IfcTunnel—a proposal for a multi-scale extension of the IFC data model for shield tunnels under consideration of downward compatibility aspects

The Industry Foundation Classes (IFC) provide a comprehensive, standardized and neutral data format to enable the exchange of digital building models. However, the current version of IFC lacks the ability to comprehensively describe infrastructure facilities such as roads, bridges, railways or tunnels in detail. This paper shows the general concept for a space oriented approach to describe shield tunnel models by extending the IFC and the integration of multiple levels of detail into the IFC standard in the scope of considering downward compatibility aspects. The proposal therefore introduces three consecutive levels of extension. Thus, we enable any IFC-viewer supporting IFC4 to visualize the exemplary instance files created in the first level by using proxy objects. The higher levels extend the standard IFC4 schema by tunnel-specific semantic elements. They also integrate an approach aiming at the representation of multi-scale models by integrating multiple levels-of-detail.