ABSTRACT
Buckling instability is a mode of slope failure associated with stratified rock masses. This paper demonstrates that buckling instability at a large-scale (>50 m slope height) can be modelled as a continuum, whereby the inherent anisotropy from the stratified nature of the rock mass is incorporated as a discrete fracture network. Three case studies of increasing complexity were used to demonstrate the capability of the anisotropic continuum Finite Element Method (FEM) for back-analysing buckling deformation. The case studies range from a single staged excavation, through a progressively excavated open pit slope, and finally to sequential unloading corresponding to the evolution of a large natural valley. The results of this study indicate that FEM analysis is a simple, fast and effective method for providing a first indication of buckling slope instability for a large-scale slope. Parametric comparison of constitutive models indicates the Generalized Hoek-Brown failure criterion typically produces more representative results than the Mohr-Coulomb failure criterion. Limitations of using infinitesimal strain theory for analysing buckling deformation are discussed.
