Thermo-hydro-mechanical behavior of energy barrettes: Field experiments and numerical simulations

Over the past two decades, the thermo-hydro-mechanical behavior of earth-contact structures such as piles, walls, slabs, and tunnels, which simultaneously provide structural support and energy supply, has been studied through various field experiments and numerical simulations. These endeavors have built an understanding of the behavior of so-called energy piles, energy walls, energy slabs, and energy tunnels. This paper explores the thermo-hydro-mechanical behavior of a novel class of earth-contact structures that has the specificity of providing structural support and renewable energy to tall buildings: energy barrettes. This study particularly presents the first field experiments and 3-D time-dependent numerical simulations of energy barrettes. The work investigates the thermo-hydro-mechanical behavior of energy barrettes for a comprehensive set of variables: geometric variables (i.e., pipe configuration, barrette aspect ratio, and barrette section ratio), site variables (i.e., barrette–soil stiffness ratio and ground effective thermal conductivity), and operational variables (i.e., flow rate of the fluid circulating in the pipes). The obtained results expand the current knowledge base to analyze the behavior of energy barrettes in multiple situations that are likely to be encountered in practice and highlight markedly non-uniform temperature, displacement, and stress fields within and around such foundations.