1. Research Fellow, School of Civil and Environmental Engineering, Nanyang Technological Univ., Singapore 639798.
2. Professor, Key Laboratory of Disaster Prevention and Structural Safety of Ministry of Education, College of Civil Engineering and Architecture, Guangxi Univ., Nanning 530004, China (corresponding author).
3. Professor, Key Laboratory of Disaster Prevention and Structural Safety of Ministry of Education, College of Civil Engineering and Architecture, Guangxi Univ., Nanning 530004, China.