Permeation grouting is a general term for grouting that is carried out to fill pervasive void space inherent to the formation of the material being grouted. Generally, this type of grouting is done within soil, however, also may be applied to consolidated materials, such as poorly cemented sedimentary formations.
The intent of the grouting is to fill void space (primarily intergranular) within the medium being grouted. Grouting may be done either to improve the soil structure or to reduce the hydraulic conductivity of the soil or rock. Grouting to improve soil structure is often done prior to excavations to act as support of excavation, improve stand up time, or reduce settlement. Soil structure may also be improved to increase bearing capacity. Hydraulic conductivity applications may be undertaken any time a reduction in gas or liquid inflow or migration is required. Permeation grouting is generally carried out in defined zones utilizing sleeve ports (also known as tube-a-manchettes) installed into soil or isolated intervals within rock. This method allows the grout to be injected at a specified location.
Permeation grouting is commonly utilized for the following applications:
- Pre-excavation grouting for excavations in soil or poorly cemented sedimentary rock
- To improve excavation conditions at portals, shallow shafts, or along alignments
- Support of Excavation
- Ground Modification
GEC has performed permeation grouting on numerous projects in many varying geologies. Typical projects include pre-excavation grout for water cut-off within shafts and slopes, ground improvement for portals, and water cut-off/support of excavation for coffer structures. GEC has the ability to place numerous grout types as well as build or modify grouting equipment to suit the job conditions.
Permeation grouting programs may be carried out utilizing both cementatious and chemical grouts.