Jet Grouting is a unique and highly innovative drilling and grouting technique used to create in situ, large diameter soil/cement columns using small diameter drill tooling.

Common Uses

  • Support foundations and excavations
  • Secure base of planned excavations

Technical Details

The process of jet grouting uses high velocity fluid jets to create cemented soil in the ground. The three principal jet grouting methods are named by the number of fluids used: single fluid (cement grout), double fluid (cement grout and air) and triple fluid (cement grout, air, and water).

Soil/cement columns are created during drill rod withdrawal. Specialized drill rods, manufactured to carry the jet grouting fluids independent of one another to the tip of the drill string, are inserted into the ground using conventional rotary drilling methods. Upon reaching the maximum treatment depth, the drill stem is rotated and withdrawn with the jet grout fluid(s) being injected under very high pressures and flow rates. The high energy jetting action constructs large diameter soil/cement columns through erosion, displacement, and mixing of the injected grout with the in situ soils.

Column size is dependent on soil type, soil density, injection pressures, flow rates of the fluids employed, rotation speed, lift rate, and type of system used. Due to the number of parameters that contribute to column size, it is standard practice to install and subsequently sample or dig up several test columns to calibrate and adjust the jet grouting parameters and design.  All of the parameters are monitored in real time so the test column results can be repeated during production.

Typically, jet grouted columns are constructed in an array or sequence to provide an improved soil mass. Keller has completed many jet grouting projects using the double fluid system (cement grout jacketed in air). These projects involved the consolidation and strengthening of water-bearing, cohesionless native soils ahead of excavation by tunnel boring machine, as well as in situ construction of deep hydraulic barrier walls.