The following pictures are from a wind farm where due to the weak conditions of the subsoil a deep foundation with piles has been necessary, using a technique known as continuous flight augering (CFA). As you can see, with the same machine we drilled and pumped the concrete in the hole. A dry hole has been made, without the use of bentonite or others drilling fluids to maintain vertical the walls of the hole: the earth is removed using an . . .