The Research On Structure Parameters Of The Large Span Composite Beam Cable-stayed Bridge

The cable-stayed bridge which has steel main beam and concrete bridge floor system is called composite beam cable-stayed bridge.Because of its advantageous structural function and economy,composite beam cable-stayed bridge developed fleetly in recent years.Based on the collecting and analysis of the design data of the composite beam cable-stayed bridge at home and abroad,the structure parameters of the large span composite beam cable-stayed bridge are studied in detailed on this paper.The major contents of this paper are as follows:(1)The development of the composite beam cable-stayed bridge is described.The researches on the structure parameters of cable-stayed bridge are summarized.Some further study problems were put forwarded.(2)Introducing the established finite element theory and regarding Wujiang river extra-large bridge as research background.Finite element model was established by using finite element software Midas/Civil.So it laid a foundation for the analysis of structure parameters of the large span composite beam cable-stayed bridge.(3)On the basis of the finite element model,the effects with variable structure parameters(structure system,the height of cable tower,the location of auxiliary pier,cable tower stiffness and cable area)on static characteristics and natural vibration characteristics of the large span composite beam cable-stayed bridge were discussed.Effect rule of large span composite beam cable-stayed bridge affected by the variable parameters were obtained.What's more,the reasonable values of these structure parameters were also got.(4)Based on the structure parameter analysis of the large span composite beam cable-stayed bridge,the structure parameter is optimized by adopting the method of principle of orthogonal test combined with finite element theory.Four factors which are the height of cable tower,the location of auxiliary pier,cable tower stiffness and cable area.Three levels among each factor were selected and the orthogonal table was established.8 indicators which can reflect the overall mechanical properties of the large span composite beam cable-stayed bridge were chosen.According to the calculated results,the structure parameters were sorted and the main factors of the indicators were found out through extremum difference analysis.Finally the optimal solution was obtained after a comprehensive comparison and analysis.