1. Research Associate, Dept. of Civil and Environmental Engineering, Michigan Technological Univ., Houghton, MI 49931-1295.
2. Ph.D. Student, Graduate Research Assistant, Dept. of Civil and Environmental Engineering, Michigan Technological Univ., Houghton, MI 49931-1295.
3. Professor, Dept. of Civil and Environmental Engineering, Michigan Technological Univ., Houghton, MI 49931-1295 (corresponding author).