Research On The Application Of BIM Technology In Interchange Planning Scheme Design

The design of interchange planning scheme controls the general direction of interchange construction,at present,it is mainly based on two-dimensional mode of thinking,and there are some problems with this approach,for example: the selection of the route is not intuitive and accurate enough,horizontal,longitudinal and cross-sectional design prone to deviation and their modifications are cumbersome,the presentation of scheme is difficult to express the design intention,the optimization of scheme can not be carried out in three-dimensional environment,and the design information is managed with low efficiency,etc.However,as a kind of data integration technology with the advantages of information dynamic correlation,synergy,visualization,simulation,optimization and graph-solving,BIM can manage project information efficiently through the parameterized model,it provides new ideas and methods to solve the problems existing in the design of interchange planning scheme.By analysising the essential difference between BIM technology and CAD technology,this paper obtains that BIM technology has the notable advantages in the fields of information management,synergetic work,visual design,performance analysis,engineering quantity statistics,drawing production and so on.By comparing various methods of scheme optimization,this paper determines to implement the optimization of interchange planning scheme with the analytic hierarchy process and the fuzzy comprehensive evaluation method.In addition,based on the discussion of the functions and applicable fields of the BIM core modeling software,Civil 3D,Raster Design,Infra Works and Subassembly Composer software of Autodesk platform are selected to carry out detailed and in-depth research on the application of BIM technology in all aspects of interchange planning scheme design,then a set of complete interchange planning scheme design system based on BIM is put forward,covering the entire process of establishment and analysis of three-dimensional digital terrain,registration of satellite images,three-dimensional selection of interchange planning scheme route,optimization design of horizontal and longitudinal alignments,visual design,superelevation and widening settings,subassembly development,assembly design and the creation of BIM model.On the basis of the proposed interchange planning scheme design system based on BIM,this paper carries out the route selection and design of three planning schemes for Pingshan interchange project,and constructs a multi-level and multi-factor evaluationindex system to make comprehensive evaluation on them,then establishes a BIM model with detailed information for the optimal planning scheme.In the design details of the support project,the practical feasibility and great advantages of the proposed design system are verified,which solves a lot of technical difficulties,such as the three-dimensional selection of the route,the design of complex alignments,the design of visual cross section,the scheme optimization under the visual environment,superelevation,widening,the development of custom subassembly,and the design of exit and entrance model.Based on the BIM model of the optimal planning scheme for Pingshan interchange,this paper studies the application and expansion methods of the model under the support of BIM technology,including analysis of three-dimensional spatial sight distance,calculation of earthwork volume based on DEM,allocation of earthwork,model drawing production,driving simulation,etc.As results,these methods realize the intuitive analysis and judgment for ramp exit and entrance and stopping sight distance,the real-time accurate earthwork calculation for the road of whole landing and the road of non-whole landing,the scientific and reasonable allocation and balance for earthwork,the quick establishment for horizontal,longitudinal and cross section drawings,the real feeling for driving situation on interchange,thereby,the value of the BIM model is exploited and embodied maximumlly.