The pounding effect at the expansion joints on the seismic response of a long-span deep-water high pier bridge with multiple approach spans under earthquake is studied considering the fluid–structure interaction effect. The nonlinear fibre element is used to simulate the main piers and transition piers. The contact element is employed to consider the seismic pounding effect at the expansion joints. The hydrodynamic pressure is applied to the main piers and transition piers in the form of added mass of graded accumulation. Forty seismic records of different earthquakes are used as input to conduct the longitudinal time history analysis of the whole bridge. The seismic responses of bridge structure with and without pounding effect are compared to analyse the impact of pounding on the structure. The results show that considering the pounding effect at the expansion joints, the seismic response of the main pier under the fluid–structure interaction effect is reduced, which indicates that the pounding is beneficial to the main pier. Due to the out-of-phase vibration between the main bridge and the approach spans, the pounding force at the expansion joints on the left and right transition piers is the largest, and the pounding transmission effect is obvious. The transmission effect makes the positive displacement amplitude of the right bearings on the top of each pier of the right approach spans increase evidently. The increased amplitude of each pier is not synchronous, which will increase the possibility of unseating.

考虑流固耦合效应，研究了地震作用下伸缩缝冲击对多引桥大跨度深水高墩桥地震响应的影响。主要桥墩和过渡桥墩采用非线性纤维单元模拟。接触单元用于考虑伸缩缝处的地震冲击效应。动水压力以分级堆积的附加质量的形式施加到主墩和过渡墩上。以40条不同地震的地震记录作为输入，对全桥进行纵向时程分析。对比了桥梁结构在有和无冲击作用下的地震反应，分析了冲击对结构的影响。结果表明，考虑伸缩缝处的冲击作用，主墩在流固耦合作用下的地震响应减小，表明冲击对主墩有利。由于主桥与引桥异相振动，左右过渡桥墩伸缩缝处的冲击力最大，冲击传递效果明显。传递效应使右引桥各桥墩顶部右支座正位移幅值明显增大。各桥墩幅度增加不同步，会增加脱座的可能性。这表明冲击对主墩有利。由于主桥与引桥异相振动，左右过渡桥墩伸缩缝处的冲击力最大，冲击传递效果明显。传递效应使右引桥各桥墩顶部右支座正位移幅值明显增大。各桥墩幅度增加不同步，会增加脱座的可能性。这表明冲击对主墩有利。由于主桥与引桥异相振动，左右过渡桥墩伸缩缝处的冲击力最大，冲击传递效果明显。传递效应使右引桥各桥墩顶部右支座正位移幅值明显增大。各桥墩幅度增加不同步，会增加脱座的可能性。传递效应使右引桥各桥墩顶部右支座正位移幅值明显增大。各桥墩幅度增加不同步，会增加脱座的可能性。传递效应使右引桥各桥墩顶部右支座正位移幅值明显增大。各桥墩幅度增加不同步，会增加脱座的可能性。