Wind-Resistant Safety Analysis of High-Speed Trains Passing Through Bridge-Tunnel Transition

When a train travels from a tunnel to a bridge, it bears a sudden wind load, and the response of the train changes abruptly, which will threaten the travelling safety. Taking a bridge-tunnel transition of a passenger dedicated line as the research background, computational fluid dynamics (CFD) simulation and vehicle-bridge coupling vibration analysis are conducted to calculate the aerodynamic forces and responses of a CRH3 train passing through the bridge-tunnel transition. The aerodynamic forces and vehicle responses of the front train, the middle train and the tail train are compared, the influences of wind attack angle on the aerodynamic force and vehicle response are studied, and the most unfavorable safety index is discussed. Results show that the closer the vehicle body is to the front, the greater the sudden variation in aerodynamic load and vehicle response will be. Compared with the 0° wind attack angle, a positive wind attack angle is relatively favorable to the train running, and the +7° wind attack angle brings a 10% decrease in the drag force and rolling moment of the train; however, a negative wind attack angle will increase the sudden variation effect of aerodynamic load and the running vehicle’s responses, and the −7° wind attack angle brings a 10% increase in the drag force and rolling moment of the train. When the wind speed is below 22.5 m/s, the CRH3 train can safely pass through the transition at a speed of 200 km/h. When the wind speed is 20.0 m/s, the train can safely pass through the transition at a speed of less than 325 km/h. With an increase in the vehicle speed and wind speed, the lateral force of the wheel axle is the first safety index to exceed the limit.