1. NSERC Post-doctoral Fellow, Center for Infrastructure Engineering Studies, Civil, Architectural, and Environmental Engineering Dept., Univ. of Missouri-Rolla, 223 Engineering Research Laboratory, Rolla, MO 65409 (corresponding author).
2. Professor Emeritus, Dept. of Civil Engineering, McMaster Univ., 1280 Main St. W., Hamilton, Ontario, Canada L8S 4L7.