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Two new cut-and-cover tunnels on the E18 motorway in Norway

Jul 23, 2024
ULMA is participating in the construction of two cut-and-cover tunnels, Bjønnås and Grenland, along the new E18 motorway that will connect the cities of Langangen and Rugtvedt in Norway.
Two new cut-and-cover tunnels on the E18 motorway in Norway
Two new cut-and-cover tunnels on the E18 motorway in Norway

The E-18 motorway is one of the most important road projects in Norway as it connects two major urban centres, Oslo and Kristiansand. It is 17 kilometres long and includes the construction of several structures such as the Bjønnås tunnel (2.5 kilometres long) and the Grenland tunnel (5.1 kilometres long). The aim is to have a four-lane infrastructure.

This project will bring multiple benefits to the area, as it will contribute to urban and commercial development by improving connections to nearby regions.

The cut-and-cover tunnels are 80-90 metres long and concrete placement has been carried out in 11-metre-long sections, with certain sections having a variable cross-section. ULMA's engineering team has designed a 10 m wide and 12 m long MK carriage. To achieve this, the customer required a flexible, cost-effective and modular system that would allow adjustments to be made if necessary and to be easily transferred to the next phase. In fact, the presence of rails has simplified the formwork and stripping process and the lifting and lowering of the segments, as well as the longitudinal displacement of the carriage, which was carried out in 7 days.

The system includes both internal and external formwork so that the customer can have a complete solution for the vault and side walls. The vibration and inspection system is also built in and thus helps to ensure the correct construction of the structure. The MK carriage is composed of standard and modular MK parts, adaptable to any geometry and different sections of the project. The safety systems are integrated, whereby the carriage itself was equipped with cantilevered working surfaces to work safely throughout the process.

Due to the complexity of the project, ULMA has not just designed and supplied the material. Our supervisors are supporting the customer throughout the process to make sure that everything is being assembled according to ULMA standards. Commitment is the basis of our relationship with our customers.