1. Lecturer, Dept. of Building and Construction, City Univ. of Hong Kong, Tat Chee Ave., Kowloon, Hong Kong.
2. Professor in Civil Engineering, National Univ. of Singapore, Kent Ridge, Singapore 119260.
3. Chair Professor, Dept. of Building and Construction, City Univ. of Hong Kong, Tat Chee Ave., Kowloon, Hong Kong (corresponding author).