Infiltration-induced Slope Instability: A multi-scale approach

Precipitation, together with erosion and earthquakes, have been recognized as the main triggering factors of shallow landslides. However, there are relatively few well-documented cases where direct relationships could be established between occurrence and features of shallow landslides, the rainfall characteristics (e.g. intensity, duration) and water retention curves. A field experiment has been performed on a steep forested slope located on the east-facing banks of the river Rhine in Ruedlingen, northern Switzerland. The aim of the experiments was to study the triggering mechanisms of the landslides induced by rainfall. The pore pressure and the degree of saturation, which are linked through the water retention curve, represent two of the main variables affecting the mechanical behaviour of unsaturated soils, and their relationships to rainfall are complex. The difference in the determination of water retention curves at different scales are analysed in this paper for Ruedlingen soil together with their effects on mechanical behaviour at multi-scale.