Cut-and-cover tunnel in Gothenburg, Sweden

A section of highway E45, between Lilla Bommen and Marieholm in in the Swedish city of Gotherburg, is being lowered as part of a greater urban development project. 800 m of the highway will be lowered 6 m and 400 m will be covered, resulting in the new Lilla Bommen tunnel. The tunnel will be equipped with access and exit ramps, as well as an underground technical building, and will form the foundation for three high rises to be built on the tunnel roof.

PEAB has engaged CN3 to optimize the execution of the 42,000 m3 concrete structures with almost 6000 tons of reinforcement through the modelling of 3D production models. In close collaboration with the contractor, CN3 has developed a system of reinforcement cages in our 3D platform. Due to the reinforcement layout for the highly strained walls, a one-sided assembly of the reinforcement cages was not possible. To address this issue, CN3 designed an assembly frame system, in which the reinforcement cages for the walls can be assembled without the need for molds. This industrialization of reinforcement design and execution led to significant reduction in assembly time and costs.

From the highly detailed production model, CN3 also delivered complete data sets for the stake out of all structural elements, which reduced the surveyors preparation time substantially – especially for the complex parts of the tunnel. From the production model, a complete quantity overview is maintained, orders managed, progress tracked, and payments to sub-contractors handled in an efficient and transparent way.

CLIENT: Trafikverket
ENGINEER: Centerlöf & Holmberg
PHASE: Design and execution

3rd Party Control & Optimization
Digital Construction Management
Advanced Modeling
Methods & Value Engineering
4D/5D Assembly Planning
Production Data & Drawings