Contiguous pile walls are constructed with small gaps between adjacent piles. The use of Contiguous Flight Auger (CFA) rigs to drill successive unconnected piles provide an economical wall. The diameter and spacing of the piles is decided based on soil type and ground water level. Large spacings are avoided as it can result in caving of soil through gaps.
Our CFA pile diameters range from 300mm, 400mm, 450mm to 750mm. Contiguous piles are suitable in crowded urban areas, where traditional retaining methods would otherwise encroach the adjoining properties our piles can be hard up on neighbouring boundaries maximising your sites footprint , these piles restricts ground movements on the backfill side.
The pile is formed by first drilling into the ground with a CFA auger, a tremie mix, grout or concrete is then injected under pressure through the auger’s hollow stem as it is being withdrawn. The grout or concrete pressure is maintained during the auger withdrawal so that it assists the extraction of material as well as exerting a lateral pressure on the surrounding soils.
On completion of this operation, a reinforcing cage is placed into the tremie mix, grout or concrete. When a CFA pile is combined with a capping beam this can show savings in cost and time in retaining wall construction. A capping beam at the top of the piles helps distribute downward pressures evenly between the piles.
CFA piles are quick to install and offer an efficient, rapid solution in most ground conditions, from gravel and clays, water charged grounds to sands, silts and soft rocks and in mixtures of strata.
No matter what type of contiguous pile wall service is needed, A Class can help you get the job done. We offer various types of piling & drillings services to clients in New South Wales and surrounding areas.
AClass Piling are the structural concrete piling consultants and experts on the east coast of Australia. We service all areas on the East coast of Australia from Tweed heads to Coffs Harbour, Port Macquarie, Newcastle, Sydney, Wollongong and Melbourne.