1. Associate Professor, College of Civil Engineering, Zhejiang Univ. of Technology, Hangzhou 310014, China (corresponding author).
2. Graduate Student, College of Civil Engineering, Zhejiang Univ. of Technology, Hangzhou 310014, China.
3. Professor, Civil & Environmental Engineering, Univ. of California, Davis, CA 95616.
4. Associate Professor, College of Civil Engineering, Taiyuan Univ. of Technology, Taiyuan 030024, China.