Loose soil or fill can be compacted at depth through insertion of vibrating probes together with a large volume of water to generate localised liquefaction of the soil. This enables the particles to rearrange themselves in a denser formation and thus increases the overall density of the soil.



The use of a vibrating probe makes it possible to reach large depths compared to compaction carried out at the surface (dynamic, rapid impact). Vibrocompaction relies on overburden pressure of soils above the treatment level (included collapse) therefore it is not very effective in the top two metres of soil generally due to a lack of vertical confinement.



This technique is usually employed to stabilise or treat hydraulic fill, for example to prevent liquefaction or limit thrust behind quay walls.


What settlement is to be expected during works?
The initial trial area defines the value precisely, but as a general rule, vibrocompaction of fill placed hydraulically generates settlement amounting to 7 to 10% of the height of the soil treated.