On the second track section between Divača and Koper, the last karst cave crossing (2TDK-080) was successfully completed in the Beka Tunnel (T2). The underground arch bridge spans a karst cave discovered during construction work with a span of 45 metres, making it the largest of a total of four arch structures on this section of the line. It is also one of the most technically challenging structures in the project.
Engineering solution for exceptional geological conditions
Construction in karst terrain poses particular challenges, as conventional solutions cannot be used here. In the Beka Tunnel, an underground arch bridge was therefore constructed to span the cave and create a safe, long-term stable foundation for railway operations. The engineering work was led by ELEA, whose tunnel and geotechnical teams developed a tailor-made solution for the complex geological conditions.
Digital planning and interdisciplinary collaboration
The ELEA iC team supported the project together with the extended iC network in the areas of tunnel planning, geotechnical engineering and BIM-based implementation. The entire second Divača–Koper railway line was planned entirely using Building Information Modelling (BIM). A total of 614 BIM models were used, enabling consistent coordination and 3D, 4D and 5D analyses for schedule and cost planning.
Technology that advances infrastructure
The completion of the final karst crossing in the Beka Tunnel impressively demonstrates how advanced engineering technology, digital planning methods and close cooperation across disciplines interact in large infrastructure projects. This is an important step on one of the most geologically challenging sections of the Divača–Koper route.
