Marginally stable slopes are a problematic context for anthropogenic excavations and artificial embankments. This topic is dealt with in this paper aimed at providing quantitative estimates of both soil deformations and displacements of the ground surface induced by the renewal works of an important highway in Southern Italy. Particularly, the original slope was firstly excavated and then reshaped, also adding a line of Concrete Piles (CP). As major work, a high embankment was built and reinforced through 12 lines of PVC coated polyester geogrids. Apart from a multilayered stratigraphy, the study area was also characterized by a landslide deposit of weak clayely soils located just beneath the toe of the Georeinforced Reinforced Embankment (GRE). Therefore, this paper investigates the role ofa the Concrete Piles towards the overall performance of the GRE-CP system, varying either the length or the diameter of the piles. FEM (Finite Element Method) seepage steady-state analysis and stress-strain analysis were performed assuming an elastic-plastic contact law at the interface between the piles and soils, and a Mohr-Coulomb contact law at the interface between the geogrids and the embankment soil. As main results, the paper outlines four principal scenarios for slope deformation and embankment performance, related to different types of piles used for the slope reinforcement.