Deep Soil Mixing (SMX)
is a ground improvement
technique that involves
the blending of a hardening
agent (usually cement
grout) with the native
soils, in situ. The process
improves the strength
and stiffness of the
native soil.
A revolving
hollow shaft with mixing
paddles and/or a section
of auger (the mixing
tool) is advanced into
the soil. As the mixing
tool is advanced, the
cement grout is pumped
through the hollow stem
of the revolving shaft
and discharged laterally
along the lower mixing
paddle where it is mixed
with the native soil.
The kneading action of
the mixing tool blends
the cement grout and
the soil. When the design
depth is reached, the
tool is withdrawn while
maintaining, or often
increasing, the rotational
speed of the mixing tool.
The resulting column
is a well-blended mixture
of native soil and cement
grout which will cure
over time to the required
design strength. Tie-down
rebar can also be installed
in the Soil Cement column
to provide uplift capacity.
