1. Assistant Professor, Dept. of Civil and Environmental Engineering, Univ. of Massachusetts, Amherst, MA 01003 (corresponding author).
2. Assistant Professor, Dept. of Civil and Environmental Engineering, Univ. of Massachusetts, Amherst, MA 01003.
3. Distinguished Professor, Dept. of Civil and Environmental Engineering, Univ. of California, Irvine, CA 92697.