Numerical Simulation of Slide-Toe-Toppling Failure Using Distinct Element Method and Finite Element Method

In blocky and layered rock slopes, toppling failure is a conventional type of instability which may occur in mining and civil engineering. If this kind of slope failure happens as a consequence of another type of failure, it is mentioned to as secondary toppling failure. "slide-toe-toppling" is a kind of secondary toppling failures, where the toe part of the slope is toppled as a consequence of a semi or non-circular sliding failure at the upper of the slope. This failure has been studied using physical modelling and analytical method. In the present study, firstly a brief review of the toppling failure in rock slopes is summarized, and the mechanism of slide-toe-toppling failure is described. Then, this failure is examined through a series of numerical modelling. Distinct element method (UDEC software) and finite element method (Phase2 software) were used in this research. Three types of slide-toe-toppling failures, including flexural, blocky, and block-flexural, are simulated. Comparison between two numerical modellings (distinct element and finite element methods) with the result of pre-existing physical models and analytical solution, illustrates that UDEC software has a better agreement than Phase2 software. This accordance indicates that this numerical code is well capable to analyze the behavior of slide-toe-toppling failure.