Displacement scenarios of a rainfall-controlled slow moving active slide in stiff clays

A model is proposed to compute displacement scenarios from rainfall scenarios of a rainfall-controlled slow moving active slide along a pre-existing slip surface. The model is calibrated and validated with reference to a well-monitored landslide in stiff clays in Central Italy. The model comprises a physically based transient groundwater analysis of the slope and a kinematic analysis relating the rate of movement and the inverse of the local factor of safetyin a critical point along the slip surface. Once calibrated and validated, the model is used as a predictive tool to evaluate displacement scenarios from three rainfall scenarios. Although the reliability of the predicted displacement scenarios is not probabilisticallyevaluated, the scenarios may be considered as defining reasonable upper and lower bounds of future displacements.