Jet grouting


Jet grouting, a ground improvement technique

One or several jets of fluid with high kinetic energy are used to break apart and mix the ground with a liquid cement slurry so as to form a column of “soil concrete”.



Jet grouting is used as a “targeted” and selective treatment for certain soil layers and can therefore, for example, “fill” karst anomalies or provide deep treatment of soft layers of soil lying under thick, compact strata. In some special cases, it is also used to mitigate liquefaction risk within a soil. Finally, the drilling machines used are small enough to work within buildings, to underpin existing structures and to operate in areas that are difficult to access.


When should this technique not be used?
Jet grouting is poorly suited, as a rule, to soils with blocks and rough gravel, to organic materials and to soils through which large volumes of water flow.

What column diameters can be obtained by Jet-Grouting?
Depending on the equipment used, the energy applied and the type of ground, columns can be implemented with diameters between 0.5 and 3.0 metres. The largest diameters are obtained by simultaneously or sequentially injecting several types of fluid (double jet = slurry + air, triple jet = slurry + air + water).

Some projects' references of...
Jet grouting

Consolidation of the Sydney airport runway, Australia


Reconstruction of Saumur castle’s north rampart, France