1. Associate Professor, Dept. of Civil Engineering, Imam Khomeini International Univ., 34149-16818 Ghazvin, Iran.
2. Ph.D. Student, Dept. of Civil and Environmental Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180 (corresponding author).
3. Ph.D. Student, Dept. of Civil and Environmental Engineering, Univ. of Oklahoma, Norman, OK 73071.