ABSTRACT
Soil nailing is an in situ ground reinforcement technique that involves the installation of closely spaced slender structural elements, commonly known as soil nails, either by driving, firing, or more commonly the “drill-and-grout” method. A soil nailed earth structure basically includes the in situ ground to be reinforced, soil nails, nail heads, and/or facing. The technique improves the stability of slopes, retaining walls, embankments, and excavations principally by transferring loads to the ground through the mobilization of tensile forces in the soil nails. The soil nails act to limit the ground deformation near the exposed facing and transfer the stresses to a more stable zone behind the reinforced soil mass. Soil nails are essentially passive elements in which tension is mobilized only if there is ground deformation. The technique evolved in the early 1970s, partly from the techniques for rock bolting and multi-anchorage systems, and partly from the reinforced fill technique. Subsequent technical development work of soil nailing was carried out independently in Europe, the Americas, and Asia from the mid-1970s to the late 2000s. The construction process generally causes minimal nuisance, both in terms of vibration and noise, to the environment. The maintenance effort required throughout the lifetime of a soil nailed structure is also minimal. More importantly, the track record has been excellent in that no major collapses have been reported in properly designed and well-constructed soil nailed structures so far. To date, the technique is commonly used for enhancing the stability of earth structures around the world. In this chapter, an overall view of the book together with the salient aspects of the evolution and history of development of the soil nailing technique, its areas of application, the key components, as well as the merits and constraints of the technique are presented.
