Hydro-mechanical mechanisms of landslide reactivation in heterogeneous rock masses of the northern Apennines (Italy)

The prediction of landslide reactivations in space and time is of relevant practical interest in the northern Apennines. Dormant or active earth slides-earth flows affect, directly or indirectly, about 1800 villages and many km of road networks. Four test sites have been studied and monitored in order to analyse hydro-mechanical conditions in and around the landslides, prior or during reactivation events. Data from monitoring systems such as electric piezometers, spring and stream discharge flow-meters, inclinometers, Time Domain Reflectometry (TDR) cables, Differential Global Positioning System (DGPS) networks and wire extensometers have highlighted some interplay between flow and mass transfers from stable rock masses to the landslide body, and within the landslide itself. Monitoring in the 2004-2006 period has covered dormancy, reactivation and suspension phases, allowing some considerations to be drawn on the hydro-mechanical mechanisms that drive the reactivation of large and deep seated landslides.