Study on the landslide mechanism of the loess slopes induced by rainfall

Abstract

To reveal the landslide mechanism of the loess slope induced by rainfall, we carried out a series of tests for loess under different permeability durations, and studied the influences of rainfall on the permeability coefficient, the soil water characteristic curve, the components, the microstructure, and the shear strength of the loess. Test results show that the total dissolved solids, the sand particles, and the clay particles will decrease, but the silt particles will increase with the permeability duration, it changes the soil original structure and influences the soil water characteristic curve of the loess. And more than 68% permeability coefficients will loss after permeability test. The infiltrated rainwater will increase the effective saturation of the soil, and the shear strength of the soil will decrease with the increasing of effective saturation. The shear strength further decreases with the infiltration time (or rainfall duration). The landslide will initial once the shear strength reduces to the geostatic stress of the soil slope. The shear strength loss of the soils induced by rainfall should be considered during slope stability analysis. This study can help to understand the initiation of loess landslide induced by rainfall.