Abstract:In the seismic design of bridges in high intensity earthquake area, compared with the ductile seismic design, by extending the natural vibration period of the structure and increasing the damping of the structure, the seismic isolation deices are used to reach the goal of depleting the earthquake capacity and reducing the seismic response of structure so as to greatly improve the seismic performance of the bridge, which has the obvious advantages of economy and easy repair after earthquake. Taking a continuous beam bridge in 8-degree earthquake zone as the engineering background, a three-dimensional spatial finite element model of the whole bridge is established. The seismic isolation performance of bridge is studied by the nonlinear time-history dynamic analysis, and compared with the corresponding non-seismic isolation bridges, the seismic isolation effect is tested. At the same time, combined with the conclusion of dynamic analysis, the refined design is carried out for the seismic structural measures of bridge. The reasonable structure design can ensure the full play of the seismic isolation device function and ensure the bridge to achieve the expected seismic performance goal.