Soil Nailing Method to prevent landslides

• Context (TH): The ‘slope stabilisation using soil nailing and Hydroseeding method’ is being adopted in the Nilgiris to prevent landslides.

Credit: Technology for Wildlife Foundation

• Soil nailing is a geotechnical engineering technique used to reinforce soil to make it more stable.
• It is used for slopes, excavations, retaining walls, etc., to make it more stable.
• It involves inserting slender rebars into the soil, laying reinforcing mesh on the slope surface, and applying concrete to form a composite body. This structure, akin to a gravity retaining wall, securely bonds reinforced rods with the surrounding soil.

Credit: Larimit

• Following the process of strengthening the slope, ‘hydroseeding’ – a process of applying a mixture of seeds, fertilizer, organic materials and water onto the soil to facilitate the growth of grass and plant life, which will help hold the topsoil together and prevent erosion.

Applications

• Stabilization of existing retaining wall
• Excavating retaining structures in urban areas for high-rise buildings and underground facilities.
• Landslide redemption
• Stabilization of highway and roadway embankments and cut slopes
• Steep cutting stabilisations
• Stabilizing of over steep existing embankments

Benefits

• It mitigates slope instability by reinforcing the soil, preventing collapse, and enhancing overall slope stability.
• It can improve the strength and stiffness of the soil while reducing the pore water pressure.
• It is a fast, flexible, and economical slope stabilisation method that does not require extensive excavation, foundation, or equipment.
• It can preserve the natural appearance of the slope by blending or vegetating the facing material.
• Provide long-term stability to existing concrete structures without demolition and rebuilding costs.

Credit: Zcctechno

Limitations

• Its effectiveness diminishes with increased depth.
• Its efficacy is highly dependent on soil conditions, and unsuitable conditions may impact the overall stability achieved.
• Environmental and safety risks associated, such as noise, vibration, dust, or slope instability during the installation process.