Inverse long-term stability analysis of a constrained landslide

Abstract

This paper deals with long-term stability analysis of a constrained landslide. The landslide has ‘nowhere’ to go and its downhill movement is slowing in time, which intuitively implies its long-term stability. However, exactly because the landslide is slowing, the shear strength on the sliding surface may decrease, leading to increase in compressive stresses at the landslide foot and, ultimately, to a failure. The proposed long-term stability analysis of such a landslide is based on an inverse analysis, which allows for the safety factor to be determined solely by curve-fitting the observed displacement data. For a safety factor lower than 1, the time of failure can be predicted using additional earth pressure measurements in the sliding layer. The proposed procedure is illustrated using the observation data from the Brattas–St Moritz landslide.