1. Project Officer, School of Civil and Environmental Engineering, Nanyang Technological Univ., Block N1, B4b-07, Nanyang Avenue, Singapore 639798.
2. Professor, School of Civil and Environmental Engineering, Nanyang Technological Univ., Block N1, 01b-36, Nanyang Avenue, Singapore 639798 (corresponding author).
3. Associate Professor, School of Civil and Environmental Engineering, Nanyang Technological Univ., Block N1, 01c-80, Nanyang Avenue, Singapore 639798.