1. Doctoral Candidate, School of Engineering and Technology, Asian Institute of Technology, P.O. Box 4, Klong Luang, Pathumthani 12120, Thailand (corresponding author).
2. Visiting Assistant Professor, Dept. of Civil and Environmental Engineering, Norwich Univ., 158 Harmon Dr., Northfield, VT 05663.
3. Professor, School of Engineering and Technology, Asian Institute of Technology, P.O. Box 4, Klong Luang, Pathumthani 12120, Thailand.