Jet Grouting Systems
Often used in ground stabilization projects, typical processes where this system is applied include ground consolidation and vertical shoring or lining. In jet grouting systems, a cement suspension is injected via a jet nozzle in to the surrounding soil wall-structure of the borehole, thereby eroding and mixing with the soil structure. This results in the formation of a subterranean grout column. Grout injection pressures fall in the range of 100 to 600 bar.
The drilling tools are specially developed to withstand the extreme pressures required. Having reached the final depth, the rods are slowly retracted at low rotational speeds, allowing the cement suspension or water to erode the surrounding bore-hole wall. By adding air to the process, the effective range of the jet stream can be increased considerably. The drilling process is normally carried out with a rotary head, but for simplex jet grouting systems, a hydraulic drifter variant is available.
In the borehole, part of the soil is eroded and then the flushing medium and cuttings is mixed with the cement slurry to form soilcrete.
Below please see the different jet grouting systems in detail.