“(Horizontal Directional Drilling takes place from ground level and does not require any construction pits or groundwater recession. Above-ground and underground infrastructure are spared in their entirety. For directional drilling, we have mini, midi and maxi rigs measuring from 25 mm to 1400 mm in diameter. All standard materials can be used, including steel, nodular cast iron and polyethylene (HDPE). We have the latest state-of-the-art systems at our disposal, such as an optical gyroscope. The probe, immediately behind the drill head, measures the three angles from the drill head to the geographic north. Special software processes the data up to drill head positions and compares these with calculated positions and the desired trajectory of the drill head."
HDD horizontal direct drilling
When to opt for HDD – horizontal Directional Drilling
HDD is the solution often used when pipelines need to be installed under rivers, canals and major roads.
What are the advantages?
- No construction required
- No groundwater recession required
- Full protection of infrastructure both above ground and below ground
- Can be used over distances of hundreds of metres
- Duration and costs are favourable in relation to the complexity of the project
How does it work?
During the pilot drilling of the drilling operation, VLTT performs continuous survey measurements. These measurements are carried out using a conventional ‘walk-over system or with a computer-controlled measurement system, depending on the depth and the accessibility of the trajectory, degree of difficulty of the drilling process, or the client’s requirements. During the drilling and reaming process, soil is removed using a drilling fluid, known as mud. The increased pressure of the drilling mud will influence the behaviour of the soil around the bore hole. Excessively high pressure might result in ground breakage. During the reaming process, this drilling mud is also used for support of the bore hole. Any extreme increase or decrease in the drilling mud pressure is an indication for ground breakage, obstacles or crumbling of the bore hole.