Special formwork and steel frames for viaduct over busy interchange

Doka formwork systems are ideally suited to infrastructure projects. Whether it's a viaduct, retaining wall or tunnel, a suitable formwork solution can be supplied for any programme of structural requirements. Such is the case for a viaduct over the busy Terbregseplein interchange. To connect the existing A16 with the A16 Rotterdam, a flyover is being constructed at Terbregseplein. A remarkable technique was chosen for the construction of the flyover: the Incremental Launching Method (ILM), in order to allow traffic to continue as usual during construction. Doka was called in as the formwork specialist to supply the formwork and steel frame for this construction method on the pre-construction site. 

"This infrastructural masterpiece is the cream of the crop for us," begins Erik Caris, Engineering Manager at Doka, enthusiastically. "The new road surface, without interfering with traffic, will be realized using Freyssinet's Incremental Launching Method (ILM). As the name of the construction method might suggest, this is a method in civil engineering in which the road surface to be realized is 'launched' from one side, so to speak. We are talking about 400 meters per direction of travel, while the traffic on the A20 and A16 can continue unhindered at all times."

Doka was engaged by construction consortium the Green Arch as formwork specialist, to supply the formwork and floor support on the pre-construction site. The flyover does not stand alone, but is part of a large infrastructure work. The flyover is built from one side and consists of two box girders. Each of the two box girders consists of 17 segments that are slid over previously completed piers. The construction of the formwork system is built in such a way that the formwork can be hydraulically lowered, the box girder bridge is pushed further and the formwork rises again. Thus the cycle repeats itself until the other side is reached. 

This construction method is special by Dutch standards. "ILM is now a proven method for builders of infrastructure in mountainous areas. In the Netherlands, however, it is being applied for the first time over a traffic interchange in use and we as Doka are very proud of that."