The Besix-Strukton partnership is building the longest underground traffic tunnel in the Netherlands – plus a tunnel that is perfectly integrated with nature.
Roermond and Ambt Montfort have the honour of becoming home to the longest underground tunnel in the Netherlands. The tunnel has a length of 2.4 kilometres and consists partly of immersed units that are produced in a construction dock and transported to the immersion site. Despite their considerable weight of 28,000 tonnes each, these units floated when the dock was filled with with water. Individual units are 150 metres long, 8 metres high and 27 metres wide. The dock and the immersion site were linked by a temporarily excavated 600-metre sheet pile canal. The contract for the specialised immersion activities was awarded to Mergor.
A tunnel integrated with nature
The tunnel constructed in Swalmen has a length of 1,000 metres and a closed section of 450 metres. The roof of the tunnel is located just below ground level, as a result of which it is camouflaged by vegetation, integrating it into the natural environment. A traditional ‘open’ excavation method was used for this construction. A special feature of the tunnel is the fact that the sheet piling is permanent. The tunnel comprises 47 sections. The environmental and urban environments were respected throughout construction, with special plant and animal species, archaeological sites and the human environment being left intact as much as possible.
The safest
2003 saw the start of the construction of the 42-kilometre extension of the A73-Zuid motorway, which extends the A73 from Venlo to Maasbracht. The largest parts of the project as whole were the tunnels in Roermond and Swalmen. The tunnels, which are equipped with an ultramodern fire extinguishing system, are already considered to be among the safest of their kind in Europe.