Temporary Cased Flight Auger

A temporary casing can be installed into the upper parts of the borehole normally to a maximum depth of 6.0M. The casing keeps out any water ingress or provides support to loose soils in the first few metres of the drill hole.

As boring proceeds, the bore is lined with casings. These lining tubes are used to support unstable ground and exclude water from the bore. Where the bore has penetrated into clay it is often unnecessary to use lining tubes and the bore is advanced 'open hole'. On reaching the depth necessary to develop the required bearing capacity of the pile, a steel reinforcement cage is placed centrally in the pile.

Self-compacting concrete is then poured and at the same time, the lining can be left in situ. The method used widely in Norfolk, Suffolk, Cambridgeshire, Essex and the UK ensures that all weaknesses in the stratum are adequately filled with concrete and cover to the steel reinforcement is maintained.