Vibration compaction (vibro-compaction, vibratory compaction or compaction by resonance) is done by the insertion of an optimized steel profile, a so-called vibratory probe. The effect of resonance in the soil layers increases the effect of densification by vibration, inducing a transient state of localized liquefaction of the soil around the probe, allowing for a decrease in soil volume (rearrangement of the soil particles into a denser configuration by decrease in void ratio) and improving the mechanical characteristics of the soil.
• An especially designed profile (vibratory probe) is attached to a powerful vibrator and inserted by vibration into the soil until the desired depth has been reached.
• Modification of the frequency of the vibrator allows the soil to vibrate at resonance resulting in densification (compaction) of the surrounding soil
The field of application of vibro-compaction is related to non-cohesive soils with a well-defined percentage of fines (see the grain size curves on the Mitchell chart)
• Extraction of the vibrating probe at the end of the operation
• Settlement reduction
• Treatment and use of non-cohesive granular soils (sands)
• Soil compaction of large construction areas
• In water-saturated sandy layers the silt and clay fractions should be relatively small according to the empirical Mitchell curves.
• In unsaturated, non-cohesive soils, the distances between the grid points of the design mesh should be smaller than in the saturated soils.
• No removal of soil
• Limited noise pollution
• Compaction of the surface layer
• Raising of the surface level (elevation).
• Deep compaction with a vibratory probe
• High efficiency of the compaction by adjusting the vibration frequencies of the probe to the resonance frequency of the vibrator-soil system (very efficient transfer of vibration energy from the vibrator to the compaction probe and to the surrounding soil).