1. Graduate Research Assistant, School of Civil Engineering, Purdue Univ., 550 Stadium Mall Drive, West Lafayette, IN 47907.
2. Assistant Professor, School of Civil Engineering, Purdue Univ., 550 Stadium Mall Drive, West Lafayette, IN 47907 (corresponding author).
3. Olson Distinguished Professor, School of Civil Engineering, Purdue Univ., 550 Stadium Mall Drive, West Lafayette, IN 47907.