1. Assistant Professor, Dept. of Civil Engineering, California State Univ., Chico, CA 95929.
2. Associate Professor, Dept. of Engineering, Penn State Altoona, Altoona, PA 16601.
3. Graduate Research Assistant, Dept. of Civil and Environmental Engineering, Washington State Univ., Pullman, WA 99164.
4. Professor and Chair, Dept. of Civil and Environmental Engineering, Washington State Univ., Spokane St., Sloan Hall 30, Pullman, WA 99164 (corresponding author).