Rapid Impact Compaction (RIC)

Originally developed by the British to repair bomb-damaged runways, RIC densifies loose soils up to 20 feet deep resulting in a verifiable bearing condition.  It uses a 7.5-ton weight that is dropped as much as 60 times per minute to compact soft areas, slabs or underground debris.  For increasing bearing capacity, minimizing settlement and providing uniform support, RIC is a great alternative when compared to the time and cost of over-excavation and re-compaction. 

Increased Bearing Capacity

RIC increases the standard penetration resistance of granular soils up to 20 feet in depth.  There also is less settlement and higher resistance to liquefaction because RIC increases N values the stiffness of the soil.

Quality Assurance

The energy and deflection of the soil is monitored on each blow, which allows the geotechnical engineer to determine when effective treatment is complete. It also enables the engineer to identify weak zones thru automated quality control.

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RIC Process

The compaction sequence is designed to work from the outside in, so that compaction of the lower zone soils occurs first followed by compaction of the upper zone. On-board monitoring tells operator when compaction is sufficient.
 

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RIC Applications

RIC represents our design-build thinking because in cases where it is appropriate, there is no need to incur the cost of over-engineered solutions.  Where situations call for foundation and slab support, liquefaction mitigation or waste stabilization, RIC has a history of success.  Situations where RIC is a solid alternative are when:

• • Over-excavation and replacement is being considered
• • Recompaction-in-place would be deeper than 5 feet
• • Foundation bearing capacity would increase in natural gravels, sands and silts
• • Fill soils 10 to 20 feet deep need to be uniformly densified, or 
• • Surcharging to densify soils within 10 to 20 feet of the ground surface is an option.

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