3. JET GROUTING

Jet-grouting is performed through different techniques, mainly through injections of  fluids varying from 1 up to 3. It is applied to loose soils, cohesive formation and decomposed rocks.
The diameters of the resulting beams vary  according to the numbers of the fluids used: from 40 to 80 cm. diameter  if the intervention is carried out with cement only (one fluid);  150-200 cm. diameter for those combining air –water-cement (2 or 3 fluids).
In case of injection pressure up to 600 bars, the resistance of the beams treated  varies between 2-4 Mpa for thin soils and between 10-20 Mpa for well-mixed sand-gravel soils.
Jet grouting is usually carried out through close settled beams actually treating a larger area of the soil.
Consequently, the beams are used as transfer vectors of vertical loads or of variable sloping stress as well as horizontal , just like for the ring-shaped crown of tangled wells or subsoil cavities  wrapped well or for holes in the subsoil.
Finally, jet-grouting is also adopted as waterproof or consolidation system, very often both functions combined.