1. Engineering Science Program and Dept. of Civil Engineering, National Univ. of Singapore, Kent Ridge, Singapore 119260.
2. Dept. of Building and Construction, City Univ. of Hong Kong, Tat Chee Ave., Kowloon, Hong Kong.
3. Dept. of Building and Construction, City Univ. of Hong Kong, Tat Chee Ave., Kowloon, Hong Kong (corresponding author). E-mail: bccwlim@cityu.edu.hk