Static pressure is the most basic form of compaction. Virtually all objects exert some degree of static pressure compaction. 

2. Manipulation

Manipulation,also sometimes referred to as kneading,acts to compress materials at a greater depth. It does so by reducing the surface area at each particular point of compaction. 

3. Impact

Both static pressure and manipulation harness the power of gravity to accomplish compaction. Impact compaction takes a more proactive approach. 

4. Vibration

Vibration forces are closely related to impact forces. In fact, the two can be easily confused. Where impact compaction involves forces that move straight down, vibration compaction consists of pressure waves that spread out through the ground in all directions. Vibratory compactors induce this type of force through the use of eccentric weights.

Rapid Impact Compaction (RIC) is a ground improvement technique that densifies shallow, loose and, granular soils. Soil treated by this method results in increased density, friction angle, and overall stiffness, which results in increased bearing capacity and decreased settlement of planned structures. Rapid Impact Compaction consists of an excavator-mounted, hydraulic pile-driving hammer repeatedly striking a circular plate that rests on the ground.  Energy is then transferred to the ground safely and efficiently, as the RIC’s foot remains in contact with the ground, which avoids concern over flying debris being ejected. Rapid Impact Compaction densifies loose-fill soils of up to 6 m deep or more. Additional benefits of rapid compaction include: an increase of the bearing capacity of the soils, minimization of settlement, and the creation of uniform support for foundation footing. Rapid Impact Compaction is an innovative solution when compared to the time and cost of over-excavation and re-compaction.

RIC is a high-frequency, controlled energy, soil compaction technique used to densify surface layers of soils (to a depth of 5 to 7 meters in most cases) with minimum impact on the immediate worksite environment. Rapid Impact Compaction is widely used to densify loose granular soils (sand or gravel) as well as loam fill and industrial brownfield sites for surface compaction, foundations and floor slab support, liquefaction mitigation and waste stabilisation.

A compaction plate is placed on the ground to be treated. A hydraulic hammer, generally weighing less than 10 to 15 tonnes, is fitted to an excavator and used to transmit compaction energy to the soil via repeated impact. Without specific site precautions, a safe working distance to sensitive structures can usually be defined on the order of 8 to 10 m, as a distance of 5 to 6 m can usually be adopted for classical structures. At that distance, noise levels are lower than 90 dBA.

It is possible to compact the ground near an adjacent site with rapid impact compaction. Rapid impact compaction suits to ground improvement in small spaces. As an example, we can apply this technique within or next to existing warehouses. In such cases, we monitor very carefully vibrations in adjacent structures during rapid impact compaction.