Our ground stabilisation techniques are based around a method of driving injection lances into soils in order to intersect the waterborne sands and gravels that constitute mobile ground.
Project specific resins are then injected through the injection lances in a continual, systematic, injection and retraction technique. On contact with water, the resin reacts to change from a low viscosity liquid, into a three dimensional, closed cell foam, that effectively fills the pores within the soils and closes off leak paths.
By careful injection under low pressure, the resin flows into the pores of the ground, reacts with moisture, and then expands to further permeate the soils. Whilst this reaction is taking place, the resin does not have any significant structural substance and will not move the ground, making it ideal for use in sensitive environments.
Once the resin has reached it's maximum expansion, the resin will continue to cure, eventually forming a mass of stabilised ground. This mass arrests the movement of water and fines within the soils, allowing for the excavation of underpins and foundations.
View of excavated sands and gravels previously injected with 3kg of Stabila P40 Resin (a forerunner to P200 Soil)
View of an excavated mass of gravels previously stabilised using our resin permeation techniques
Advantages of resin injection in ground stabilisation
- Ground that requires stabilisation does not need to be dewatered in advance or during the injection works.
- The kit is small and highly mobile, allowing access in very tight locations; through doorways etc.
- The resin is injected in low viscosity liquid form, allowing it to penetrate into pores inaccessible to conventional cementitious grouts.
- The cured resin is hydrophobic and does not change its properties once cured.
- The resin reacts quickly and can be adjusted with the use of accelerators. Typically, the resin reacts within a few minutes and is fully cured, allowing for excavation the following day.
- Low pressure injection prevents the possibility of hydro-fracture of soils and damage to adjoining structures. Pump pressure is always set to zero and gradually increased just enough to move the resin through the soils. There is no need to increase pressure beyond this point.
- The foaming action of the resin significantly reduces the volume and weight of injected product. A foaming factor of 4 times the injected volume is used in calculations. In 40% voided soils, this equates to 100litres of resin injected per m3. The equivilant in cementitious grout would be 400litres.
- The environmental impact of the resin is minimal. Once cured, the resin becomes inert and can be easily excavated for further developments.
- Minimal impact on groundwater. the resin displaces it locally rather than drawing it out of the ground.
Injection lances can usually be driven in by hand tools up to a depth of two to three metres. Beyond this, a drilling rig is generally required. It is therefore advantageous in areas to be treated, to locally reduce the ground level to water table level.
Please take a look at our ground stabilisation case studies for more information on how we have used our resin techniques on live projects and how they can help you. Or to speak to us, please call us on +44 (0)1869 346001 or email us at firstname.lastname@example.org
An excavated H2OX grout ball