1. Assistant Professor, Dept. of Civil Engineering, Lebanese American Univ., P.O. Box 36, Byblos, Lebanon (corresponding author).
2. Ph.D. Candidate, Dept. of Civil Engineering and Engineering Mechanics, Columbia Univ., New York, NY 10027.
3. Assistant Professor, School of Civil Engineering, Purdue Univ., 550 Stadium Mall Dr., West Lafayette, IN 47907.