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Considering the need to reduce our dependence on unsustainable energy sources and reducing the carbon footprint associated with building climate control, shallow geothermal energy represents an attractive sustainable technology for providing renewable heating and cooling. The temperature field generated around ground-coupled heat exchangers, and thus their energy efficiency, fundamentally depends on the heat transfer mechanism and the thermal properties of the materials involved. While the thermal properties of materials that make up the system can be defined with some certainty, little is known about the impact of contact thermal resistance at the soil-structure interface. Contact thermal resistance will reduce heat exchange efficiency and increase mechanical impacts associated with temperature changes within energy geo-structures. This paper describes a laboratory test method to quantify the contact thermal resistance of soil-concrete interfaces. The methodology is first evaluated using numerical analysis, and then validated against a test using a limestone aggregate concrete and fine, silica sand at differing levels of compaction.

The stability of slopes and hillsides involving rock or soil masses depends crucially on the occurring geological and geotechnical conditions. The village of Monsanto, municipality of Idanha-a-Nova, is located on a granitic inselberg. The tourist interest of the village lies largely in the fusion of the granitic rock mass with the man-made constructions and in the aesthetics of several granitic boulders scattered throughout the village. In the present work the geological and geotechnical characterization of the rock mass has been carried out, namely by the field survey of the entire intervention area and by a set of laboratory tests on samples collected in the field (ultrasound propagation velocity and the uniaxial compression test). Based on this information, the shear strength of the discontinuities was estimated and a kinematic analysis was performed using the Dips 7.0 commercial software, with the objective of defining the predominant sets of joints and identifying the most probable failure mechanisms in each hillside.