What is the best way to compact soil?

Rapid Impact Compaction (RIC) is an innovative dynamic compaction device mainly used to compact sandy soils, where silt and clay contents are low. RIC closes the gap between the surface compaction methods (e.g. roller compaction) and the deep compaction methods (e.g. deep dynamic compaction) and permitting a middle-deep improvement of the ground. RIC has been used to treat a range of fills of a generally granular nature and some natural sandy and silty soils 

RIC is a process where loose subsurface soils are improved using an excavator-mounted 7.5 ton hydraulic hammer. The hammer is rapidly raised and lowered onto a 1m diameter plate, which densifies the soil, in-place, without the need for undercut and replace. The average compaction point is hit 30-80 per minute.

Use within 30 feet of a Building – Because Rapid Impact Compaction provides a low magnitude of impact loading at a very high frequency, the peak particle velocity remains relatively low (less than 2 inches per sec) at a distance of 30 feet from the source. This is different from Deep Dynamic Compaction which has a low frequency and a high magnitude of loading so vibrations are greater from DDC when compared to RIC.