1. Professor, Dept. of Civil and Environmental Engineering, Univ. of Wisconsin, Madison, WI 53706.
2. Associate Professor, Dept. of Civil and Environmental Engineering, Univ. of Wisconsin, Madison, WI 53706.
3. Design Engineer, Structural Division, KPFF Consulting Engineers, 6080 Center Dr., Suite 300, Los Angeles, CA 90045; formerly, Research Assistant, Dept. of Civil and Environmental Engineering, Univ. of Wisconsin, Madison, WI 53706.
4. Design Engineer, HDR, 251 South Lake Ave., Suite 1000, Pasadena, CA 91101-3020; formerly, Research Assistant, Dept. of Civil andEnvironmental Engineering, Univ. of Wisconsin, Madison, WI 53706.