1. Associate Professor, Dept. of Civil and Environmental Engineering, Univ. of Michigan, 2040 GG Brown, 2350 Hayward, Ann Arbor, MI 48109-2125 (corresponding author).
2. Assistant Professor, Dept. of Civil and Environmental Engineering, Univ. of Illinois Urbana-Champaign, 3110 Newmark Civil Engineering Laboratory, MC-250 205 North Mathews Ave., Urbana, IL 61801-2352.
3. Professor, Dept. of Civil and Environmental Engineering, Univ. of Michigan, 2040 GG Brown, 2350 Hayward, Ann Arbor, MI 48109-2125.