Seismic Response Analysis Of (72+128+72)m Continuous Beam Bridge

With the development of transportation,high-speed railway has become an important mode of transportation for people to travel.Due to the advantages of prestressed concrete box girder,it is often applied to the superstructure of high-speed railway bridges.The damage of the bridge structure under the action of earthquake will bring great inconvenience to the transportation and have a serious impact on the local economy.Therefore,seismic design should be considered when designing the bridge structure.In this paper,Midas Civil/2015 is used to study the finite element model of the new Zhengzhou-Wanzhou high-speed railway(72+128+72)m continuous beam bridge.The seismic response analysis of the structure under the multiple and rare earthquakes is mainly carried out.:(1)Explain the seismic damage and failure modes of continuous beam bridges in earthquakes,and introduce seismic design methods.(2)Establish a model considering the interaction between pile and soil and the bottom of the pier,and analyze and compare the dynamic characteristics of the two models.(3)Using the response spectrum analysis method,the displacement and internal force response of the two models in the direction of the bridge and the transverse bridge under the multiple earthquakes of the continuous beam bridge are analyzed,and the results are compared.(4)Using the time-history reaction analysis method to analyze the seismic response of the model considering the effect of piles and soils under the action of multiple earthquakes,and according to the norm,select three seismic records with similar seismic wave spectrum characteristics of the site to act on the bridge structure.The displacement and internal force of the Shunqiao and Hengqiao directions are analyzed and compared with the results of the response spectrum,and a reasonable design method is proposed.(5)The elastoplastic analysis of the bridge structure under the rare earthquake is carried out,and the plastic hinge unit is built in the plastic hinge of the pier bottom.The state of the plastic hinge at the bottom of the pier and the displacement of the pier top are analyzed and studied.Design recommendations and reinforcement measures.