The INSER® pile or screw-in moulded pile is moulded into the ground, inserted using a delivery tool, without soil extraction. It is inserted (without vibration) using a specific auger that penetrates into the ground by a lateral displacement effect of the ground. Unlike the traditional auger pile, the soil is not extracted from the ground but is pushed and compressed laterally, thus improving the load-bearing capacity of the INSER® pile. 

Keller rig installing displacement CFA piles

Common uses

Piles crossing loose ground layers
Piles anchored in sandy or sandy-gravelly soils
Small to medium diameter piles

Process

The INSER® type moulded screw pile is made using a discharge auger mounted on a heavy carrier. 

Drilling is carried out to the final depth to be reached. Once the depth is obtained, a concrete (minimum C25/30) is pumped by the central core of the tool. The concrete occupies the footprint left by the tool as it rises. The INSER® pile can be equipped with a reinforcement cage sized to absorb horizontal forces and moments applied at the pile head. 

During the entire duration of the construction of a pile, the drilling and concreting parameters are recorded and returned in computerised form. 

Advantages

Increased load-bearing capacity compared to a hollow auger pile of the same diameter
Limited over-consumption in loose ground
Limited amount of excavated material, a positive feature in polluted areas