ABSTRACT
Active slow-moving landslides in clayey soils exhibit continuous movements generally related to changing ground water levels. This chapter highlights the importance of groundwater modelling for the prediction of these types of movements through the analysis of a well-documented case history: the Porta Cassia landslide on the Orvieto hill in central Italy. The international literature offers different models to compute landslide displacements from measured pore pressure data. The analysis refers to an active translational landslide in stiff clays on the Orvieto hill, in central Italy. The kinematic model, used to compute the timedependent displacements of the Porta Cassia landslide, employs a phenomenological relationship between the velocity of the slide and the shear stress level acting along the slip surface. The state of stress at the selected point along the slip surface is computed using the infiniteslope scheme, assuming the slip surface parallel to the ground surface and the computed pore water pressure.
