Performance of complex energy geostructures

Abstract

Energy geostructures are innovative technologies that combine the functions of structural support and geothermal energy harvesting. To date, theoretical, computational, and experimental investigations have explored independently the performance of different types of energy geostructures, i.e. energy pile, walls, slabs, and tunnels. However, there seemingly exists limited knowledge on the performance of energy geostructures that integrate different types of geostructures in a unique building solution, despite being common solution in practice. This paper addresses this knowledge gap by providing a computational study of the performance of two real-world installations of energy geostructures. The study resorts to 3-D, time-dependent, thermo-mechanical finite element simulations that consider the dynamic building thermal energy needs and the operation of the considered installations over a design lifetime of fifty years. The work reveals that the energy, geotechnical, and structural performance of complex energy geostructures is complex. The structural performance of such geostructures exhibits responses that are counterintuitive and different compared to those that would be predicted by simplified modeling approaches referring to individual types of energy geostructures. Accordingly, this investigation calls for attention in the analysis of complex energy geostructures and judgment in the application of simplified design methods.