1. Research Assistant, Dept. of Civil Engineering, Univ. of British Columbia, 6250 Applied Science Ln., Vancouver, BC, Canada V6T 1Z4 (corresponding author).
2. Professor, Dept. of Civil Engineering, Univ. of British Columbia, 6250 Applied Science Ln., Vancouver, BC, Canada V6T 1Z4.
3. Assistant Professor, Dept. of Civil and Environmental Engineering, Carleton Univ., 1125-3432 Colonel By Dr., Ottawa, ON, Canada K1S 5B6.
4. Research Assistant, Dept. of Civil Engineering, Univ. of British Columbia, 6250 Applied Science Ln., Vancouver, BC, Canada V6T 1Z4.