EVALUATING THE SAFETY OF HIGH-SPEED TRAINS AT THE ACTION OF DOWNBURST

A set of safety evaluation methods of high-speed trains under the action of downburst are established by using physical simulator. The results show that under the combined effects of wind speed field and pressure field of downburst, the wind load acting mechanism is significantly different for each relative position of the train distance from the downburst center. Under the action of downburst, the side force contributes the most to the wheel rail lateral force, and the overturning moment contributes the most to the wheel rail vertical force. The evaluation index for the safe operation of trains such as transverse force, derailment coefficient, wheel unloading rate first increase and then decrease as the radial distance increases. The relative radial distance of r/D_jet= 0.83(D_jet denotes nozzle diameter) is the most unfavorable radial position for the safe operation of trains. The train safety operation indicators increase with the increase of wind speed and vehicle speed, and the critical wind speed of downburst for safe train operation decreases sharply with the increases of vehicle speed.