Jet Grouting uses high-velocity fluid jets to construct cemented soil of varying geometries in the ground.
Process
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 is 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 significant 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.
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Specialist contacts
Lucian Spiteri, PE, is a Vice President Pre-Construction at Keller North America.
Lucian has more than 20 years of experience in geotechnical engineering and construction. He holds a Bachelor of Science in Civil Engineering from Manhattan College and has developed deep expertise in ground modification and construction dewatering, including various grouting techniques and systems using wells, wellpoints, and ejectors.
Lucian has contributed to major infrastructure projects such as the Second Avenue, East Side Access, and Number 7 Line Extension in New York City, as well as complex remediation efforts, including a large-scale sinkhole stabilization in Florida and rehabilitation work at the World Trade Center site.
Maxwell Pucciarello, PE, is an Engineering Manager at Keller North America.
Max's role includes oversight and management of Keller's design, estimating, procurement, and QA/QC for specialty grouting jobs, with scopes of work including jet grouting, compaction grouting, rock grouting, and permeation grouting (e.g., cement and chemical). This includes the most complex geotechnical projects, with a wide array of applications, such as temporary and permanent underpinning, bathtub excavations, tunneling, liquefaction mitigation, foundations, support of excavation, and hydraulic barriers.
Max earned a Bachelor of Science degree in Civil Engineering from Rutgers School of Engineering and is a licensed Professional Engineer.
Common uses
- Control of groundwater or excavation of unstable soil (water-bearing or otherwise)
- Underpin foundations
- Provide excavation support
- Seal the bottom of planned excavations
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
- Low headroom equipment enables construction in limited spaces such as basements
- Can target specific soil layers at depth without having to treat soils above
- Jet grouting can be combined with other techniques to provide a comprehensive and cost-effective geotechnical solution
- Can usually be done without disrupting normal facility operations
- Containerized, highly mobile support equipment reduces mobilization and demobilization costs and time
Quality assurance
An in situ test program is generally installed before production to meet the project's intent and ensure that the jet grout program is successful. Based on a review of the project borings, the application, and previous project experience, initial jet grout parameters (or sets of parameters) are established and executed in the field for the test program. The test program will specifically demonstrate the jet grouted elements' column spacing, overlap, and geometry of the jet grouted elements. The test program will also verify the consistency of the grout batching, evaluate the equipment functionality, and confirm the real-time recording and reporting of the jet grout parameters. These processes establish a standardized protocol for each specific soil type that is consistent and repeatable for the production columns.
Keller’s proprietary data acquisition (DAQ) system enables us to continuously monitor and record specific jet grout parameters at the rig. The DAQ interface provides real-time information to the drill rig operator, while the column construction data is uploaded wirelessly to a server soon after completion for report generation. These reports can then be reviewed in near real-time by project management and submitted to the client.
Related projects
Infrastructure
ADA upgrades at 14th Street
Keller provides groundwater control and excavation support solutions to facilitate ADA upgrades to NYC subway stations.
Institutional
South Shore University Hospital
Keller installed two jet grout bottom seals to keep a dry excavation for underground fuel storage tanks and a pump station at Northwell Health’s Bay Shore campus expansion
Infrastructure
West Lynn Sewer Separation Phase 3
With the increasing severity of weather events and urbanization leading to higher water flows, sewer system improvements are consistently underway to increase capacity. In West Lynn, the installation of a 54-inch force main was underway when Keller was contacted to formulate a ground improvement solution to allow for the safe installation.
Commercial
First Morris Bank
When soil conditions were not amenable to conventional underpinning techniques, Keller’s design-build jet grouting solution provided both underpinning and excavation support in one operation.
Residential
Aston Martin Residences
Keller’s multi-technique solution provides groundwater control and deep foundations for luxury high rise constructed feet away from Biscayne Bay.
