1. School of Civil Engineering, Harbin Institute of Technology, Harbin 150090, People's Republic of China, Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA 91125, USA
2. Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA 91125, USA,
3. School of Civil Engineering, Harbin Institute of Technology, Harbin 150090, People's Republic of China