Seismic Response Analysis And Seismic Isolation Research Of (60+100+60)m Continuous Beam

Prestressed box continuous beam is widely used in railway bridges because of its good integrity,high torsional stiffness,uniform and reasonable internal force distribution in each section,convenient construction and economical material consumption.China is a country with frequent earthquakes.Through the investigation and study of Tangshan and Wenchuan earthquakes,it is found that the damage of railway bridges caused by earthquakes is mainly the bending and shear damage of pier roots,and the characteristics of continuous beams such as heavy weight and high pier height are not conducive to earthquake resistance.Therefore,it is imperative to study and analyze the seismic response of continuous beams.In this paper,the(60+100+60)m prestressed concrete continuous beam of Langzhuo Intercity Railway is taken as the research object,and the vibration isolation model without considering pile-soil interaction and the vibration isolation model with friction pendulum bearings are established respectively.The dynamic characteristics,response spectrum analysis,linear and nonlinear time-history response analysis and parameter sensitivity analysis of friction pendulum bearings are carried out respectively.The main work is as follows:(1)The Midas Civil finite element software is used to analyze and compare the dynamic characteristics of the model without vibration isolation and the model with or without vibration isolation bearing.(2)Using response spectrum analysis method,the internal force and displacement response of continuous beam model with or without live train load and with or without vibration isolation bearing are analyzed under frequent earthquakes,and the results are compared and analyzed.(3)Using the time-history response analysis method,under the frequent and rare earthquakes,three seismic wave records are selected and amplitude modulated according to the code,and the influence of the application of friction pendulum bearings on the isolation of continuous beams is analyzed.(4)Two seismic waves are selected to analyze the parameter sensitivity of the friction pendulum isolation bearing from four aspects: the layout scheme of the isolation bearing,the sliding spherical curvature radius of the lower bearing plate,the friction coefficient between the slider and the lower bearing plate and the height of the pier.