On The Stability Of Tongwamen Bridge

The CFST X-type arches improve the lateral stability by sloping the arc ribs,so it is ofen used in the designs of CFST arch bridge with small ratio of the width to the span.Tongwamen bridge is a half-through CFST arch bridge,its span is 238m,and the width of its roadway is10m,so the truss ribs in-plane is sloped into X-shapc to improve its lateral stability.As the CFST X-type arches with longest span all over the country presently, the design of Tongwamen bridge can be used for reference of adopting CFST X-type arches in the design of arch bridges with small ratio of the width to the span.The software Ansys6.0 is used to analysis the stability of the state after construction of Tongwamen bridge,linear method is used in analyzing the finite element model of the bridge,the coeffient of stability of different state after construction is given.On the basis,the effect of different factors such as the arrangement of lateral brace,the sloping angle of arch ribs,the stiffness of bridge deck system,the effect of non-orientedly conservative loadings of the hanger and tie bar etc is discussed.The different coefficients of stability of changing these factors are given,so the factors that are vital to the lateral stability of X-type arches are found,and the rationality of the methods taken to enhance the lateral stability of Tongwamen bridge is evaluated.On basis of summarizing the characteristics and virtues of the design of Tongwamen bridge, the effect of different factors to the CFST X-type arches is given in the end of the paper,its useful for reference to the readers who engage in bridge design.