| With the rapid development of urban rail transit,the earthquake resistance of urban bridges has become increasingly prominent,and the municipal engineering has put forward higher requirements for the comprehensive performance of seismic isolation of bridges.The Triple Friction Pendulum Isolation Bearing(TFPS),as a new type of seismic isolation bearing,has a good energy dissipation mechanism and can provide a large enough horizontal displacement to meet the seismic isolation design with engineering structures with different stiffness and damping.In this paper,taking a joint viaduct continuous beam bridge in Zhengzhou as the engineering background,the research on the seismic isolation performance of the triple friction pendulum bearing applied to the viaduct was carried out.The solid model of the triple friction pendulum bearing was established by the finite element software ANSYS,and the displacement cloud diagram and the force-displacement hysteresis curve of each stage of the bearing during the sliding process were obtained;at the same time,the finite element analysis of the full bridge was established based on the Midas Civil software Model,using nonlinear time-history analysis method,the seismic response of urban viaducts with triple friction pendulum bearings and nonisolated bearings has been successively studied,as well as seismic wave intensity,bearing parameters(sliding surface radius and friction coefficient)on isolated bridges.Research on the impact of earthquake response.The main conclusions are as follows:(1)The triple friction pendulum bearing can produce five sliding stages with different swing stiffness when different sliding surfaces are combined during movement.Under different load excitations,it can enter different sliding states through its own structure to ensure good vibration isolation performance..The numerical simulation results are in good agreement with the theoretical analysis.(2)The triple friction pendulum bearing can effectively extend the basic period of the urban viaduct under earthquake action,reduce the internal force response of the pier,and make the internal force and displacement distribution of each bridge pier more uniform.Requirements,give full play to the superior seismic performance of triple friction pendulum bearings.(3)The triple friction pendulum bearing can provide greater horizontal displacement and can effectively resist the earthquake action of different magnitudes.And under different earthquake magnitudes,the vibration isolation performance of the triple friction pendulum bearing is better than that of the friction single pendulum bearing.(4)The bearing parameters have a great influence on the isolation performance of the triple friction pendulum bearing.As the radius of the sliding surface of the bearing increases,the hysteretic performance of the bearing continues to increase,and the internal force and displacement of the pier decrease with the increase of the radius of the bearing.Increasing the friction coefficient of each sliding surface can effectively reduce the bearing displacement of isolated bridges under rare earthquakes,and at the same time will not cause the increase of seismic response amplitude of isolated bridges under design and frequent earthquakes. |
