DOI: 10.5592/CO/HG.2026.41
Autori: BOJAN SUSINOV , JOSIF JOSIFOVSKI , SEAD ABAZI , ALEKSANDRA NIKOLOVSKA ATANASOVSKA
Sažetak:
This paper examines and evaluates the impact of intense rainfall on slope stability and proposes an approach for incorporating this influence into slope design. The main objective is to demonstrate that the infiltration of atmospheric water affects the natural moisture content of the soil, leading to a reduction in the initial suction and finally decreasing the shear strength of unsaturated soils. Therefore, the use of a more advanced concept for numerical slope stability analysis is recommended, in which the mechanical and hydraulic behavior of the soil is analyzed simultaneously as a multiphase system over time through a fully coupled flow–deformation analysis. Such an approach represents one of the most advanced and realistic types of analysis, capable of explaining the phenomena that occur as a result of seepage processes, changes in the degree of saturation, and variations in the physico-mechanical properties of the soil. For the successful application of such analyses, it is necessary to have a proper understanding of the hydraulic characteristics of the soil, their constitutive relationships, as well as the intensity of rainfall. The stability analysis of sandy materials shows that changes in the degree of saturation begin immediately after the onset of rainfall due to infiltration processes. After three hours of intense rainfall with an intensity of 30 mm/h, the effect of moisture change extends to a depth of approximately 1.0 m, while the upper 0.5 m of the slope becomes fully saturated. The highest suction occurs in the zone where the degree of saturation is lowest, approximately 2.0 m below the crest of the slope. The greatest reduction in suction is observed at the slope surface, where the material becomes saturated due to the influence of rainfall. The maximum deformations occur at the crest of the slope. As a result of the reduction in the shear strength parameters of the soil, the factor of safety decreases from 1.63 to 1.59 under the influence of rainfall.