Three-dimensional Distinct Element Method for stability analysis of marble quarries in the Apuan Alps (Italy)

Abstract

The present article analyses and proposes an innovative dynamic planning methodology, supported by computer tools and in-situ measurements, for the optimization of the planning techniques of underground marble quarries. The abovementioned planning methodology has been implemented in ‘Cava Piastreta’, an underground marble quarry located in the Apuan Alps, Italy. The entire excavation area has been characterized with tridimensional topographic surveys, geotechnical traditional surveys, and radar surveys, as well as stress-level measurement campaigns through a CSIRO cell. When an underground excavation project concerning stone material is designed, it is mandatory to have an instrument allowing a forecast of the stress-strain behavior of the rock mass. To this end, the rocky outcrop can also be represented by different mathematical models to schematize the geomechanical behavior. The accuracy and reliability of the simulation of the mechanical response of the fractured mass depend on the exactness with which the rocky outcrop is defined. Therefore, the geometric modeling phase acquires prominent importance. To better address the discontinuous nature of the studied rocky mass, the distinct element method has been used in modeling the mechanical behavior of the mass itself. Given the peculiar geometrical characteristics of the excavation site in question, the deterministic approach has been chosen to simulate as closely as possible the position of the major discontinuities identified in-situ. The present article thus aims to briefly describe a study that has been developed over the last years intended to deepen the analysis of the geostructural characterization of the excavation site, as well as to compare the obtained results through the geometrical tridimensional modeling with the values measured in-situ.