Bored piles are piles where the removal of spoil forms a hole for a reinforced concrete pile which is poured in situ. The spoil is replaced by the pile, hence 'replacement' piles as opposed to displacement piles where soil is forced away by driving or screwing the pile Bored piles are a very effective, state-of-the-art construction element with many applications in foundation and civil engineering.
Common uses
- As heavy foundations, securing deep excavation especially close to existing buildings as well as stabilising and retaining slopes
- In a variety of infrastructure projects such as tunnelling, road or bridge construction as well as flood protection
- Retain ground alongside an excavation pit or close to adjacent buildings, often combined with other techniques such as ground anchors or soil nails
- For slope stabilisation to prevent landslides, or protect existing buildings
Process
A temporary casing is installed and soil drilled out using specialised tools. If the hole requires support to remain open, additional casing or drilling fluid can be used. Full length reinforcing steel is lowered into the hole which is then filled with concrete. Bored piles can be drilled to depths in excess of 60m and typical diameters range up to 2.4m.
Advantages
- Very high load capacity
- Various diameters available from 450mm upwards
- Can be installed in a wide range of soil and rock conditions
- Minimal settlement and deformation
- Minimum vibration
