Effect of degree of freedom of movement on the bearing capacity and efficiency coefficient of pile group adjacent to sandy slope

Understanding the behavior of the pile group near the slope is an important factor in designing a structure adjacent to the slope. There are very little research on the vertical capacity and efficiency coefficients of pile group near slope, so the study about the behavior of pile group adjacent of the slope is very important. The purpose of this study is to investigate and compare the bearing capacity and efficiency coefficient of vertical pile group under axial loading in the near sandy slopes in two modes of free horizontal movement and no free horizontal pile movement by testing the physical model of pile group. Also in the this study, horizontal force applied to the pile group with free lateral movement is investigated with the FLAC3D software. For this purpose, a series of experiments were performed on the physical model of 2 × 2, 2 × 1, 3 × 1 and 3×3 pile groups adjacent to the dry sandy slope without horizontal displacement and the results were obtained with previous research of other researchers in which the lateral displacement of the pile group has been free, compared. The results of the physical model tests show that the bearing capacity and efficiency coefficient of the pile group is dependent on the pile distance, the pile group configuration, and the liner pile-group direction relative to the slope direction. Also, the results of the physical model tests show that the bearing capacity and efficiency coefficient of the pile group with free lateral movement have higher values than the pile group without lateral movement. Numerical analysis results show that the lateral force applied to the pile group decreases by increasing the spacing of the piles, and the ratio of horizontal force to axial force in the linear pile group decreases with increasing number of piles.