1. College of Civil Engineering, Zhejiang Univ. of Technology, Hangzhou, Zhejiang 310014, PR China.
2. Ph.D. Student, School of Civil Engineering, Harbin Institute of Technology, Harbin, Heilongjiang 150090, PR China (corresponding author).
3. Associate Professor, College of Civil Engineering, Zhejiang Univ. of Technology, Hangzhou, Zhejiang 310014, PR China.