Research On Key Influencing Factors Of Construction Control Of Long-span Cable-stayed Bridge

Nowadays,cable-stayed bridges are increasingly favored by people among large-span bridges because of their unique structural features,beautiful appearance and economic cost.With the development of market economy and the increasing span of cable-stayed bridges,we need to set higher for the construction technology of long-span cable-stayed bridges.At present,there are more researches on the design theory of long-span cable-stayed bridges than on the construction technology of cable-stayed bridges by domestic and foreign scholars.This article takes Jiashao Bridge as the engineering background,and the main research contents and achievements are as follows:(1)Explained the theoretical calculation method of the unstressed cable length and the applicability analysis of the cable,and briefly introduced the four calculation methods of the unstressed configuration of the main tower and the main beam.Distinguished two different concepts of installation line shape and manufacturing line shape,and also discussed in details of the similarities and differences between the two line shapes.Introduced the zero initial displacement method and the tangential initial displacement method for two different solutions.Made conclusions on the calculation theory of installation and manufacturing line shape based on linear and geometric nonlinear theory,and also summarized two common methods of calculating and manufacturing line shape in practical engineering.(2)Under linear conditions,calculated the installation line shape,manufacturing angle,manufacturing size,and manufacturing line shape of the main beam,and also calculated the mounting alignment of the main beam,the manufacturing angle between the beam sections,the manufacturing dimensions,and the manufacturing line shape after considered the geometric nonlinearity of the structure.Among them,the accurate calculation of the unstressed manufacturing angle between the beam sections is the key to determine the manufacturing size and manufacturing line shape.Also simply compared the difference between the linear and nonlinear conditions of beam installation and manufacturing.(3)The traditional error adjustment method can eliminate the influence of the calculation parameters on the cable force of the bridge and ensure the internal force status of the bridge.However,for long-span cable-stayed bridges,when the productionof the stay cables is completed,problems such as too long or too short stay cables may occur during the construction process,which may affect the normal construction.Based on the geometric control principle,the unstressed cable length as the control parameter,it is a scientific error adjustment method to comprehensively consider the cable force and the unstressed cable length.On the basis of ensuring the bridge cable force,the method eliminates the influence of calculation parameter error on normal construction,and has great practical significance for the construction control of long-span cable-stayed bridges.