Calculation Of Main Cable Shape In Construction Of Single Tower Self-anchored Suspension Bridge

With the "One Belt,One Road" policy proposed,China’s economy has entered a period of rapid development,and bridge construction has also ushered in a new prosperous period.The unique self-anchored suspension bridge has a beautiful shape and adaptability to the engineering environment.Win the favor of engineers.Compared with the traditional anchored suspension bridge,the construction of the single-tower self-anchored suspension bridge is relatively late,and the related research information is limited.The design theory and calculation method mainly follow the traditional suspension bridge design theory,and the problem of insufficient calculation accuracy is more and more obvious..Therefore,based on a certain bridge,this paper analyzes the main cable configuration of the single-tower self-anchored suspension bridge and the main cable shape during the system conversion process as follows:(1)The calculation method of the main cable bridging line shape of the single tower self-anchored suspension bridge is summarized.Based on the fine iterative calculation of the main cable bridging line shape of the long-span suspension bridge,the main cable line of the single tower self-anchored suspension bridge is derived.The method and the segmented catenary method are used to solve the formula,and the MATLAB software is used to perform the least squares and dichotomic iterative programming calculations for the two algorithms,which lays a foundation for the calculation of the push pre-bias and the empty cable.(2)According to the principle of equal length of cable without stress,combined with the proposed Newton Broyden rank 1 method,the pre-offset of cable saddle is solved iteratively.At the same time,the relevant iterative calculation is programmed to improve the calculation speed and precision.Then,the air cable state of the single-tower self-anchored suspension bridge is analyzed and studied.The initial configuration of the main cable of the ground-anchored suspension bridge is calculated,combined with the change of the self-weight of the main cable and the initial length of the main beam.The air cable shape of the anchor suspension bridge is refined and iteratively solved.(3)Based on the engineering case,select a reasonable sling tensioning scheme,and combine the axial deformation of the main beam with the thrust of the saddle to study the influence of the main cable configuration change during the system conversion process,and consider the influence analysis of the stability function.The tangent stiffness matrix of the plane beam element is extracted,and the overall structure is incrementally iterated according to the relationship between the internal force and the configuration,until the shape change of the structure satisfies the accuracy requirement.Then,in order to meet the structural stability requirements,the balance equations are established according to the vertical deformation of the main beam,the axial deformation of the boom(cable)and the change of the main cable configuration,and the saddle thrust and its balance during the construction process.The amount of change in the boom force is analyzed analytically.(4)Based on a single tower self-anchored suspension bridge,the accuracy and rationality of the algorithm are verified.