Deep-water bridges located in a V-shape canyon may suffer from spatially varying ground motions due to the canyon topography. This paper focused on the effect of canyon topography on the seismic responses of a deep-water continuous rigid-frame bridge that crosses a V-shape canyon. The ground motions in three example sites with different topography conditions were simulated by the numerical spectral element method. A database with one hundred point-sources considering the uncertainties of seismic magnitude and source location was sampled and adopted to simulate the seismic waves propagating from the source to the bridge site. Nonlinear seismic response analyses of the example deep-water bridge were performed under the simulated spatially varying ground motions considering the hydrodynamic added mass on the piers. The effects of the canyon topography on the seismic wave field, peak ground acceleration at bridge foundations, and seismic responses of the bridge were analyzed. According to the example studies, the canyon topography induces a significant spatial variation of the ground motions for the bridge in the canyon. Compared with the canyon topography, the influence of water within the canyon on the ground motion is slight. Neglecting the effect of canyon topography leads to the inappropriate assessment of the seismic fragility of the deep-water bridge in both component and system levels.

由于峡谷的地形，位于V形峡谷中的深水桥梁可能会遭受地震动的空间变化。本文重点研究了峡谷地形对穿越V形峡谷的深水连续刚构桥的地震响应的影响。用数值谱元方法模拟了三个地形条件不同的地点的地震动。采样了一个包含一百个点源的数据库，该数据库考虑了地震震级和震源位置的不确定性，并被用来模拟从震源传播到桥梁现场的地震波。考虑到墩上的流体动力附加质量，在模拟的空间变化地震动下对示例深水桥进行了非线性地震响应分析。分析了峡谷地形对地震波场，桥梁基础处的峰值地面加速度以及桥梁地震响应的影响。根据示例研究，峡谷地形引起峡谷中桥梁的地面运动的显着空间变化。与峡谷地貌相比，峡谷内的水对地震动的影响很小。忽略峡谷地形的影响导致对深水桥的地震易损性在组件和系统水平上的不适当评估。峡谷的地形导致峡谷中桥梁的地震动发生明显的空间变化。与峡谷地貌相比，峡谷内的水对地震动的影响很小。忽略峡谷地形的影响导致对深水桥的地震易损性在组件和系统水平上的不适当评估。峡谷的地形导致峡谷中桥梁的地震动发生明显的空间变化。与峡谷地貌相比，峡谷内的水对地震动的影响很小。忽略峡谷地形的影响导致对深水桥的地震易损性在组件和系统水平上的不适当评估。