Dynamic replacement (DR) is an extension of the dynamic compaction technique. In contrast with dynamic compaction, dynamic replacement is developed to treat soft cohesive soil and even peaty soil.
This technique starts out by producing a crater with light pounding. The craters are then backfilled with granular materials (e.g., aggregate, stone, gravel or rock pieces up to 300 mm size) that will lock together under subsequent heavy pounding. This pounding process is repeated until a noticeable decrease in crater formation occurs. This essentially results in a large diameter granular column being formed. The large diameter granular column, which is usually called as DR column can have diameter of 2.5 to 3.0 m and length of 5 to 7 m.
These columns acting as two functions;
- bearing capacity provider to increase rate of embankment construction,
- large drain path for dissipation of access pore water pressure.