Hendriks precon formwork for pillars for the Groene Boog [Green Arc] flyoverA pillar formwork puzzle
De Groene Boog, a consortium comprising Besix, Dura Vermeer, Van Oord, John Laing, Rebel and TBI, under contract to the Directorate-General for Public Works and Water Management (Rijkswaterstaat) is designing and constructing a new road ring in Rotterdam North. A flyover will be constructed near the Terbregseplein traffic junction, after which the road will continue a few hundred metres further up in a semi-submerged tunnel through the Rotte River. Hendriks precon developed and supplied the pillar formwork for the flyover. Hendriks precon also signed on for the tunnel formwork to be used for the sunk tunnel.
Anyone who is regularly on the road or who regularly listens to the traffic reports will no doubt be familiar with the Terbregseplein, which is one of the busiest traffic junctions in the Netherlands. Almost every day there is a traffic jam at the A13 motorway near Overschie and the A20 between the Kleinpolderplein and Terbregseplein traffic junctions. Because road users try to circumvent the traffic jams, the local roads also become clogged. To improve Rotterdam’s accessibility and the quality of life of local residents near the A13 and A20 motorways, a direct connection will be constructed between both motorways.
This Green Arc [Groene Boog] runs like a ring around Rotterdam North. The latest insights relating to quality of life and sustainability will be put into practice in this project. The road will be optimally integrated into the landscape to the maximum possible extent and will be energy-neutral. Noise pollution will as much as possible be prevented by making use of enhanced sound-deadening asphalt.
Incremental Launching Method
As part of the Groene Boog, a flyover will be constructed near the Terbregseplein traffic junction, whose road deck will be pushed across the existing infrastructure as a kind of pre-construction structure, without disrupting traffic. It is the first time that this Incremental Launching Method will be used in the Netherlands. The total length across which the road deck will be pushed is 400 metres in each driving direction. Twenty pillars provide the necessary support for the road deck.
A pillar formwork puzzle
Hendriks precon, in close cooperation with the De Groene Boog, developed, engineered and supplied the necessary formwork. André Boeren, General Foreman at De Groene Boog: ‘The formwork makes it possible to pour pillars of various heights. The height of the pillars varies from 8.50 to 13.40 metres.’ The formwork is mounted on a lattice structure attached to a concrete plate and is braced on all sides.
‘The pillars are equipped with a trapezoidal section to which the formwork is bolted,’ says André Boeren. ‘The architect wanted the section to terminate exactly 10 cm below the upper edge. Because the pillars furthermore are of different heights, we are making use of multiple trapezoidal profiles of various heights. This way we can remove the formwork from one pillar and add the rebar and formwork to the next one every two weeks.’