An optimum design of mine pillars necessitates a reliable estimation of the rock mass strength. It is known that the Hoek-Brown failure criterion, with its strength parameters obtained using the Geological Strength Index, tends to underestimate the confined strength of interlocked jointed hard rock masses. Therefore, geomechanical designs based on this approach could lead to oversized pillars due to the underestimation of the pillar core strength. In this study, a two-dimensional finite element program was used to investigate the strength and failure mechanisms of jointed pillars. For this purpose, a previously calibrated grain-based model of heat-treated marble, an analogue for a highly interlocked jointed rock mass, was upscaled to simulate jointed pillars of various width-to-height ratios. The simulation results showed that the slope of the pillar stability curve obtained from this approach is steeper than those of existing continuum and discontinuum models of jointed pillars. This is attributed to the high degree of block interlock leading to higher rock mass strength at the pillar core. It is demonstrated that this modeling approach provides more realistic results in terms of pillar failure process compared to other continuum models, in which the rock mass is simulated as a homogeneous material.

矿柱的优化设计需要可靠地估计岩体强度。众所周知，Hoek-Brown 破坏准则的强度参数使用地质强度指数获得，倾向于低估互锁节理硬岩体的约束强度。因此，由于低估了柱芯强度，基于这种方法的地质力学设计可能导致过大的柱。在这项研究中，二维有限元程序用于研究连接柱的强度和破坏机制。为此，先前校准的热处理大理石的基于颗粒的模型（高度互锁的节理岩体的类似物）被放大以模拟各种宽高比的节理柱。仿真结果表明，采用这种方法得到的柱体稳定性曲线的斜率比现有的有节理柱体的连续体和不连续体模型的斜率更陡峭。这归因于高度的块体互锁导致柱芯处更高的岩体强度。结果表明，与将岩体模拟为均质材料的其他连续模型相比，这种建模方法在支柱破坏过程方面提供了更真实的结果。