1. Soil Mechanics and Foundations Research Laboratory, Faculty of Engineering, Cairo University, Giza, EG (Corresponding author), e-mail: tyelkady@yahoo.com
2. Civil Engineering Dept., College of Engineering, King Saud Univ., Riyadh, SA e-mail: ena_almahpashi@hotmail.com
3. Civil Engineering Dept., College of Engineering, King Saud Univ., Riyadh, SA e-mail: Shamrani@ksu.edu.sa