Geolock can be applied for isolating existing landfills and for cut-off walls in dikes, dams and lowered carriageways. Geolock has an unrivaled number of applications which are very competitive compared to traditional materials.

The number of contaminated sites discovered in the Netherlands is still rising daily. The ground is also contaminated in many places as a result of industrial work or leaking storage tanks. Cleaning up the contaminated ground is very expensive, and technically and financially not always feasible. Contaminated ground can also be decontaminated on location by flushing with water or steam. This solution is also not financially attractive for large areas of contamination.

An alternative, in these cases, is enclosing the contaminated ground, whereby the contamination cannot spread. In answer to this problem, Cofra has developed a watertight system called Geolock.


-The main properties of Geolock are:
- Simple installation procedure
- The installation is suitable for all raw materials
- The lock construction ensures optimum waterproofing
-Geolock is resistant to a large number of chemicals, including acids, salts, bases, alcohol, oils and hydro- carbons.

This variety of configurations give the designer the opportunity to choose between several different sheet piling configurations with a large difference in flexural strength.


Geolock can be installed using a steel plate in combination with a vibrator to place the panels at the correct depth. This system is only suitable for installation in relatively soft subsoil. For installation at greater depths, a bentonite/cement wall is always constructed beforehand in which the Geolock screen can be installed. The advantage of this method is that a completely waterproof construction is produced. In this way, installation is also possible in any type of ground and to a greater depth. A check on the locking connection is possible with the application of a precursor during installation or by using an electronic control system.


In principle, Geolock’s range of application is divided into three groups:

- Vertical isolation of contaminated ground
- Cut-off walls in civil engineering
- Gastight screens at lower groundwater levels

Meanwhile, the system has been applied in a large number of countries including Japan, US, UK and Italy. As well as isolation systems for refuse dumps, it has been used with cut-off walls for lowered highways, aqueducts and dams as well as gas-proof screens in places where methane gas has penetrated surrounding buildings. It is also an effective vertical sealant for vacuum drainage.