Hendriks formwork for pillars fly-over De Groene Boog

De Groene Boog, a consortium of Besix, Dura Vermeer, Van Oord, John Laing, Rebel and TBI, is designing and building a new ring road in Rotterdam-North on behalf of the Directorate-General for Public Works and Water Management. At the Terbregseplein junction, a fly-over will be constructed, after which the road will pass under the river Rotte in a semi-sunken tunnel a few hundred metres further on. Hendriks developed and supplied pillar formwork for the fly-over. Hendriks also designed the tunnel formwork used for the sunken tunnel.

Anyone who is regularly on the road or listens to the traffic jam reports will no doubt be familiar with Terbregseplein, which is one of the busiest traffic junctions in the Netherlands. Almost every day, there are traffic jams on the A13 near Overschie and the A20 between Kleinpolderplein and Terbregseplein. As road users try to avoid these traffic jams, local roads also clog up. To improve Rotterdam's accessibility and quality of life for local residents around the A13 and A20, a direct connection between the two motorways is being created.

This Green Arch runs like a ring around Rotterdam North. The project puts into practice the latest thinking on liveability and sustainability. The road will be fitted into the landscape in the best possible way and will be energy-neutral. Noise nuisance will be avoided as much as possible by using extra noise-reducing asphalt.

Incremental Launching Method

As part of De Groene Boog, a flyover will be built at Terbregseplein, whose road surface will be slid over the existing infrastructure as a kind of pre-construction, without hindering traffic. This is the first time this Incremental Launching Method has been used in the Netherlands. The total length over which the road surface is shifted is 400 metres per direction of travel. Twenty pillars will provide the necessary support for the road surface.

Puzzling with pillar formwork

For the piers, Hendriks developed, engineered and delivered a formwork in close cooperation with De Groene Boog. André Boeren, main contractor at De Groene Boog commented, "The formwork allows pillars of different lengths to be poured. The pillar height varies from 8.50 to 13.40 metres." The formwork is mounted to a latticework structure fixed to a concrete slab and supported on all sides by braces.

"The piers feature a trapezoidal profile that is bolted is the formwork," says André Boeren. "The architect wanted the profile to end exactly 10 cm below the top edge. Moreover, because the piers have different heights, we use several trapezoidal profiles of varying lengths. Every fortnight, this allows us to strip one pillar and reinforce and form the other."