Vibro Compaction or Vibro Densification as it is sometimes called, is a process for the compaction of deep, loose non-cohesive soil layers, which is used to improve the bearing capacity and settlement characteristics of the soil.
What it is:
Loose soil or uncompacted fill is compacted at depth by penetration of a vibrating probe combined with a large input of water to cause localized soil liquefaction. This settles grains in a denser matrix and increases overall compaction of soil mass.
How it works:
A crane inserts a vibrating probe into the existing soil, injecting air and or water. The probe is then raised and lowered by tiers from its base to the working platform level, to form a column of dense sand.
Why it’s used:
Applicable in clean granular soil, this process reduces the risk of liquefaction and densifies soil down to depths exceeding 30 m. The technique can also increase bearing capacity and reduce settling.
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).