1. Renwick Professor, Dept. of Civil Engineering and Engineering Mechanics, Columbia Univ., New York, NY 10027 (corresponding author).
2. Associate Research Scientist, Dept. of Civil Engineering and Engineering Mechanics, Columbia Univ., New York, NY 10027.
3. Ph.D. Candidate, Dept. of Civil Engineering and Engineering Mechanics, Columbia Univ., New York, NY 10027.