Based on the Navier-Stokes equations set up with arbitrary Lagrange-Eulcr description

a integral finite element model used to analyze the seismic response of bridge piers in deep water and considering close fluid-structure interaction（FSI） was established.Effects of the close FSI on the relative displacement

shear force and moment responses of the bridge pier were analyzed and the close FSI and its effects under different water depth were discussed.The results of the case study indicate that the displacement and internal force of bridge piers will increase obviously when the FSI is considered.When the peak displacement of input earthquake wave is larger

effects of the FSI on the displacement response of the pier will be larger and effects of the FSI on the internal force response of the pier will be smaller.Effects of the close FSI on seismic response of the pier are related to the frequency characteristics of the input earthquake wave.Additionally

Effect of the water depth on internal force response of the pier are more significant than that on the displacement response of the pier.