Discover the commitments behind the Canal
Find here the structural commitments of the Société du Canal Seine-Nord Europe and the project partners.
Discover the commitments behind the Canal
Find here the structural commitments of the Société du Canal Seine-Nord Europe and the project partners.
The diaphragm walls of the lock chamber were constructed between December 2025 and February 2026, and excavation is now underway. We explain how these operations are carried out, with supporting images.
The installation of the diaphragm walls this winter creates a "watertight box" within which the lock will be built. Before proceeding with the civil engineering work, the earth it contains must be excavated to a depth of nearly 12 meters (see video below).
To excavate the lock above water and keep the construction site dry, a pumping system is used. The groundwater, continuously extracted, is first redirected to a filtration basin, before gradually returning to the ground.
The lock chamber is the first part of the lock to be excavated in successive stages, in several sections. The excavated earth is loaded into dump trucks which transport it to a storage area, located within the construction site.
After excavating the first four meters to a depth, struts (cylindrical steel supports) are put in place to support the walls. The diaphragm walls are also planed to remove excess concrete or earth, in order to obtain a smooth surface.
As the lock chamber is excavated, earthmoving equipment (excavators and loaders) is lowered to the bottom of the excavation, and the earth is brought back up using a telescopic excavator. Once the bottom of the lock chamber is reached, a first layer of concrete, called "levelling concrete," is poured. This allows the workers to work on a flat, earth-free surface until the construction of the foundation slab, that is, the final floor of the lock.
To reduce the environmental impact of transporting materials and the disruption to local residents, the Seine-Nord Europe Canal Company is committed to modal shift, particularly from road to waterway. A concrete example is this construction site where, of the 27,800 tonnes of excavated material, 78%, or 23,000 tonnes, are being transported by boat.
Learn more about modal shift
