1. Associate Member, ASCE
2. Assoc. Engr., Montgomery Watson Mining Group, 165 South Union Blvd., Ste. 410, Lakewood, CO 80228; formerly, Grad. Student, Dept. of Civ. Engrg., Colo. State Univ., Fort Collins, CO 80523-1372.
3. Prof., Dept. of Civ. Engrg., Colo. State Univ., Fort Collins, CO 80523-1372 (corresponding author). E-mail: shackel@engr.colostate.edu