1. Graduate Student, Dept. of Civil and Environmental Engineering, American Univ. of Beirut, P.O. Box 11-0236, Riad El Solh, Beirut 1107 2020, Lebanon.
2. Assistant Professor, Dept. of Civil and Environmental Engineering, American Univ. of Beirut, P.O. Box 11-0236, Riad El Solh, Beirut 1107 2020, Lebanon (corresponding author).