Concrete pouring operations for the floors of the lock gate recesses continue throughout this month and the installation of reinforcement steel for the walls also continues. The last diaphragm walls for the lock chamber are currently being placed and OpenIJ is making preparations to move the flood defence a little so that the last diaphragm walls for the seaward side of the lock chamber wall can be installed.
Activities in the cofferdams
On the east side of the lock, work is being carried out in various cofferdams. The last concrete pouring operations for the floor are taking place and the reinforcement steel structure for the walls has now become visible. Four cofferdams have been built in the water. Number 1 in the picture indicates an opening between two of these cofferdams. From south to north, the following cofferdams are visible: the cofferdam for the lock gate recess of the inner head, the two inner head lock sill cofferdams, and the cofferdam for the lock gate rebate.
The lock gate rebate is necessary to create a watertight seal with the lock gate. The space between the two lock sill cofferdams is left open to form a passageway through which a dredger can reach the area to start dredging away the sand out of the future lock chamber.
The last diaphragm walls for the lock chamber
The last diaphragm walls for the lock chamber are being installed in November (numer 2 in the picture). The last part of the lock chamber wall at the north-eastern corner could only be installed after the eastern part of the cut-off had been removed (a cut-off is a construction formed below the ground to minimise water seepage). Now that the cut-off has been removed and the last corner of the construction site has been filled up with sand, the last diaphragm walls can be constructed here. After completion of these operations, OpenIJ will continue with the construction of the guard wall connecting the new sea lock with the Middle Lock.
Temporary flood defence
A sheet pile wall has been installed in the water south of the North Lock (number 3 in the picture). This sheet pile wall will be anchored and completed next month. After that, the rocks will be removed from this newly constructed basin behind the sheet pile wall and an underwater search for unexploded ordnance will be carried out. The area will be filled up in December in order to move the flood defence in a seaward direction. When these operations have been completed, the diaphragm walls of the lock chamber on the seaward side of the lock gate can be installed.