1. Department of Civil Engineering, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
2. Department of Mechanical and Aerospace Engineering, University of Miami, Coral Gables, FL 33124
3. Department of Mechanical and Aerospace Engineering, University of Miami, Coral Gables, FL 33124 e-mail:
4. Department of Civil Engineering, Zhejiang University, Zijingang Campus, Hangzhou 310058, China;
5. Department of Engineering Mechanics, Zhejiang University, Yuquan Campus, Hangzhou 310027, China