Responses of Structural Components of a Full-Scale Nailed Retaining Structure under the Influence of Surcharge Loading and Nail Head Configuration: A Numerical Study

Abstract

Soil-nailing is a simple and economical method of stabilizing cut slopes and retaining excavation. Most of the soil-nailing related studies, in particular the experimental work, were conducted in idealized or homogeneous ground, but such a result might not necessarily be representative. Thus, for a more representative study, instead of treating the ground as homogeneous it should be treated as a system of horizontal layers. This study assessed the performance of a full-scale nailed retaining structure for a foundation pit of a 20-storey building through a series of numerical analyses. The influence of full-face facing thickness, nail head geometrical configuration (size and thickness) and surcharge loading on the response of the structural components of the soil-nailing system adopted is the main concern. The results were evaluated in terms of axial force, shear force and bending moment of the structural facing element and the horizontal displacement of the soil retained behind the facing element. In both cases, the distribution of nail axial (tensile) force in each nail reinforcement was also compared and evaluated. It was found that the thickness of full-face facing affected the facing shear force and bending moment, while the surcharge loading influenced the facing axial force and the horizontal displacement of the retained soil and that the magnitude of the axial force registered at the fixed end was governed by the size of the discrete nail head.