1. Professor, College of Civil Engineering and Architecture, Guangxi Univ., Nanning 530004, China.
2. Ph.D. Candidate, College of Civil Engineering and Architecture, Guangxi Univ., Nanning 530004, China.
3. Associate Professor, College of Civil Engineering and Architecture, Guangxi Univ., Nanning 530004, China.
4. Associate Professor, School of Civil and Environmental Engineering, Nanyang Technological Univ., Singapore 639798 (corresponding author).