Single Column Mixing—Double Rotary Head (SCM-DRH)—First Experiences with a New Soil Mixing Tool

The single column mixing–double rotary head (SCM-DRH) method of deep mixing has been in operation now for a couple of years. The use of two counter-rotating mixing tool components achieves exceptionally intensive levels of mixing between soil and slurry. Therefore, the newly developed SCM-DRH tool represents a significant improvement of the single column mixing tool, as it enables to move the borderline of suitable soils for soil mixing applications. As it acts like a compulsory mixer, the grade of achievable homogeneity allows intensive levels of mixing between soil and slurry and the construction of soil mix columns not only in granular soils but also in cohesive soils where soil mixing usually gets to its limits. The paper will focus on initial field trial studies on the system and the different applications of the system, for instance soil improvement for settlement control, and also experiences made in various countries.