Dynamic compaction is one of the ground improving methods which arises high level of energy on the surface of the earth. This energy is applied by frequent raising and dropping of a weight with 5 to 27 tons and 9 to 30 meters high.
Weight with the help of a normal crane and with using a single cable and a lifting wheel with free pulley which allows the cable to be opened, lifted and released with the least amount of friction. By applying energy in soil surface, holes are created which are filled and compacted with fine-grained materials. Improvement depth usually changes from 3 to 11 meters which are respectively depth corresponding to the heavy and light energy. By applying high level of energy, surface soil deposits depth stays on an equal depth of the pit and put it in weak condition. This surface layer sometimes in a grid with points close together and by applying a low surface energy under the title of ironing is dense. In dynamic compaction method, there is a restriction of depth improvement. The heaviest weight which can be lifted by common equipment is about 6 tons with the fall height of 23_27.4 meters which contributes to a maximum depth of improvement about 11 meters. If the improvement is desired further depth, contain equipment can be applied to raise 27 tons weight from 30 meters height to reach a depth of 14 meters. If deeper compaction is required, the combination of dynamic compaction must be considered with other improving methods such as injection and stone columns. Major application of dynamic compaction including two items: (1) compaction of weak deposits, (2) the collapse of large holes.