Analysing the stability of bimslopes (i.e. slopes made of bimrock (block-in-matrix rock)) is challenging because bimrock has a complex internal structure. In the study reported here, a stochastic finite-element analysis with the shear-strength-reduction method was conducted to elaborate how dispersed oversized rock particles influence the stability of a vertical bimslope. Numerical models with different rock compositions were generated and analysed to characterise the definiteness and randomness. The factor of safety and the failure zone were used to establish the relationship between slope stability and fractal dimension (FD) of rock-size distribution and rock spatial variability. The numerical results show that the FD and spatial locations of the rock particles influence bimslope stability indirectly, with the key indicator for the skid resistance of a bimslope being the compactness of the rock composition crossing the sliding surface with given volumetric block proportion. This finding also highlights the validity and feasibility of stochastic analysis in outperforming deterministic analysis. Overall, the present findings offer a reference for further understanding of the collapse mechanism and reinforcement measures of existing bimslopes.

中文翻译：

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分散岩石颗粒对边坡稳定性影响的数值研究

分析双石斜坡（即由双石（块状基质岩石）构成的斜坡）的稳定性具有挑战性，因为双石具有复杂的内部结构。在此报告的研究中，采用剪切强度折减法进行了随机有限元分析，以详细说明分散的超大岩石颗粒如何影响垂直双坡的稳定性。生成并分析不同岩石成分的数值模型，以表征确定性和随机性。使用安全系数和破坏区域来建立边坡稳定性与岩石尺寸分布和岩石空间变异性的分形维数（FD）之间的关系。数值结果表明，岩石颗粒的FD和空间位置间接影响双坡稳定性，评价双坡抗滑性能的关键指标是在给定体积块比例的情况下穿过滑动面的岩石成分的致密性。这一发现还强调了随机分析优于确定性分析的有效性和可行性。总体而言，本研究结果为进一步了解现有双坡的崩塌机理和加固措施提供了参考。