Engineering Geological and Hydrogeological Characterization of Acero Landslide (Upper Sturla Valley, Northern Apennine)

This work describes the results of the geotechnical and hydrogeological characterization of a very slow landslide involving Acero, a village in the Northern Apennine. Through boreholes and geophysical surveys, it was possible to obtain a geological profile of the landslide, while through some monitoring activities we were able to obtain information about displacements and water table. Laboratory tests completed the definition of the geotechnical and mineralogical properties of the soil. The landslide shows maximum speed values of 1.5 cm/y, with maximum accelerations during heavy rain periods. This landslide has been classified as a residual state type and can be considered as dormant or active, depending on vertical effective stress and pore pressure variations. The hydrogeological risk mitigation is carried out through the interpretation of the landslide trigger and evolution mechanisms such as the reduction of the water table level.