1. Assistant Professor, Dept. of Civil Engineering, College of Engineering, Univ. of Tehran, P.O. Box 4563-11155, Tehran, Iran (corresponding author).
2. Ph.D. Student, Amirkabir Univ. of Technology, P.O. Box 4311-159163, Tehran, Iran; Head of Track and Technical Structure Dept., Iranian Railway Research and Training Center, 1519630807 Tehran, Iran.
3. Expert, Technical Structure Dept., Iranian Railway Research and Training Center, 1519630807 Tehran, Iran.