Research And Engineering Application Of Parametric Modeling Of Tunnel Portal Design Based On BIM

With the development of economy and technology in our country,the construction of transportation infrastructure has entered a new era,and it has become an inevitable trend to apply BIM technology to the full life cycle of tunnel construction.The application of BIM technology will make the design,construction,and maintenance phases of tunnel engineering more efficient,more convenient,more systematic,and more intelligent.At present,the application of BIM technology in tunnel engineering is still in its infancy.One of the main reasons is the lack of high-efficiency parametric modeling software for professional services dedicated to tunnel engineering.As a result,the efficiency of using three-dimensional forward design in tunnel engineering is too low to completely replace the existing traditional twodimensional design.At present,the mainstream modeling software is insufficient for the development of parametric modeling of tunnel engineering,and at the same time,there is a lack of systematic research on the parameterized model library of tunnel structure.In order to promote the development of parametric modeling of tunnel engineering,this thesis firstly proposes the principle of selecting tunnel structural parameters based on BIM by combining the characteristics of tunnel engineering and the concept of BIM design.Based on this principle,this thesis systematically studies the control parameters of various common tunnel portal structures.Finally,this thesis carries out the secondary development of the parametric modeling program for the tunnel portal based on MicroStation,and the practicality of the program is verified through actual engineering applications.The main research contents and results of this thesis are as follows:(1)This thesis summarizes the basic situation of the current mainstream BIM platform including Autodesk,Dassault and Bentley.Through comprehensive comparison,the Bentley platform,which is more suitable for the development of tunnel engineering,is selected as the main research platform.Then this thesis studies the secondary development method,programming environment,and related API interface functions of the core modeling software MicroStation under the Bentley platform,and determines to use MVBA as the main tool of research and development;(2)This thesis summarizes the types and characteristics of common tunnel portals,and analyzes the similar structural characteristics of various tunnel portals.Consequently,the tunnel portal type is divided into slanting cut portal and end wall portal to make the research more systematic.This thesis proposes the principle of selecting tunnel structural parameters based on BIM,combining the BIM design concept and the characteristics of the tunnel structure.This principle divides the tunnel structure parameters into necessary parameters,reference parameters and transfer parameters.And then,based on this principle,this thesis systematically studies and extracts the control parameters of various tunnel portal structures to provide a theoretical basis for the development of parameterized modeling programs for tunnel portals;(3)This thesis uses MVBA to develop a parametric modeling program for tunnel portals based on MicroStation secondary development,and studies the auxiliary functions of the BIMbased parametric modeling program for tunnel portals.By using this program,designers can quickly create a 3D model of the tunnel portal by inputting parameters,which can effectively improve the efficiency of 3D modeling of the tunnel portal and the experience of design;(4)Through the application of engineering examples,the practicability of the parametric modeling program of the tunnel portal is verified,and the parametric modeling process of the tunnel portal is summarized.Practical result shows that this program can effectively improve the experience of the three-dimensional forward design of the tunnel portal,which has good practical value.