1. PhD Candidate, Dept. of Civil, Architectural and Environmental Engineering, Drexel Univ., Philadelphia, PA 19104; formerly, Graduate Research Assistant, Dept. of Civil Engineering, Colorado State Univ., Fort Collins, CO 80523-1372.
2. Professor, Dept. of Civil Engineering, Colorado State Univ., Fort Collins, CO 80523-1372 (corresponding author).
3. Professor and Chair, Dept. of Civil and Environmental Engineering, Bucknell Univ., Lewisburg, PA 17837.