Research And Application Of Key Technologies In Multi-point Floating Jacking Construction Of Large-span Steel Truss Girder

Taking the construction of a super bridge as the background,combined with relevant design and construction materials and related literature of similar projects at home and abroad,this paper studies the construction technology of large-span,large-tonnage steel truss girder spanning busy waterways using floating jacks.Firstly,the main construction methods for the erection of steel truss beams across the river are summarized and compared and analyzed.Then,the key factors affecting the stability and safety of the erection of steel truss beams are determined and analyzed in combination with the engineering example of the erection of steel truss bridges by floating jacking.parameters,use modeling,finite element analysis and numerical calculation to find the best value of key parameters,and then combine the construction site environment to optimize the floating jacking construction process and calculate and verify the optimized process method.The rationality of process optimization is analyzed.Similar construction reference and reference are given through the analysis and optimization of the floating jacking process.This paper introduces the floating jacking system,the floating jacking construction technology and the floating jacking construction operation process in detail.By consulting the relevant materials and combining the actual situation of the research project,it gives the necessity of using the floating jacking construction method for the research project,and then summarizes the application scope of the floating-over jacking construction method.Then,combined with the research project,the construction process and construction control points of the floating jacking of large-span steel truss girder are analyzed.Through the analysis of the project implementation process,the impact of the steel truss girder is determined from the aspects of the floating stability and precision control of the erection of the steel truss girder and the control of the erection time.The three key parameters of erection efficiency are the number of cantilever segments of the steel truss girder,the position of the floating support and the number of support points.Through finite element analysis,when these key parameters change,the mechanical properties,deformation and fulcrum reaction of the steel truss girder are affected.The influence of force and overturning is used to determine the best parameter values,and then the float-over jacking process method is actually optimized on the construction site.Then,the construction efficiency is improved to the maximum extent.Finally,the technical and economic comparison of the two construction schemes of the traditional floating-over jacking method and the optimized and improved floating-over jacking method is carried out,and the necessity of optimizing the traditional construction technology is further demonstrated.Through the successful implementation of the research project,a reasonable and efficient large-span,large-tonnage,and complex river bank steel truss girder floating jacking construction method is provided,which provides a reference for the safe and efficient implementation of similar projects.Through research,it is proved that the use of multi-pivot floating jacking method to erect large-span,large-tonnage steel truss beams with complex river banks is feasible,with low cost,high safety factor and high construction efficiency.social benefit.