1. Department of Civil Engineering, Xiamen University, Xiamen 361005, China
2. Department of Civil and Structural Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
3. Department of Civil Engineering and Mechanics, Huazhong University of Science and Technology, Wuhan 430074, China
4. School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA