1. Research Fellow, Dept. of Civil Engineering, Bldg. 60, Monash Univ., Clayton, VIC 3800, Australia.
2. Doctoral Candidate, Dept. of Civil Engineering, Bldg. 60, Monash Univ., Clayton, VIC 3800, Australia.
3. Professor, Dept. of Civil Engineering, Bldg. 60, Monash Univ., Clayton, VIC 3800, Australia (corresponding author).