1. Structural Engineer, Krech Ojard & Associates, Eua Claire, WI 54701; formerly, Structural Engineer, Sheppard Engineering, P.C., 966 Livernois Rd., Troy, MI 48083.
2. Associate Professor, Dept. of Civil Engineering, Univ. of Minnesota, 500 Pillsbury Dr., Minneapolis, MN 55455 (corresponding author).