Soil thermal behavior in different moisture condition: an overview of ITER project from laboratory to field test monitoring

  • Eloisa Di Sipio
  • David Bertermann
Thematic Issue
Part of the following topical collections:
  1. NovCare - Novel Methods for Subsurface Characterization and Monitoring: From Theory to Practice


The thermal properties of soils can be considered one of the most important parameters for many engineering projects designing. In detail, the thermal conductivity plays a fundamental role when dimensioning ground heat exchangers, especially very shallow geothermal (VSG) systems, interesting the first 2 m of depth from the ground level. However, the determination of heat transfer in soils is difficult to estimate, because depends on several factors, including, among others, particle size, density, water content, mineralogy composition, ground temperature, organic matter. The performance of a VSG system, as horizontal collectors or special forms, is strongly correlated to the kind of sediment at disposal and suddenly decreases in case of dry-unsaturated conditions in the surrounding soil. Therefore, a better knowledge of the relationship between thermal conductivity and water content is required for understanding the VSG systems behavior in saturated and unsaturated conditions. Key challenge of ITER project, funded by European Union, is to understand how to enhance the heat transfer of the sediments surrounding the pipes, taking into account the interactions between the soil, the horizontal heat exchangers and the surrounding environment. In detail, changes of soil moisture content in the same climatic conditions and under the same thermal stress for five different soil mixtures have been monitored in the ITER test site. The relationship with precipitation and natural/induced ground temperature variations, reaching also water freezing point, are here discussed.


Soil Water content Soil freezing Thermal conductivity Very shallow geothermal energy Geothermal helical heat exchangers 



This work was supported by the European Union. ITER project ( has received funding from the European Union’s Framework Program for Research and Innovation Horizon 2020 (2014–2020) under the Marie Skłodowska-Curie Grant Agreement No. [661396-ITER]. Special thanks to REHAU AG&Co and Fischer Spezialbaustoffe Gmbh companies and their representative Ing. Mario Psyk and Mr. Thomas Popp for their valuable support. We thank Hans Schwarz and Johannes Müller of the University of Erlangen for assisting in laboratory and field tests data acquisition and Giordano Teza of the University of Padua for the review of the systematic error description.


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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Friedrich-Alexander University (FAU) Erlangen-Nuremberg, GeoCentre of Northern BavariaErlangenGermany

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