1. Ph.D. Candidate, Dept. of Civil and Environmental Engineering, Tufts Univ., Medford 02155, MA (corresponding author).
2. Professor, Dept. of Civil and Environmental Engineering, Tufts Univ., Medford 02155, MA.
3. Professor, Dept. of Civil Engineering, City College of CUNY, New York 10031, NY.
4. Research Structural Engineer, Federal Highway Administration, Office of Infrastructure R&D, McLean 22101.