineering and Architecture, Changsha University of Science and Technology, Changsha, China.
4. Former Graduate Student, Key Laboratory of Civil Engineering Safety and Durability of China Education Ministry, Department of Civil Engineering, Tsinghua University, Beijing, China 100084.