1. Ph.D. Student, School of Civil, Environmental and Mining Engineering, Univ. of Adelaide, SA 5005, Australia.
2. Research Associate, School of Civil, Environmental and Mining Engineering, Univ. of Adelaide, SA 5005, Australia.
3. Professor, School of Civil, Environmental and Mining Engineering, Univ. of Adelaide, SA 5005, Australia (corresponding author).
4. Senior Lecturer, Dept. of Civil Engineering, Univ. of Malaya, 50603 Kuala Lumpur, Malaysia.