Deep Soil Mixing

As a top provider of design-build Geostructural Design & Construction services, Schnabel is renowned as a leader among soil mixing contractors in the nation. This involves a specialized process called deep soil mixing.

Deep soil mixing is an advanced technique in which cement grout is mixed directly with soil in-situ (on-site), designed to enhance the solidity of the soil and decrease its permeability. This method is particularly effective in creating impermeable structures that retain the earth and firm barriers to control groundwater, while simultaneously improving the soil’s supportive properties.

Regardless of the unique environmental factors or operational challenges you face, Schnabel has the expertise and breadth of knowledge to offer the perfect deep soil mixing solution tailored to your specific requirements.


As a frontrunner in the industry of soil mixing contractors, Schnabel recognizes the importance of comprehensive soil mixing in establishing robust earth-retention structures. When executed accurately, this process generates a substantive soilcrete blend that displays enhanced solidity and minimized permeability.

Soil mixing is frequently employed in the construction of earth-retaining structures, particularly when a groundwater cut-off is necessary. In typically scenario, Schnabel creates a continuous groundwater cut-off wall by drilling a series of overlapping soilcrete columns.

To empower the mix with additional strength, steel piles are often incorporated into the soilcrete while it is still in a wet state. This fortification enables the treated ground to bridge between the respective piles. A soil mix wall’s reduced permeability provides a relatively dry environment for the excavation to proceed, with minimal drawdown of the surrounding water table.

In scenarios where excavation isn’t required, soil mixing still proves effective in creating an impermeable underground barrier. This technique is crucial for reducing seepage through dams or containing contaminated groundwater. In addition to these applications, soil mixing shines in the fortification of foundational soils – enhancing their overall strength and lowering the tendency towards liquefaction during seismic events.

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soil mixing services

Boston Museum of Fine Arts

Schnabel constructed a cement deep soil mixed (CDSM) wall for the excavation support system at the Boston Museum of Fine Arts in Massachusetts.

soil mixing contractors

Patriots Plaza

Schnabel used several techniques such as deep soil mixing, pressure grouting, and secant piles to provide both excavation support and to impede groundwater flow into the excavation at the Patriots Plaza project in Washington D.C.

Schnabel designed and installed a soil mix wall to support an excavation that was within three feet of the historic Boston Museum of Fine Arts. The low vibrations during installation and increased stiffness of a soil mix wall helped protect the priceless artifacts in the museum. Schnabel worked closely with our client John Moriarty & Associates to ensure project success.

Harry W. Schnabel, P.E., , Boston Museum of Fine Arts Project


Schnabel is the sector’s most operationally efficient Geostructural Design & Construction contractor. We optimize efficiencies by leveraging decades of experience and design/build expertise to innovate processes and approaches that are consistently proven to deliver optimal outcomes for our clients.