A soil mix wall is a type of retaining structure or cutoff wall constructed by blending the existing ground material with a cementitious grout using specialized equipment.
Soil mixing is a ground improvement technique that enhances the engineering properties of soil. It works by injecting cementitious grout into the ground and blending the materials in-situ. This process creates a hardened, low-permeability mass of treated soil.
How are Soil Mix Walls Constructed?
Soil mix walls are specifically constructed by overlapping elements of soil mixed ground, and inserting structural piles for reinforcing.
Here's a breakdown of the process:
- Soil Mixing: Large drill rigs or mixing tools penetrate the soil, simultaneously injecting a binding agent (typically cement grout or a mix of cement and other additives).
- Blending: The tools blend the injected grout thoroughly with the existing soil, creating a homogeneous mixture.
- Element Overlap: Successive mixing passes are performed with significant overlap. This creates a continuous, solid wall structure composed of the treated soil.
- Reinforcement: Where structural support is needed (e.g., for retaining walls or deep excavations), structural elements like steel beams or piles are inserted into the wet soil mix before it hardens.
This creates a durable, rigid wall with improved strength and reduced permeability compared to the native soil.
Applications of Soil Mix Walls
Soil mix walls are versatile and used in various civil engineering projects, including:
- Excavation Support: Providing temporary or permanent shoring for deep excavations in urban areas or near existing structures.
- Seepage Control: Creating impermeable cutoff walls for dams, levees, or contaminated sites to prevent water flow.
- Slope Stabilization: Improving the stability of unstable slopes.
- Environmental Remediation: Containing contaminated soil or groundwater.
By utilizing the in-situ soil, this method often reduces the need for importing or exporting large volumes of material, offering potential cost and environmental benefits.
