1. Professor, School of Civil Engineering and Architecture, Changsha Univ. of Science and Technology, Changsha 410004, China (corresponding author).
2. Associate Professor, School of Civil Engineering and Architecture, Changsha Univ. of Science and Technology, Changsha 410004, China.
3. Edwin B. and Norma S. McNeil Distinguished Professor, Dept. of Civil and Environmental Engineering, Louisiana State Univ., Baton Rouge, LA 70803.