1. School of Civil Engineering, Fujian University of Technology, Fuzhou 350118, P. R. China
2. School of Civil Engineering, Central South University, Changsha 410075, P. R. China
3. School of Civil Engineering and Architecture, East China Jiaotong University, Nanchang 330000, P. R. China
4. China Railway Guangzhou Engineering Group Co, Guangzhou 511459, P. R. China