BIM FOR METRO STOCKHOLM

The Tunnelbana metro system in Stockholm is facing a new expansion project, starting in late 2018, will build a new metro line from Odenplan to Arenastaden. It stretches over four kilometres and includes three new underground metro stations. Amberg was responsible for finding engineering solutions for the metro tunnels as well as modelling and coordinating the project with BIM.

Building in a dense urban environment, the project held many challenges. One of them was to figure out how to cross a current metro city line and connect the new tunnels to the existing network—all while factoring in hard granite and gneiss formations with numerous weakness zones, as well as low rock cover situations with only approximately four meters of rock.

The engineering challenges were tackled by conducting model calculations as well as geotechnical calculations for difficult areas.

Working with 3D BIM models made information easily available to all technical stakeholders. Since all issues related to geometry such as connections to stations were synchronized across software platforms, the data was reliable, and all issues could be resolved more accurately. The 3D geometry was also used as the source of information for setting up the calculation models.

Besides implementing BIM processes, Amberg was also responsible for consulting the client during the entire construction project, project planning for reinforcement during excavation and installation of lining as well as establishing the final designs.

"The 3D model allows a detailed design of complex geometry, with a smooth exchange of geometric data within various software applications such as modelling, numerical 3D calculation, 2D design of drawings, bill of quantities. The model is constantly updated which requires quick and clear communication. Synchronized processes allow us to detect errors or clashes very quickly. That way, all involved stakeholders are always up to date, which makes working on projects more efficient."

- Elisabeth Sattlegger, Project Engineer