Continuous flights of auger (CFA) are seen on large piling rigs, the larger rig enables the installation of large diameter piles that can reach greater depths than that of a mini piling rig. PSS has the experience and correct operational skills to use drilling rigs of all sizes and applications to fulfil the requirements of your pile design.
Technical Info
Diameter: 350mm – 800mm.
Depth: 25m.
Ground Condition: gravel, sand, silt, clay and soft rock.
Benefits
Quietest method of piling.
Ideal in soft ground conditions.
Fast and economical method.
Low vibration.
Used near existing structures.
Process
CFA piling is a technique typically used in built up areas as it is a quiet and virtually vibration free application. Piles can be installed close to existing structures and do not required the use of casings to support the pile structure during concrete pumping.
INSTALLATION
A length of hollow stem auger is drilled to depth, the head of the auger is designed to cut through clay / soil or rock. During penetration, the soil travels up the flight of auger due to its conical. The spoil is cleared away on ground level.
EXTRACTION
The piling rig has an on-board computer in the cabin, this tells the operator what is happening as the auger is slowly extracted from the pile whilst pumping concrete through the hollow stem. The concrete is monitored as it is pumped at a controlled rate to ensure structural integrity is maintained. A wire frame can then be inserted into the curing concrete.
