Mass Soil Mixing (MSM), or mass stabilisation, is a ground improvement technique that improves soft or loose soils, by mechanically mixing them with either wet grout or dry cementitious binder.

Mass mixing illustration

Common uses

Increase bearing capacity
Decrease settlement
Increase global stability
Encapsulate contamination

Process

The mass soil mixing process is typically constructed in pre-defined ‘cells’ of the order of 4m x 4m in plan area. Commonly the cells are mixed adjacent to others to form a 100% mass stabilised zone, all with a designed strength and stiffness.

Soils vary widely in their ability to be mixed, depending on the soil type, strength, water content, plasticity, stratigraphy, and texture. Organic soil and peats can often be stabilised, but laboratory testing is always recommended prior to design.

Treatment is possible to depths up to 5m to 6m.

Large obstructions are pre-excavated to remove ahead of the soil mixing process. 

Pre-production laboratory testing is used to determine the mix methodology, energy, and binder content. Keller has developed proprietary equipment and software for the real-time control and monitoring of mixing parameters during the mixing process. Samples are taken of during production and cured in a controlled environment for testing.

Advantages

Quiet and vibration free
Environmentally-friendly as uses readily available materials
Almost no spoil
Economical
Can replace more expensive deep foundation methods
Flexible in application
Reduces construction time

Quality assurance

Pre-production laboratory testing is used to determine the mix methodology, energy, and binder content. Keller has developed proprietary equipment and software for the real-time control and monitoring of mixing parameters during the mixing process. Samples are taken of during production and cured in a controlled environment for testing.