Drainage and injection drilling systems

Drainage and injection drilling systems are essential for stability and safety in tunneling and geotechnical works. Our systems control groundwater, reduce pressure, and prevent erosion and water ingress. They install easily with standard drilling equipment, ensure controlled discharge, and can be enhanced with vacuum pumps for low-permeability ground — delivering reliable dewatering for temporary or permanent applications.

AT – Drainage System

The AT – Drainage System provides long-distance, proactive groundwater control ahead of the tunnel face. It minimizes water ingress, reduces hydrostatic pressure, and supports stable excavation. With installation lengths of 12–30 m and longer if required, it uses a coupled, cased drilling method for deep, secure penetration. The system enables effective dewatering at a safe distance, drains ground ahead of the tunnel drive, and lowers water pressure in fault zones — delivering reliable performance for demanding underground conditions.

AT – Tubespile™ Vacuum Lances

AT – Tubespile™ Vacuum Lances are designed for temporary or semi-temporary drainage around the tunnel perimeter. The system consists of an exterior steel tube with a PVC drainage tube inserted after drilling. It is an uncoupled, single-pass solution with typical installation lengths of 3 to 5 meters. The vacuum lance reduces water content in the surrounding ground, improving stability during excavation.

AT – GRP Injection System

The AT-GRP Injection System is a self-drilling solution with glass-fiber-reinforced pipes for ground improvement or waterproofing, ideal where steel is unsuitable or where TBMs will later excavate the pipes. It enables flexible installation in both jointed rock and weak ground and works with standard drilling equipment and TBM setups.

Features

Fast and efficient installation

Drainage and injection drilling systems can be installed using conventional drilling machines, enabling rapid deployment in tunneling and civil engineering works. The self-drilling concept allows drilling and casing to be completed in a single step, significantly reducing installation time.

Fast and efficient installation

Drainage and injection drilling systems can be installed using conventional drilling machines, enabling rapid deployment in tunneling and civil engineering works. The self-drilling concept allows drilling and casing to be completed in a single step, significantly reducing installation time.

Drainage and injection drilling systems can be installed using conventional drilling machines, enabling rapid deployment in tunneling and civil engineering works. The self-drilling concept allows drilling and casing to be completed in a single step, significantly reducing installation time.
Reliable performance in challenging ground

The systems are suitable for a wide range of geological conditions, including flowing and ravelling ground. This ensures consistent drainage performance and stable operation even in difficult environments.

Reliable performance in challenging ground

The systems are suitable for a wide range of geological conditions, including flowing and ravelling ground. This ensures consistent drainage performance and stable operation even in difficult environments.

The systems are suitable for a wide range of geological conditions, including flowing and ravelling ground. This ensures consistent drainage performance and stable operation even in difficult environments.
Flexible adaptation to site constraints

Drainage tube lengths can be easily adapted to restricted space conditions, making the systems highly versatile across different project layouts and excavation geometries.

Flexible adaptation to site constraints

Drainage tube lengths can be easily adapted to restricted space conditions, making the systems highly versatile across different project layouts and excavation geometries.

Drainage tube lengths can be easily adapted to restricted space conditions, making the systems highly versatile across different project layouts and excavation geometries.

AT – Pipe Umbrella System

Drainage drilling is often combined with pre-support measures such as the AT – Pipe Umbrella System or injection chemicals for ground consolidation or waterproofing.
The AT – Pipe Umbrella System, also known as the “canopy tube method” or “long fore-poling,” installs pipes ahead of the tunnel face and parallel to the planned excavation contour.

AT - Pipe Umbrella System brochure (PDF)

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