1. Structural Engineer, Parsons Brinckerhoff, 999 3rd Ave, Suite 2200, Seattle, WA 98104.
2. Graduate Research Assistant, Dept. of Civil and Environmental Engineering, Pennsylvania State Univ., University Park, PA 16802.
3. Associate Professor of Civil Engineering, Dept. of Civil and Environmental Engineering, Pennsylvania State Univ., University Park, PA 16802 (corresponding author).