In this paper, uniaxial compression tests on layered rock specimens are numerically modelled using the discrete element method to investigate the effect of a soft interlayer on the strength and deformation of rock specimens. For these simulations, the thickness and dip angle of the soft interlayer were varied. Thirty-five numerical models for different cases were established after calibrating the micro-mechanical parameters of the hard and soft rock materials. The computational results were analysed in terms of three aspects: the stress–strain curves, micro-crack propagation patterns, and particle velocity fields. The stress–strain curves indicate that increasing the thickness and dip angle of the soft interlayer causes the peak stress and ultimate strain to drop by up to 42% and 34%, respectively. The thickness of the soft interlayer has a greater influence than that of the soft interlayer dip angle on the uniaxial mechanical behaviour of the rock specimen. Additionally, crack propagation patterns and particle motion in the layered rock models indicate that the cracks develop preferentially along the soft interlayer and that the notable failure features of the layered rock models are stepped failure modes that occur at greater dip angles.

中文翻译：

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层状岩体单轴压缩试验的离散元数值模拟

本文使用离散元方法对层状岩石样本的单轴压缩试验进行了数值模拟，以研究软质夹层对岩石样本强度和变形的影响。对于这些模拟，改变了软中间层的厚度和倾角。在校准硬，软岩石材料的微机械参数后，建立了针对不同情况的三十五个数值模型。计算结果从三个方面进行了分析：应力-应变曲线，微裂纹传播模式和粒子速度场。应力-应变曲线表明，增加软夹层的厚度和倾角会使峰值应力和极限应变分别下降多达42％和34％。软质夹层的厚度对岩石标本的单轴力学行为的影响大于软质夹层倾角的影响。此外，层状岩石模型中的裂纹扩展模式和颗粒运动表明，裂纹优先沿软质夹层发展，层状岩石模型的显着破坏特征是在较大倾角处出现的阶梯破坏模式。