Resonant compaction

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.

Construction chart

Construction sequence

• 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

Fields of application

• 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.

Environmental impact

• Vibrations

• No removal of soil

• Limited noise pollution

• Compaction of the surface layer

• Raising of the surface level (elevation).

Technical specifications

• 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).

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