Physical and mechanical characterization of ornamental stone for numerical modelling of the quarry exploitation activities. The case of Cava Lorgino (Northern Italy).

This master's thesis focuses on the determination of physical and mechanical parameters of ornamental stone from Cava Lorgino in Northern Italy, with a primary objective of creating a numerical modeling for quarry exploitation activities. Four distinct types of metamorphic rock exploited in the quarry and defined here as classic, blue, brown, and black marble, were analyzed by measurement and laboratory tests to define the physical and mechanical properties of the rock. Since this type of rock shows an anisotropic features two different analysis directions were considered: parallel (verso) and orthogonal (contro) to the foliation plane. With this aim specimen with different shape and directions (cubic, prismatic, and cylindrical) were collected to carry out a range of physical measurements and mechanical laboratory tests. These tests included ultrasonic pulse velocity (UPV) measurements to determine shear and compression wave velocity, subsequently enabling the calculation of elastic-dynamic parameters like Young's modulus, shear modulus, bulk modulus, and Poisson's ratio. Furthermore, uniaxial, triaxial compression and 4-point bending tests, were performed on the two considered directions to evaluate the mechanical properties. The laboratory results were processed to identify the maximum compressive and tensile strength of each material and the anisotropic features, useful for numerical modeling. The intact rock strength parameters were obtained considering both the Hoek and Brown and Mohr-Coulomb criteria. The results showed different deformability and strength, as well as anisotropic behavior for each considered metamorphic rock. Subsequently, a numerical model of the quarry was developed in the UDEC software, a Distinct Element Method (DEM) tool, to analyze quarry stability conditions. The numerical simulations were carried out to consider the variability of the physical and mechanical properties of the rock in order to take into account the heterogeneous nature of the quarry, including mixed zones of different rock types. The outcomes of the UDEC software simulations provided valuable insights into the stability conditions of the quarry, identifying potential failure zones and enhancing the understanding of quarry exploitation activities in the context of ornamental stone extraction.