1. School of Civil Engineering, Central South University, Changsha 410075, Hunan, P. R. China
2. State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures, Shijiazhuang Tiedao University, Shijiazhuang 050043, P. R. China
3. Department of Architecture and Civil Engineering, City University of Hong Kong, Kowloon, Hong Kong, P. R. China