1. Associate Professor, Dept. of Civil and Environmental Engineering, Villanova Univ., 800 Lancaster Ave., Villanova, PA 19085 (corresponding author).
2. Dept. of Civil and Environmental Engineering, Villanova Univ., 800 Lancaster Ave., Villanova, PA 19085
3. Analytical Graphics, Inc., 220 Valley Creek Blvd., Exton, PA 19341.
4. Daylor Chair of Civil Engineering, Dept. of Civil and Environmental Engineering, Villanova Univ., 800 Lancaster Ave., Villanova, PA 19085.