HOW HEIC WORKS TO PROVIDE EFFICIENT, EFFECTIVE COMPACTION
High Energy Impact Compaction (HEIC) involves the transfer of compaction energy into the soil by means of the lifting and falling motion of non-circular rotating masses. The rotation of such masses to their highest point results in an effective potential energy build up and further rotation of these masses results in the conversion of this potential energy into a falling kinetic energy. The amount of energy transferred is closely related to the amount of potential energy generated in the lifting process. Impact compaction is thus a process of transferring impact loads similar to these found in dynamic compaction, on a continuous basis.
DEPTH OF INFLUENCE (DOI)
Higher surface contact pressure coupled to a relatively large contact area leads to a vastly increased depth of influence. Boussinesq clearly shows that for a point load on the surface, the stress distribution in depth is greater as the contact area increases.
Ground improvement is typically measured to effective depths of 1.5 – 3.0m
Compaction Methods Compared
SOIL COMPRESSIBILITY & COMPACTOR APPLICATION ZONE
The energy is transferred in the form of a “rolling impact” resulting in a relatively longer load duration, leading to a softer soil response to the load and hence an enhanced soil compressibility is achieved.
MATERIAL MOISTURE
Ability to compact over a wider range of moisture contents, particularly dry of OMC.
COMPACTION CAPABILITY
Ability to compact the material to a higher maximum dry density
COMPACTION LOADS
The contact stresses measured during impact measure between 300-1200kPa, dependent on material and soil conditions, equating to typical compaction loads of between 120-250 ton
COMPACTION PRODUCTIVITY
Higher operating speeds of 10 – 13 kph, and increased depth of influence result in increased productivity – up to 10 times greater volume than conventional methods.
HEIC Key Points
- Dynamic loads on a continuous basis
- Thick lift compaction
- 100% Coverage, no “bridging effect”
- Large contact area
- Increased energy and contact stresses
- Many applications
- Enhanced compressibility
- Increased depth of influence
- Continuous strength balance profile
- Higher productivity – 7,000 to 10,000m3 / shift / machine