Dynamic Replacement (DR) is the variation of Dynamic Compaction, and consists in delivering impact energy to the ground by means of dropping a large mass from a significant height.
Why is it used?
Dynamic Replacement is a cost effective method of ground improvement for settlement control in shallow soft clays and embankment stability.
How does it work?
Large inclusions are introduced into soft soils to relatively shallow depths (5-7 metres), in order to modify the global modulus of the soil and render it suitable for purpose. The lateral spread the columns, during installation inhibits the achievement of greater depths.
In contrast to Dynamic Compaction (DC), Dynamic Replacement is applied in soft, saturated cohesive soils, soft organic, impermeable soils. The effect of the impacts from the falling mass – that generate the benefits of DC- are not realized in these ground types; instead the imprint created by repeated drops of the falling mass is progressively backfilled with granular material and driven into the ground to form a column of relatively high modulus, permeable material.