1. Design Engineer, Michael Baker Jr., Inc., Madison, WI 53719; formerly, Graduate Student, Dept. of Civil and Environmental Engineering, Univ. of Wisconsin–Madison, Madison, WI 53706.
2. Professor, Dept. of Civil Engineering, Univ. of Minnesota, Minneapolis, MN 55455.
3. Professor, Dept. of Civil and Environmental Engineering, Univ. of Wisconsin-Madison, Madison, WI 53706 (corresponding author).