Data-driven and multi-physics coupling-based optimization and energy-saving assessment of bridge piers thermal control systems by energy piles

This study proposes a data-driven, multi-physical field coupling optimization strategy for energy piles based on thermal control. The strategy aims to mitigate concrete cracking in high-altitude bridge piers, which is caused by temperature differences, while reducing the excessive energy consumption of traditional thermal control systems. Annual measurements revealed that solar radiation intensity is the key factor affecting temperature differences between sunlit and shaded pier surfaces. The largest temperature variation amplitude occurred in winter, and the highest cracking risk was also observed during this period. Simulations determined that concrete tensile stress exceeded the tensile strength when the temperature variation amplitude on the sunny side exceeded 14.7 °C, which formed the basis for designing a dynamic operation strategy. Photovoltaic Systems (PVsyst) simulations demonstrated that the dynamic strategy achieved an annual energy-saving rate of 57% compared to the fixed strategy, with summer energy savings reaching 73%–88%. The optimized approach reduced system power generation requirements, nominal photovoltaic (PV) power, module area, and energy storage capacity by 56.6%, 33.3%, 33.3%, and 70.3%, respectively, resulting in significant cost reductions. These findings provided valuable insights for the intelligent temperature control and sustainable maintenance of bridge infrastructure.