ABSTRACT
Dropping of a Heavy Weight The repeated dropping of a heavy weight on to the ground surface is one of the simplest of the methods of compacting loose soil.
The method, known as deep dynamic compaction or deep dynamic consolidation may be used to compact cohesionless or cohesive soils. The method uses a crane to lift a concrete or steel block, weighing up to 500 kN and up to heights of 40 to 50 m, from which height it is allowed to fall freely on to the ground surface. The weight leaves a deep pit at the surface. The process is then repeated either at the same location or sequentially over other parts of the area to be compacted. When the required number of repetitions is completed over the entire area, the compaction at depth is completed. The soils near the surface, however, are in a greatly disturbed condition. The top soil may then be levelled and compacted, using normal compactiing equipment. The principal claims of this method are:
1. Depth of recompaction can reach up to 10 to 12 m. 2. All soils can be compacted. 3. The method produces equal settlements more quickly than do static (surcharge type) loads.
