Cutter Soil Mixing (CSM) enhances the engineering properties of soils, and/or reinforces soil masses by mechanically mixing the in situ soils with a binder slurry, typically comprising either cement or bentonite slurry, or a combination of the two.

Common Uses

  • Temporary Shoring of Deep Excavations
  • Cut-Off walls to mitigate seepage or contaminant transport
  • Reduce liquefaction potential
  • Enhance slope stability
  • Provide structural support

Technical Details

Cutter Soil Mixing (CSM) is a specialized deep mixing technique that can be utilized in almost any soil type. The process incorporates cutter wheels, rotating about horizontal axes, and mounted on the end of a Kelly Bar, cutting their way into the soils to form a panel of improved soil that is rectangular in plan. As the cutter head advances, binder slurry is pumped through a nozzle situated between the wheels and mixed with the in-situ soils.  The action of the cutter teeth and cutting fins, combined with the shear plates situated just above the wheels, serves to develop a thoroughly mixed soil mass. The addition of additional binder on the withdrawal stroke, combined with high rotation speed of the cutter wheels serves to blend the soils and slurry further and create a well-mixed in-situ product.

Cutter Soil Mixing creates strengthened and stiffened individual soilcrete elements, commonly referred to as panels. Treatment is possible to depths of up to 50 m depth using very large base carriers, however typical panel depths are in the order of 25 to 35 m. For very dense soils or soft rock, pre-drilling can be used to improve productivity. The ease of the process is contingent on soil type, strength, water content, plasticity, and texture.

The Paramount project in Richmond, BC is the deepest cutter soil mixing (CSM) depth achieved by Keller in Canada. Watch the CSM rig in action creating a structural cut-off wall.