1. Assistant Professor, School of Highway Engineering, Chang’an Univ., Xi’an 710064, China; formerly, Ph.D. Student, Dept. of Civil and Environmental Engineering, Hong Kong Polytechnic Univ., Kowloon 51800, Hong Kong.
2. Associate Professor, Dept. of Civil and Environmental Engineering, Hong Kong Polytechnic Univ., Kowloon 518000, Hong Kong (corresponding author).