The dynamic compaction technique is used to densify the ground to great depths thanks to the creation of very high energy waves. The technique was invented and developped by Mr. Louis MENARD and MENARD .
It requires the use of pounders weighing 15 to 40 tons released in free fall from a height of 10 to 40 meters. The arrangement of the impact points and the other parameters of the treatment (energies, phasing, rest periods) depend on the characteristics of the soil to be treated and on the results of the trial zone.
This ground treatment process is used for the foundations of buildings, or to stabilise large areas of embankment work or loose soil.

Saint-Etienne Industrial and Business Park

The site is an old mining discovery zone filled in over around sixty meters deep.
A total surface of six hectares are foreseen as building area. The settlements monitored over a six month period thanks to 21 measuring points ranged from 5 to 43 cm.
The ground improvement solution chosen was deep dynamic compaction with an energy of 700 t.m, combined with standard 300 t.m compaction
The soil characteristics of the worst zone were as follows up to 12 meters deep :
0.37 MPa < Pl-Po < 0.86 MPa
3.0 MPa < Ep < 8.8 MPa