Risk of shear failure and extensional failure around over-stressed excavations in brittle rock

Rock Failure Energies and Failure Processes

Carving rock by indenting sharp objects into the surface under an impact force has been a favored method of fragmentation for millenia . However, as rock gets harder the lifetime of these sharp tools becomes short and, in a compromise hardened bits of rounder contour have become more common, particularly when driven by mechanical power. To better understand the behavior of these newer generatio...

Flexural Toppling Failure in Rock Slopes: From Theory to Applications

Toppling failure is one of the most common modes of failure of rock slopes in layered rock strata. Flexural toppling is one of the well-known modes of the failure. This type of failure occurs due to bending stress. In this article, a brief yet comprehensive review of toppling failure is presented. Firstly, the conditions and general mechanism of the failure are described. Then, experimental, th...

Modeling of Brittle Failure and Comparisons

A numerical multiple crack interaction model was developed to simulate the failure process in brittle solids containing significant populations of flaws. The model, which is 2D, allows for the growth of microcracks on a regular array of potential crack sites. Individual cracks may be oriented vertically, horizontally or at 450 to the sample axes. Quasi-static equilibrium equations are expressed...

Brittle Failure Mechanism in Thermoelectric Skutterudite CoSb3

Skutterudites based on CoSb3 have high thermoelectric efficiency, but the low fracture strength is a serious consideration for commercial applications. To understand the origin of the brittleness in CoSb3, we examine the response along various shear and tensile deformations using density functional theory. We find that the Co−Sb bond dominates the ideal strength. Among all the shear and tensile...

Multiscale failure modelling of quasi - brittle materials