Diaphragm walls


Diaphragm walls are wall cast in the ground using armoured concrete. With this structural support technique, we can reach excavation depths up to 40 metres.

To build a diaphragm wall, we dig a trench of several metres using a grab. During the excavating, we introduce bentonite into the trench, which protects the trench from collapsing. Next, we lower an armouring cage in the trench and start filling it with concrete.

After Soetaert became a part of Jan De Nul Group in 2016, we invested heavily in the equipment for developing diaphragm walls. Subsequently, we completed several diaphragm wall projects and we continuously have new ones on the agenda. We realised the R41-tunnelling project in Aalst, the Beatrix Lock in the Netherlands, and the preparatory works for Oosterweel in Antwerp.


  • Vibration free and limited noise production
  • Soil and bentonite removal
  • Earth-retaining construction


Diaphragm walls are not just used as earth- and water retaining walls for large and complex construction pits, but also a continuous or loadbearing walls for tunnels and parking projects, or even as quay and lock walls.