Soil Nailing
Soil nailing is an engineered earth retention method that utilizes an array of grouted tensile elements (“soil nails”) combined with a well-drained wire mesh and shotcrete facing to create a stable reinforced soil mass. Soil nailing can be used for temporary or permanent earth support applications and is particularly effective in limited-access areas and/or for irregularly-shaped excavations.
Soil nail wall construction is a staged “top-down” process where the soil is excavated and stabilized in 5- to 6-foot increments. The height of each increment is limited by the soils’ ability to temporarily remain stable as the soil nails are installed. Each nail is installed by drilling a near-horizontal hole into the soil, inserting a central steel bar, filling the hole with grout, and installing a steel bearing plate at the end of the bar. After the nails are constructed, drainage panels and wire mesh-reinforced shotcrete facing are installed. This incremental process is repeated until the final excavation depth is reached.
For permanent walls where an aesthetically appealing finish is required, the shotcrete facing can be sculpted and stained to meet architectural or landscaping requirements. Alternatively, precast facing panels can be used in lieu of sculpted/stained shotcrete.
