Dynamic Soil–Structure Interaction Effects on 3D Integral Railway Bridge under High-Speed Moving Loads

Here, we have studied a ballastless double-track fivespan integral bridge subjected to China Railway High-speed train loading. Soil–structure interaction (SSI) is considered to assess the resonant response of each span of this bridge. Finite element method is used to analyse the 3D bridge model. Four soil conditions, viz. fixed base, hard soil, medium soil and soft soil are considered to examine the dynamic response of the bridge. For each soil condition and for all the spans, it is observed that the resonant speeds correspond to higher modal frequencies. This study reveals the occurrence of resonance phenomenon for all the spans of an integral bridge, suggesting the importance of moving load analysis. Finally, the vertical resonant responses of the central span of an integral bridge and a continuous bridge are compared.