1. Ph.D. Student, Dept. of Civil and Environmental Engineering, Washington State Univ., 2001 East Grimes Way, 200W PACCAR, Pullman, WA 99164-5815.
2. Assistant Professor, Dept. of Civil and Environmental Engineering Washington State Univ., 2001 East Grimes Way, 248 PACCAR, Pullman, WA 99164-5815 (corresponding author).