Thermo-Mechanical Coupling Model for Energy Piles: Dynamic Interface Behavior and Sustainable Design Implications

This study introduces an advanced temperature variation model for the pile–soil interface of single energy piles, developed through extensive numerical simulations across diverse operating conditions. Unlike existing models, it explicitly accounts for thermal interactions at the interface by adopting uniform material properties and initial temperatures, enabling precise heat transfer predictions. An iterative algorithm based on the load transfer method quantifies the pile’s thermo-mechanical response to temperature fluctuations, demonstrating significantly improved accuracy in settlement prediction compared to conventional methods. Validation against two field case studies demonstrates the model’s robustness across varied geotechnical contexts. Parameter analysis identifies soil thermal conductivity and load transfer characteristics as critical factors influencing pile behavior, thereby facilitating design optimization. This approach enhances energy pile efficiency by up to 20%, promoting the utilization of renewable geothermal energy and reducing carbon emissions in infrastructure projects, thus contributing to sustainable geotechnical engineering practices.