The Voronoi grain-based breakable block model (VGBBM) based on the combined finite-discrete element method (FDEM) was proposed to explicitly characterize the failure mechanism and predict the deformation behavior of hard-rock mine pillars. The influence of the microscopic parameters on the macroscopic mechanical behavior was investigated using laboratory-scale models. The field-scale pillar models (width-to-height, W/H=1, 2 and 3) were calibrated based on the empirically predicted stress-strain curves of Creighton mine pillars. The results indicated that as the W/H ratios increased, the VGBBM effectively predicted the transition from strain-softening to pseudo-ductile behavior in pillars, and explicitly captured the separated rock slabs and the V-shaped damage zones on both sides of pillars and conjugate shear bands in core zones of pillars. The volumetric strain field revealed significant compressional deformation in core zones of pillars. While the peak strains of W/H=1 and 2 pillars were relatively consistent, there were significant differences in the strain energy storage and release mechanism. W/H was the primary factor influencing the deformation and strain energy in the pillar core. The friction coefficient of the structural plane was also an important factor affecting the pillar strength and the weakest discontinuity angle. The fracture surface was controlled by the discontinuity angle and the friction coefficient. This study demonstrated the capability of the VGBBM in predicting the strengths and deformation behavior of hard-rock pillars in deep mine design.

中文翻译：

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使用基于 Voronoi 颗粒的易碎块模型研究应力引起的矿柱渐进破坏


提出了基于有限离散元组合法（FDEM）的Voronoi颗粒易碎块模型（VGBBM），以明确表征硬岩矿柱的破坏机制并预测变形行为。使用实验室规模的模型研究了微观参数对宏观力学行为的影响。现场尺度矿柱模型（宽度到高度，W/H=1、2 和 3）是根据 Creighton 矿柱的经验预测应力应变曲线进行校准的。结果表明，随着 W/H 比的增加，VGBBM 有效地预测了岩柱从应变软化到伪延性行为的转变，并明确捕获了分离的岩板和岩柱两侧的 V 形损伤区，柱核心区域的共轭剪切带。体积应变场显示支柱核心区存在显着的压缩变形。虽然W/H=1和2柱的峰值应变相对一致，但应变储能和释放机制存在显着差异。 W/H是影响柱芯变形和应变能的主要因素。结构面摩擦系数也是影响支柱强度和最弱间断角的重要因素。断裂面由不连续角和摩擦系数控制。这项研究证明了 VGBBM 在预测深部矿山设计中硬岩矿柱的强度和变形行为方面的能力。