1. Ph.D. Student, Dept. of Civil and Environmental Engineering, Utah State Univ.; Logan, UT 84322-4110 (corresponding author).
2. Professor, Dept. of Civil and Environmental Engineering, Utah State Univ., Logan, UT 84322-4110.
3. PhD Student, Dept. of Civil and Environmental Engineering, Univ. of Michigan, Ann Arbor, MI 48109.