VHP — jet grouting (Very High Pressure)
VHP — jet grouting (Very High Pressure)
VHP jet grouting (Very High Pressure) injects cement grout into the ground at high pressure, blending the soil into a soilcrete column. These columns can be combined into a wall or used as a load-bearing pile. The slender tooling and near-vibrationless process make VHP especially well suited to underpinning beneath existing foundations and to sites with restricted access.
When to use
- Urban sites with limited headroom or access — feasible with mini-rigs
- Underpinning beneath existing foundations or slabs
- Adjacent to monuments or vibration-sensitive structures (near-vibrationless installation)
- Heterogeneous soils (sand, silt, clay) where mechanical soil mixing struggles
- Combined retention and hydraulic cut-off (VHP wall)
- Bored piles with central reinforcement where conventional piles cannot be installed (VHP pile)
What we deliver
- Sizing of column diameter, spacing and reinforcement (steel tube, GEWI bar or HEB profile)
- Capacity (VHP pile) or earth- and water-pressure (VHP wall) analysis to Eurocode 7
- Grout mix specification, target strength (UCS) and permeability
- Layout, cross-sections and full calculation report
Technical notes
- Near-vibrationless — suitable right next to historical or weakly founded buildings
- Soilcrete strength is highly soil-dependent (typically 15–35 MPa UCS in sand, 4–15 MPa in clay) — quality control through wet-grab and UCS testing is essential
- Permeability of a well-executed wall typically 10⁻⁸ to 10⁻⁹ m/s — usable as a cut-off screen
- On request we supervise pile load tests and on-site quality monitoring
Related services 
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