Deep Foundations

Bored cast in-situ Piling
Bored pile foundations have been one of TASC’s areas of specific competence since it first started operating. Piles with diameter 45cm up to 200cm can be carried-out in every kind of soil by using powerful and versatile rigs. A broad range of tools is used for drilling e.g. auger, bucket, core barrel, chisel, rock auger, down-the-hole hammer, as suitable for the crossed subsoil formations. Drilling is performed with the use of a temporary casing and/or bentonite slurry to guide the drilling tools and support the sides of the pile borehole.

CFA - Continuous Flight Augers
CFA piles are constructed by drilling the entire pile length with a continuous flight hollow stem auger, then pumping concrete through the stem while extracting the auger. A reinforcement cage or H beam is subsequently vibrated into the fresh concrete. This technique, applied in the right soil conditions, allows for quick and inexpensive construction of foundation elements.

Micropiles range in diameter from 15cm to 30cm, 20cm diameter being the most widely used. They are installed by the same small drill rigs used for the anchors and bolts, in a variety of applications. They are used as foundation supports, shoring walls, underpinning systems, and for a variety of other applications. Micropiles are a versatile tool in the hand of the designer who can solve many problems difficult to treat by other means. They combine the high bearing capacity with the operational flexibility and speed. In particularly delicate situations, such as underpinning structures, micropiles can be preloaded using a rigorously controlled system, in order to assure minimum settlement.

Barettes are rectangular (strip) piles excavated with a mechanical or hydraulic grab. Excavation is carried-out under bentonite slurry, with a reinforced concrete guide wall at the top.Tools and procedure are essentially the same as those used to construct diaphragm walls, the latter consisting practically of adjoining strip piles with joints in-between.