1. Ph.D. Candidate, School of Civil Engineering, Changsha Univ. of Science and Technology, 960 Wanjiali S Rd., Changsha, Hunan 410114, China.
2. Associate Professor, School of Civil Engineering, Changsha Univ. of Science and Technology, 960 Wanjiali S Rd., Changsha, Hunan 410114, China (corresponding author).
3. Professor, Dept. of Civil and Environmental Engineering, Louisiana State Univ., Baton Rouge, LA 70803.
4. Professor, School of Civil Engineering, Changsha Univ. of Science and Technology, 960 Wanjiali S Rd., Changsha, Hunan 410114, China.