1. Ph.D. Candidate, Dept. of Civil and Environmental Engineering, Univ. of Michigan, 2350 Hayward St., G.G. Brown Bldg., Ann Arbor, MI 48109.
2. Lecturer, School of Natural and Built Environments, Univ. of South Australia, North Terrace and Frome Rd., Adelaide, SA 5000, Australia.
3. Associate Professor, Dept. of Civil and Environmental Engineering, Univ. of Michigan, 2350 Hayward St., G.G. Brown Bldg., Ann Arbor, MI 48109 (corresponding author).