1. Research Associate, Dept. of Civil and Environmental Engineering, Hong Kong Univ. of Science and Technology, Clear Water Bay, Hong Kong, China.
2. Ph.D. Student, Zachry Dept. of Civil Engineering, Texas A&M Univ., College Station, TX 77840.
3. Chair Professor, Dept. of Civil and Environmental Engineering, Hong Kong Univ. of Science and Technology, Clear Water Bay, Hong Kong, China (corresponding author).