1. Dept. of Civil and Environmental Engineering, Univ. of Alberta, 9211 116 St. NW, Edmonton, AB, Canada T6G 1H9.
2. Dept. of Civil and Environmental Engineering, Univ. of Alberta, 9211 116th St., Edmonton, AB, Canada T6G 1H9.
3. Professor, Dept. of Civil and Environmental Engineering, Univ. of Alberta, 9211 116th St., Edmonton, AB, Canada T6G 1H9 (corresponding author).