An essential part of the Koralmbahn line, the Granitztal tunnel chain with a length of about 6.1 km runs between the Lavanttal and the Jauntal valleys and crosses the Deutsch Grutschen, the Granitztal and the Langer Berg. In early 2016, Austrian Railways ÖBB made a decision for the Granitztal tunnel chain project, which was then already under construction, to test the 3D model‐based Building Information Modelling (BIM) design method in addition to conventional 2D design. One essential precondition for the application of the BIM method on transport infrastructure projects was recognised as the required data structures. In addition to the definition of general project requirements and standards for BIM, work started on the structuring and classification of the construction elements required for the tunnel structure and their properties. Of equal importance are the spatial positioning and location of the construction elements and the definition of topological relationships to each other. The article gives an insight into the current state of development of BIM data structures for tunnel structure and track superstructure at the ÖBB and is intended to make a contribution to initiating the development of such data structures by all the disciplines involved in tunneling and transport infrastructure. The prime intention is to provide the BIM data structures produced in this way as an active contribution to the further development of the open BIM standard IFC (Industry Foundation Classes) in the IFC Underground Construction Group at buildingSMART

Digitalisation in the construction industry has been progressing continuously and bringing major changes for everyone involved in virtually all areas. Austrian Federal Railways ÖBB has been pushing BIM (Building Information Modelling) for the construction and rehabilitation of their infrastructure. By means of various pilot projects, the basics and the processes required for design and construction are developed and applied with a strong focus on system operation. For Granitztal tunnel and a total length of ≈6.1 km, the as‐built design of the civil structures is done with an element‐based, open BIM model. As part of the handover to the maintenance and operation division, the data of civil structures relevant for operation are derived from the BIM model, validated by means of automatic methods and transferred to the facility management system (AVS, Anlagen‐Verzeichnis‐System). In the absence of an IFC (Industry Foundation Class) structure tunnel, a semantic and spatial data structure is developed. Furthermore, the model will be enriched with components of railway equipment. On the other hand, there is the over‐100‐year‐old Karawanks tunnel as part of the railway section between Villach and Jesenice. The line has been in operation since 1906 and includes the ≈8 km‐long, single‐tube Karawanks tunnel. The current situation of the tunnel including the superstructure and technical equipment no longer meets performance, safety and durability requirements and is being rehabilitated within an international cooperation project between Austria and Slovenia. The focus in this BIM project is set on the as‐built design and merging data of the existing historic tunnel structure with information of new components implemented during refurbishment. A core task is the structured transfer of data contained in the BIM model to the facility/asset management system of ÖBB (AVS) and the Slovenian infrastructure operator. The case histories of Granitztal tunnel and Karawanks tunnel are used to describe the implementation of BIM, including the development of required data structures, validation mechanisms and data delivery to the asset management.

The BIM pilot project ”New Köstendorf‐Salzburg Line“ for ÖBB‐Infrastruktur AG covers a new twin‐track section about 21 km long involving a wide variety of different engineering structures and a corresponding need for close interdisciplinary collaboration within a sensitive project space. The pilot project successfully achieved its objective of generating a largely software‐independent overall model and transferring the knowledge gained to the Employer's Information Requirements and subsequently to a BIM execution plan. In addition to internal coordination meetings, a preliminary external meeting took place to discuss the model elements required for a government agency as part of an approval process and the availability of such elements by means of direct access to the model.By adopting an integrated, collaborative approach to project management, it was possible to define extensive procedures and workflows adapted to the needs of the respective project partners for the single‐discipline models (specialist models) and to coordinate an overall federated model. The results of the co‐ordinated overall model show the ample opportunities afforded by a parameterised ground model for transparent risk and project assessment, paving the way for a holistic, phase‐based infrastructure information model. In this regard, the authors felt that it was important to adapt the project partners' established internal procedures only minimally and to translate them into BIM‐compatible, cooperative workflows.