Comparison of different two-dimensional idealizations for a geosynthetic-reinforced pile-supported embankment

Embankment construction on soft ground has increased considerably over recent years as a result of the increase in infrastructure development activities and because of the unavailability of suitable land. Geosynthetic-reinforced pile-supported (GRPS) embankments provide an effective and reliable solution to the problem of constructing embankments over soft ground. The combination of geosynthetic reinforcement and piles can alleviate the uneven surface settlements on the embankment crest while reducing the embankment load transferred to the soft foundation soil. This paper presents a numerical analysis based on the FEM carried out on a GRPS embankment. Analysis was carried out in both a two-dimensional (2D) plane strain condition for different 2D idealizations of piles and in a three-dimensional (3D) condition. The interaction between geosynthetic and soil was taken into consideration during the analysis. The results obtained for the 2D models are compared with the 3D model results. The stress transferred to the piles and foundation soil, lateral displacements, development of settlements at the base of the embankment on both the foundation soil and piles, and the generation and dissipation of excess pore water pressures during and after construction for both 2D and 3D models are discussed.