1. Assistant Professor, Civil and Environmental Engineering, Colorado State Univ., Fort Collins, CO 80523-1372 (corresponding author).
2. Professor, Civil and Environmental Engineering, Colorado State Univ., Fort Collins, CO 80523-1372.
3. Engineer, Nelson Engineering, Jackson, WY 83001.
4. Graduate Research Assistant, Civil and Environmental Engineering, Colorado State Univ., Fort Collins, CO 80523-1372.