Multi-LOD BIM for underground metro station: Interoperability and design-to-design enhancement

Underground metro stations as essential large-scale infrastructures that ease the traffic congestion on the overcrowded urban surface should be thoroughly designed, constructed and maintained. Building information modelling (BIM) has been increasingly employed for project design authoring, construction monitoring and operation management to promote digital engineering. Geotechnical design engaging numerical modelling techniques is an indispensable process for underground construction projects. These cross-disciplinary processes employing heterogeneous applications are yet to be coordinated in an efficient way, and thus improved interoperability can streamline the processes and optimise engineering design. This paper proposes an extension to the primary standard for openBIM data exchange – the Industry Foundation Classes (IFC) to facilitate wider adoption of BIM in underground infrastructure design, construction and management. Then a multiple level-of-detail (LOD) metro station BIM model is introduced to represent information at distinct levels of geometric and semantic richness required for varying application scenarios. Finally, we suggest a workflow underpinned by heuristic techniques, as an intermediate solution, to enhance the interoperability between a BIM authoring tool and a numerical modelling program for geotechnical analysis, and exemplify the workflow with the State Library Station of Melbourne. The proposed workflow offers an automated error-free, design-to-design solution, and hence enables the efficient exploration of design scenarios and construction optimisation before IFC is adopted by geotechnical modelling software.