1. Graduate Engineer, Walter P. Moore and Associates, Inc., Las Vegas, NV 89119.
2. Doctoral Student and Research Assistant, Dept. of Civil Engineering, Washington Univ. in St. Louis, St. Louis, MO 63130 (corresponding author).
3. Edward C. Dicke Professor of Engineering, Dept. of Civil Engineering, Washington Univ. in St. Louis, St. Louis, MO 63130.
4. Assistant Professor, Dept. of Civil and Environmental Engineering, Univ. of South Carolina, Columbia, SC 29208.