Jet Grouting uses high velocity fluid jets to construct cemented soil of varying geometries in the ground.
- Underpin foundations
- Provide excavation support
- Seal the bottom of planned excavations
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.
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.
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.