1. Associate Professor, Dept. of Civil and Environmental Engineering, Univ. of Western Ontario, London ON, Canada N6A 5B9 (corresponding author). E-mail: hongh@.eng.uwo.ca
2. Assistant Professor, Dept. of Civil and Environmental Engineering, Univ. of Western Ontario, London ON, Canada N6A 5B9.
3. Graduate Student, Dept. of Civil and Environmental Engineering, Univ. of Western Ontario, London ON, Canada N6A 5B9.