The effect of soil-structure interaction on coupled vibration of a continuous rigid-frame bridge and vehicles under high speed vehicle load was discussed. With BDAP V2.0 (bridge dynamic analysis program) , the natural frequencies and dynamic responses of the bridge under vehicle load were calculated by using a new bridge model ( whole-pile model), considering the interaction of lateral displacement and bending angle on group-piles. Comparing with the commonly used consolidation model and the equivalent-stiffness model, the dynamic response of the bridge, especially, its lateral dynamic response varied a lot by considering soil-structure interaction. While the maximum dynamic accelerations droped, the maximum dynamic displacements grew obviously, the maximum error reached 31% . For a high speed railway bridge located in soft ground with high-pile cap foundation, the whole-pile model was proposed to analysis the coupled vibration of the vehicle and the bridge.%针对某高速铁路上一座位于软弱地基处的连续刚构桥,为研究考虑桩-土相互作用对上部结构和车辆动力响应的准确影响,避免由于桩顶横向位移和弯曲的耦合作用带来的误差,建立包含桩基础的整体桥梁模型(全桩模型),对比以往常用的墩底固结模型和在承台底施加弹簧约束的模型(等效刚度模型).计算分析了三种模型的自振特性,使用桥梁动力分析程序BDAP V2.0分别进行动力仿真分析.对比分析表明:考虑桩-土相互作用对桥梁横向振动有较大影响,其中横向动位移显著增大,最大误差达31％,而横向加速度降低;全桩模型由于考虑了桩-土相互作用以及横向位移和弯曲的耦合作用,比墩底固结模型和等效刚度模型要合理;高速铁路桥梁位于软弱地基处且具有高桩承台时,应采用考虑桩-土-上部结构动力相互作用的有限元模型进行车桥动力仿真分析.
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