Auger Boring

Horizontal auger boring is a trenchless technology technique that DM Civil has been utilising since the mid 1980’s. DM Civil owns auger boring machines that give the capability to install steel casing from DN250 to DN2600.

Auger boring methodology cuts a hole in the ground into which the steel casing is progressively pushed by hydraulic rams on the rear of the boring machine thrusted against the back of the boring pit. The boring machine and casing are set up on tracks to the required position, line, level and grade. The cutting head is attached to augers, located inside the steel casing, and this is driven by the boring machine. These augers transport the soil back through the flights and into the boring pit for removal. Line and grade can also be controlled to reasonable tolerances by combining our pilot-guided boring technology, if required.

DM Civil has a range of cutting heads from closed face for sand soils, clay heads, soft rock heads for rock up to approximately 20 MPa, and small boring unit roller rock heads for competent rock up to 175 MPa in strength.

After the steel casing is installed, the service pipe can be sleeved inside on centralising brackets and the annulus grouted, or alternatively the casing can be jacked out with a same diameter product pipe made from concrete, clay, concrete coated steel gas pipe, GRP or GRC pipe.

Auger boring is typically used for bores up to 50 metres in length. However, auger bores of up to 100 metres have been successfully installed. Set up times and productivities are relatively fast, and equipment costs cheaper, when compared with microtunnelling machines. This technique is a very cost effective methodology used for bores under roads, railway lines, services and structures, in dry ground conditions, where line, level and grade are not critical.