Soil Nail Wall

Soil nailing is a stabilization method of reinforcing existing soil by installing threaded steel bars into slopes or cuts as wall construction proceeds from top down. Grouted bars are installed to create a stable mass of earth, first step in building a solid wall. The nailing process creates a single block of earth able to hold-back its overburden. Soil nailing is an economical means of creating shoring systems and retaining walls. Often, nailing is less disruptive than other means of constructing retaining systems.

Soil nailing not only works in tension, but also bending and shearing forces. Generally, the process increases bonding strength of media through its ability to carry tensile loads. A constructed face is usually required over shoring bars, typically made of a shotcrete cover, which is reinforced using woven mesh over steel plates. Permanent walls are usually built with a cast-in-place face over nailing.


Soil Nail Advantages:

Used to follow irregular curves.
Equipment is portable for tight spaces.
The technique is flexible, easily modified.
Creates less noise and traffic obstructions.
Less impact on nearby properties.

Requires minimum shoring space.

Animation

To begin the first segment of a soil nail wall, cut a five foot face along the line of the future wall.

Drill a horizontal row of holes into the cut face on about five foot centers. Drill through the unstable zone and into the stable zone.

Pump grout into each hole, filling it from the bottom-up.

Insert threaded bar or tendon into each hole.

Apply first layer of reinforced shotcrete, leave soil nail heads protruding.

Install bearing plates and locking nuts on each soil nail head.

Apply second coat of reinforced shotcrete, This segment of the soil nail wall is now complete.

Build another wall segment along the same line and directly below the first segment.

Continue adding segments until base of the soil nail wall is at desired elevation.