Such structural element which provides load transfer to the ground in excavation reinforcement application is called nail (Fig. 1.1). Soil nails are usually installed at an inclination of 10 to 20 degrees with horizontal and are primarily subjected to tensile stress.
Tensile stress is applied passively to the nails in response to the deformation of the retained materials during subsequent excavation process. Soil nailing is typically used to stabilize existing slopes or excavations where top-to-bottom construction is advantageous compared to the other retaining wall systems.
As construction proceeds from the top to bottom, shotcrete or concrete is also applied on the excavation face to provide continuity. Fig. 1.2 depicts cross section of a grouted nailed wall along with some field photographs of the same in Fig. 1.3. In the present era, soil nailing is being carried out at large in railway construction work for the stabilization of side lopes in existing track-road or laying of new tracks adjoining to an existing one.
Authors: Amit Prashant | Mousumi Mukherjee