Parameterized Generation Design Of Metro Shield Tunnel Based On IFC

With the continuous deepening of China's urbanization construction,the metro has taken advantage of its significant advantages in alleviating urban traffic congestion and enhancing urban transport facilities,which has created a wave of subway construction in major cities across the country.In the field of subway tunnel construction,the design of the tunnel model is still at the level of 2D plane design.However,2D design methods have inherent disadvantages in visualization,information integration,and achievement conversion,and are not suitable for the design of heterogeneous structures with rich design parameters and complex component association in tunnel engineering.As the application value of BIM(Building Information Model)becomes more prominent in the construction industry,shield tunnel construction practitioners have gradually introduced the BIM platform and service tunnel model design work to express the 3D spatial relationship in building structural components.However,the difficulty in designing a shield tunnel model is that the tunnel is not a simple geometric pile of many segments.Instead,with tunnel design axis as the fitting target,it needs to arrange all the segment positions in each ring through typesetting calculations,and to form an overall tunnel model.Therefore,the traditional "painting" BIM method,which has to copy,splice,and rotate rings directly,cannot generate an accurate tunnel construction drawing model.In view of this,designers urgently need a generation design method that can automatically calculate the location of the segments as the tunnel design parameters are adjusted,so that the tunnel model can be quickly and accurately generated to guide the subsequent construction process of the tunnel.This is essentially a parametric generative design idea.At present,the main problems to realize the generation and design of tunnel segments include:(1)The existing BIM platform does not include the relevant building components of the shield tunnel,and the information standards of the components are missing;(2)The lack of a suitable typesetting algorithm for parametric design,causing the computer impossible to identify the relationship between the tunnel componets such as segments;(3)There is a lack of parameterized design methods that use parametric design tools,simultaneous output fitting typesetting schemes,and shield tunnel models.(4)The IFC(Industry Foundation Classes)standard is a good way to expand the relevant components of the tunnel.However,at present,the IFC-based shield tunneling research only presents the IFC model of the shield tunnel from the perspective of design information.It does not consider the rationality in the view of construction process,making the current IFC-tunnel model cannot be used for the generation design of tunnel components such as segment.For this reason,combined with the segment assembly construction process,this paper proposes an IFC-based parameterized tunnel design method.Based on the analysis of the parameterized design requirements and problems of shield tunneling,the theory of shield tunnel assembly and IFC standard were firstly combed,and a new algorithm was proposed to solve the typesetting problem and by using homogeneous transformation mathematics.Then,from the perspective of segment assembly process,the IFC extension model for shield tunnel segment assembly was established to solve the rationality problem of the tunnel component information standard.Finally,with the aid of the parameterized design tool,the generation logic of the tunnel model is constructed,and the IFC file of the segment and the typesetting algorithm are imported to realize the rapid and accurate generation of the tunnel model.The empirical verification results show that the IFC-based parametric generation design method proposed in this paper can quickly output a complete and accurate tunnel model.This method not only solves the problem of generating design in the design stage,but also can be used for error control and dynamic rectification of segment assembly in the construction stage,which has important engineering application value.