Grouting involves the injection of a pumpable product (slurry), which will subsequently stiffen, into the soil or into man-made material (masonry), in order to consolidate the soil or structure or make it impermeable, through filling all the voids it contains.

The slurry can fill the voids in the ground, the cracks within rock, solution cavities (it is then referred to as fissure and permeation grouting) and/or displace the surrounding soils through a bottom-up process or by fracturing (compaction grouting or solid injection – see the section on the subject – and strain injection). Grouting with soil displacement may be used to prevent potential damage to the structure brought about by excavations (galleries and tunnels, major urban excavations, etc.) and this is called compensation grouting (see the relevant section).

Quality control during grouting is a key success factor for successful completion of the process. Soletanche Bachy has its own in-house control system, called SPICE (and GROUT I.T. in the USA), the development of which started in the 1980s. The system drives the vast amount of data required for each grouting operation, at every level of production: the setting-up stage (borehole geometry and the calculations of the volumes of grout needed) the acquisition and injection settings, controlling the grouting plant (monitoring the pumps, acquiring flowrate and injection-pressure data), and tracking quality and production.


The software package developed by Soletanche Bachy comprises a suite of interactive programmes:

  • CASTAUR groups together all the exploration data and establishes the location of grout holes.
  • SPICE is installed in the grouting plant and controls all grouting operations, including the electro-hydraulic grouting pumps.
  • SPHINX organises all the grouting data and presents them in a graphic format.

The advanced features of this package make it enormously helpful in the grouting process:

  • Safety, data collection and subsequent control of operations in the field are extremely precise and rigorous.
  • Quality: powerful synthesis and analytical tools produce fast, automatic reports and diagrams ;
  • Performance: higher productivity, along with efficient control that fits in with the increasingly high turnaround rate.