21 / 2025-07-09 21:27:43

TEST EVALUATION OF SLOPE DEFORMATION AND FISSURE NETWORK WITH DIFFERENT SURFACE SHAPES UNDER THE ACTION OF UNDERGROUND MINING

Geological disasters ; landslide ; underground mining ; deformation failure mode ; fissure evolution

The mountainous region of southwest China is abundant in mineral resources. However, the complex topographic and geological conditions in these areas make underground mining susceptible to triggering geological hazards. To comprehensively understand the hazard mechanisms associated with mining slope instability, generalized models of linear, concave, and concave-convex slopes were developed. The entire process, from the formation of mining fissure networks to the ultimate slope instability, was analyzed using base friction tests, digital photogrammetry for deformation measurement (DPDM) technology, and fractal theory. The results demonstrate that as the mining area, number of mining layers, and mining depth increase, the formation and discontinuities undergo continuous adjustments and dislocation, leading to diversification in their interactions and developmental trajectories. Fissure networks and disruptions within the formation periodically propagate toward the surface, increasing the proportion of space occupied by fractured rock mass, which consequently decreases the integrity and stability of the slope. The displacement and shear strain of the overlying strata intensify, with the maximum displacement typically occurring in the direct roof and the upper-middle part of the slope, while the maximum shear strain is concentrated in the direct roof, the leading and trailing edges of the slope, and the shear failure zones on the slope surface. The deformation and failure modes are influenced by the shape of the slope: linear and concave slopes predominantly experience creepsliding and fracturing, whereas concave-convex slopes are more prone to bending and fracturing. The fractal dimension is directly proportional to mining depth, while the probability distribution index is inversely proportional to mining depth, indicating that the fissure development mechanism evolves from micro fissure formation to large scale fissuring. The increased complexity in the boundaries of the fissure network is accompanied by expansion, compaction, and penetration. These findings provide a basis for accurately assessing and effectively mitigating mining-induced geological hazards in slopes with similar geometric configurations.