1. Professor, Key Laboratory of Structural Engineering and Vibration of China Education Ministry, Dept. of Civil Engineering, Tsinghua Univ., Beijing 100084, China.
2. Researcher, Bridge Technology Center, CCCC Highway Consultants Co., Ltd., Beijing 100088, China; formerly, Ph.D. Candidate, Dept. of Civil Engineering, Tsinghua Univ., Beijing 100084, China.
3. Associate Professor, Dept. of Civil and Environmental Engineering, Louisiana State Univ., Baton Rouge, LA 70803 (corresponding author).