Dynamic compaction (DC) involves the use of high-energy heavy tamping passes to densify loose coarse-grained soils. The engineering properties of a wide range of soils can be substantially improved using this method. The treatment is achieved by a combination of the weight, drop height, grid pattern, number of passes, position of the ground water table and the underlying soil properties.
With dynamic replacement, the DC method is applied in highly compressible cohesive soils to reinforce the weak layers. The tamping with heavy weights is used to repeatedly drive granular fill material into the underlying compressible soils to form large columns.