Multi-auger Deep Soil Mixing (DSM)
DSM method 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 six augers configurations depending on the purpose of the deep mixing. The soil-cement produced generally has higher strength, less compressibility, and lower permeability than the native soils.
The cementitious materials are generally delivered in a grout or slurry form from ports in the cutting heads located in the lower ends of the multiple shafts. The multiple shafts consist of mixing paddles or a combination of discontinuous auger flights and mixing paddles depending on the soil types and the purposes of soil-cement columns.
DSM is effective for liquefaction mitigation of seismically sensitive soil layers, foundation improvement under future structures and in-situ stabilization of contaminated soils for environmental remediation among other uses.
Proven Technology
Since its development in 1975 by the Port and Harbor Research Institute of Japanese Ministry of Transportation, thousands of projects have been completed. It is also proven to be effective for liquefaction prevention.
Reliable in Strength Gain
Required strength can be obtained reliably by setting a proper cement dosage according to the conditions of soil to be treated.
Environmentally Friendly
The drilling and mixing operation is low noise and low vibration, and does not generate dust.
Reduce Construction Period
Soil-cement gains strength and reduces compressibility faster than conventional soil improvement methods and shortens the construction period.
Computerized Operation System
The computerized operation system controls, monitors, and records the drilling rate, mixing depth, auger rotational speed, and grout injection rate. This operation system minimizes human errors and provides reliable soil-cement product as the design intended.
Construction Sequence
| Step 1 | Step 2 | Step 3 | Step 4 | Step 5 |
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Setting up auger tool at pile position |
Drilling and mixing soil with cement grout | Pumping of cement grout while mixing | Withdrawing auger while mixing | Installation of mixed column is completed |
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Basic DSM Treatment Patterns
Each stroke of the multiple auger produce a block or panel of soil-cement columns . The cement panels are then extended to various patterns as shown below for various applications.
Block Type
Wall Type
Grid Type
Column Type
Tangent Column
Tangent Wall
Tangent Grid
Tangent Block
Application and Design
DSM is an in-situ soil treatment technology which modifies the engineering properties of existing soil in well defined zones such as columns, panels, or blocks. Through the design of the engineering properties and treatment patterns, DSM constructs subsurface soil-cement structures for a wide variety of applications in the areas of civil engineering construction and environmental remediation.
Alternative Technologies
Soil Mixing Wall
RSW mixes in-situ soils with cement grout or other reagents slurries using a multiple shaft auger to produce continuous subsurface soil-cement walls for excavation support, groundwater or underground pollutants control, or ground reinforcement. The soil-cement is usually reinforced with steel H-piles when used for excavation support along with groundwater control.
Large-diameter
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.