9.4.6 Soil Nailing
It is a soil reinforcement technique that places closely spaced metal bars or rods into soil to increase the strength of the soil mass by resisting against tensile, shear, and bending stresses imposed by slope movements. Soil nails are either installed in drilled bore holes or secured with grout, or they are driven into the ground. The soil nails are generally attached to concrete facing located at the surface of the structure (figure 23). The function of the facing is to prevent erosion of the surface material surrounding the soil nails, rather than providing structural support.
This is a method of in situ reinforcement utilising passive inclusions that get mobilized in case of slope movement occurs. It can be used to retain excavations and stabilize slopes by creating in situ reinforced soil retaining structures.
Figure 23: Application of soil nail for reinforcing the slope
Figure 24: Application of soil nailing in the field