1. Graduate Student, Dept. of Civil Engineering, Univ. of Moratuwa, Moratuwa 10400, Sri Lanka.
2. Senior Professor, Dept. of Civil Engineering, Univ. of Moratuwa, Moratuwa 10400, Sri Lanka (corresponding author).
3. Professor, School of Engineering, RMIT Univ., Melbourne, VIC 3001, Australia.