Vibroflotation technology or vibro compaction method is used to compact loose granular soils to increase bearing capacity; to reduce settlement; and to reduce the potential of liquefaction.
Vibro Compaction (VC) can improve non-cohesive soils by rearranging the grain distribution pattern through the application of cyclic vibrations to compact the soil. The main equipment used for the vibro compaction is a heavy plunge vibrator called vibroflot, which is cylindrical in shape with a diameter ranging from 30 to 50 cm and capable of generating lateral vibrations with an amplitude ranging from 5 to 48 mm. Often, the bottom part of the vibroflot is equipped with jets where water or air is pumped in order to enhance the soil compaction. The vibroflot with a leading pipe penetrates the ground under its own weight with simultaneous action of vibration. The compaction occurs as the vibroflot is surged up and down. The compacted column has a diameter ranging from 1.5 to 3.5 m depending on the grid of compaction points and the type of soil.
Vibro Compaction is best suited for non-cohesive soils such as loose sands, gravels and sandy gravels. Soils containing over 10% of silt and clay fraction are not suitable for this method.
Vibro Compaction can be used for the foundation of various facilities such as parking lots, airport runways, roads and structures on areas reclaimed from the sea. It is well suited for the foundation of facilities with uniformly distributed pressure onto the subsoil. It significantly reduces the settlement and leads to the unification of the foundation conditions (i.e., minimise the differential settlement).