SOIL STABILISATION

Soil stabilisation during underground construction is an alternative for, amongst others: underpinning work, Berlin-wall and sheet piling. Soil injection can be used to pass on the loads of existing structures to a lower level and/or to retain soil.

Soil stabilisation using soil injection is mainly applied during underground construction adjacent to existing buildings. It is mostly used when it concerns buildings with steel foundations. Injecting the sand under the adjacent property means excavation can take place without the need for a soil retaining wall or underpinning of the foundation. Soil injection is carried out vibration-free, which eliminates another construction risk. As soil injection is carried out using the permeation grouting technique (the controlled saturation of the void in sand layers with injection fluid), the sand that has to be injected must be permeable. Soil injection with water-glass and hardener can only be carried out in sand. A quick test can be carried out in the first instance by inspecting the adhesive jacket cone probe. If the friction ratio is < 1.2%, then soil injection can be considered as an option.

The following are just some of the benefits of using soil injection for soil stabilisation:

• Vibration-free method;
• Optimum use of space because excavation can be carried out directly next to the foundation;
• Settlement-free due to lack of vibration or excavation work
  under Berlin-wall;
• Location of equipment can be up to 50 metres from the worksite,
  which in turn frees up space where the foundation has to be underpinned.

Workingmethod for soil stabilisation using soil injection

A dimensional calculation of the injection body is made by the structural engineer on the basis of the desired excavation depth and pressure that has to be absorbed. This desired cross-section of the injection body is used when compiling the engineering drawing. The engineering drawing includes the foundation that has to be retained, the desired injection bodies, the individual injection points including depths and angles, as well as a top view of the work. The drawing is consulted during the execution to insert the injection tubes following our patented system under the foundation.

B&P Bodeminjectie B.V. has successfully applied soil stabilisation for the construction of:

• Multi-storey car parks;
• Basements;
• Soil retaining walls/embankments;
• Sewage routes.

It is definitely worthwhile exploring other solutions instead of just the conventional ones when starting any underground construction project. Please don’t hesitate contacting us and let us map out the options available to you for your project.