Considerations on the deformation of Ridracoli dam foundation based on the analysis of monitoring data

The behaviour of the Ridracoli arch-gravity dam in the 2002-2020 operation years has been analysed, by applying "statistical"models of increasing complexity to the time series of pendulum and long-base extensometer measurements. The modelling approach has proved robust. A satisfactory estimate of the reservoir load, thermal and irreversible drift components has been obtained for most of the instruments. As expected, the influence of temperature is lower for the instruments deeply embedded in the rock mass. The deformations recorded on the left and right bank of the dam have shown a minor influence of the anisotropic proprieties of the rock mass, well characterized by the mechanical tests performed at the time of dam construction.