1. Chaired Professor and Dean, College of Civil Engineering, Hunan Univ., Changsha 410082, China; and Research Professor, Dept. of Civil Engineering, Univ. of Southern California, Los Angeles, CA 90089 (corresponding author).
2. Ph.D. Student, College of Civil Engineering, Hunan Univ., Changsha 410082, China; and Research Assistant, Sapienza Univ., Via A. Gramsci 53, Rome 00197, Italy.
3. Research Assistant, College of Civil Engineering, Hunan Univ., Changsha 410082, China.