Mountainous regions, particularly the Lesser Himalayas, face persistent slope stability challenges due to complex geological formations and extreme climatic variability. This study investigates the potential of Nano-silica (NS) as an eco-efficient soil stabilizer for enhancing the mechanical behaviour of fine-grained soils in these terrains. Consolidated undrained (CU) triaxial tests were performed on clay of intermediate plasticity (CI), silt of intermediate plasticity (MI), and low-plasticity clay-silt (CL-ML) soil types treated with different NS contents and subjected to various curing durations. To develop reliable predictive insights, both linear and non-linear regression models were constructed using essential geotechnical parameters, including cohesion, internal friction angle, and the pore-water pressure ratio. A novel model simplification process was employed to derive explicit closed-form equations for the Factor of Safety (FoS), retaining only the most influential terms. The non-linear models demonstrated high predictive accuracy, with R2 values exceeding 0.97, outperforming their linear models for all the soil types stabilized with NS. These interpretable regression models offer a practical tool for slope stability assessments in NS-stabilized soils. The integration of material innovation with simplified computational models contributes to resilient and sustainable infrastructure design in data-scarce highland regions.



