Monitoring And Numerical Analysis Of Walking Push Construction Of Steel Box Beam In Cross-Highway

With the acceleration of China’s urbanization process,the construction of municipal engineering is booming.The continuous emergence of long-span bridges is bound to face the problems of crossing the existing traffic and complex construction environment.The jacking method does not affect the traffic of the existing traffic,the construction equipment is light,the construction site is easy to manage,and it is suitable for the jacking construction across expressways.It is more and more popular in bridge construction Application.As the first time to use the jacking method to construct the municipal bridge across the expressway in Hefei,the jacking span is large and the longitudinal slope of the bridge type design is two-way slope,so it is difficult to control the jacking linear of the bridge,the structural system changes constantly with the jacking process,and the structural stress of steel box girder,guide beam and temporary support is complex.The relevant research and analysis are not very sufficient,so it is of great significance to study it It has important engineering significance.Based on the jacking project of Hefei Xingye Avenue crossing Liu Ye high-speed steel box girder,this paper introduces the construction technology of steel box girder jacking construction,uses the finite element software MIDAS / civil to carry out the stress and deformation analysis of walking steel box girder during the whole process of jacking construction,and carries out comparative analysis combined with monitoring data,and timely adjusts the jacking construction parameters.The research results can provide reference for similar projects in the future It can provide reference for the design and construction of bridge launching engineering.The main contents and conclusions of this paper are as follows(1)From the aspects of project overview,pushing system,pushing support,pushing process of steel box girder and linear control,this paper introduces the construction technology of walking pushing construction of steel box girder across expressway,designs the assembling support and pushing support,analyzes and studies the linear in the construction process,and obtains that the actual linear is basically consistent with the design linear,and provides reference for stress control;(2)Using numerical simulation method and finite element software MIDAS / civil,the deformation and internal force variation laws of steel box girder jacking support,guide beam and steel box girder are studied,and the influence of steel box girder jacking construction on the jacking support is analyzed.The results show that the structure is relatively stable during the jacking process,and the strength and stiffness of steel box girder,guide beam and temporary support meet the specification The error is within a reasonable range;(3)This paper analyzes the monitoring data of steel box girder jacking construction site,studies the deformation and internal force variation law of guide beam,box girder and jacking support in the actual jacking process of steel box girder,analyzes and summarizes the monitoring data,compares with the numerical analysis results,verifies the rationality of the numerical analysis method and the safety of the structure,and obtains that the guide beam design is more conservative,and then compares with the numerical analysis results According to the actual monitoring data,the finite element model is established to optimize the design of the bridge guide beam,which can ensure the safety of the launching construction and save the cost at the same time.