Rock fracturing modeling employing the heterogeneous CVBM mode
heterogeneous CVBM, laboratory tests, characteristic stresses, rock mechanics, spatial and structural variability
Understanding rock behavior at the laboratory scale is an essential part of predicting the response of rock masses, given the similarity in fracturing modes and the relationship between characteristic stresses and strength at the field scale. Numerous researches have been developed trying to represent the rock behavior by means of numerical models. Several of them consider the texture and internal heterogeneity of these materials, employing Voronoi polygons and calculation methods based on discrete elements. In recent years, a better representation of joint behavior in RS2 software has allowed the development of the so-called CVBM (Continuum Voronoi Block Model) or RS2-VTM (RS2 Voronoi Tesselated Model), based on the finite element method, whose advantage lies in the shorter processing time that allows for a more efficient calibration. Although these models were able to represent the behavior of granitic rocks, only the effect of the Voronoi block structure has been considered so far. In this research three types of heterogeneities (geometric, material and contact) were inserted into the compression and indirect tensile models, numerically representing the behavior of Diorite Äspö by means of CVBM. The effects of changing various mesoscopic parameters and spatial and structural variability on the macroscopic response of the material were analyzed, defining a calibration procedure for the heterogeneous CVBM. In the analyses an attempt is made to study the relationship between the complex phenomena occurring within the rocks and the non-linear macroscopic behavior exhibited by this type of material, evaluating the effect of texture and heterogeneity on the response at the laboratory scale