Study On Seismic Performance Of Continuous Girder Bridge With Invisible Cover Under Different Bearing Schemes

In this paper,a continuous bridge with invisible bent cap in a city is taken as the research object.Combined with the structural characteristics of the continuous bridge,the analysis and calculation model of the bridge is established by using the finite element software 。 According to the layout scheme of basin rubber bearing,high damping rubber bearing and friction pendulum isolation bearing,the seismic response law of bridge under different bearing schemes is studied.The main contents include the following aspects:(1)The finite element dynamic analysis models of continuous beam bridge with basin type rubber bearing,friction pendulum isolation bearing and high damping rubber bearing are established respectively.The response spectrum method is used to calculate the internal force of basin type rubber bearing under earthquake action,The time history analysis method is used to calculate the internal force of the friction pendulum isolation bearing and high damping rubber bearing under earthquake action.According to the results of internal force calculation,the pier reinforcement is carried out.Building fiber model with XTRACT,according to the reinforcement results,the moment curvature analysis of the pier column is carried out.The isolation scheme is selected according to the analysis results.(2)Based on the finite element dynamic analysis model,the time history analysis method is used to analyze the bridge with different support schemes of molecular basin rubber bearing,high damping rubber bearing and friction pendulum bearing.The maximum bending moment at the bottom of the pier,the maximum shear force at the bottom of the pier and the displacement at the top of the pier are selected to analyze the seismic performance.Through the analysis,the internal force of the pier and the displacement time history response of the pier top under different schemes are obtained.According to the analysis results,the seismic performance of different bearing schemes is obtained.(3)Based on the principle of energy balance,the hysteretic energy consumption and energy time history of the two isolation schemes under different seismic excitations are analyzed,and the seismic energy response distribution law and the hysteretic energy consumption performance of bearings under different seismic excitations are studied.