Gravitational instability analysis of the Prato Carnico village.

This paper reports in situ test results and monitoring performed to characterise the development of a gravitational phenomenon. Analysis made it possible to create a 3D subsoil model to identify the main preferential paths of groundwater seepage, the boundaries of the subsidence area and the relationships between rainfall and displacements. The results of seepage and stability analyses highlight some aspects that characterise the kinematical mechanism of the slope. Displacements show a constant increase over time independently from the pluviometric regime. Stratigraphic sections and geophysical investigations highlight that the subsidence basin was formed just above a morphological bedrock depression and was filled with weathered gypseous arenite and sandy silt. The slow and constant sinking of the cover may be ascribed to the progressive collapse of the voids created through karstification within the gypseous rock mass and which attract loose material from above causing vertical and horizontal movements