Research On Integrated Construction Control Of Cable-stayed Anchor Cable Of CFST Arch Bridge

Domestically constructed concrete-filled steel tubular arch bridges,except for a few rotating construction and less bracket construction methods,are mostly constructed by cable hoisting and cantilever assembly.For the early construction of concrete-filled steel tubular arch bridges in China,the construction scheme of the anchor cable is adopted.However,due to the inability to accurately simulate the saddle and the buckle,and the unbalanced horizontal force of the buckle will cause the tower to be biased,the arrangement of the buckle and the anchor is generally used in the subsequent construction.In recent years,the construction scheme of the integrated anchorage cable has been adopted in China,and the steering cable saddle structure has been improved.This paper takes the main span 320 m Matan Hongshui River Bridge as the research object,and carried out the following work:(1)On the basis of collecting domestic and foreign research,the simulation method of the suspension cable saddle and the strop unit on the pulley is used to carry out the accurate simulation of the cable saddle analysis in the control analysis of the arch bridge construction process.Based on the stiffness equation,the elastic shear stiffness calculation formulas for the single cable saddle,two cable saddles and the thrust resistance of the pier(tower)are derived.Based on the basic principle of finite element analysis and the exact solution of the elastic catenary,the two-unit "saddle unit" is established by using the internal force relationship between the cable and the saddle in equilibrium.Since the length of the integrated cable section of the anchorage cable is longer than the length of the anchorage cable section,the geometric nonlinear problem of the cable is analyzed by the analytical method of the catenary.(2)Research on the simulation method of the integrated construction of the anchor cable,combined with the steering cable saddle unit and the simulated arch hinge shaft friction method,the automatic calculation formula of the upstream and downstream cable forces during the rib installation is derived,and the finite element method is used to establish the Matan Hongshui River.The bridge construction control model compares the theoretical calculation with the construction measured data to verify the correctness of the construction simulation method.Finally,the analysis of the influence of the buckle-anchor integration on the arch rib shape and the tower offset is carried out.(3)Based on the optimization theory of the existing cable-stayed cable-stayed cable force,compared with the optimization goal of controlling only the arch line shape of the arch ribs,the cable-force optimization method with “process-result” dual control is proposed to further establish the construction error.The real-time optimization model of the cable-stayed cable sling force is proposed,and the calculation method of the “feasible domain” of the construction error is proposed,and the genetic algorithm for the automatic optimization calculation of the cable force optimization is discussed.According to this "process-result",the actual construction monitoring of the Matan Hongshui River Bridge is carried out to realize the high-precision control of the integrated construction of the CFST arch bridge.