# Finite Element Modeling of the Soil-Nailing Process in Nailed-Soil Slopes
## 8 Conclusions  
The finite element modeling of various stages of the soil-nailing process, i.e., construction stages and overburden pressure stages, was carried out, simulating with in-house developed laboratory models, in the present study. The soil-nailing process built in the laboratory models was idealized as a plain strain problem and modeled in PLAXIS software. The laboratory models of the soil-nailing process consisted of a Perspex sheet box filled with sandy soil, a Perspex sheet facing, steel bars for reinforcement and a steel plate for foundation. The stress-strain behavior of the sand was represented by a Hardening-Soil model, and the soil-nail interface was described by the Coulomb friction model. The behavior of the soil-nailing process during the construction stage and under overburden pressure were investigated in terms of the horizontal movement of the face of the slope, vertical settlement of the foundation and stress conditions in slope soil mass. The results of the FE model were also compared with the laboratory model results. The sensitivity analysis of the experimental set-up for plain strain condition verification was carried out by three-dimensional modeling of the nailed-soil slope. The following conclusions may be drawn from the present study. * The developed FE model has the potential to simulate the performance of a field nailed-soil slope during construction and working stages. * The measured results for lateral displacement and settlement of the strip footing during construction and overburden pressure stages are higher than FE-simulated results of the soil-nailing process. * From the sensitivity analysis, it can be inferred that the experimental set-up used in the investigation is found to be sensitive to the toe soil depth, and the plain strain condition assumption is not fully satisfied. Figure 27: Plots of horizontal displacement of the nailed-soil slope in the experimental set-up dimensions model, model with increased depth and model with increased width. (**a**) Experimental set-up dimensions model. (**b**) Model with increased toe depth. (**c**) Model with increased width. Figure 28: Plots of vertical displacement of the nailed-soil slope in the experimental set-up dimensions model, model with increased depth and model with increased width. (**a**) Experimental set-up dimensions model. (**b**) Model with increased toe depth. (**c**) Model with increased width. * The developed FE models could provide guidance for the construction/maintenance of soil-nailed cut slopes in granular soils/weathered rocks. * The lateral displacement of the slope's facing occurs in the slope's middle third during the construction stages, and lateral displacement further increases with the application of overburden pressure. The minimum lateral displacement is at the upper third of the slope at various stages of investigation. The overburden pressure stages exhibit a higher reduction in facing lateral displacement and stresses within the soil mass with the increase of soil density as compared to the construction stages. * Shear stresses increase near the top surface of slope and slope face as well as near and under the foundation at the construction stages, while, within the nailed-soil mass, the values are constant. As expected, zero shear stresses are developed at the reinforced mass. In overburden pressure stages, shear stresses are enlarged with the rise of the overburden pressure. Conceptualization, M.H.M. and M.A. ; methodology, M.H.M. and M.A. ; resources, J.M. ; writing--original draft preparation, M.H.M. and M.A., writing--review and editing, J.M. ; project administration, S.A.; funding acquisition, M.A. All authors have read and agreed to the published version of the manuscript. Funding for this research was given under award numbers R.G.P2/190/43 for Large Group Research Projects by the Deanship of Scientific Research, King Khalid University, Ministry of Education, Kingdom of Saudi Arabia. Institutional Review Board Statement: Not applicable. Informed Consent Statement: Not applicable.