Earthquake - How It Works

Click here for: Rotary Decompaction Article

Why Decompact? Soil compaction is now a major problem for all sports turf facilities throughout the world and can be recognised in many different ways:

• Excess surface moisture and slow drying turf due to deeper compaction preventing the percolation of water through the soil profile.
• Water run off due to surface compaction preventing penetration and absorption, especially on banks and sloping surfaces.
• Poor durability and turf density due to inhibited root development in compacted rootzones.
• Low drought tolerance due to shallow rooting of the turf causing burn off in dry weather.
• Poor air and water movement in the soil causing the under utilisation of nutrients and low capillary action of moisture.

So what’s the solution? EarthQuake Tremor Rotary Decompactors.

A: The EarthQuake Tremor has a high torque rotor with a number of flanges. Each flange has three backward raked (angled) blades. We can simplify this by considering a set of three flanges. Looking from the side,the blades are timed so that blades from flanges 1,2 and 3 will enter the soil before the next blade of flange 1. B: Looking from straight above the flanges and rotor we can see flanges 1,2,and 3 at different stages of entry. This staggered arrangement is key for understanding how EarthQuake Tremor creates decompaction. Diagrams C,D and E further simplify by considering just two flanges.

C: As the first blade of flange 1 reaches maximum depth in the soil there is minimal loosening, because the sideways force of the blade is less than the confiningforces of the rootzone mass. D: As the next blade from flange 2 reaches maximum depth,there is now space to permit the leftward movement of the soil block (X).

E: On the next blade entry the soil moves to the right (Y),pushed by the second blade of flange 1 into the slot made by flange 2. Diagrams C,D and E are for two flanges only, the disruption pattern for more flanges is more complex but the principle remains the same – sideways displacement of the soil by one blade into a slot cut by an adjacent blade. F: This diagram shows a representation of the soil displacement pattern as the EarthQuake Tremor passes. The soil failure pattern is complex and is not a simple wave, but the soil undergoes short and longer wavelength displacement (although this is a function of forward and rotor speed). This can be seen and felt when observing the EarthQuake Tremor in the field. The sideways displacement of the soil results in vibration and fissuring of the soil,which helps loosen without causing significant irregular surface heave.

Summary In replicated experiments, the EarthQuake Tremor has been shown to cause significant soil/rootzone loosening. Whilst loosening of this type will always be as variable as the soil/rootzone, one of the key benefits of EarthQuake Tremor is that it loosens to full blade working depth. This is accomplished by sideways displacement of soil blocks by the blades from one flange into a slot cut by the blade from an adjacent flange, and through associated soil fissuring.

The graph above demonstrates penetration resistance made using a Finlay-Irvine soil cone penetrometer fitted with a square inch base area cone, in tests conducted by Cranfield Centre for Sports Surfaces. Measurements were made in 11 locations per sub-plot replicate, pre and post treatment to determine the loosening effect of the equipment. © Cranfield University Silsoe, 2003