Evaluation of train runnability for cable-supported steel bridges subject to cross wind

Abstract

To evaluate the effects of train-wind-bridge interactions on the runnability of a train, the contact forces of wheels were calculated under crosswind conditions using the VI-Rail program. Based on the results of the program, the critical wind velocity is directly dependent on the velocity of the train. The Yeongjong Bridge was examined using the ERRI model which is stabilized train model of the VI-Rail program. Fluctuating wind velocities, simulated by ARMA, were used as inputs of both the Buffeting analysis program and the VI-Rail program. Since the program has some inherent limitations regarding the modeling of the substructures, the displacements obtained by the buffeting analysis were used as track irregularities of the rail in considering the interaction between the bridge and the train. Fluctuating wind velocities were also taken into consideration according to the moving location of the train. Kalkers FASTSIM algorithm was used to consider non-Hertzian problems in order to accurately calculate the contact forces. Consequently, runnability was evaluated with wheel unloading and derailment calculated by the vertical and lateral force of a wheel. The critical wind velocities as a function of the velocity of the train were represented by the CWC. After the evaluation of runnability, its parameters were evaluated by comparing the effect of the fluctuating wind velocity on the bridge and the train. The results indicate that a detailed analysis of the parameters must be conducted, in order to accurately evaluate runnability based on train-wind-bridge interactions.