Rock and Soil Nail

Basic Concept

Soil nailing is a construction technique generally used for the stabilization of naturally unstable slopes or securing of over-steepened existing slopes, as well as the stabilization of retaining walls or embankments. For Underground applications, soil nails are also referred to as rock nails or bolts.

The basic concept of a soil or rock nail is based on the installation of longitudinal reinforcement elements into the ground. Hence, this load-bearing system significantly differs from ground anchors (actively tensioned) and tensile piles, as the nail is installed un-tensioned (passive system). Consequently, nails increase the load-bearing capacity of the entire structure and act as a group of elements, withstanding tensile and shear forces acting on the nails. The center-to-center distance of nails must be chosen as such they are able to act as a complete nailing system. Prior to nail installation, the excavation face is generally supported by shotcrete, precast concrete elements, mesh, or geotextiles. The design of a nail head construction depends on the application and the intended lifetime of the structure.

Conventional nail systems consisting of solid threaded bars are installed into pre-drilled holes and subsequently grouted. DSI rock and soil nails are installed self-drilling, and are either grouted simultaneously during drilling or afterwards.