1. Assistant Professor, Dept. of Civil Engineering, Engineering College, Univ. of Anbar, Ramadi, Anbar 31001, Iraq (corresponding author).
2. Senior Lecturer, School of Engineering, Univ. of Liverpool, Liverpool, Merseyside L69 3GL, UK.
3. Lecturer, Dept. of Civil Engineering, Engineering College, Univ. of Anbar, Ramadi, Anbar 31001, Iraq.