Assessment of Geocell Confinement for Sustainable Stabilisation of a Landslide-Affected Road: Australian Case Study

Abstract

This paper presents a case study of a road embankment affected by landslide activity that was subsequently stabilised using geocell reinforcement. The project involved a temporary accessway, approximately 80 m long and 8 m wide, located along Wattamolla Road, NSW, Australia. Stability assessments were undertaken using finite element modelling to evaluate the influence of geocell confinement on embankment performance. Unlike conventional approaches, in which geocell reinforcement is represented as an equivalent composite soil layer with increased apparent cohesion and unchanged friction angle, this study explicitly models the reinforced layer as granular soil subjected to externally applied lateral confining pressures. The behaviour predicted using this methodology was compared with that obtained from the traditional equivalent composite soil approach. The analyses indicate that even relatively low confining pressures significantly reduce lateral spreading of the infill material, promoting a more uniform strain distribution and reducing localised deformation. The results further demonstrate that geocell-induced confinement improves stress transfer within the reinforced layer and enhances embankment performance under traffic loading. In addition, the study shows that confinement is stress-dependent, with increasing surcharge loads mobilising greater hoop stresses within the geocell system and, consequently, generating higher levels of lateral confinement. The results suggest that modelling geocell reinforcement through stress-based confinement provides a more realistic representation of reinforcement mechanisms and offers valuable insights for the analysis and design of reinforced earth structures. By improving embankment stability and controlling deformation, geocell reinforcement may also extend infrastructure service life, minimise disruption associated with maintenance or slope failure and reduce dependence on more material-intensive stabilisation solutions. Collectively, these benefits contribute to resource efficiency, infrastructure resilience, and reduced whole-of-life intervention requirements.