1. Professor, Univ. of Michigan, Dept. of Civil and Environmental Engineering, 2340 GG Brown, Ann Arbor, MI 48109-2125 (corresponding author).
2. Graduate Student Research Assistant, Univ. of Michigan, Dept. of Civil and Environmental Engineering, 2340 GG Brown, Ann Arbor, MI 48109-2125.
3. Visiting Student Scholar, Univ. of Michigan, Dept. of Civil and Environmental Engineering, 2340 GG Brown, Ann Arbor, MI 48109-2125.