Construction World February 2022

CRANAGE & HEAVY LIFTING

Whenever people talk about the quality of life, Stockholm is at the top of the list. To keep it at the top, the city is digging deep. A new superhighway, mostly designed as a tunnel, is intended to guide traffic around the city – with help from Doka. It’s a double- first for the formwork experts from the Swedish branch. DOKA: AN ALL-ROUND SUCCESS

S tockholm 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 Sixties-era motorway in the west of the city, is still the most important north-south 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 project under the rugged land of skerries and holms to the west of the metropolitan region for this project. A mega project. And a feat of strength too, as a good 18 kilometres of the 21-kilometre route run through the rocky underground. Special solutions for special projects Special projects require special solutions. It’s no coincidence that the “A-team” of Spaniards, Poles and Austrians also includes representatives from the local Doka branch, 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 in the Skärholmen district, southwest of the city centre, built using the open-cut method, each 130 and 160 metres long. The Swedish team broke new ground by working on this tunnel type. Yet, in actual fact, the project only reflects why Doka is a highly sought partner for formwork in large construction projects, no matter how unique the typology. The engineers’ secret to success: adapt proven systems with special elements to on-site circumstances in such a way that concreting feels like a revelation. The underground railway concept for cars An example of this is using the SL-1 all-round model structure to create an SL-1 “model Stockholm bypass” structure. Because the construction of the route did not

involve just any kind of tunnel – these were circular tunnels, like the ones you find in underground railways. So the team around Doka Project Manager Håkan Bratt adjusted the system and took it from the world of rail travel to the world of road travel. According to him, the local contractor Comsa received an economical rental solution intended to implement a tunnel format of this kind without complications. Of course, a design like this depends on more than just a few additional structures. Because maximising every solution to make formworking quick and easy is just as important as delivering the best solution. “We are very satisfied with the support we have received from Doka, especially Håkan Bratt and Lukas Palme. They came up with constructive ideas, always trying to optimize the solutions. They helped us to plan the formwork cycles so we were able to stay on schedule”, says Martin Klimt, Blockmanager for concrete/formwork at Comsa. Efficiency every step of the way But how can the formwork be quickly converted and easily moved from one place to the other? Wheels and winches provide the necessary mobility for the systems, while an on- site service for precise cutting of wooden formwork beams shortens working distances. Processes are optimised and streamlined for efficiency wherever possible. Take material use, for example: Instead of keeping two or

29 CONSTRUCTION WORLD FEBRUARY 2022