Static And Dynamic Analysis Of Long Span Continuous Rigid Frame-Arch Composite Bridges

With the increasing driving speed and driving load of railway train,the static and dynamic performance of the bridge structure is also put forward more strict requirements.In order to meet the needs of high-speed train for bridge linetype,the combination system bridges are more and more widely used in the railway engineering.Continuous rigid frame concrete filled steel tube arch composite bridge is one of the most important type of them.In this paper,long span railway bridge(Bozhou bridge for short)crossing Guohe river of Bozhou is taken as the engineering background.Therefore,this paper focuses on the static and dynamic performance of the Bozhou high speed railway bridge,and analyzes the local stress of the combined part of the beam,arch and piers of the bridge.The main contents of this paper are as follows:(1)Midas/Civil finite element software and CSB software are used to establish the finite element model of the bridge,and the whole process of the construction is simulated.The results of two software calculations are compared and analyzed,and the stress and deformation state of bridge under different construction stages are checked.The tension and tension sequence of bridge hangers are studied to find out the suitable initial tension and tension sequence of tension.(2)The three-dimensional solid element model of the connecting part of the beam arch pier of Bozhou bridge is established by the large general finite element program Midas FEA.The boundary conditions and the equivalent load are simulated under the two conditions of the maximum cantilever state and completion state.The influence of the three direction prestressed tendons of beam arch pier connection is considered,and the stress distribution of the joint of beam arch pier is analyzed.(3)The response spectrum method is used to analyze the dynamic response of the Bozhou bridge under the effect of the horizontal earthquake level(basic horizontal acceleration 0.1g).The seismic input of three directions is defined to compare and analyze the internal force,displacement and stress of the section of the bridge at this time.(4)According to the bridge site and the structural characteristics,three seismic waves of EL Centro wave,Taft wave and San Fernando wave are selected for the dynamic time history analysis of the Bozhou bridge under the E1 and E2 seismic levels.The internal force and displacement time history curves of the Bozhou bridge are obtained,and the dynamic response of the bridge under the action of two different seismic levels is compared.