In accordance with the guidelines provided by the American FHWA-NHI-14-007, the main collapse mechanisms to which a slope or an excavation face reinforced with the Soil Nailing technique may be subjected are indicated in Figure 3.
Fig. 3 – Potential failure mechanisms of a wall reinforced with the Soil Nailing technique (American guidelines FHWA-NHI-14-007): (a) internal stability (the failure surface involves both soil and nails); (b) global stability (the failure surface does not involve the nails); (c) pullout failure of the reinforcement; (d) tensile failure of the reinforcement; (e) structural failure of the lining; (f) sliding.
The following sections outline the methodologies used to perform checks against the failure mechanisms indicated in Figure 3.