1. Department of Civil Engineering, Shiraz Branch, Islamic Azad University, Shiraz, Iran, Telephone: +98 91 373010529; Telefax: +98 71 36410068;
2. Department of Civil Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India, Telephone: +91 22 25767344; Telefax: +91 22 25767302;(corresponding author)