Construction of a soil nailed wall is completed in lifts. An earth berm is left in front of the future wall at each lift. Soil nails are installed through the berm to the design length required. Once installation of nails is complete the berm is trimmed to the back of the shotcrete wall. Welded wire mesh is placed and shotcrete is sprayed onto the face. Excavation to the next level can proceed once adequate curing of the concrete has occurred. This sequence continues until excavation to final grade is complete.
In some applications vertical nails are installed behind the back of the shotcrete wall prior to commencement of any excavation. These vertical nails project below the base of the future excavation and provide a “toe” for the shotcrete wall in addition to increasing its stiffness.
The equipment required for installation of shotcrete walls is smaller than standard caisson drilling equipment which can make this system an excellent choice in areas with restricted access.