Abstract Triaxial compression tests are conducted on semi-through jointed mudstone samples at conditions of different confining pressures and inclination angles. With the help of microscopic tests (SEM and XRD), the corresponding mechanical behaviors and failure mechanisms are better interpreted. A binary-medium constitutive model for semi-through jointed mudstone samples is proposed based on experimental results. In the framework of this model, the geomaterial is composed of the elastic-brittle cementing material and the elastoplastic frictional component which are represented by bonded elements and frictional elements respectively. The bonded element breaks into the frictional element gradually and these two parts together withstand the external loads. Subsequently, the strain concentration factor is introduced to connect local mechanical behaviors and macro average features by utilization of homogenization theory, and the breakage ratio to reveal the breakage evolution inside the representative volume element. The model parameters are determined on the basis of triaxial test results. Comparisons of predicted and tested curves are given and discussed specifically in aspects of stress, strain values and deformation stage descriptions. The model shows effects of inclination angles and confining pressures on jointed mudstone deformation features and gives good predictions qualitatively and quantitatively.

中文翻译：

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半贯通节理泥岩样品力学特性及二元介质本构模型

摘要 在不同围压和倾角条件下，对半贯通节理泥岩样品进行了三轴压缩试验。借助显微测试（SEM 和 XRD），可以更好地解释相应的力学行为和失效机制。基于实验结果，提出了半贯通节理泥岩样品的二元介质本构模型。在该模型的框架内，土工材料由弹脆胶结材料和弹塑性摩擦部件组成，分别用粘结单元和摩擦单元表示。结合元件逐渐进入摩擦元件，这两个部分共同承受外部载荷。随后，引入应变集中因子以利用均质化理论将局部力学行为和宏观平均特征联系起来，并通过破损率揭示代表性体积元素内部的破损演变。模型参数是根据三轴试验结果确定的。在应力、应变值和变形阶段描述方面，给出和讨论了预测曲线和测试曲线的比较。该模型显示了倾角和围压对节理泥岩变形特征的影响，并在定性和定量上给出了良好的预测。模型参数是根据三轴试验结果确定的。在应力、应变值和变形阶段描述方面，给出和讨论了预测曲线和测试曲线的比较。该模型显示了倾角和围压对节理泥岩变形特征的影响，并在定性和定量上给出了良好的预测。模型参数是根据三轴试验结果确定的。在应力、应变值和变形阶段描述方面，给出和讨论了预测曲线和测试曲线的比较。该模型显示了倾角和围压对节理泥岩变形特征的影响，并在定性和定量上给出了良好的预测。