Energy diaphragm walls for Turin metro

The increasing need for renewable sources of energy for heating and cooling of buildings and infrastructures makes energy geostructures an innovative and interesting technology, which is rapidly spreading all around the world. This category includes all underground structures that are in contact and can exchange heat with the subsoil, being transformed into low enthalpy geothermal systems. The thermal activation of diaphragm walls, which are normally required in urban constructions such as underground car parks or cut and cover tunnels, is the focus of this paper. Thhe results of Finite Element numerical analyses, performed to estimate the heat exchange achievable by the geothermal activation of section 1 of the Turin Metro Line 2 tunnel currently under design in Italy, are described.