Response analysis of high-speed rail system accounting for abrupt change of foundation stiffness

A relatively recently developed method known as the moving element method (MEM) is further extended to deal with moving loads that travel along inhomogeneous visco-elastic foundation. The proposed computational scheme is applied to investigate the dynamic response of high-speed rail system for the situation where there is an abrupt change of foundation stiffness. The influence of different factors, including the degree of change of foundation stiffness, traveling velocity of the train and the severity of track irregularity, on the response of the train as well as the track is examined and discussed. The phenomenon of ‘jumping wheel’, which occurs when there is a momentary loss of contact between the wheel and track, is accounted for in the proposed model. Results are presented to illustrate the effect of ‘jumping wheel’ on the dynamic response of the train-track system.