1. Graduate Student and Research Assistant, Dept. of Civil, Construction, and Environmental Engineering, Iowa State Univ., 405 Town Engineering, Ames, IA 50011-3232.
2. Wilson Engineering Professor and Associate Chair, Dept. of Civil, Construction and Environmental Engineering, Iowa State Univ., 376 Town Engineering, Ames, IA 50011-3232 (corresponding author).
3. Assistant Professor, Dept. of Civil and Environmental Engineering, Lafayette College, 321 Acopian Engineering Center, Easton, PA 18042.