1. Research Assistant Professor, Dept. of Civil and Environmental Engineering, Univ. of Tennessee, Knoxville, TN 37996-2010.
2. Professor, Dept. of Civil and Environmental Engineering, Univ. of Alaska, Fairbanks, AK 99775-5900.
3. Edwin G. Burdette Professor, Dept. of Civil and Environmental Engineering, Univ. of Tennessee, Knoxville, TN 37996-2010 (corresponding author).