Bored Piles | Bored Piling Construction Sydney
Bored piles are commonly used as a foundation solution when the conditions of the ground are considered fair to good, i.e. there is; no threat of shallow water table, soils are cohesive or rock and spoil removal is not a problematic or costly trait (such as contaminated / asbestos or acid sulphates). Bored Piles drilled into rock conditions, enhance the chances of minimising any foundation settlement. Australian Bored Piling experts provide top of the line bored piling services in Sydney and surrounding areas. We own a various type of track mounted drilling rigs and excavators which are capable and available to drill depth up to 30m into high strength rock
Bored Piles are drilled with circular augers, cleaned then filled with concrete and steel reinforced cages. The Soil / Rock is removed using certain designed drilling tools, such as soil augers, rock augers, core barrels and clean-out buckets, which can reach a depth of up to 30m and range in diameter from 200mm OD to 1200mm OD. We have several methods available to support the walls / sides of the pile during its construction. This is assessed and selected in accordance to the ground condition being drilled into i.e. soft soils, stiff clays or rock layers, the level of the ground water found and the environmental constraints on site. In the case where a drilled hole requires intervention to remain open (before the soil/sand collapses the hole), we use a steel liner / casing which can be permanent or temporary.
Bored Piling or Bored Piles are an effective solution to piling where various load cases are applied to the pile such as; uplift, tension, lateral load, moment or large pile loads required.
CFA Piles | CFA Piling Continuous
CFA PILES Continuous Flight Auger (CFA Piling) Piling is a cast in-situ process, very suited to soft ground where deep casings or use of drilling support fluids might otherwise be needed. The sides of the hole are supported at all times by the soil-filled auger, eliminating the need for temporary casing or bentonite slurry.
The construction sequence of a CFA pile;
- Drilling a full length auger with a hollow stem (temporarily plugged) into the soil using a constant penetration rate
- After reaching the design toe or RL level, concrete is pumped through the hollow stem of the auger while the auger is extracted at the same time. It is important that the auger always remains embedded into the concrete and that a positive concrete pressure is maintained throughout the placement of concrete.
- CFA piles have to be poured to platform level to facilitate reinforcement installation and avoid pile necking.
- After completion of the concrete placement process the reinforcement cage is thrown into fluid concrete (which is known as a tremmie or grout mix)
CFA Piles Features & Uses:
CFA piles are suitable a foundation piles, for secant pile walls, contiguous pile walls and soldier pile walls. The most common size cfa piles are 300mm, 450mm, 600mm, and 750m m diameter, with larger sizes by exception. They can be constructed to depths in excess of 30 meters.
An important feature of present day CFA Piling is the use of a reliable flow meter to monitor and record the whole process of construction of this type of pile. The items recorded are usually penetration / uplift per revolution, auger depth, concrete supply per increment of auger uplift during placing, and injection pressure at the auger head.