Evaluation of Drilled and Grouted Soil-Nailed Slope Stability through Automated Modelling and Parametric Analysis

https://doi.org/10.46610/JoGS.2026.v011i03.002

Abstract

Soil nailing is a commonly practiced geotechnical technique for stabilizing slopes and excavations, achieved by installing closely spaced grouted steel bars. This study examined soil-nailed slope stability using numerical and analytical approaches, considering nail length, spacing, inclination, and soil properties. Finite Element Method (FEM) simulations in PLAXIS 2D, based on the Mohr-Coulomb model, were conducted to analyze soil-nail interactions under static loads. A comprehensive literature review and parametric studies of over 137,200 configurations, automated using Python, produced design charts for soil types such as clayey sand and silty sand. The results emphasized soil cohesion (56.71%) and excavation depth (20.10%) as the most critical parameters, with nail length (7.32%) also being significant. Granular soils, such as silty and clayey sand, achieved higher success rates (75.76%) than fine-grained silty clay (5%), underscoring the importance of soil type. The reliability of the numerical modelling approach was verified and validated by comparing the obtained results with established theoretical concepts and literature. Recommendations highlight the necessity of site-specific investigations, construction monitoring, and the integration of numerical modelling with empirical data to improve soil nail wall design. This provides a national framework for safe and efficient slope stabilization, particularly in rugged terrain such as that of Nepal.