Research On Mechanical Performance Of Steel Truss Arch Bridge In Construction Phase On Based On BIM Model

Large span steel truss arch bridges have many advantages such as rich types and structural forms,beautiful shapes and high structural load-bearing capacity,which makes them highly competitive among highway and railway bridges.First of all,with the increasingly mature development of BIM technology,it has brought benefits to the development of the whole construction industry,but in the field of bridge engineering,the application of BIM technology is relatively small,so it is especially important to apply BIM technology to bridge engineering.Secondly,in order to ensure that bridge construction proceeds smoothly and meets quality and safety requirements,it is of some significance to calculate and analyse the mechanical properties of bridges at different stages of construction.This paper is based on the Jianghan seven bridge project,which is a 132m+408m+132m three-span continuous steel truss tied arch bridge with a complex structure,large span,many rods,large material consumption and great construction difficulties.In this paper,a BIM model of the whole bridge has been set up with the background of the Jianghan Seven Bridges project,and detailed engineering information has been added to the model.Research on the application of BIM model in actual engineering,such as the deepening application of the BIM models with the extraction of component information,the determination of the bar’s center of gravity,collision checking,visualization and delivery,and the derivation of construction plans,BIM model as a carrier combined with BIM collaborative management platform application to improve project management efficiency in the construction process.The practical application of BIM technology can provide a lot of convenience for the bridge in the construction process and improve the construction efficiency.Use the BIM modeling software Rhino to build a three-dimensional line model of the full bridge,and use parametric modeling to solve the difficult modeling problems of the variable width section,variable bend section,and the main truss connection system in the bridge,such as different angles and slopes,and then study the collaborative interaction between the Rhino software and the finite element analysis software Midas Civil,compared with the traditional modeling in the Midas Civil software,it greatly improves the modeling efficiency while ensuring the accuracy of the model.Through the research in this direction,a certain direction is provided for the establishment of the bridge finite element analysis model.The calculations for each construction phase of the whole bridge were carried out in the Midas Civil finite element analysis software in conjunction with the actual construction process,and the calculation results of the key construction stages are statistically analyzed.The first step is to analyse the stresses in the upper chord,lower chord and web of the steel joist arch and the displacements in the upper and lower chord members.Through calculation and analysis,it is determined that the stresses and displacements of each member meet the requirements during the critical construction stage,and the stresses and displacements of each member of the steel joist arch are derived and the distribution law of stresses and displacements is grasped;The mechanical calculations of the construction phase of the sling pylon during the tensioning of the cables showed that the strength and stiffness of the main structure of the sling pylon met the requirements;finally,the stability of the whole bridge at different stages of construction was analysed,and the stability coefficients and instability modes of each stage were obtained,and the stability of each stage met the requirements.The results of the calculation and analysis can provide some theoretical basis and help in the actual construction process of the bridge.