Applied Sciences

Integrating CAD-based mine maps with GIS through ETL tools requires an intermediate spatial data format suitable for a range of applications. This industrial case study compares GeoJSON, GeoPackage and GML, each uncompressed and in ZIP archives, using production mine workings maps of three underground copper mines of KGHM Polska Miedź S.A. (1,179,967 vector features). The comparison was undertaken to support the enterprise’s internal mine map data integration needs. Eleven operations were timed in FME, GDAL/OGR and QGIS, covering local and network reading and writing as well as interactive display. Uncompressed GeoPackage was the fastest in nine of the eleven operations; in local reading in FME, it required 7.0 s, compared with 48.2 s for GeoJSON and 191.6 s for GML, and it was 24.76% and 39.94% smaller, respectively. ZIP compression reduced file sizes by 90.75–94.68%, with GeoJSON producing the smallest archive. Compression shortened network reading of GeoPackage and network writing of the text-based formats in FME (GeoJSON: from 991 to 172 s), but it slowed local reading and, for GeoPackage, zooming in QGIS (from 9 to 388 s). Working, transport and archival formats should therefore be selected against separate criteria, and format efficiency must be combined with change detection, concurrency control and limited disk operations in the ETL process.

Temperature-dependent mechanical behavior and wetting-induced swelling affect the stability of underground structures in expansive mudstone. Three modified constitutive models were evaluated against temperature-controlled triaxial compression and laterally constrained swelling tests. The Mohr–Coulomb strain-softening and Hoek–Brown-based unified hardening–softening models incorporated temperature effects and equivalent swelling strains. The unsaturated unified hardening model was extended through equivalent temperature–stress mapping. Mechanical calibration used data from 12 triaxial conditions, supplemented by evaluation at 40 °C after recalibration at 20 and 60 °C. Swelling parameters calibrated at 20 °C were held constant at higher temperatures. For the 12 calibration conditions, the Mohr–Coulomb model yielded the lowest errors in peak deviatoric stress and deviatoric stress at 5% axial strain. The hardening–softening model improved pre-peak response and peak-strain estimates relative to Mohr–Coulomb. The unsaturated model achieved the lowest pre-peak normalized root-mean-square error of 10.10% and a swelling mean absolute error of 0.22 percentage points across 40–80 °C, but overestimated deviatoric stress at 5% axial strain. The sensitivity results support a staged calibration procedure involving initial parameter estimation followed by joint refinement using the designated calibration data. These findings provide a basis for model selection and parameter calibration in analyses of temperature-dependent mechanical and swelling responses of expansive mudstone.

Dynamic failure of roadways subjected to mining-induced seismicity poses a major challenge to support design and coal burst control in deep coal mines. Using the roadway of the 3102 working face at M Coal Mine in Inner Mongolia, China, as the engineering background, a UDEC-Trigon model was established to compare four support schemes: unsupported, bolt support, combined bolt and cable support, and combined support with bolts, cables, and hydraulic props. The results show that support configuration significantly affects roadway deformation, particle velocity, stress redistribution, and fracture development. Bolt support alone provides limited improvement, whereas the introduction of cables markedly reduces rib deformation, high-velocity ejection zones, and fracture propagation. The maximum left- and right rib displacements decrease from 0.75 and 0.65 m under the unsupported condition to 0.12 and 0.25 m under combined bolt and cable support, respectively. Tensile cracks are more widely distributed than shear cracks, with tensile failure dominating the shallow surrounding rock and shear failure occurring mainly in deeper zones. Fractal analysis further indicates that combined bolt and cable support effectively suppresses crack development and reduces fracture network complexity, whereas hydraulic props provide only limited additional improvement. Based on the numerical results, an optimized bolt and cable reinforcement scheme combined with roof pre-splitting blasting was implemented in the field. The maximum deformations of the roof, ribs, and bottom were reduced by 40.0%, 60.0%, and 55.6%, respectively. These findings provide a reference for support design and coal burst mitigation in deep coal roadways.