Analysis of Post-Construction Settlement of Pile-Supported Geosynthetic-Reinforced Embankment

Pile-supported geosynthetic-reinforced embankments, as effective foundation improvements, are being used increasingly often in the construction of highway and railway engineering at present. The geosynthetic-reinforced load transfer platform in the horizontal direction was simulated to the thin plate, and then the differential equation of the curved surface and the nonlinear foundation model were used to solve the analytical expression of the post-construction settlement of the reinforced area, and the engineering example was used to verify it. Furthermore, a finite element model was developed to simulate the settlement. The analysis utilized a static general step and incorporated a linear elastic–perfectly plastic model with the Mohr–Coulomb failure criterion. The numerical result of 19.7 mm was consistent with the theoretical prediction of 20.1 mm, demonstrating a mere 2.0% relative error and substantiating the validity and accuracy of the theoretical model. The analysis examined how bending stiffness, the subgrade reaction coefficient, pile spacing, and embankment height affect post-construction settlement. The results demonstrate that the settlement increases with larger pile spacings or lower values of the subgrade reaction coefficient and bending stiffness. Notably, the settlement increases with embankment height only until a critical height—calculated from the bearing capacity of the inter-pile soil—is exceeded. Based on this, it was found that the subgrade reaction coefficient was identified as the most influential parameter, followed by pile spacing and then bending stiffness. These findings lead to practical recommendations for engineering practice.