1. Professor, Centre for Infrastructure Engineering and Safety, School of Civil and Environmental Engineering, Univ. of New South Wales, Sydney, NSW 2052, Australia (corresponding author).
2. Scientia Professor, Centre for Infrastructure Engineering and Safety, School of Civil and Environmental Engineering, Univ. of New South Wales, Sydney, NSW 2052, Australia.
3. Professor, Dept. of Civil Engineering, Tsinghua Univ., Beijing 100084, China.