1. Ph.D. Student, Dept. of Civil and Environmental Engineering, Univ. of Alberta, Edmonton AB, Canada T6G 2W2.
2. Golder Associates, Ltd., Calgary, Alberta, Canada.
3. Emeritus Professor, Dept. of Civil and Environmental Engineering, Univ. of Alberta, Edmonton AB, Canada T6G 2W2.
4. Professor, Dept. of Civil and Environmental Engineering, Univ. of Alberta, Edmonton AB, Canada T6G 2W2 (corresponding author).