1. Ph.D. Candidate, Dept. of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332.
2. Postdoctoral Researcher, Dept. of Engineering, Univ. of Cambridge, Cambridge CB2 1PZ, U.K. (corresponding author).
3. Ph.D. Candidate, Schofield Centre, Univ. of Cambridge, Cambridge CB3 0EL, U.K.
4. Associate Professor, Dept. of Civil and Environmental Engineering, Politecnico di Milano, 20133 Milano, Italy.
5. Professor, Dept. of Civil and Environmental Engineering, Bucknell Univ., Lewisburg, PA 17837.
6. Director of Research, Dept. of Civil and Environmental Engineering, Universitat Politècnica de Catalunya, 08034 Barcelona, Spain.
7. Professor, Dept. of Civil and Environmental Engineering, Syracuse Univ., Syracuse, NY 13244.