The Oosterweel project involves the construction of a road interchange between the E17 and E34 freeways, which will also complete the ring road around the city of Antwerp. The Oosterweelknoop tunnel is the third lot of the project, for which Fontec– Soletanche Bachy’s Belgian subsidiary – is a subcontractor for the Rinkoniên consortium (Artes / Mobilis TBI / Boskalis / CIT Blaton / Stadsbader).
The tunnel will be constructed using diaphragm walls, anchored in boom clay at a depth of around 26m. This will provide a horizontal support for working in open excavation, and a watertight screen to prevent the immersed tunnel from rising due to water in the surrounding soil. Around 110,000m² of diaphragm walls will be installed, ranging in thickness from 800mm to 1,500mm.
To ensure the stability of the walls, 3,350 anchors, up to 51m long, will also be required. More than two-thirds of the anchors will be drilled below the water table, through a sluice. Service pulls will reach 1,400kN. The test block for the anchors was built upstream: 14 IRS anchors with test pulls of up to 3,000kN.
Also as part of the Oosterweel project, in April, dredging for a temporary navigation channel commenced around the Scheldt Tunnel construction site. The six-lane 1.8km tunnel is being built by TM Roco, a consortium of Besix, Stadsbader Contractors, Deme Group and Jan De Nul.
In May, TM Roco also started work on the project’s Channel Tunnels
