Incorporating several reinforcements, referred to as “nails,” into the soil to hold it in place. The other end of the “nail” is fastened to a thin, grouted concrete wall. Sturdy iron rods are pushed into the ground in short lengths to anchor them at the other wall increasing friction at the junction of the reinforcement and the soil. Cement grout can be pressure-grooved onto the nail surfaces. The 1970s saw the introduction of soil nailing in France. It might be referred to as in-situ soil reinforcement employing a variety of installed nails as inactive additions to a grid.
VARIOUS TYPES OF SOIL NAILING
- Grouted Nail: Following excavation, holes are first drilled in the slope face or wall, and then the nails are inserted into the holes that had already been created. Cement grout is then used to fill the drill hole.
- Driven Nail: During excavation, nails of this type are driven mechanically into the wall. This kind of soil nailing may be installed extremely quickly, but it does not offer a good level of corrosion protection. Typically, this is done as a temporary fix.
- Grouted Nail: Following excavation, holes are first drilled in the slope face or wall, and then the nails are inserted into the holes that had already been created. Cement grout is then used to fill the drill hole.
- Driven Nail: During excavation, nails of this type are driven mechanically into the wall. This kind of soil nailing may be installed extremely quickly, but it does not offer a good level of corrosion protection. Typically, this is done as a temporary fix.
ADVANTAGES
- It is not dependent on heavy equipment.
- It is economical where the geometry of the wall is complex and where space restrictions exist.
- Since nails are of low strength steel, the need for corrosion protection stands reduced
- Construction can be carried out with little disturbance to the environment in terms of noise and vibration.
- Due to the system’s need for some soil displacement in order to mobilise resistance, soil nail walls might not be suitable for applications requiring very precise deformation control for structures and utilities located behind the proposed wall. Although it comes at a higher expense, post tensioning can lessen deflections.
- Soil nail walls are not well suited where significant volumes of groundwater seep into the excavation because it is necessary to maintain a temporarily unsupported excavation face. Existing utilities may impose limits on the position, inclination, and length of soil nails.
- Permanent subterranean easements are needed for soil nail walls.
- Only suited for excavation above groundwater; less suitable for coarse-grained soil and soft clayey soil, which have short self-support times and soils prone to creeping.
