1. a Water & Water Structures Engrg. Dept., Faculty of Engrg. , Zagazig University , Zagazig, Egypt E-mail:
2. b Civil Engrg. Dept., College of Engrg. , King Saud University , P.O.Box 800, Riyadh, 11421, KSA E-mail:
3. c Civil Engrg. Dept., College of Engrg. , King Saud University , P.O.Box 800, Riyadh, 11421, KSA E-mail: