Influence of sulfate corrosion on the seismic performance of subway stations

Subway stations embedded in the soil, particularly when groundwater is present, are more susceptible to corrosion because of the presence of sulfate ions. Sulfate corrosion can lead to a reduction in the stiffness and strength of underground structures, thereby affecting their overall seismic performance. After analyzing the evolution of the strength and stiffness of sulfate-corroded concrete, the homogenization method is used to calibrate the strength and deformation behavior of concrete at different corrosion durations. Subsequently, the influence of sulfate corrosion on the load-carrying and deformation capacities of the ceiling, bottom slabs, and sidewalls of the subway station is investigated, and the seismic performance limits of each component are calibrated. Then, a three-dimensional finite element model is established to simulate the seismic response of the subway station. The deformation and internal forces of the sulfate-corroded structures are analyzed, and the influence of sulfate corrosion on the seismic performance of the subway station is evaluated. The results indicate that the longer the erosion time, the more severe the earthquake-induced damage. The slabs and sidewalls of the corroded structures are prone to leakage. When carrying out seismic design for subway stations, it is important to consider sulfate corrosion, with particular attention to the bottom slabs and sidewalls.