1458 combined with GSI-based quality characterization and a disturbance factor D, allowing laboratory-scale intact properties to be reduced to rock-mass-scale conditions influenced by mining-induced degradation. The rock strength parameters at the excavation level were adopted from laboratory testing of core specimens and complemented by intact-rock constants required for constitutive and failure descriptions used in the numerical modelling (e.g., the mᵢ constant in the Hoek–Brown criterion). In the workflow, a clear distinction was maintained between intact-rock properties—primarily governed by the material behaviour of the specimen—and rock-mass behaviour, which additionally reflects discontinuities, jointing, and scale effects. The intact-rock input parameters representative of the excavation horizon, used as the basis for subsequent rock-mass parameter estimation and/or model calibration, are summarized in Table 1 Table 1 - Intact-rock strength and deformability parameters adopted for the excavation horizon and used as input for the analyses. Parameter !! "" Cohesion # Angle of friction ∅ Poisson's ratio % Density & '# Unit MPa GPa MPa o – g/cm3 – Value 45.0 33.5 20.5 32 0.22 2.28 8 2.3. Convergence monitoring Model validation was based on underground convergence monitoring conducted using roof-to-floor telescopic convergence indicators (“convergometers”) installed at selected locations within the panel, including long-life excavations and zones influenced by the mining front and the mined-out area. These devices consist of two coaxial sleeves of different diameters, where one sleeve moves inside the other; a millimetre scale enables direct reading of closure. A known limitation of this approach is the relatively low reading frequency and limited sensitivity to short-term deformation increments. Figure 5 - Location of convergometers within the analysed mining panel (left) and results of convergence measurements in the analysed panel (right) For comparison with numerical outputs, convergence in the model was defined as the sum of roof deflection magnitude and floor heave: s= ‘’1CC3‘−’3HCC1 (1) where ’1CC3 is total roof displacement taken as an absolute value due to the sign convention (negative roof displacement in the model).
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