Study on the Impact of Spontaneous Combustion of Coal Gangue on Photovoltaic Pile Foundations and Surface Structures

With economic growth, constructing photovoltaic power plants on gangue mountains holds significant potential for the development of renewable energy and the effective utilization of gangue mountains. However, it is crucial to account for the impact of the spontaneous combustion of coal gangue on surface structures and the mechanical performance of pile foundations. This study uses COMSOL Multiphysics software (version 6.2) to conduct a simulation by establishing a multiphysical coupling model of the temperature field, oxygen concentration field, and seepage velocity field, simulating the dynamic evolution of spontaneous combustion in gangue mountains. The reasonableness of the model was verified by comparison, and a mechanics module was added to explore the effects of pile foundations and ground surfaces at high temperatures. The results indicate that the spontaneous combustion of coal gangue initially generates high-temperature regions beneath the slope of the pile, which gradually expand outward. Due to thermal expansion, thermal stress and displacement occur in both the gangue mountain and pile foundations, potentially compromising the stability of the foundations and increasing the risk of structural failure. These findings can serve as valuable references for the construction of photovoltaic power plants and the effective utilization of gangue mountains.