Analysis of deformations occurring at the edge of a rock cliff underneath a historical center

The gate of the ancient town of San Leo, located at the edge of a rock cliff overlying a clay substratum, is threatened by small but continuous deformations of the rock mass. A comprehensive analysis, performed by means of numerical FEM and DEM models and of in situ surveys and monitoring, suggests that the upper part ofthe cliff is affected by toppling. Numerical models also confirm the adequacy of the criteria adopted for the stabilization measures, which seem to reduce the deformation rate, as well as the necessity to monitor the cliHQ due to the severe state of stress and to the extension of deformation phoenomena.