1. Professor, Dept. of Civil and Environmental Engineering, Washington State Univ., Pullman, WA 99164-2910 (corresponding author),
2. Graduate Student, Dept. of Civil and Environmental Engineering, Washington State Univ., Pullman, WA 99164-2910; mailing address: Brown & Caldwell, 501 Great Circle Rd., Nashville, TN 37228.
3. Research Scientist, Dept. of Civil and Environmental Engineering, Washington State Univ., Pullman, WA 99164-2910.