The Deep Soil Mixing Technique
Deep soil mixing is an in situ ground improvement technique that enhances the characteristics of weak soils by mechanically mixing them with a cementitious binder. The action of mixing materials such as cement, fly ash, lime or bentonite with soil causes the properties of the soil to become more like soft rock.
Deep Soil Mixing Ltd (DSM) provides two types of deep soil mixing for geotechnical and environmental applications, including mass mixing, and column mixing. Both systems offer wet and dry soil mixing solutions which enable the additives to be placed as wet slurry or dry powder. They are able to tackle some of the most difficult soil conditions, ranging from flood plains and soft soils through to contaminated land.
Pipeline Corridor: Laying the pipeline in a soil mixed corridor eliminates settlement concerns.
Mass mixing is used in situations where a whole area of very soft or contaminated ground requires improvement. The procedure involves mixing a cementitious binder into peat, silts or soft clay and is carried out with a mixing tool that has been installed on an excavator machine. By mixing in both the horizontal and the vertical direction the substances combine to form a much improved structural quality material that in some instances can be used as fill. Mass mixing is applied at depths between one to six meters and applications include mass stabilisation of dredging mud, canal management, road construction, ground strengthening and land remediation.
2.0m soil mixed column.
Soil mixed columns may be single or overlapping triple columns installed up to 23m in depth for installation of cut-off walls or to improve the bearing capacity of the soil, for example on embankments at risk of soil erosion. Retaining walls for flood defence schemes, cofferdams or any other purpose may be built economically using soil mixing if the ground conditions are suitable. Granular materials such as sands and gravels are mixed with cement slurry to form solid walls.
Triple auger overlapping provides a continuous underground wall.
Deep Soil Mixing Ltd (DSM) uses a single auger system fitted with an innovative double rotary mixing head; or a triple auger system fitted to a telescopic leader rig.