Maddalena exploratory adit: feedback on hydrogeological and geothermal aspects

The 7.5 km long and 6,3 m diameter La Maddalena pilot tunnel is part of the international project of the new high speed rail link between Turin and Lyon, on the Italian side of the project (Chiomonte, TO). Among the geological surveys that are systematically performed during the excavation of the pilot tunnel, groundwater inflow and temperature of water and rock mass are measured. This paper analyses the recorded data to April 2016 in order to verify the hydrogeological and geothermal forecasting models and assess the energy potential of the inflows that are expected to be intercepted by the future base tunnel excavation. The collected data confirm the possibility of a sustainable management of groundwater and heat geoexchange.