Cable Force Research And Stability Analysis Of CFST Tied Arch Bridge

With the continuous development of infrastructure construction in China,the concrete-filled steel tubular tied arch bridge stands out in the choice of bridge type because of its beautiful appearance,strong spanning ability and low basic requirements.The CFST tied arch bridge belongs to the beam-arch combination system,and the external statically set internal high-order statically indeterminate structure.During the process of tensioning the boom,the cable force of the boom affects each other,and the tension of the bridge structure is different.Therefore,the study of the cable force of the suspension bar in this type of bridge construction has great practical significance.This paper firstly reviews the theory and method of cable force calculation for cable-stayed bridges by consulting relevant literatures at home and abroad,and provides a theoretical basis for the optimization calculation of the cable force of the tied arch bridge.Taking a 60 m concrete-filled steel tubular tied arch bridge as an example,the finite element model was established by using Midas/Civil software to simulate the construction stage of the bridge,and the initial tension of the bridge boom and the initial tension of the construction stage were calculated.Referring to the methods of cable-stayed bridge calculation into a completed bridge by calculating arc bridge into a completed bridge,based on factors such as bending moment and displacement rule out does not apply to the calculation method of the bridge,establish the reasonable completed bridge,and then through the reverse-formal analysis in a variety of derrick tensioning sequence established under the tension forces under a tensioning construction,creep and shrinkage of multiple iterative process greatly reduce the influence of geometric nonlinearity,the tension forces in under the action of get into a completed bridge closer to the reasonable completed bridge,at the same time to calculate the actual tension scheme under the core concrete and steel tube arch rib stress meet the material requirements.Based on the theory of structural stability analysis,the stability analysis of the bridge is carried out in the construction stage and the operation stage of the bridge,and the influence of several parameters on the overall stability of the tied arch bridge is studied under the action of constant load.Finally,some conclusions are drawn,which are of guiding significance to practical engineering.