Coupled Vibration Analysis of Railway Continuous BEAM Bridge and Vehicles with Soil-Structure Interaction

Simulation computation of vehicle-bridge coupling vibration and field experiment are carried out in a long-span continuous beam bridge of an intercity railway. And the effect of soil-structure interaction on the coupled vibration of continuous beam bridges and vehicles under high speed vehicle load was discussed in this paper. With BDAP V2.0(Bridge Dynamic Analysis Program), which is certificated by National Copyright Administration, the natural frequencies and dynamic responses of the bridge under vehicle load are calculated by using a more complex bridge FEM model(whole-pile model), which can take account of the interaction of lateral displacement and bending angle on group-piles. In order to assess the influence of soil-structure interaction on bridge dynamic response and evaluate the actual dynamic response of a long-span continuous beam high speed railway bridge, dynamic loading tests were made at the speed varying from 200km/h to 380km/h to get the vertical dynamic displacements in the mid-span and the lateral and vertical amplitude and acceleration of some typical points in the beam and pier. With a comparison of simulation computation results of different bridge FEM models and field experiment results, we can draw some conclusions, which is beneficial to research and design of long-span continuous beam bridges in high speed railway: Compared with commonly used consolidation model and equivalent-stiffness model, the dynamic response of the bridge with whole-pile model, especially the lateral dynamic response, varies a lot by considering soil-structure interaction. While the maximum dynamic accelerations get lower, the maximum lateral amplitudes become higher. And the results of field experiment show that with whole-pile model, a precise and reasonable simulation computation result can be gained because soil-structural interaction is also taken into account. For a high speed railway bridge located in soft ground with group-piles foundation, whole-pile model is proposed to analysis the coupled vibration of vehicle and bridge.