A section of highway E45, between Lilla Bommen and Marieholm in in the Swedish city of Gothenburg, was to be lowered as part of a greater urban development project. 800 m of the highway was lowered 6 m and 400 m was covered, resulting in the new Lilla Bommen tunnel. The tunnel is equipped with access and exit ramps, as well as an underground technical building, and forms the foundation for three high rises to be built on the tunnel roof.
PEAB sought for CN3 to optimise 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 developed a system of reinforcement cages on 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 could be assembled without the need for moulds. The industrialisation of the reinforcement design and execution led to a 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 surveyor’s preparation time substantially – especially for the complex parts of the tunnel. From the production model, a complete quantity overview was maintained, orders were managed, progress was tracked, and payments to sub-contractors were handled in an efficient and transparent way.
On our infrastructure project in the city of Gothenburg CN3 helped us reduce risk and increase productivity on site significantly.