The Czech construction firm Subterra is making progress on its portion of the Skärholmen tunnel project in Sweden, which constitutes the third-longest urban tunnel globally. The tunnel is a crucial part of a 21-kilometer bypass around Stockholm, designed to address persistent traffic issues on the E4 highway. Subterra's involvement began in 2014, securing contracts for access tunnels and later winning the bid for the four-kilometer Skärholmen section.
Stockholm's unique geography, with numerous islands and the convergence of the Baltic Sea and Lake Mälaren, necessitated the construction of the tunnel to enhance transportation efficiency. Subterra faced unexpected challenges during the project, particularly in the section beneath the lake, where geological conditions were more demanding than initially anticipated. This led to a reevaluation of the project design, including the construction of a protective structure using large cement-covered pipes. Despite encountering setbacks, Subterra's completion of their segment is a significant milestone in a project that aims to connect six districts, providing better accessibility and urban development opportunities. Notably, the tunnel will link an island housing the Swedish royal family, streamlining their transportation.
The Skärholmen tunnel project is part of a broader 21-kilometer bypass, initially estimated to cost 35 billion SEK. However, the project has experienced delays and cost overruns, with the Czech segment's budget increasing from 1.739 billion SEK to 3.4 billion SEK. The overall completion of the bypass is now expected between 2029 and 2030, a deviation from the initial projection. The project stands out for its adoption of Building Information Modeling (BIM), providing a digital 3D model of the complex tunnel structure.
This innovative approach facilitates better coordination of construction activities and enhances future maintenance capabilities. Moreover, the tunnel's design features a unique straight ceiling, a departure from the curved ceilings typical in Central European tunnel construction. This is made possible by employing the drill and blast method, a combination of drilling and explosive excavation suitable for the specific geological conditions prevalent in Sweden, characterized by solid granite and magnetite.
In conclusion, Subterra's role in the Skärholmen tunnel project contributes to the realization of an ambitious bypass that aims to improve traffic flow and connectivity in the Stockholm region, despite facing challenges and adjustments in the course of its construction.
Created by CzechTrade team Scandinavia