JET GROUTING

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 (slurry grout jet surrounded by an air jet) and the triple fluid system (water jet surrounded by an air jet, with a separate grout port). The jet grouting process constructs soilcrete panels, full columns, or partial columns with designed strength and/or permeability.

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.

Advantages

• Effective across the widest range of soil types of any grouting system, including silts and most clays
• Ability to construct soilcrete in limited spaces and around subsurface obstacles such as utilities, provides unique design flexibility
• Low headroom equipment enables construction of soilcrete in limited spaces such as basements
• Ability to work around subsurface obstacles such as utilities, provides unique design flexibility
• Can target specific soils layers at depth without having to treat soils above
• Can often result in construction schedule savings
• Can usually be done without disrupting normal facility operations
• Containerised, highly mobile support equipment reduces mobilisation and demobilisation costs and time
• Can often result in construction schedule savings