1. Ph.D. Candidate, Dept. of Civil and Environmental Engineering, Univ. of Michigan, Ann Arbor, MI 48109.
2. Professor, Dept. of Civil and Environmental Engineering, Univ. of Michigan, Ann Arbor, MI 48109 (corresponding author).
3. Associate Professor, Dept. of Civil and Environmental Engineering, Univ. of Michigan, Ann Arbor, MI 48109.