Influence of Subgrade Differential Settlement on Riding Performance of High-Speed Train

Abstract

The differential settlement of subgrade may accelerate degradation of tracks, lower passenger comfort and increase derailment risk of trains, especially in high-speed railway. In this paper, a dynamic analysis model for train-ballasted track-subgrade system is established to study the effect of different settlement profiles in a deeper insight, in which the subgrade settlement is simulated by Gaussian function profiles with different amplitudes and longitudinal lengths. In the case study, the dynamic responses of train vehicles and track structure subjected to 100 kinds of differential settlements of subgrade are calculated with the CRH2 high-speed train at different speeds. Results show that the performance indicators of running trains increase obviously with the train speed; the accelerations of the passenger car-bodies increase not only with the amplitude of the settlement, but also depend on the length of the track deformation; the shorter is the longitudinal length of settlement, the bigger the derailment risk is; the greater is the amplitudes of subgrade differential settlement, the bigger the probability of poor passenger comfort and risk of derailment are.