A feature of this pile is the flexibility of size (300mm to 2500mm diameter), depth, and speed of installation under ideal conditions of non-collapsing dry soils. The installation procedure causes no undue noise and is effectively vibrationless. In view of the size of plant used, clear headroom and an open site results in better production than in congested areas.
For augered piles, the hole is excavated by rotary action of an earth boring machine until suitable founding material has been reached. The depth capacity of available auger machines under unlimited headroom conditions is in excess of 50m in penetrable soil. This depth may be extended with percussion drilling techniques.
Obstructions may present a problem, and if any handwork is required to remove these, the shaft diameter should not be less than 900mm.
If the sides of the hole collapse or are liable to collapse, or if excessive water is entering above the base of the pile, temporary retractable casing is installed. If ground water cannot be controlled by pumping and / or temporary casing to allow concreting in the dry, then concrete is placed under water using a tremie pipe.