Concrete Filled Steel Tubular Arch Bridge Support Cable Crane Cable Force Reasonable Deduction Optimal Design Method

The large-span CFST arch bridge is developing rapidly in recent years due to its elegant appearance and economical span. Raw support cable hoisting method is adopted for the construction of most CFST arch bridges, which is developed into jack cable inclined pulling and buckling method later. Precise calculation of proper buckling force is needed in the multi-segment hoisting method t o make sure that the structural stress and g eometry under bridge complete stage can meet the requirements.Based on comprehensive collection of existing research documents in and beyond the country, the characters of cable hoisting method is analyzed and the calculation method for proper bucking force used frequently at present is generalized and compared in this paper. The Raw support cable hoisting method for the construction of empty steel tube is studied and calculation method for proper bucking force based on optimization theory is put forward. And to optimization problem of the multi-object function for arch rib hoisting, the "3 stages" multiple optimization calculation method is put forward, which is used to solve multiple discrimination object problem in the buckle optimization design through means such as trying to modify the object function and to add restraint conditions.The Maocao Bridge in Nan county, Hunan province is taken as engineering background and the advancing analysis of space finite element method is adopted to calculate the proper buckling force based on optimization theory. Based on the "3 stages" multiple optimization calculation method, the optimization design of buckle is undertaken. The proper buckling force which satisfies the best geometry of arch axis is obtained, which solves the multi-object function optimization design for proper geometry of arch axis, uniform allocation of buckling force and least consumption of buckle effectively.