In granular soil:

  • Grouting with tubes-à-manchette (TaM) with annulus grout

Work sequence:

  • Drilling with temporary casing (optional)

  • Placement of annulus grout

  • Installation of TaM

  • Casing extraction (eventual)

  • Additional annulus grouting

  • Grouting of each manchette with double packer

In sound rock:

Upstage grouting: Procedure of drilling a hole to full (required) depth in one operation and grouting from the bottom of the hole towards the surface in successive stages, by setting a single packer at predetermined depths.

In weathered and unstable rock

Downstage grouting: Procedure of drilling a hole to a limited depth, setting a single packer and grouting the hole, per- mitting the grout injected around the hole to set sufficiently to prevent it from entering into the hole when the hole is cleaned.

  • Re-drilling through the hardened grout

  • Drilling the hole to the next deeper stage

  • Setting the packer at the bottom of the previously grouted stage or as directed by the Engineer and grouting of the new stage



Grouting for piling and diaphragm walls: Backfilling of cavities and large voids, either by gravity or by low pressure grouting by means of sleeve pipe.


Consolidation grouting underneath dikes and dam foun- dations: Injection of the first ground layer underneath the foundation that might be impaired by excavation and blasting.


Tightening and seepage mitigation

Grouting underneath dam and dike foundations: Granular soil

  • Pore permeation grouting with tubes-à-manchette (TaM)

  • Filling of soil pores in order to reduce the permeability and

  • to provide a seepage barrier underneath the (coffer-) dam foundation


Curtain grouting underneath dam and dike foundations: Rock

  • Fissure grouting

  • Grouting of fissures and cracks of the rock to provide a seepage barrier underneath the dam foundation

Ground Improvement

Compaction grouting: Compaction grouting is a way to consolidate foundation soil by injecting low mobility grout. This process is used to prevent settlements or to stabilize structures which have settled. Holes are installed by either drilling or a drive string, attached with a sacrificial point. Low mobility grout or mortar is injected in upwards stages with a low volume, using high pressure pumps. The injection rod is withdrawn at a controlled rate to give the grout a globular shape. The grout is injected until a predetermined pressure is reached or the ground begins to heave upward.