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12.12.2023

Behind the scenes of the Koralm Tunnel

Together with ARGE BTA KAT, we reach the first major construction milestone in the Koralm Tunnel project. Who from pde Integrale Planung is behind it? We introduce our BIM experts and provide an insight into the impressive structure in the video.


The Koralm Tunnel stretches over a length of 33 kilometers and connects Styria with Carinthia. The tunnel consists of two driving tunnel tubes, an emergency stop in the middle and no less than 69 cross-passages as well as two shafts connecting the tunnel to the surface. pde is providing the BIM services for this project, including overall and specialist coordination as well as modeling.

ARGE BTA KAT is currently carrying out a total of 7 trades in the PORR and Rhomberg consortium as general contractor. pde Integrale Planung is supporting the project as a partner with technical expertise in the BIM services to be provided and is thus "jointly" setting new standards.

BIM overall coordinators


Their task is to integrate the technical expertise into the project at the coordinative level. They bring together the necessary pieces of the puzzle from the technical and commercial components and combine the services of the commissioned players from planning and execution for the project-relevant implementation of the BIM services. Further tasks are:

  • Solving challenges and ensuring a functioning project flow between the stakeholders from planning, modeling and execution
  • Establishing and structuring digital process flows for the implementation of project-relevant goals
  • Networking relevant project competencies by setting up communication platforms

For model-based work, as well as for execution on the construction site, the ultimate goal is for all specialist areas to work together like clockwork. Communication within the team is an important success factor in a major project such as the Koralm Tunnel. This allows strengths to be pooled and promotes cross-divisional cooperation.

BIM specialist coordinators

They assume central responsibility for the smooth integration of the respective trade, e.g. construction services (shell construction), mechanical systems and tunnel equipment. They also ensure that a clear and consistent flow of communication is maintained, enabling efficient implementation of the project. Further tasks are:

  • Coordination of the specialist trades and quality control
  • Clear exchange of information with the modeling team and other trades for a common understanding
  • Identifying and resolving conflicts between different technical requirements
  • Compliance with and implementation of BIM standards for a consistent way of working, e.g. creation of an element catalog
  • Processing and integration of attribution and parameter filling in the model

Tools such as augmented reality (AR) are used to create a comparison between the specialist model and reality. The specialist model is continuously compared with the basic model on the construction site and serves as an aid and tool. Not only for BIM specialist coordination, but also as a supporting tool for construction work.

You can read more about the use of AR and BIM in the following news item: Digital duet: BIM and augmented reality.

BIM Modeler


Your task is to create 3D models that are coordinated and enriched with information for further use. The BIM Modeler plays a crucial role in the coordination and collaboration between different disciplines by visualizing complex construction projects virtually, providing a clear guide for construction and maintenance. Other tasks include:

  • Creating precise, accurate and complete 3D models in collaboration with various specialist departments
  • Continuous adaptation and maintenance of the models based on project developments and changes
  • Integration of structural, technical and architectural information
  • Identification and resolution of conflicts and clashes in the model to anticipate issues on site
  • Clear communication with the team to promote understanding of the digital model

BIM modelling is therefore not just a tool for visualization, but a dynamic instrument that forms the basis for model-based, collision-free and therefore more efficient construction.

BIM employees in the Koralm Tunnel

The activities of pde's overall and specialist coordination and modeling will continue to provide exciting tasks and diverse challenges within the major Koralm Tunnel project until 2025.

Do you also want to plan construction projects that inspire generations? Then apply now on our careers page.