1. Associate Professor, Key Laboratory of Civil Engineering Safety and Durability of China Education Ministry, Dept. of Civil Engineering, Tsinghua Univ., Beijing 100084, China (corresponding author).
2. Graduate Student, Beijing Engineering Research Center of Steel and Concrete Composite Structures, Dept. of Civil Engineering, Tsinghua Univ., Beijing 100084, China.
3. Graduate Student, Dept. of Civil Engineering, Tsinghua Univ., Beijing 100084, China.
4. Professor, Lyles School of Civil Engineering, Purdue Univ., West Lafayette, IN 47907.