Pile head displacements with different cross sectional shapes under lateral loading and unloading in granular soils

Piles in structures’ foundations, which are used to load transmission from main structure to bed, are generally subjected to lateral loads. In order to study the effect of concrete pile geometry on its structural behavior, several models with different shapes and dimensions were selected and analyzed assuming the nonlinear behavior for soil. The behavior of pile models were studied, evaluated, and tabulated using numerical analysis in different conditions such as: changes in pile geometry and shape and soil properties. Therefore, the displacements of piles` head situated in granular soil with different compaction levels under a lateral load were studied in loading and unloading cycles. The dissipated energy was calculated based on pile head displacements in different load steps in the first and second cycles of loading. The "performance index" is defined as the ratio of dissipated energy to the maximum pile head displacement to compare these two factors effect on different pile models' behavior concurrently. It was observed that piles with rectangular cross sections and smaller width, have the maximum dissipation of energy and the minimum displacement occurs in dense soil.