Under lateral loading on a pile group, each pile bears different lateral force depending on its position among the group. This effect of pile position is remarkable in comparison between outer piles and the other. So, the effect appears remarkably in lateral resistance elements at the outside of foundation used for seismic retrofit. The author have studied the pile group effect accounting the pile position. This paper presents a simple method to compute the pile group effect considering the pile arrangement through the 3D-FEM analysis and its comparison with experimental results.
