Sectional Flight Auger (SFA) piling is a bored soil replacement piling technique ideal for working inside buildings and on sites with restricted access, allowing the installation of CFA piles of up to 900mm in diameter to be installed in restricted access sites with a headroom of just 3.75m. SFA techniques adding and removing augers i.e splitting of augers during the pile construction to achieve the design depth.
Our expertise means we can install SFA piles of up to 900mm diameter and 25m deep, using our specialist low headroom Hütte, Klemm and Soilmec piling rigs.
Using specially developed rigs within our fleet, such as our Hutte 207 rig with an adapted 4m mast, this technique is fast, quiet and virtually vibration-free.
SFA piles are constructed using a sectional hollow stemmed helical auger bored into the ground, additional sections of auger are added to achieve design depth. On reaching founding level, concrete is pumped through the hollow stem as the augers are simultaneously withdrawn and removed. Spoil/pile arisings are brought to the surface during the augering and concreting process, removed from the auger by the auger cleaner. The pile reinforcing cage is then inserted into concrete shaft.