1. Dept. of Civil Engineering, Faculty of Engineering, Mazandaran Univ., P.O. Box 484, Babol, Iran.
2. Dept. of Civil Engineering, Dalhousie Univ., 1360 Barrington St., Halifax, NS B3J 1Z1, Canada (corresponding author). E-mail: farld.taheri@dal.ca
3. Dept. of Civil Engineering, Dalhousie Univ., 1360 Barrington St., Halifax, NS B3J 1Z1, Canada.