Multiscale numerical simulation of rock slope instabilities

Abstract

The apparent shear strength of rock discontinuities is lower than that of small scale samples. At the same time, the sliding behavior is characterized by marked instabilities. Numerical algorithms permit to calculate contact forces at any point and to describe the stick-slip transition. On the other hand, the critical aspects are not captured by classical theories. Multiscale simulations show that the contact domain between two rough surfaces is a lacunar set. This explains the size-dependence of the apparent friction coefficient. By applying an increasing tangential force, the regime of partial-slip comes into play. However, the continuous and smooth transition to full-sliding predicted by the Cattaneo–Mindlin theory is not occurring in real situations.