Influence of Lifting Force Arrangement on Mechanical Performance of Large-span Steel-concrete Composite Girder

WANG Yanming; ZHU Shuaitong; ZHANG Xiansong; LIANG Bin

doi:10.15926/j.cnki.issn1672-6871.2024.05.008

Abstract：In order to study the influence of the lifting force arrangement on the mechanical performance of the long-span steel-concrete composite girder which using the lifting-composing construction method,based on the Qinhe grand bridge along the Taihang expressway,the effects of different first and secondary lifting force,the number and distance of lifting points on the stress,deformation,stability,and bridge deck compressive stress reserve of the steel-concrete composite girder were studied by using the Midas-Civil finite element software and a control variable method.The sensitivity of different factors on the steel-concrete composite girder was analyzed through variable normalization,moreover,the optimal scheme was selected,and the implementation effect was monitored on site.The results show that the stress of upper flange of the steel girder,bridge deck,and bridge deflection are most sensitive to the secondary lifting force,with sensitivities of 0.61,1.95,and 0.16,respectively.The stress of lower flange of the steel girder is most sensitive to the number of lifting points,with a sensitivity of 0.20.The theoretical optimal pre-bending of Qinhe grand bridge is 78％,the final scheme arranges 5 groups of lifting points with distance of 11 m,and the first and the secondary lifting forces are 1 500 kN and 6 500 kN,respectively.The on-site monitoring results show that the construction effect of the scheme is consistent with the theoretical analysis results,and the on-site lifting force is reasonably arranged.The on-site monitoring results show that the implementation effect of the scheme is consistent with the theoretical analysis,and the lifting force is reasonably arranged.The research results can provide reference for similar projects.