Construction technique & application

By utilising a telescopic kelly bar our large rotary rigs create the pile bore through the removal of the soil in sections, approximately a metre deep, until the design depth has been reached. At this stage full depth reinforcement cages, steel sections or permanent casings can be easily installed prior to the placement of concrete. Where piles are used for deep basements it may be permissible to leave the concrete at a low level in order to reduce pile trimming.

Rotary piling is generally used in dry stable soils and rocks. However in cohesionless soils, piles may still be formed with the use of casing or drilling fluid to support the bore.

For small diameter piles operating in stable soils throughout the foundation depth, our CFA rigs can efficiently create an open hole auger (OHA) pile. It is also worth noting that our mini rigs adopt a sectional flight method to create the pile bore as their mast height restricts the use of a kelly bar system.

Plant & equipment

We have a wide variety hydraulic rigs ranging from 2.5T to 80T. This provides pile sizes ranging from 250mm to 2500mm and up to 77m depth. The short mast height and small footprint of some of the rigs mean that most sites are accessible with our equipment.