Parallel Session A-7: Shallow geothermal energy - Chair: Ramakrishna Bag

A pilot system was created to explore using hydro-geothermal energy from a tunnel drainage system for de-icing roads. The system consisted of a field with heat pipes monitored by temperature sensors and validated by a numerical model. The study found positive results, showing potential benefits such as increased road safety and accessibility in winter, reduced environmental impacts, and being used in summer to cool down roads.

The majority of energy piles are cast-in-place concrete piles. A better alternative is to use precast concrete segmental driven energy piles, which can be cast in large quantities with high quality assurance at a concrete factory, after which they are transported and installed into the ground. This study aims to present a novel method of casting and installing segmental energy piles that utilize an innovative steel joint for connecting the precast concrete segments on-site. In addition to structural integrity, the steel joint provides the possibility of a leak-proof coupling for heat-exchanging pipes.

Energy pile foundations have been extensively studied during the last two decades. The thermo activation of pile foundations, has been used in other energy geostructures. This study presents results from a series of full scale field tests of a soldier piled energy wall section. At the excavation completion, the thermo-mechanical response of piles to continuous and cyclic thermal loads were monitored to investigate the potential effects of such thermo activation pattern. The thermally induced strains within the piles were analysed. For the tested case, the results show negligible thermo-mechanical impact of these operational schemes.

Energy geostructures, represent a local source of renewable heating and cooling. Therefore, they represent highly compelling energy systems to decarbonise the building sector. When dealing with energy geostructures in urban environments, additional challenges arise due to the typical presence of waste heat emissions in the underground, which change the extraction/injection potentials of geothermal heat exchangers. This study concisely investigated the thermal performance of energy barrettes using field experiments and 3-D finite element simulations. This work particularly explores the performance of several energy barrettes included in a complex foundation located in an extremely dense urban area underneath the Testimonio II.