1. Graduate Student Researcher, Dept. of Civil and Environmental Engineering, Michigan State Univ., East Lansing, MI 48824-1226.
2. Associate Professor, Dept. of Civil and Environmental Engineering, Michigan State Univ., East Lansing, MI 48824-1226 (corresponding author).
3. Associate Professor, Dept. of Civil and Environmental Engineering, George Washington Univ., Washington, DC 20052.