Finite Element Parametric Study of Nailed Non-Cohesive Soil Slopes

Computational modeling offers a cost-effective approach to exploring complex geotechnical behavior. This study uses PLAXIS 2D finite element software to simulate nailed soil slopes under plane strain conditions, with models calibrated against laboratory-scale experiments involving a sand-filled Perspex box, steel nail reinforcements, and a rigid foundation. The soil mass, structural elements, and reinforcements are modeled using fifteen-node triangular elements, five-node plate elements, and two-node elastic spring elements, respectively. In this paper, parametric studies evaluate the influence of slope angles, mesh density, domain dimensions, constitutive models, and reinforcement configurations. Both prototype-scale and 3D-approximated models are included to assess scale effects and spatial behavior. The results highlight the significant impact of model size and material behavior, particularly when using the Hardening Soil model and its small-strain extension. Reinforcement optimization, including nail length reduction strategies, demonstrates the potential for maintaining slope stability while improving material efficiency. Validation against experimental data confirms that the numerical models accurately capture deformation patterns and internal stress development across different construction and loading phases. This study observed that the Hardening Soil (small-strain) material model significantly improved slope performance by reducing settlements and better capturing stress behavior, especially for steep slopes. Optimized redistribution of nail lengths across the slope depth enhanced stability while reducing reinforcement usage, demonstrating a cost-effective alternative to uniform configurations. The findings offer practical guidance for optimizing nailed slope stabilization in sandy soils, supporting safer and more economical geotechnical design for real-world applications.