Field test on thermal control for bridge piers on plateau through energy pile

Abstract

This study presents a sustainable thermal control method (energy pile technology) for bridge piers in high-altitude regions, addressing the challenges posed by temperature variations in mass concrete structures. The proposed method involves integrating various heat exchange tubes within the pile foundation, pile cap, and bridge pier concrete to harness shallow geothermal energy. This paper summarizes failure cases of bridge structures due to the impact of thermal loads. Through three field tests on a plateau, the feasibility and practicality of the energy pile technology are verified. The system exhibits promising results, achieving a maximum temperature difference reduction of 3.9°C and a reduction of 53.4%. Furthermore, the method has effectively reduced the expansion strain on the sunny side of the bridge piers, with a maximum reduction of up to 44.4%. Importantly, the energy pile technology has minimal impact on the pile foundation, with negligible constrained stress variation. The study evaluates the heat exchange efficiency and energy efficiency of the energy pile-based system, reporting stable heat exchange rates and a comprehensive Coefficient of Performance (COP) reaching up to 4.0. The findings highlight the potential of this sustainable temperature control methodology to enhance the resilience and longevity of critical infrastructure in challenging climates.