This study presents a numerical analysis of a road embankment constructed over soft subsoil and reinforced with geogrids and jet grout columns to enhance stability and reduce deformation. The two-dimensional finite element software PLAXIS (PLAXIS 2D Version 2023.2) was employed to simulate both the static and dynamic behavior of the system under real field conditions, utilizing geotechnical parameters obtained from in situ and laboratory tests. The unreinforced embankment exhibited significant vertical and lateral displacements, attributed to inadequate compaction and insufficient bearing capacity of the foundation soil. Finite element simulations were first used to replicate the observed field performance, confirming the accuracy of the modeling approach. Subsequently, reinforcement strategies involving the integration of jet grout columns and geogrid layers were analyzed to assess their effectiveness. The jet grout columns significantly improved subsoil stiffness, while the geogrid reinforcement contributed to the stabilization of embankment slopes. The results demonstrated a 220% increase in the safety factor and a 65% reduction in total settlement compared to the unreinforced case. Additionally, dynamic analysis revealed that while the embankment maintained marginal stability at a horizontal acceleration of 0.30 g, it failed under a 0.40 g seismic load. These findings highlight the critical role of combined reinforcement techniques and process-based modeling in ensuring not only the stability of road embankments on weak soils but also their contribution to sustainable infrastructure development through improved durability, resource efficiency, and extended service life.
Aktaş et al. (Wed,) studied this question.