Research On Cable Force Calculation Methods For Construction Of Super Long-span CFST Arch Bridge

The long-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 to make sure that the structural stress and geometry under bridge complete stage can meet the requirements.On the background of the research items'Hejiang Yangtze River No.1 Bridge ,a series of analysis for non-bracket cable-stayed suspension supporting methods are presented in this paper. The main subjects are summarized as follow:①Based 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.②To apply the zero moment method, zero displacement method and the unknown load factors affecting matrix optimization analysis methods are adopt to calculation the cable forces in the process of lifting arch rib for the Hejiang Yangtze River No.1 Bridge. Compared the both advantages and disadvantages of the several methods and discussed these methods to know about the guiding significance for construction control.③Propose a cable force calculation method based on the goal of bare arch deformation. Introduced the principle of controlling the ribs linear in the construction stage. Deduced the installation elevation of the next construction stage according to observation points elevation which have been installed with the method of analytic geometry. Discussed the coordinating calculating of the arch rib tangent installation to ensure the construction linear. Proposed the principle that the geometric control is proposed as the main and cable tension control is proposed as supplementary in the construction stage.④Study buckle cable nonlinear influence in the process of lifting arch ribs, take corrective buckle cable elastic modulus and iteration to reduce the buckle cable nonlinear influence, at the same time considering the impact of large deformation and reasonable treatment in the process of optimizing model to ensure that the tangential rib installation. ⑤Analysis of the influence of the wind loads, temperature loads and tower deviation for lifting arch ribs, appropriate method is proposed for the above factors to reduce the impact of them for construction control, and further ensure the linear state in concrete-filled steel tubular rib.