Sealing slabs with soft gel injection grouting
Economical and environmentally sound
Sealing slabs are used to seal the surface of construction pit bases against groundwater rising from below. Stump-Franki Spezialtiefbau produces very economical, safe soft gel injection slabs with an excellent carbon footprint as an alternative to the jet grouting method. Stump-Franki has obtained three general type certifications from the DiBt for its soft gels:
- Stump organic soft gel
- Stump silicate gel SIG-60
- Stump Silitight 69
The injection boreholes for inserting the injection pipes are drilled by means of flush drilling or pile driving across the entire floor of the construction pit, and are at a fixed distance from each other. The soft gel is injected into the pore spaces of the subsoil in the injection horizon through the injection lances/valves installed in the boreholes. The soft gel is injected in the same way as the conventional penetration injection: pump pressures or pump rates are set so that the stable injection mixture can penetrate into the pore spaces of the soil and thus reduce its permeability.
Underpinnings / pore injection with sleeve pipes
If the soil conditions are suitable, pore injection can be used to form structurally effective underpinning bodies in addition to waterproofing bodies. Our experts have extensive experience and expertise in performing this demanding injection work.
Subsoil sealing / fissure injection
Secure seals in any environment
The choice of binder and rheological properties depends on the size of the fissures. As a rule, when working in stable rock, the injection borehole is first drilled to its final depth and then grouted section by section. The length of the grouting sections is selected according to the distances between the fissures.
Rock injection grouting is often used to seal the subsoil under a dam. We have a broad range of technical capabilities, which allows us to adapt our equipment systems to enable us to drill long holes with directional accuracy, even in confined spaces.
Elevation injection grouting
Controlled elevation for high safety
Tunnel construction projects or changes in the groundwater level can cause structural subsidence. The resulting misalignments can be corrected with elevation injections. Our extensive measurement systems allow us to guarantee a high level of safety during execution.
Preservation of historic buildings
In addition to subsoil injections, this technique is also used to rehabilitate old buildings. Combining specialist foundation engineering and the preservation of foundations and masonry in listed buildings is one of our core competencies.
Secured for the long term
Cavity backfilling involves drilling into selected cavities and backfilling them with a suitable injection agent. This method is especially widespread in regions with abandoned mines.
Using modern processing and conveying technology, we are able to permanently secure large cavities by selectively filling them with defined materials.
Displacement and compaction
Displacement injections, also known as compaction grouting, are carried out in the same way as lance injections. Mortars and thick slurries are used as grout. Injecting the grout displaces the surrounding soil and compacts it. The injection volume can be flexibly adjusted depending on the soil layer. This allows for the compaction of individual layers as well as the creation of continuous columns that act as load-bearing elements.