The cased CFA system is particularly suited to contiguous and secant retaining walls as the temporary casing helps to improve vertical tolerances. The lead casing and auger are fitted with tungsten tipped cutting teeth providing superior cutting power to keep the pile vertical and the ability to cut into female piles to achieve watertight retaining secant walls.
Cased CFA piles are formed by drilling a hollow stemmed auger encased with a string of segmental casing of similar length into the ground to design depth. The drilling system includes twin rotary drive units that turn in opposite directions independently allowing pile arisings to exit at the head of the casing while simultaneously installing the casing. Pile arisings then fall through a full-length telescopic chute to ground level.
On reaching founding level, high slump or flow concrete is pumped through the hollow stem auger in a controlled manner ensuring a static head while the auger and casing is extracted simultaneously. Pile arising continue to exit at the head of the casing. The pile reinforcing cage is then inserted into the concrete.
Throughout the installation process sophisticated onboard computers monitor both the boring and concreting process. The cloud based online data portal allows engineering teams to monitor their contracts and individual pile installation from remote locations in real time.