1. Assistant Professor, College of Civil Engineering, Chongqing Univ., Chongqing 400044, Singapore; formerly, Ph.D. Candidate, School of Civil and Environmental Engineering, Nanyang Technological Univ., 50 Nanyang Ave., Singapore 639798 (corresponding author).
2. Professor, School of Civil and Environmental Engineering, Nanyang Technological Univ., 50 Nanyang Ave., Singapore 639798.