Seismic Response Analysis And Mitigation Study Of (64+108+64+108)m Continuous Beam Bridge

Prestressed concrete continuous beam bridge is widely used in China's high-speed railway projects by virtue of its advantages such as large spanning capacity and service performance.However,bridge is often extremely vulnerable during earthquakes.Because of the frequent occurrence of earthquakes in China,it is necessary to conduct in-depth research and seismic control of the seismic response of prestressed concrete continuous beams.In this thesis,the continuous beam(64+108+108+64)m of Lianzhen Railway is taken as the research object,and the finite element model is established by Midas Civil.It is analyzed by dynamic characteristics,response spectrum analysis,time-history response analysis,and shock absorption research.The main contents are as follows:(1)The hazards of the earthquake to the bridge,the damage form of the bridge structure and the commonly used seismic analysis methods are described.At the same time,the application of viscous damper in bridge vibration reduction is introduced.(2)Two kinds of prestressed concrete continuous beam models considering pile-soil action and pier bottom consolidation were established respectively,to analyze and compare the dynamic characteristics.(3)In the case of frequent earthquakes,the response spectrum analysis and time-history response analysis method are used respectively to analyze the transverse beam and the longitudinal seismic response of the continuous beam with or without train live load.Then the displacement and internal force of continuous beam in seismic response are analyzed,and the results are compared.(4)The elastoplastic time-history response analysis of continuous beam under the rare earthquake is carried out,and the plastic hinge element is established at the bottom of pier.Based on the state analysis and research of plastic hinge,the aseismic design suggestions and reinforcement measures of continuous beam are put forward.(5)The viscous damper is added as a continuous beam damping device.Afterwards it compares the influence of the viscous damper position on the damping effect,and optimizes the installation position of viscous damper.In addition,the control parameters of viscous dampers are studied.