Investigating the role of kinematics and damage in the failure of rock slopes

Abstract

Recent developments in numerical codes provide an important tool for modeling brittle fracture associated with the failure of rock slopes. This is particularly important in simulation of rock slopes that may initially appear kinematically stable but if brittle fracture is considered within the model, stress-induced release surfaces may cause slope failure. This paper investigates the inter-relation between kinematics, failure surface geometry and damage leading to the failure of high rock slopes using a three-dimensional lattice-spring code. Two new methods are introduced to quantify damage in our numerical simulations. In the first method, an “ellipsoid of damage” is defined to encompass newly created cracks within a given rock Slope Model. Geometrical characteristics of the ellipsoid including volume, length and orientation of its axes allow quantification of damage within a model. In the second method, damage is quantified using “damage intensity” parameters, D21 and D32. In this method damage is defined as the ratio of total length/area of the newly created cracks within the model to the sampling area/volume. The combined use of these two approaches allows a quantitative description of the intensity and extent of damage development within the rock Slope Models. Our numerical simulation results highlight a strong relationship between kinematics, failure surface geometry and damage in the failure of high rock slopes.