Static And Dynamic Analysis Of Long-span Railway Cable-stayed Bridge With Unequal-height Towers And Hybrid Girder And Detailed Stress Analysis And Optimization Of Steel-concrete Joint Section

In this thesis,the(30+46+300+97+62.39)m long-span four-line railway cable-stayed bridge with unequal-height towers and hybrid girder is taken as the research background.Firstly,the structural characteristics and domestic and foreign examples of unequal-height towers cable-stayed bridge and hybrid girder cable-stayed bridge is briefly introduced.According to the design plan of this bridge,the simulation method of each component of this bridge is introduced and a whole bridge space model based on beam elements is established by MIDAS/CIVIL.According to the actual construction steps,the construction stage is simulated,and the displacement and stress properties of the main girder,unequalheight towers and stay cables during the construction process are calculated and analyzed.At the same time,according to the corresponding codes,the load combination and calculation of the individual loads are applied and the relevant conclusions are reached.Considering the pile-soil-superstructure dynamic interaction,self-vibration characteristics of this cable-stayed bridge is analyzed in completed stage.With reference to relevant codes,the seismic response of this bridge is calculated and analyzed by both the response spectrum method and the linear time history method according to the load combination with and without vehicles.The combination of steel beams and concrete beams of hybrid beams is briefly introduced.Based on solid elements and shell elements as well as beam elements,a minute integrated element model is established by using the finite element software ABAQUS.Then the stress of each component of the steel-concrete joint and stiffness variation are calculated under the most unfavorable load combination,then an optimization plan and relevant conclusions are proposed.