Reinforcement of soil layers with insufficient bearing capacity (clay and peat layers)
URETEK HYBRIDINJECTION®
URETEK is recognised worldwide as a specialist in high-quality technical solutions for the repair of subsided concrete floors and foundations.
Unstable or subsided foundations of residential houses and buildings are one of the factors responsible for damage to façades and the stability of structures. In soil layers with insufficient bearing capacity and very low conical strength, such as clay and peat, soil compaction techniques using expansion resins do not yield satisfactory results, as the stress achieved in these soils is insufficient. URETEK has also developed a specialised, non-disruptive method for these soil layers to stabilise subsided concrete structures and foundations.
With the patented URETEK Hybrid Injection® method, geotextile elements are installed directly beneath the subsided foundations, down to the soil layer with sufficient bearing capacity. This element consists of an injection lance wrapped in a geotextile tape. URETEK’s two-component expansion resin is then injected into the element. The expansion resin expands inside the element, causing its volume to increase (up to 30 times its original volume). The element then expands by between 40 mm and 360 mm. This creates an extremely stable element that supports the structure on the stable soil layer with sufficient bearing capacity. The foundation is thus stabilised.
The injection process is carefully monitored using a high-precision laser measuring device.
Technical data:
- Injection depth (current) of up to 8 metres below ground level
- Diameter of the expanded element: 360 mm
- Load-bearing capacity of up to 15 tonnes (150 kN) per element
- The expansion resin contains no CFCs, formaldehyde or radon
- Average installation capacity of 6 elements per working day
Grouting
At intervals of 1.75 to 2.00 metres along the façade, outside the residential building, injection holes with a diameter of 80 mm are drilled into the foundation. A metal casing is inserted into these boreholes until it reaches a layer with sufficient bearing capacity. The Hybrid Injection® element is inserted into this metal casing. The casing is then removed, leaving the element in place. A specially developed injection gun is connected to the lance of the inserted element.
Expansion
A high-performance, expansive two-component expansion resin is injected into the element at low pressure through this injection lance. The two components react immediately after injection, causing rapid and significant expansion inside the element, thereby increasing its original volume by up to 30 times. This expansion resin allows the element to expand by between 40 mm and 360 mm. During the injection process, the injection lance is removed from the element, which is then filled evenly to just below the foundation. This process is carefully controlled by a computer to precisely monitor the formation of the element in the subsoil.
Stabilisation
Once the Hybrid Injection® element has been filled to just below the foundation, there is a minimal upward movement of the foundation. This means that the foundation is stabilised. The injection process is monitored using a high-precision laser measuring device. Each element can bear loads of up to 15 tonnes (150 kN) and transfers the forces from the foundation to the stable soil layer with sufficient bearing capacity in the subsoil. This method is also suitable for the preventative treatment of foundations.
Benefits of URETEK HYBRIDINJECTION®
- Minimal disruption
- No pile driving
- The repair is completed in just a few days
- Quick and cost-effective
- No extensive work required to realign the foundations
- Can also be applied from the inside
- Environmentally friendly, so it can be used anywhere