1. Graduate Student Research Assistant, Dept. of Civil and Environmental Engineering, Michigan Technological Univ., Houghton, MI 49931 (corresponding author).
2. Associate Professor, Dept. of Civil and Environmental Engineering, Michigan Technological Univ., Houghton, MI 49931.
3. George T. Abell Professor of Infrastructure, Dept. of Civil and Environmental Engineering, Colorado State Univ., Fort Collins, CO 80523-1372.