Large Span Concrete Filled Steel Tubular Frame Tied Arch Bridge Arch Optimized Design

Rigid frame tied arch bridge is a new type bridge in concrete-filled steel tube arch bridge field .Different from arch-beam composite system, arch and pier are consolidated with no bearing support and prestressed steel strand is used as a bar to balance the thrust of the arch. Through Type rigid frame tied arch bridge is a type of Self-balancing bridge, needless of vice-span and having a greater span ability, so it has a strong competitiveness for crossing the railway, road and canal.Arch system is very important in the application field of concrete-filled steel tubular. At present, there is not much foreign research about concrete-filled steel tubular arch bridge linear and the arch section of the Optimal Design In our country , Optimal research about bridge linear are plentiful while it's very limited in the latter .Because most cross-section values are defined by the previous design experience , there is no Norm to accord to and design is too conservative. In this paper a under-supported frame tied arch bridge is used as an example, the author consider the economic applicability of arch, using the total cost of arch as the objective function and Ansys Finite Element software optimization tool for linear and cross-section of the arch, for the purpose that it can be referenced by practical engineering design.In this paper, the main work are as follows:(1) Select values of the cross-section and the arch axis of Concrete-filled steel tubular arch bridge from theory and practice(2) Establish the space finite element model, analyse the construction process.(3) The author establishes mathematical model of optimization ,use the total cost of arch , boom and tie bar as the objective function , use the deflection caused by stable bearing capacity of arch , local capacity , live load and the stress of steel pipe and concrete as constraints;(4) Based on APDL of ANSYS Secondary development, the author works out the optimization procedure, optimize linear and cross-section of the arch; (5) Check the Optimization results with Midas/civil software to verify the rationality of the Optimization results.