For enhancing stability evaluations and safety conditions of Carrara marble quarries (Apuan Alps, Tuscany, Italy) the UOIM (Operative Unit of Mining Engineering) has developed a twin approach of analysis: this is based, on one hand, on the application of an experimental campaign addressed to in-situ stress estimation, large scale geo-structural analysis and rock mass characterization and, on the other hand, on numerical analyses that can be able to modeling materials with multiple intersecting discontinuities when simulating excavation. The aim of this activity, is to drive the concept that, apart from the obvious objective of exploit a natural resource, the main purpose of the quarry project should be to prevent instability of the rock mass, in every step of the foreseen exploitation. The main results of the discontinuous numerical analysis are presented with reference to the reported case of Fantiscritti quarries assuming a crack initiation threshold for rock mass based on deviatoric stress levels, following the relation σ1 – σ3 ≅ 0.2σc (20± 4 MPa).

1. Introduction

The quarrying district of Carrara (Apuan Alps, Tuscany, Italy) is one of the most intensively quarried areas in the world: this condition often entails the need of approaching almost all exploitation with reference to a large scale problem, involving the study of the basin in which other quarries – still active or not - are nearby located; this is also the case of the Fantiscritti (Carrara) area, to which the reported study is referred. An important role on the development of failures within the rock mass and on its global stability is played by the marble tectonical genesis, the huge topographic gradients of Apuane Alps ridge, the geo-structural assessment of marble deposits and the excavation geometries (also related to all the excavations nearby located).

This content is only available via PDF.
You can access this article if you purchase or spend a download.