Calculation Model Of Concrete-filled Steel Tubular Arch Bridge

In China,arch bridge has been rapidly developed with its fast,large span,beatuful appearance,and many other advantages,since the first CFST.The span of Wu Gorge Yangtze River Bridge reach 460m.CFST is still direct to a greater span, but also to the direction of large-scale,and application areas and range are also expanding.However, the theoretical study is also lagging behind in the engineering practice, the calculation model of CFST arch rib is one of them.This article aimed to the CFST arch bridge with dumbbell section and CFST arch bridge with four limb lattice section,Studied the calculation model cross-section of these two types'cross-section.Firstly,based on the spatial beam element combination method,divided the steel pipe upper limb and lower limb of dumbbell arch,concrete in steel pipe,batten plate and core concrete into seven parts to simulate beam element,aggregate beam element stiffness matrix for space beam element stiffness matrix,derivation stiffness matrix of dumbbell section space beam element through the matrix converter,reduce the number of element nodes, proof the correctness of spatial beam element combination method through examples.Secondly,for the problem that lattice method formula of CFST arch bridge with dumbbell section exists,put forward modified lattice formula.The formula considered the axial force that batten plate beared and moment that upper and lower chord beared,improved the calculation accuracy,compared displacement and internal force differences of lattice method formula before and after amendment throgh examples. For CFST arch bridge with four limb lattice section,put forward computing model of equivalent flexural rigidity method and equivalent pulldown rigidity method for batten plate and concrete in batten plate,and gave relevant formula;analyse influence to the results that the value of equivalent thickness elastic modulus brings;Compared the calculation results and calculation accuracy of different analog methods to four limb lattice vertical batten plate and horizontal batten plate.Finally, With practical Xinlongmen Bridge engineering examples,compared the difference calculation results of equivalent flexural rigidity method and equivalent pulldown rigidity method.On this basis,carry out simulation analyses of the construction process,and the results provide design construction monitoring with theoretical basis.