Study on instability mechanism of shallow soil slopes in the red beds of Hunan Province under rainfall conditions

Abstract:

Red beds are typically considered as “prone-to-slide strata”， and shallow soil landslides can easily occur under rainy conditions. Therefore， it is of great importance to study the stability of shallow soil slopes in red bed areas under rainfall conditions. In this research，the shallow soil slopes in the red bed areas of Hunan Province is taken as an example， the stability of shallow soil slopes in red bed areas under different slope gradients， rainfall intensities， saturated hydraulic conductivities， and initial water contents is investigated by employing the modified Green-Ampt infiltration model， the specific impact patterns of these factors on slope stability is also analyzed. When the slope gradient is less than 45°， the safety factor decreases as the slope increases； when the slope gradient is greater than 60°， the safety factor increases with the slope. The wetting front depth changes insignificantly with the rainfall intensity， and the safety factor changes insignificantly with the rainfall intensity； the depth of the wetting front increases and the safety factor of the slope decreases as the saturated hydraulic conductivity increases； the safety factor decreases as the initial water content increase. The results can provide a theoretical basis and practical guidance for slope protection engineering in red bed areas.