MiniJET technology - a new type of micropiles

The technology consists in the construction of jet grouting columns using hollow rods of highly resistant steel.  When implementing them, they function as a complete group rods allowing high pressure injection of cement grout (up to 400 bar). After the drilling the hollow rods remain as a reinforcement inside the column “MiniJET” (Fig.1).

Fig. 1 Scheme of the drill-injection system “MiniJET“

 

The MiniJET columns can be implemented with diameters between 300 mm and 600 mm depending on technical needs and on geological conditions. Instead of the usual jetting group it is provided the usage of a system for drilling/injection, which remains inside and consists of drilling bit with 3 nozzles. The nozzles are mounted directly on the drill bit, which remains inside.

Fig.2 Drilling bit with jet-nozzles	Fig.3 Completed jet grouting body

 

Fields of applications of the technology "MiniJET”

The system is particularly suitable for reinforcement of foundations with tension loads, foundation micropiles, construction elements like anchors and soil nails, for consolidation during the construction and stabilization of the soils.

In the following figures are presented different fields of application of the technology “MiniJET” in the geotechnical engineering. 

Fig.4 Soil nails and anchors for slope reinforcement	Fig.5 Anchors of foundation slabs in water saturated soils
Fig.6 Miropiles for strengthening of existing foundations	Fig.7 Schematically mounted permanent anchor with polyethylene protection
Fig.8 and Fig.9 Soil nails for stabilization of landslides and slopes