Bored piling is a method that involves boring a circular hole into the ground, installing steel reinforcement and filling the bore hole with concrete to form a pile. Boring is carried out to the design depth by means of either a crane mounted or a track mounted hydraulic drilling rigs. Bored pile foundations are suitable for a wide range of ground conditions. Bored piling generates less noise and vibration as compared with conventional driven piling methods.
Apart from building foundation piles, the bored piling method is also used to form Contiguous and Secant bored pile walls for earth retention system. A contiguous bored pile wall is formed by installing closely spaced bored piles, with a small gap between adjacent piles, typically 75 to 150mm. A secant pile wall is formed by installing overlapping bored piles. Secant piles are usually adopted where there are particular concerns about groundwater inflow.