Manufacturing Error Analysis And Optimal Adjustment Of Main Girder Of Long-span Composite Girder Cable-stayed Bridge

The composite beam cable-stayed bridge has many advantages(good engineering economy,convenient construction and reasonable force),It has been widely recognized and favored by many engineers,and widely use this kind of structure.This kind of bridge is generally assembled by bolting between adjacent main beams,and the error cannot be eliminated by adjusting the width of the weld.This paper will take the Chi-bi Yangtze River Highway Bridge as the engineering background,use the finite element software BDCMS to establish the full bridge model(Chi-bi Yangtze River Bridge),and carry out research work on the random error behavior in component manufacturing in the construction control of long-span composite beam cable-stayed bridges.The research contents are as follows:(1)Introducing the classification of cable-stayed bridges,the structural characteristics and development history of superimposed beam cable-stayed bridges,and the research status of construction control theory and parameter error adjustment during construction control is described in detail.(2)By generating multiple sets of random numbers on length manufacturing error and angle manufacturing error.Calculating the stress-free assembly line shape and bridging line shape both two types of errors(analysis and comparison),three representative sets of data are selected for discussion.According to the analysis,the manufacturing error of the length in the main girder has no obvious influence on the alignment of the main girder,while the manufacturing error of the angle in the main girder has a greater impact on the alignment of the main girder.(3)Select the group with the most unfavorable factor(the largest height difference in the closure section)from the multiple sets of data to adjust the cable force.Combined with the possible situations in the actual construction process,it is divided into beam sections,all prefabricated and accurately measured.The specific error of the beam section and the failure to measure all the errors in time due to the failure of all prefabrication are two cases,and on this basis,it is divided into three objectives for cable force adjustment,namely one-time cable force adjustment for the whole bridge,and one-time cable force adjustment for the current section.Adjust to target and adjust to the cantilever end.By combining the influence matrix method and the least square method with the information of the specific cable adjustment conditions,the cable force of the whole bridge is optimized and adjusted,and the optimized cable force is substituted into the finite element model for calculation.Data such as linearity and internal force are used to carry out targeted evaluation work.The above research is carried out in this paper.When the bridge adopts the self-adaptive stress-free state construction control method,and the error of each component in each stage of construction is accurately measured,the alignment and internal force of the bridge can be optimized and adjusted,which is the future for the same type of bridges.provide relevant experience in calculations and construction control.