Effect Of Suspender Arrangement On Mechanical Properties Of Through Concrete Filled Steel Tube Tied Arch Bridge

Concrete-filled steel tube arch bridge has outstanding advantages in structure.From its birth to now,it has been highly praised by bridge engineers all over the world and widely used in highway and railway fields.The rapid development of concrete filled steel tube arch bridges is mainly due to the complementary role of steel tube and concrete in the use process,which makes the advantages of the two materials fully play,making them have the advantages of strong span adaptability,flexible and beautiful shape,large bearing capacity,good adaptability of foundation and meeting the requirements of rapid construction in modern society.In the composite Arch-Girder bridge,the suspender can be either a straight suspender,or an oblique suspender or a net suspender.Vertical suspenders are neat and beautiful,easy to construct,simple to construct at the anchorage point of the suspender,and complex to construct at the anchorage point of inclined suspenders and reticulated suspenders.Considering this,oblique suspender arch and reticulated suspender arch are not common in our life.However,under the same conditions,compared with vertical suspender arch,inclined suspender arch and reticulated suspender arch have obvious effect on reducing bending moment and displacement of tied beams and arch ribs.Vertical stiffness of the structure has been improved a lot,while transverse stiffness has little effect,and they also have more prominent advantages in economic cost and beautiful appearance.However,considering the complexity of construction,it is seldom used in China in the initial stage.In recent years,it has gradually appeared in people’s vision.In this paper,the static characteristics and dynamic response of 128 M tied arch bridge of Yinchuan South Bridge on Yinwu Railway are taken as the main lines.The main research work includes the following aspects:(1)By consulting a large number of documents and materials,this paper introduces in detail the origin and development of arch bridges,the characteristics of steel tube arch and the research status of tied arch suspender arrangement.The suspender arrangement of concrete filled steel tube arch bridge is summarized.(2)Based on the 128 M tied arch bridge of Yinchuan South Bridge on Yinwu Railway,a spatial finite element model of the 128 M tied arch bridge is established by Midas Civil,and the actual construction process of the bridge is analyzed.(3)On the basis of the bridge model,try to design the skew suspender arch model and the mesh suspender arch model to study the internal force and deflection changes of the bridge structure under different suspender arrangement.The results show that,compared with the vertical suspender arch,the oblique suspender arch and the net suspender redistribute thebending moment of the arch rib,which makes the stress of the bridge structure more uniform,and the vertical displacement will be significantly reduced.(4)Based on the dynamic theory of arch bridge,three finite element models of tied arch bridge with suspender arrangement are established by ANSYS finite element software.The natural vibration characteristics of the bridge are analyzed by Lansos method,and the effects of different suspender arrangement on the natural vibration and dynamic response of the structure are studied.The results of ANSYS simulation show that inclined suspender arch and net suspender arch can obviously increase the natural frequency of the vibration in the arch bridge deck,and have little influence on the natural frequency of the external vibration,and have significant effect on reducing the dynamic response of the bridge.The ANSYS-UM interface is imported into the multi-body dynamics software UM,and the dynamic response of the bridge is analyzed by combining the CRH2 train in UM.The dynamic effects of speed and suspender arrangement on tied arch bridge are studied respectively.