Rapid Impact Compaction densifies shallow, granular soils, using a hydraulic hammer, which repeatedly strikes an impact plate on the ground surface.

Rapid impact compaction

Common uses

Increase bearing capacity
Decreases settlement


Energy is transferred to the underlying loose granular soils rearranging the particles into a denser formation. The locations of impact are typically located on a grid pattern, with spacing determined by the subsurface conditions and foundation loading and geometry.


Treated granular soils and fills have increased density, friction angle, and stiffness
Low cost treatment to soils 3-4m in depth
Smaller equipment with faster mobilisation
Enables shallow foundations to be used opposed to deeper more expensive foundation solutions

Quality assurance

The energy and deflection of the soil is monitored and recorded at each location, which allows the geotechnical engineer to determine when effective treatment is complete. It also enables the engineer to identify weak zones (red dots) or debris zones throughout the treatment area so that any remedial actions that may be required can be minimised resulting in cost savings.