1. Postdoctoral Research Fellow, Chair of Foundation Engineering, Soil and Rock Mechanics, Ruhr-Universität Bochum, 44801 Bochum, Germany (corresponding author).
2. Professor, Faculty of Civil Engineering, K.N. Toosi Univ. of Technology, 1996715433 Tehran, Iran.
3. Ph.D. Candidate, Chair of Foundation Engineering, Soil and Rock Mechanics, Ruhr-Universität Bochum, 44801 Bochum, Germany.
4. Professor, Chair of Foundation Engineering, Soil and Rock Mechanics, Ruhr-Universität Bochum, 44801 Bochum, Germany.