Stabilising soil injections

Application

Depending on the applications and the required quality, various stabilising soil injections can be used:

• Soil consolidation by means of hard gel injection with water glass and hardener;
• Soil consolidation by means of injection of ultrafine ground cement;
• Soil consolidation with BioGrout by injecting specific natural bacteria and additives;
• BioSealing leaks by injecting specific nutrients and minerals;
• Restoring packing density or subsidence by means of compensation grouting.

The required use, local soil condition and working conditions will determine the choice. Our recommendation will include a comparison with alternative techniques such as jet grouting, ground freezing, mechanical compaction and soil nailing.

Stabilising soil injection is used in permeable soil, such as sand.

A final design will be made once soil analysis has shown that the soil is suitable for injection.

The substance to be injected, grid, injection speed and injection order all determine the result.

The injection lances are vibrated or drilled into the soil. The injection fluidis mixed in the right dosage and then pumped into the soil under constant monitoring through the fittings of the injection lances. Simultaneous injection through multiple lances is possible.

By injecting overlapping columns, walls can be formed with constructive and water-retaining properties.

By calculating a retaining wall structure (anchored, strutted or otherwise), these injections can provide solutions such as:

• Soil- and water-retaining screens for building pit excavations immediately next to adjacent structures or in and underneath existing foundations;
• Slope stabilisation underneath existing abutments of viaducts and bridges for road or railway widening;
• Lift shafts in existing (monumental) buildings;
• Connections between walls or sheet piles or repair of opened sheet piling locks for excavations.

Other applications include:

• Repair of foundations and upholding of existing buildings.
• Soil stabilisations for conduits.
• Sealing combi walls, sheet pile or diaphragm or slurry wall leaks.

Pros and Cons

• The technique is vibration-free and low-noise.
• The irregular shapes of the injection masses must be taken into account.
• Limited footprint and can be used in confined spaces.
• Can be used underneath existing foundations or adjacent structures.
• Drill holes and injection lances can be made at an inclination.
• Injection is only possible in sand and gravel layers.
• Drilling mud at working level during fitting of the lances.

Applicated