Pressure Grouting

Grouting covers a wide ranges of services in geotechnical construction.  Generally grouting is the process of injecting a fluid into a rock or soil mass and the grout hardens in place to fill voids, improve the strength or to reduce water flow.  Grouting has many applications each with its own technology.

This construction technique has evolved into very specialized work.  Our staff are pioneers and were the first to utilize the Grout Tracker GIS based technology to organize the data for decision making and to produce reports.  Our staff was also the first to develop and successfully utilize instruments to measure the grout pressure at the point of injection utilizing down hole pressure transducers.

Grouting services performed by TerraFirm include:

  • Foundation Grouting is frequently associated with Dam Foundations and it is also used to consolidate soils. The process involves drilling holes into the foundation and injecting a grout under low to moderate pressures to force the fluid into voids where it hardens consolidating the material.
  • Compaction Grouting is the process of drilling or driving pipes into soil and injecting with “Low Mobility Grout.” The intent of the stiff grout is to create a bulb that expands “compacting” the adjacent soils.  The process is used to increase the density of soil or to relevel structures.  Compaction grouting is also used to treat soils and rock susceptible to sinkholes from karstic features.
  • Permeation Grouting is the process of injecting a very fluid grout into voids, usually in alluvial soils, rock or some silts. The grout can be Portland cement based, microfine cement or a chemical depending on the void size to be permeated.  Commonly this type of grouting is performed with sleeve pipes or “tube a manchettes” to allow very controlled placement.
  • Jet Grouting is the process of consolidating material in place by using a combination of air, high pressure water and/or high pressure grout to erode the soil and mix with grout to form columns. The column diameter created varies with the pressure used and the material being jetted.  Ten feet (3 meter) diameter is considered a large column.
  • Mine Grouting is the process of filling abandon mines to allow surface development. This typically requires construction of containment barriers.
  • Compensation Grouting is utilized as a proactive treatment when ground subsidence is likely such as tunneling under structures. Pressure grouting is performed in advance and during the tunneling to compensate for any ground loss to minimize impact at the surface.

Difficult Access Work

We specialize in difficult access projects.  In situations where access is difficult or equipment is not readily accessible, we have the expertise to design and build equipment to perform the required construction.