Thermo-mechanical behaviour of energy pile in underground railway construction site

摘要

The use of geothermal pile foundations is an environmental friendlyway to extract/storage energyrnfrom/in the ground. The operating principle of these innovative structures is based on energy transfer betweenrnthe ground and the fluid flowing inside the probes inserted in the pile, in order to feed heat pumps dedicatedrnto buildings heating and cooling. Nevertheless, very limited installations are recorded in Italy, and only fewrninformation are available regarding the impact of thermal processes on the structural performance of energyrnpiles. In the present work, the geo-energy research group has analysed the thermo-hydro-mechanical behaviourrnof an energy pile installed in pyroclastic soils and rocks, as an element of a sheet pile wall. The developed model,rnsolved numerically by using finite elements, is then used to forecast the behaviour of an actual pile subjected tornthermo-mechanical loads and to design a proper experimental campaign in the underground railway constructionrnsite of Piazza Municipio in Napoli, Italy.rnThe multi-pile experimental set-up is equipped with fibre optic sensors system that allows the evaluationrnof strains and temperature distributions along the piles during cooling and heating processes. Once thernmeasurements will be available, the developed model will be verified and validated against on field experiments.