Jet Grouting uses high velocity fluid jets to construct cemented soil of varying geometries in the ground. Hayward Baker leads the industry in providing jet grouting solutions since initially promoting the technology in the US over 30 years ago.

Common Uses

  • Underpin foundations
  • Provide excavation support
  • Seal the bottom of planned excavations

Technical Details

Jet grouting creates in situ geometries of soilcrete (grouted soil), using a grouting monitor attached to the end of a drill stem. The jet grout monitor is advanced to the maximum treatment depth. Then high velocity jets (cement grout with optional water and air) are initiated from ports in the monitor. The jets erode and mix the in situ soil with grout as the drill stem and monitor are rotated and raised.

Depending on the application and types of soils, one of three variations is used: the single fluid system (slurry grout jet), the double fluid system and the triple fluid system. The jet grouting process constructs soilcrete panels, full columns, or partial columns with designed strength and/or permeability.

Double fluid system

The double fluid system uses a slurry grout jet surrounded by an air jet.

Jet grouting is effective across the widest range of soil types of any grouting system, including silts and most clays. The soilcrete geometry and physical properties are designed based on the in-situ soils. Because it is an erosion-based system, soil erodibility plays a major role in predicting geometry, quality, and production. Cohesionless soils are typically more erodible by jet grouting than cohesive soils.

Triple fluid system

The triple fluid system uses a water jet surrounded by an air jet, with a separate grout port.

Jet grouting’s ability to construct soilcrete in limited spaces and around subsurface obstacles such as utilities, provides  unique design flexibility. In any situation requiring control of groundwater or excavation of unstable soil (water-bearing or otherwise) jet grouting is often a preferred solution.

Usually, jet grouting can be accomplished without disrupting normal facility operations. The development of containerized, highly mobile support equipment has reduced mobilization and demobilization costs and time. Jet grouting can often result in construction schedule savings.