1. Assistant Professor, Dept. of Civil and Environmental Engineering, National Univ. of Singapore, Singapore 117576, Singapore (corresponding author).
2. Engineer, KKLim & Associates Pte. Ltd., Singapore 159349; formerly, Undergraduate Student, Dept. of Civil and Environmental Engineering, National Univ. of Singapore, Singapore 117576, Singapore.
3. Professor, Dept. of Civil and Environmental Engineering, National Univ. of Singapore, Singapore 117576, Singapore.