We use our trenching machines for the placement of shields for groundwater protection and purification. Normally these trenchers are used for the placement of drainage tubes. We have designed and constructed a special casette that enables us to use it for this dual purpose. This special cassette is attached to the trencher boom and by doing so, vertical shields can be inserted.
The shields are available as:
These are mounted by specialists from ground level up to 5,0 meters deep. We use LDPE foil with a thickness of 0,5 mm.
Applications of the foil screens:
- Prevention of seepage and tunnelling in dikes
- Reduction of flow in long-term dewatering
- Separation of clean and contaminated sites
- Prevention of groundwater lowering in areas adjacent to dewatered areas
- Isolation of contaminants
An advantage of foil screens is that they can be applied cheap and easily. The foil screens overlap each other.
These are applied to a depth of 2.5 up to 7.0 meters below the ground level. For the cement- bentonite shields we uses a pre-mix that is mixed with water on location. This pre-mix is fabricated on the basis of pre analysis for the specific demands of the work.
Areas of application for cement-bentonite shields are:
- Separation of clean and polluted areas.
- Countering seepage at underpasses and tunnels etc.
Advantages of cement-bentonite shields, that have been installed by trenching machines, are the lower costs and simplicity in comparison with a deep wall digger. An impermeability of 1*10 -12 m/s can be obtained.
This technique mixes the soil with injected bentonite or cement sludge. Dependant on the technical demands of the stabilisation wall, other types of sludge can be injected. This technique is applicable to 8 meters under the ground level. De quality is homogeneous throughout the total height of the shield and is independent of the original soil composition.
Filling trenches with sand can also effectively create a shield.
The filled trench will fill with water from various groundwater layers. This water can be treated. The sand shield should be seen as a collecting shield for further treatment of the collected water via means such as pumped drains or collecting pits.
The installation of underground cables can be realized by our trenching machines. The advantage of this system are to minimise time, costs and also damage to the cable.
Cable trenching is always time-sensitive and highly skilled and we take great care to perform it properly, with well trained people equipped with the right tools for this demanding and essential job.
as a result of current laws and regulations, execution plans, proper control and measurement systems are absolutely required. By using the latest well monitoring and flow-measuring systems we can provide remote data readouts and supply these in digital form. We have all the knowhow and equipment to help and advise you with planning and implementation. Through cooperation with our specialists at an early stage the implementation of dewatering can enhance the quality and efficiency of your entire project. This can be accomplished through pre-analysis of our geo hydrologists and ‘surprises’ can be avoided.