Mangjiedu deep-water bridge locates in an area where earthquakes occur quite frequently, therefore the hydrodynamic force on the piers induced by the earthquake will be considerable. A semi-analytical and semi-numerical approach for earthquake induced hydrodynamic force on elastic rectangular hollow bridge pier was developed. Based on linear radiation wave theory, the interior and exterior hydrodynamic forces on pier were got by eigen function expansion method. This method avoided solving fluid-solid model directly, and was efficient for bridge engineering. The modal analysis, spectrum analysis and transient analysis were introduced respectively and the results showed that the influence of hydrodynamic force can not be neglected for Mangjiedu bridge because the 168 meter high piers could almost all in water.
