Deep Soil Mixing

Deep ground improvement by mechanical mixing.

Projects constructed over soft, loose or highly variable ground strata generally require deep foundations or ground improvement to ensure adequate foundation capacity and acceptable total and differential structural settlements.  In some circumstances ground improvement techniques, including deep soil mixing, can provide a more cost effective solution than deep piled foundations. 

Some soft, loose or weak soils are susceptible to liquefaction under seismic loading conditions.  Liquefaction of the soil can induce rapid and significant ground settlements and lateral movements that can cause catastrophic failure of any structures on the liquefied area. The strength and stiffness improvements achieved by deep soil mixing can be an effective ground improvement strategy to address liquefaction risk.

The deep soil mixing process forms columns of cemented material in the ground by mechanically mixing the in-situ soil with an introduced binder agent such as cement or lime.  The binder can be introduced either by injection of a wet slurry or dry binder systems through the mechanical mixing tool.

By forming grids or lines of soil mix columns the “improved” ground has increased strength and stiffness and has more uniform load/settlement response properties.  

Where sites require deep soil mixing the CMW team collaborate with project developers, engineers and specialist contractors to deliver robust solutions for significant developments and critical infrastructure thereby ensuring that project performance specifications are met despite the presence of problematic soils.