Dynamic compaction is a method that is used to increase the density of the soil when certain subsurface constraints make other methods inappropriate.
It is a method that is used to increase the density of soil deposits. The process involves of dropping a heavy weight repeatedly on the ground at regularly spaced intervals.
The weight and the height determine the amount of compaction that would occur. The weight that is used, depends on the degree of compaction desired and is between 8 tonne to 36 tonne.
The height varies from 1m to 30m. The impact of the free fall creates stress waves that help in the densification of the soil. These stress waves can penetrate up to 10m.
In cohesionless soils, these waves create liquefaction that is followed by the compaction of the soil, and in cohesive soils, they create an increased amount of pore water pressure that is followed by the compaction of the soil.