PROJECT APPLICATION
Formwork solutions for the Stockholm Bypass A new superhighway, mostly designed as a tunnel, is intended to guide traffic around the Swedish capital. Stockholm is growing faster than London and faster than any other European city. But when it comes to traffic, the Swedish city is at a ‘standstill’. The frequently congested Essingeleden, the 60s-era motorway in the west of the city, is still the most important northsouth connection. But traffic is soon set to flow again. For years, construction has been underway on a new road, the Förbifart Stockholm, better known as the Stockholm Bypass. The Trafikverket, Sweden's traffic authority, has commissioned the excavation of a tunnel under the rugged land of skerries and holms to the west of the metropolitan region for this project. It is a mega project and a feat of strength, too, as a good 18 km of the 21 km route run through the rocky underground.
Special solutions for special projects
The underground railway concept for cars
The team formed to implement the project includes Spaniards, Poles and Austrians, as well as representatives from the local branch of Doka, who have applied their expertise in formwork at various points of the western bypass. The main focus of their work has been two circular tunnels, 130 m and 160 m long, in the Skärholmen district, southwest of the city centre, built using the open-cut method.
An example of this is using the SL-1 all-round model structure to create an SL-1 ‘model Stockholm bypass’ structure. The construction of the route involved circular tunnels, like the ones in underground railways. So the team adjusted the system and took it from the world of rail travel to the world of road travel.
The Swedish team broke new ground by working on this tunnel type. The project also demonstrated Doka’s expertise in formwork for large and unique types of construction projects. The engineers were able to adapt proven systems with special elements to on-site circumstances.
Special projects, such as the Skärholmen tunnel in Sweden, require special solutions.
The local contractor received an economical rental solution intended to implement a tunnel format of this kind without complications. A design like this depends on more than just a few additional structures. Maximising every solution to make formworking quick and easy is just as important as delivering the best solution. Doka came up with constructive ideas to optimise the solutions, and helped in the planning of the formwork cycles so as to ensure staying on schedule.
In Stockholm’s district Skärholmen, Doka’s heavy-duty supporting system SL-1 is being used to shape two circular tunnels using the cut-and-cover method. THE SINGAPORE ENGINEER January 2022
29
