Forward simulation of displacement rates variations due to groundwater level changes induced by deep drainage wells in Succiso earth slide (northern Apennines, Italy)

The Succiso landslide is a large scale active earth slide located in the northern Apennines of Italy, in the upper Enza river basin (Province of Reggio Emilia, Emilia Romagna Region). It extends from 1075 to 800 m a.s.l., affecting an area of about 0.5 km2 for a length of about 1.6 km and a maximum width of 500 m. The landslide area is characterized by flysch and claystone bedrock, by glacial and landslide deposits of various type and by more than 2000 mm rainfall per year. The landslide is named after the village of Succiso, that was damaged by acceleration of earth slide movements in 1951, 1952 and, quite severely, in 1966 and 1972. Succiso was first declared, according to law 445/1908, as “to be consolidated” (DPR n 201 of 14/02/1957) and, later on, as “to be transferred” (DL n°976 of 18/12/1966 – G.U. 24/4/70). From 1972 to 2008 the landslide did not underwent any other particular acceleration event and presumably, it moved at rates in the order of few cm/year, as it does presently. Consequently, the village of Succiso was again re-classified as “to be consolidated” (DGR n° 686 of 12/05/2008). Following such recent administrative act, and in order to define, design and construct consolidation works, the local technical basin service (Emilia Romagna Region) has undertaken an intensive geological, geotechnical investigation and monitoring survey that allowed to define the geological model and the on-going kinematics of the landslide's deposit. This work describes a geotechnical softsoil-creep model, in order to analysing the potential benefits, in terms of decrease in displacement rates, induced by the building of a deep drainage wells in the Succiso earth slide.