1. Assistant Professor, Dept. of Civil and Environmental Engineering, North Dakota State Univ., Fargo, ND 58108 (corresponding author).
2. Professor, Dept. of Civil and Environmental Engineering, Virginia Polytechnic Institute and State Univ., Blacksburg, VA 24061.
3. Professor, Dept. of Civil and Environmental Engineering, California State Univ., Fullerton, CA 92831.