Research On BIM Full Parametric Modeling And Joint Mechanical Properties Of Steel Truss Arch Bridge

The 7th Jianghan Bridge in Wuhan with a total length of 2754 m is the city’s seventh passage across the Han River.The main bridge across the river is a(132+408+132)meter three-span continuous half-through steel truss arch bridge,and its main span of 408 meters is the second place among domestic bridges of the same type.The structure of the bridge is complex and the bridge construction is difficult.On the Hankou side of the main bridge,because the road planning has the overall variable bending section of the bridge deck and the main truss,this paper adopts BIM technology,proposes and uses a fully parametric method to establish a high-precision BIM model for actual project construction.In order to verify the mechanical performance of the bridge structure,using the method of combining the BIM model and the finite element model,the overall deformation and displacement of the bridge and the mechanical performance of the key node A8 of the main truss arch variable bending section were studied.The main work and results as follows:(1)According to the actual construction needs,the BIM application idea of using BIM technology combined with the development of fully parametric modeling technology for high-precision modeling of the full bridge model of Jianghan Seven Bridges was determined.According to the characteristics of the project,the necessity of research on the special location nodes of the bridge was analyzed.And research ideas and methods.(2)Developed a full-parameter modeling method based on BIM technology,established a “R+GH+TS” collaborative design platform with a full-parameter method,and compiled the model using the “B-Rep method” to make the Jianghan Seven Bridges model accuracy reach LOD500,and Carrying out process guidance and simulation of actual construction,realizing practical construction applications such as BIM model 4D simulation,on-site component list,on-site component hoisting and transfer,and improving the construction efficiency of some procedures in the construction process.(3)In order to improve the reusability and continuity of the BIM model,the BIM model is converted into a format file supported by the finite element software using a fully parametric method,and the BIM model is modeled and formatted.It realizes the docking of BIM model and finite element software,improves the work efficiency of model pre-processing in the process of finite element software analysis,and simplifies the work flow of finite element software model pre-processing.(4)Carry out the finite element analysis of the full bridge according to the force of the full bridge,use the BIM model,combined with the MIDAS CIVIL finite element software for model pre-processing,realize that different types of cross-sections can be imported through the BIM model,and calculate the full bridge’s self-weight load according to the finite element software Under the displacement situation,the displacement data is derived,and the data is used as the displacement boundary condition of the local finite element analysis.(5)Determine the position of the A8 node of the upper chord variable bending section of the bridge main truss with a special stress condition of the full bridge,and use it as the part of the local finite element analysis,combined with the fully parametric method,to complete the pre-processing of the A8 node model;use ANSYS finite element The analysis software analyzes the stress of each member of the model,compares and analyzes the influence of the stress of different members and the position of the node,compares and analyzes the influence of the increase of stiffeners on the strength of the local structure,and verifies whether the structure meets the existing specifications.