Should I wet gravel before compacting? - HENGDA RIC

Start adding gravels few inches, wetting it will help, then start to compact the first layer of the gravel. Check the firmness of the first layer, once it is stable enough, start adding more layer of gravels and start compacting.

RIC technique is performed at the surface of a terrain and it comprises of a heavy excavator which is equipped with a specially designed arm onto which the hammer is attached. Within the hammer, a 5 to 10 drop weight is hydraulically lifted till a required height after which the weight is dropped using a hydraulic acceleration. This whole process of lifting and dropping of the weight takes place with a frequency of 40 to 90 times a minute.

During the compaction of a location, the foot remains into contact with the soil. The impact of the hammer on to the foot initiates the compaction process. The movement of the foot into the ground, the heavy weight of the equipment and high energy transfer is also causing densification. The dense compaction grid ensures that a homogeneous compaction is reached throughout the area. This is caused because the impact locations are also affected by the compaction of nearby points which results in improving the overall performance.

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.

This compaction energy brings the soil particles into a more densely packed structure. The compaction energy is transmitted safely and efficiently as the compaction foot remains in contact with the ground. No flying debris occurs during the compaction process. The hammering of the foot by the impact weight is the reason of the sub-soil compaction. Indeed, the huge amount of energy developed upon the hammering process and transmitted to the ground through the foot, pushes the backfilling material into a denser structure.

The compaction process can be optimized using an advanced GPS logging system. Using an advanced data logger located inside the cabin, the operator of the RIC rig can easily adjust the compaction energy in terms of the dropping height and the number of blows. He can also record the cumulative settlement, the settlement per blow and the applied energy.

The rapid impact compactor as a means of quickly repairing damage runways. It works by imparting dynamic energy through a falling 'drop-weight, which is dropped from a controlled height onto a patented foot. 

With heights of 9 to 12 tones applied to the foot , the 'drop-weights' falls from relatively short height of only 1.2 meters at a rate of 40 to 60 times a minute. 

Effective compaction depths vary with the nature of hte soil compacted, but depth of up to 8m have been reached with a 9t rig.

This results in The Rapid Impact Compactor transferring energy to the ground in a significantly more effective manner as the 'foot' stays in contact with the surface, never actually leaving the ground. It is because of this impacting sequence that we can ensure that the transfer of energy into the ground is carried out in the most efficient way possible.