1. Department of Structural Engineering, Tongji University, Shanghai 200092, P. R. China
2. School of Civil Engineering, Southwest Jiaotong University, Chengdu 610031, P. R. China
3. State Key Laboratory of Disaster Reduction in Civil Engineering, Shanghai 200092, P. R. China
4. Wind Engineering Research Center, Tokyo Polytechnic University, Kanagawa 243-0297, Japan