Pile-to-pile interaction in free-head piles subjected to lateral loading in sandy soil

Piles and pile foundations are used to transfer structural loads to deeper layers of soil or rock medium. Piles are subjected to laterally loads as well as vertical and oblique loads. Laterally loads can be caused by earthquake forces, earth pressures, wind loads, wave forces, etc. In this study, the interaction between free-head piles subjected to lateral load buried in sandy soil was investigated experimentally and numerically with finite element method. In experimental study, lateral loads were applied to a single pile and pile groups of 5D, 3D and D spacings and the piles were vertically embedded in the sandy soil. The laterally loads were applied to the piles buried in the sandy soil at the surface level. The piles with a diameter of D=0.05 m and length-to-diameter ratios of L/D=10 and L/D=20 were used in experiments conducted on both loose and dense sands. The results obtained from the experiments were compared with the results obtained from the Plaxis 3D to optimize the material model parameters. Parametric studies were performed to investigate the interaction of large diameter piles with the soil and pile properties used in the finite element model of the experimental setup. As a result, it is seen that the soil relative density has a significant effect on the interaction between free-head vertical piles. Also, it was determined that the interaction between piles decreased with increasing pile length.