Depending on the impact system, dynamic compaction can be divided into two techniques:
- Traditional dynamic compaction.
- Rapid-impact dynamic compaction.
In the classic dynamic compaction technique, a steel weight is hung from a crane. It is raised to a certain height, and then dropped onto the ground. The weights weigh between 10 and 20 tons, and the height from which it is dropped varies depending on the energy to be transferred to the ground surface, but usually ranges from 15 to 30 metres.
Rapid-impact dynamic compaction uses a weight of around 7 tons, or sometimes more, raised by hydraulics to a height of around 1.2 m and then dropped onto a specially designed steel base plate 1.5 m in diameter, at a frequency of around 50 beats per minute. Normally, at each stage around 40 to 60 beats are applied at each compaction point, and are distributed on a triangular or square grid, measuring 1.5 to 2 m on each side.
GEOCISA has extensive experience in this technique, in terms of both design and construction.