Raito Soil Mixing Wall (RSW)

RSW uses multiple auger, paddle shafts rotating in alternating directions to mix in-situ soil with cement grout, bentonite slurry, clay slurry,  or other stabilizing reagent slurries to install continuous subsurface soil-cement walls for excavation support and groundwater or underground pollutants control, or ground reinforcement; column blocks, lattice, or areal patterns for stabilization.   The soil-cement is usually reinforced with steel H-piles when used for excavation support along with groundwater control.  Applicable subsurface soils are soft to hard silt and clay, loose to very dense sand, gravel, a cobble soils, cobble and boulder soil and bedrock with predrilling.

RSW shoring installations facilitate sheer excavation for grade separation or underground construction in a dense urban environment where there isn’t enough room for sloping and where low noise/low vibration construction may be required. The RSW method offers advantages over traditional pile and lagging methods by also providing groundwater cutoff in high water table environments.

Application and Design

Excavation Support Wall

RSW walls constructed with wide flange or soldier pile steel beams are very stiff and offer a cost-effective alternative to slurry walls and secant pile walls.  

Steel H-pile or other reinforcement members are installed inside the soil-cement wall to resist the lateral forces before the soil-cement hardens.  The reinforce soil mix wall becomes a structural wall for excavation support and groundwater control. 

High demand for space and constantly rising land const in major cities increases the construction of multiple level basements underneath new buildings and RSW is the most effective method for it.

Cutoff Wall

RSW method installs soil-cement-bentonite walls or soil-bentonite walls for use as barriers to contain groundwater or underground pollutants.

Ground Reinfrocement

RSW also installs a soil-cement wall, panel, grid or block to maintain ground stability and control ground movement or for liquefaction prevention.

Construction Sequence

Step 1 Step 2 Step 3 Step 4 Step 5 Step 6 Step 7
Drilling and mixing soil with cement grout Pumping of cement grout while mixing Withdrawing auger while mixing Drilling second column - same as the Step 1 Second column - Same as the Step 2 Second column - Same as the Step 3 Drilling third column between the 1st and 2nd to form the wall

Alternative Technologies

Multi-auger DSM

DSM is an in-situ soil mixing technology that mixes existing soil with cementitious materials using mixing shafts consisting of auger cutting heads, discontinuous auger flights, and mixing paddles.  The mixing equipment varies from single to eight shaft configurations depending on the purpose of the deep mixing. 



RAS Column is an advanced deep soil mixing method based on mechanical soil mixing technology to produce soil-cement column of 1.4m to 2.5m diameter.  The mixing head is equipped with the counter rotation mechanism.  This unique mechanism efficiently breaks and mixes in-situ soil with cement-based reagents, producing more homogenous and higher quality soil-cement columns.

Shallow Soil Mixing

SCM is a method to mechanically mix in-situ soil with cement powder or slurry. SCM provides two different mixing equipments, Rotary Blender and Bucket Mixing, to be selected depending on improvement objectives and depth. The unique mixing mechanism provides efficient, cost effective and quality improvement. Larger plant is not necessary. 

Raito, Inc.

32960 Alvarado-Niles Rd., Suite 680, Union City, CA 94587

Phone: +1-510-259-9900  Fax: +1-510-259-9901

Toll Free: 1-866-DEEP-MIX (1-866-333-7649)

Email: info@raitoinc.com