Studying the effect of geometrical nail layout on the performance of soil-nailed walls: Physical and numerical modeling

Abstract

Soil nailing is a reliable method of stabilising earth and rock slopes, but the geometrical layout of soil nails has not been well studied. The current research examined the effect of the geometrical layout of soil nails using analytical and physical modelling. The results of limit equilibrium analysis for different nail layouts are presented. The target gravity level was 50 g for centrifuge models and all models had a safety factor of 1.35 at this level. The parameters studied were base nail length, angle of nail tail extension, horizontal spacing of nails, and nail density. The limit equilibrium results showed that, when longer nails were used, the nail density could be decreased. The results of centrifuge modelling confirmed that different layouts at a similar safety factor did not show similar levels of displacement. Also, nail density was the most influential parameter affecting soil-nailed wall performance. An empirical relationship was observed between displacements of the wall crest and nail density. An interesting similarity was observed between the predicted slip surface and the slip surface that formed during physical modelling.

A Numerical Study of a Soil-Nail-Supported Excavation Pit Subjected to a Vertically Loaded Strip Footing at the Crest

“…Their results show that the shear strength of the interface increases with the increase in grouting pressure and that pressure-grouted nails give better strength than gravity-grouted nails. The conclusions provided by [10,11] have also been observed by Sabermahani and Nuri [12], who have conducted centrifuge and numerical studies to examine the effect of nail length, nail angle, horizontal spacing, and nail density on the response of a nailed slope, and concluded that nail density was the most influencing factor in their centrifuge study.…”

Application of the Nailing Technique to Stabilize a Slope in a Section of the Twinning of Road and Rail Infrastructure

“…These nails are usually placed parallel to each other. The length and inclination must be adapted to the shape of the nailing and the properties of the soil [27]- [29]. Habitually, the nails utilized have a similar length and equal inclination.…”