Design And Optimization Analysis Of Deformation Monitoring Model For Large Span Simply Supported Steel Truss Bridge

Bridge is an important part of the transportation network.Presently,there is a rapid development of engineering construction in our country.With large span bridges emerging in endlessly,new requirements have been put forward on the bridge engineering quality.With a rapid development of smelting technology of steel,the bridge construction has obtained the enormous development since the 1950 s.At present,the main structural forms of steel structure bridges at home and abroad are steel box girder structure,large span steel truss structure,steel pipe or steel box arch structure and a variety of steel composite beam structure,etc.The large steel truss bridge is an ideal bridge type crossing the river and deep ravine because of the advantages of rational bear force,light weight,high strength,and high stiffness and so on.Construction safety monitoring and analysis of long span steel truss bridge is a key step in connection design and construction,which is very important to bridge construction safety.It is of great economic and engineering value to improve the technical level of construction safety monitoring and analysis for long span steel truss bridge.This paper combined with specific projects,aiming at the construction monitoring process of long span steel truss bridge,and analyzed the changes of line and stress in the construction process of long span steel truss bridge,and evaluated the safety state of the bridge.The finite element model of the bridge is established and some optimization is done.The main contents include:(1)Study on measuring method of long span steel truss bridge.Combined with the specific situation of large span steel truss bridge.Comprehensively compared between traditional measurement technology,electronic measurement technology,and automated measurement technology.Analyze the advantages and disadvantages of different measurement methods,in accordance with "complementary advantages and disadvantages,accurate and reliable" principle of choice measurement.(2)Summary of construction monitoring program of steel truss bridge.Combined with the development of steel truss project domestic and foreign about the construction of large-span steel truss girder monitoring theory,principles,methods,purpose,etc.made a brief overview.Combined with the specific circumstances of the project to develop a construction monitoring program,and several important parameters in the monitoring process are analyzed and studied.(3)The finite element method is used to establish an effective full-bridge finite element model.The stresses and linear changes of the bridge undercarriage,rotation,translation and falling beam are analyzed by using the large-scale general finite element software ABAQUS / Standard.Combined with accurate measurement means to achieve the purpose of safety monitoring.The modified model can be used to predict the bridge shape change and deduce the Deflection Variation of Steel Truss Bridge within the allowable error range.The results show that the model can preferably predict steel truss beam deflection changes on the natural conditions,meet the actual variation,and thus greatly help to ensure construction safety.