ABSTRACT
The West Link, an 8 km railway tunnel in Gothenburg, Sweden, features a rare and unique structural system. Stations are constructed in crystalline rock resulting in caverns with a span width of 50.0 m. The rock cavern is supported by singular rows of reinforced concrete columns in addition to rock bolts and shotcrete. Several challenges in the design were encountered mainly associated with uncertainties in geological conditions and low rock cover. A holistic monitoring system was implemented to survey the structural behaviour of rock mass and concrete structure to verify the design requirements. The loading of the concrete structure followed a progressive stepwise excavation sequence. The load distribution within the primary system of reinforced concrete and rock mass depends on interactions in the form of deformations and stressredistribution in short and long-term aspects. The paper summarizes the faced challenges an lessons learned from the design and planned monitoring process.
