Vibroflotation is a technique of ground improvement that involves the use of vibration at depth to improve the soil. This technique is mainly applied to granular soils to densify the material and prevent liquefaction in case of earthquake and/or to increase its load bearing capacity.
Vibroflotation is performed by inserting a vibrator vertically into the soil following a regularly spaced grid. The vibrations passing through the soil provide a transient state of liquefaction, allowing a rearrangement of the soil particles into a denser configuration.
Vibroflotation consists of 2 steps that are penetration and compaction respectively. The vibrator firstly penetrates the soil to the desired depth with the assistance of vibration and water or air jetting. Thereafter it is raised in stage to compact the soil layer by layer.
Generally it is performed using a triangular grid layout. The distance between the grid points is depending on the type of soil to be treated and its initial density, the result to be obtained, the type of vibrator and compaction procedure to be used.