Influences of Soil-Structure Interaction on Coupled Vibration of Train-Bridge System: Theoretical and Experimental Study

A numerical solution for the dynamic response of train-track-bridge coupled system taking into account the influence of soil-structure interaction is studied and verified by field experiments. A three-dimensional vehicle-track-bridge coupling dynamics model is developed, in which the vehicle subsystem, the track subsystem and the bridge subsystem are coupled through wheel-rail interaction and track-bridge interaction, respectively. The soil-structure interaction between the bridge foundation and the soil is simulated by spring stiffness exerted on group-pile foundation. In a case study, the dynamic responses of a high-speed train and a continuous beam bridge are calculated by three models, that is fixed-base model, equivalent-stiffness model and the proposed whole-pile model. The comparison of simulated and experimental results show that soil-structure interaction has significant influence on the lateral dynamic response of the bridge; The whole-pile model is proposed to study the coupled vibration of bridge and vehicle, which gives more reasonable simulation result than the other two models.