1. Postdoctoral Fellow, Dept. of Civil and Environmental Engineering, Hong Kong Polytechnic Univ., Hung Hom, Kowloon, Hong Kong, China; Postdoctoral Fellow, Laboratoire Navier, École des Ponts ParisTech, Paris 77420, France.
2. Associate Professor, Dept. of Civil and Environmental Engineering, Hong Kong Polytechnic Univ., Hung Hom, Kowloon, Hong Kong, China (corresponding author).