Low mobility (compaction) grouting involves the injection of a low slump, mortar grout to densify loose, granular soils and stabilise subsurface voids or sinkholes.
Process
An injection pipe is inserted, typically to maximum treatment depth, and the grout then injected as the pipe is slowly removed in lifts, creating a column of overlapping grout bulbs. The expansion of the grout bulbs displaces surrounding soils and the grouting increases the density, friction angle, and stiffness of surrounding granular soils.
You can increase effectiveness by sequencing the compaction grouting from primary to secondary to tertiary locations. In all soils, the high modulus grout column reinforce the treatment zone.
Common uses
- Suitable for rubble fills, poorly placed fills, loosened or collapsible soils, karst conditions, and liquefiable soils
- Often selected for treatment beneath existing structures because the columns do not require structural connection to the foundations
- Reduce liquefaction potential
- Decrease or correct settlement
- Increase bearing capacity
- Stabilise sinkholes or reduce sinkhole potential
Advantages
- Often more economic than conventional approaches such as removal and replacement, or piling
- Can be done where access is difficult and in limited space
Quality assurance
Keller can provide complete solutions which combine compaction grouting with real-time monitoring of affected structures, and has a variety of rig types to accommodate access constraints.