Fluid-structure interaction between the two-train-meeting slipstream and the overhead electrification catenary support structure in the high-speed railway tunnel

The overhead electrification catenary support structure (OESS) inside a tunnel is a key component of the catenary system. When two trains meet inside a tunnel, the intense slipstream effects generated by their fast movements induce strong dynamic responses of the OESS, affecting collection quality and operational safety. Based on the fluid-structure interaction (FSI) numerical method, this study establishes a three-dimensional model of the high-speed train-tunnel-OESS-air system. The dynamic response characteristics of the OESS under high-speed train meeting conditions are systematically investigated, and the effects of train meeting position, OESS installation location, and train operating speed are clarified. The results indicate that the dynamic response and aerodynamic load of the OESS are most significant when trains meet in the middle of the tunnel, with particularly severe longitudinal fluctuations. The positive peak acceleration of the OESS during tunnel-middle meetings in the X direction is 6.77 and 1.77 times that during meetings at the tunnel portal and quarter-point, respectively. The OESS at the tunnel portal suffers the most significant wind speeds, with peak wind speeds in the X, Y, and Z directions exceed those at the quarter-point OESS by 37.21%, 126.89%, and 47.33%, respectively, resulting in the most significant fluctuations in dynamic response and aerodynamic load. Among the OESS components, the mast pole experiences the highest peak longitudinal force, followed by the support brace, with the steady arm being the lowest. During tunnel-portal meetings, the positive peak longitudinal force on the mast pole is 2.72 and 34.42 times that on the support brace and steady arm, respectively. Turbulence intensity near the portal OESS is higher and vortex shedding more intense, yielding higher peak power spectral density values for the aerodynamic load. The findings may be valuable for the location selection and wind-resistance design of OESS in high-speed railway tunnels. © 2026 Elsevier Ltd