Dynamic Compaction is the introduction of multiple passes of high energy impacts at ground level by repeatedly dropping steel tampers of 6 to 30 tons from drop heights of 30 to 100 feet. This high level impact creates a shock wave that increases and improves the density of the soil and reduces the void ratio, exposing loose zones and soft spots throughout the process. In doing so, the need for off-site removal of the existing soils for replacement with compacted granular fill or implementation of more costly ground improvement or deep foundation options can be reduced or eliminated.
The degree of soil improvement depends on the total amount of energy applied to the soil; the more energy imparted to the soil, the greater the level of improvement. The depth of improvement is correlated to three things: the amount of weight being dropped, the height from which it is dropped, and the nature of the soil being improved.