Approach to 3D study of large-plane rock failures using 2D slices. Case study of marble

There are several known cases of plane failures involving large blocks of rock in limestone and marble quarries. Stability 2D analysis, such as that developed by the limit equilibrium method of Hoek and Bray (1981), faces certain difficulties. It makes sense that block geometry is variable depending on the sections that we set, and this is just one of the differences considered among the chosen sections. Moreover, the loading conditions induced by blasting or water inflows, are not equal in every section. Taking advantage of the strength of these large potentially movable blocks, considered as a set of sections, it is possible to transfer the force requirements among them to compensate for the lack of resistance of some specific sections with extra surrounding ones. In this paper, we provide an example of back analysis of a large 40,000 t sliding marble block.