New stage in the construction of the lock in sector 1

The construction of the Montmacq – Cambronne-lès-Ribécourt lock begins with the creation of a watertight enclosure, made up of concrete walls called diaphragm walls.

Diaphragm walls are constructed by excavating trenches up to 20 meters deep using a mechanical excavator. These trenches are stabilized with a mixture of water and bentonite clay, which prevents groundwater infiltration and soil erosion. A reinforcing cage is then inserted before concrete is poured into it. Being denser than the bentonite, the concrete displaces the bentonite, filling the trench and thus forming the wall.

The walls of the lock chamber are built first, then those of the upstream and downstream heads of the lock and finally, of the pumping station (see photo below).