Dynamic Replacement



If the ground cannot be dynamically compacted directly due to high fines content within the soil, a fill material must be added. The incorporation ratio is generally between 10 and 15%, and is higher than that of stone columns.



The technique can be carried out with or without pre-excavation. Pounding and filling of the reinforcement pilars alternates accordingly during execution. The material incorporated is either placed over the whole treatment surface prior to pounding and pushed into the pilars during the project, or stored at a regular intervals around the worksite and directly incorporated in the pilars.



The technique is particularly well suited to areas under high load (high backfill, storage tanks, etc.) and also allows for rapid drainage of the ground.


Can I use dynamic replacement in organic soils?
The large diameters (2 to 2.5 metres) and low slenderness ratio of dynamic replacement pilars make them suitable for treating very loose, waterlogged and highly organic soils. If need be, preloading can be carried out to reduce residual settlement.

Is it necessary to pre-excavate pilars to carry out dynamic replacement?
No, because the initial pounding of the platform is generally sufficient to form the crater that initiates the dynamic replacement pilars. After filling this crater, pounding drives the “compacted plug” into the soil, which then serves as the basis for the formation of the rest of the pilar.

King Abdullah University Science Technology