Cased CFA - Piling

The latest developments for accuracy and reducing ground settlement risk when CFA Piling.

In some ground conditions where soft or loose material overlies stiff ground at depth, the auger penetration rate slows down and the continuous flight can act like an Archimedes Screw in the soft material above. The soft or loose material gets drawn onto the auger and flighted upwards. This is called entrainment and can result in excess use of concrete and ground settlement.

In these specific ground conditions Cementation Skanska use the latest computer controlled Cased Flight Auger Pile system. This method allows the continuous flight auger to bore within a casing which penetrates with the auger. If hard layers are encountered at depth, no material can be entrained onto the auger because it is inside a protective casing. As the pile is concreted, the casing is withdrawn.

This system has been used very successfully in tight urban sites and in particular to install very accurate Retaining Walls, with no settlement of the ground during pile construction.