Dynamics of saturation phenomena and landslide triggering by rain infiltration in a slope

ABSTRACT Landslide triggering evaluation is one of the key issues for the landslide risk analysis.Geological, geo-morphological, and geotechnical aspects, as well as hydrologic factors have to be accounted for in carrying out triggering and stability analyses. In this respect some aspects, such as mechanical and hydraulic behaviour of soil, rainfall characteristics, mechanics of rain infiltration, pore pressure evolution, and their mutual influence, have to be considered and pointed out. The paper reports a numerical approach which analyses the dynamics of soil matrix suction during rainfall infiltration and its effect on shear strength in order to, coupling hydrologic and geotechnical aspects, follow stability evolution during and after a rainfall event. The analysis of some case records, which occurred during a well-documented event, has shown a good agreement with the modelled phenomena, as far as stability condition evolution is concerned. The importance of the experimental soil parameter evaluation is particularly addressed.