Effect of rectangular and triangular grids of columns on load transfer mechanism of column-supported embankments

The soil arching mechanism predominantly governs the load transfer mechanism of geosynthetic reinforced column-supported embankments. An extensive amount of literature is available examining the arching mechanism within the embankment fill over a grid of columns arranged in a rectangular pattern. However, the research relevant for load transfer mechanism over a grid of columns arranged in a triangular pattern is scarce, despite both triangular and rectangular patterns are widely used in practice. Hence, this paper aims to investigate the mechanism of soil arching in an embankment supported by columns in a triangular pattern using 3D numerical models based on the finite element method. Also, a comparison between the load transfer mechanisms in triangular and rectangular grids of columns is presented. Based on these results, a visual boundary of the soil arch above a grid of columns was developed. Results from this study clearly show that columns experience lower settlements and the geosynthetic reinforcement was less effective when the column arrangement is in a triangular pattern, compared to a square arrangement of columns.