While similar in concept to tiebacks, soil nails are installed in rows across the face of an excavation and are typically covered with reinforcement and shotcrete. The number of soil nails per row, as well as the row spacing, is largely dependent on earth conditions and design loads.
Soil nail shoring systems include steel thread bars secured in place with grout. Steel reinforcing mesh is laid over the face of the excavation, connecting the steel bars together. Concrete is then sprayed over the mesh in the form of shotcrete. These types of walls are relatively inexpensive and can be used for both permanent and temporary shoring in a variety of ground conditions.