Assessment of track-ground coupled vibration induced by high-speed trains

As high-speed trains operate in more and more countries and their maximum speed increases, the vibration induced by the train has become an important issue. The dynamic coupling between the vehicle, track and ground has to be assessed for its effects on safety, stability and maintenance costs. A particular issue, especially for soft soils, is the critical speed at which the train reaches the wave speed in the ground leading to large deflections of the track and ground. The aim of this paper is to develop a three-dimensional time-domain approach that describes how the moving dynamic loads of a high-speed train are distributed through the track components. This model should allow the critical speed to be determined and the vibration of the whole system to be analysed. To represent the complex vehicle/track/ground system a finite element approach is used based on the ABAQUS software. Rather than using a user-defined subroutine to apply the moving loads, the multi-body vehicle model and track/ground system are coupled as deformable bodies using a contact model that allows for large scale motion of the vehicle relative to the track.