Toppling failure analysis of rock slopes based on a three-dimensional discontinuous deformation analysis method

Abstract

The present study focused on the study of the toppling failure of rock slopes using a three-dimensional discontinuous deformation analysis (3D DDA) method. The failure conditions and their related impact factors of toppling rock slopes were derived by building the corresponding mathematical models based on the limit equilibrium method (LEM), and the deficiency of the existed LEM for analysing the toppling system was pointed out. Several numerical examples, such as a single rock block of different dimensions, classical toppling rock slope model, and multiple rock blocks of different distributions, were adopted to investigate the toppling failure mechanisms under different conditions. The results showed that the 3D DDA is a very powerful numerical tool to study the failure mechanisms of toppling rock slopes and simulate the failure process of various toppling rock slopes with different distributions of structural planes inside rock mass. The controversial safety factor of the slope stability was avoided in the 3D DDA numerical simulation. Through the 3D DDA results, some more real phenomena of slope failure could also be observed and explained. For example, the slope block toppling tended to be toppling-sliding rather than pure toppling. In addition, the general laws of toppling slope failure were presented.