Rock Slope Stability Design

This paper explores the numerical analysis used to determine the global stability Factor of Safety (FS) of the rock slope. The methodology presented herein was employed by the author during the design of the railway cut in Central Bohemia. Both traditional and numerical methods were applied in designing of the protective stabilization measures for the new rock slope. The analysis supports the results obtained from the conventional geotechnical approach, specifically using the "limit equilibrium method" along the primary planar shear surface, within a rock mass where anisotropic behaviour is influenced by the strikes and dips of discontinuity surfaces, such as bedding planes and schistosity. The Anisotropic Jointed-Rock Model (AJRM) used in the numerical analysis offers a significant advantage by accounting for the anisotropic behaviour of the rock mass - an aspect often overlooked in standard slope stability methods or when isotropic constitutive models are used in numerical simulations. Furthermore, mathematical modelling proves beneficial in cases where different constitutive models are required for various geotypes. The combined use of the Jointed-Rock model for the rock mass and the Hardening-Soil model for the quaternary part of the slope within a unified calculation environment provides additional advantages. The primary objective of the static analysis was to design the rock cut within the geological context of metamorphosed pre-Cambrian rocks, specifically gneiss, located in the southern part of Central Bohemia.