1. Professor, Dept. of Civil Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180-3590 (corresponding author).
2. Research Asst. Professor, Dept. of Civil Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180-3590.
3. Professor, School of Civil and Environmental Engineering, Cornell Univ., Ithaca, NY 14853-3501.
4. Engineer, Mueser Rutledge Consulting Engineers, New York, NY 10017.