In violent earthquakes, ground motion is considered to change dramatically in the process of spatial propagation. Strong spatially varying exists in ground motion near fault area, and it can cause the large-span and large stiffness structure to be damaged. In this paper, a typical long-span steel box arch bridge is selected as an engineering case. In order to simulate the spatial variation of near fault ground motion accurately, the records that sampled in former earthquake are used as ground motion input. The shaking table experiment and finite element analysis are used as analysis means. Through the analysis of the internal force and displacement response of the key position of the arch rib, it is found that the spatially varying in the near fault ground motion can bring severe seismic response. If the spatially varying is ignored, the damage of the bridge will be seriously underestimated.

在剧烈地震中，地面运动被认为在空间传播过程中发生了剧烈的变化。断层附近的地震动存在强烈的空间变化，会引起大跨度、大刚度结构的破坏。本文以一座典型的大跨径钢箱拱桥作为工程案例。为了准确模拟近断层地震动的空间变化，将前次地震中采样的记录作为地震动输入。采用振动台试验和有限元分析作为分析手段。通过对拱肋关键部位内力和位移响应的分析，发现近断层地震动的空间变化会带来剧烈的地震反应。如果忽略空间变化，