Auger Boring is a non-man entry technique and consists of a cutting head attached to a helical auger. The rotation of auger flights simultaneously rotates cutting head and removes spoil from the tunnel. As the cutting head advances, pipes are driven into ground by means of surface jacks. Auger Boring systems are non- steerable so the line and level of boring are set at the drive pit by guidance rails. Any deflection of the tunnel axis from planned alignment is usually non correctable. Auger Boring technique is most suitable for short crossing with cohesive soil.
Although it is still used in some places because of low investment cost, Auger Boring technique has some disadvantages. It cannot be applied in saturated soils because of ground collapse risk. In addition to that, this technique may over excavate the annular space that may settle with time and damage the nearby structures and installation itself.
- No disruption to traffic.
- Low noise level.
- Applicable only after water table.
- Good performance in cohesive soils.
- Non man-entry pipes can be installed.
- Drive and reception shafts are required.
- Large boulders are problem.
- Cannot be steered.
- Risk of ground settlement.
- Lengths Up to 50 meters
- Diameters 300 to 1500 mm
- Materials Steel Pipes only
Auger Boring Procedure