A spatial train-track-tunnel coupled dynamics model for assessing influences of curved railway line on circular tunnel vibrations

A spatial train-track-tunnel coupled dynamics model is established in this paper, which exhibits high computational efficiency and can effectively capture the influences of curved railway lines and the spatial dynamic interactions between the subsystems. In the model, the circular tunnel and grouting area are simplified as a dual-layer cylindrical shell with finite length and then are modelled using semi-analytical method for high computational efficiency. The effects of surrounding soil are simulated using unified viscous-spring artificial boundaries. After being verified by the field measurements, the proposed model is employed to assess influences of curved railway line on the train-induced vibrations of circular tunnel. The results indicate that there are significant differences in tunnel vibrations induced by trains moving on curved railways compared to straight railways, and tunnel vibrations are not monotonously reduced by decreasing the train running speed. The model enables more realistic assessments of the train-induced vibrations of circular tunnels, particularly in the cases involving curved railways. •A spatial train-track-tunnel coupled dynamics model is established.•The model is verified by field measurements under hammering load and train load.•New characteristics of train-induced vibrations of tunnel in curved railway are revealed.•Engineering recommendations for assessing and reducing environmental vibrations induced by running trains are provided.