1. Research Fellow, School of Civil and Environmental Engineering, Nanyang Technological Univ., Singapore 639798.
2. Professor, School of Civil and Resource Engineering, Univ. of Western Australia, Crawley WA 6009, Australia.
3. Ph.D. Candidate, School of Civil and Resource Engineering, Univ. of Western Australia, Crawley WA 6009, Australia.
4. Associate Professor, School of Civil and Environmental Engineering, Nanyang Technological Univ., Singapore 639798 (corresponding author).