The properties of soft–hard interbedded rock masses are significantly impacted by the strength of rock layers and the characteristics of interface surfaces. This study investigates the mechanical properties of soft–hard interlayered rock masses by preparing rock-like specimens with different interface angles. Uniaxial and triaxial compression tests were conducted to examine the compression mechanical characteristics of the specimens. Experimental results demonstrated that in the uniaxial compression tests, the peak strength of the two-layer rock-like specimen exhibits an initial decrease followed by an increase as the interface angle increases. Similarly, the peak strength of the three-layer rock-like specimen also follows a “U-shaped” pattern. The failure of both specimens shifts from tensile failure to shear failure. In the triaxial tests, the strength of the two-layer rock-like specimen initially increases and subsequently decreases as the interface angle increases. In contrast, the intensity of the three-layer rock-like specimen exhibits a decreasing trend, transitioning from shear dilation or tensile failure to shear failure. By utilizing the damage constitutive model to compute the compressive strength of the composite specimen, it was observed that the deviation from the experimental value did not exceed 2.5%, and the overall shape of the curves was in good agreement. Consequently, it is affirmed that the damage constitutive model developed in this study can accurately capture the pre-peak phase of the stress–strain relationship in soft–hard interlayered rock-like specimens, thus providing a valid representation of their mechanical behavior.

中文翻译：

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软硬互层岩体压缩力学特性及本构模型

软硬互层岩体的性质受岩层强度和界面特征影响显着。本研究通过制备具有不同界面角度的类岩石试样来研究软硬夹层岩体的力学特性。进行单轴和三轴压缩试验来检查样品的压缩力学特性。实验结果表明，在单轴压缩试验中，两层类岩石试件的峰值强度随着界面角度的增大呈现先减小后增大的趋势。同样，三层岩石样本的峰值强度也遵循“U”形模式。两个样本的破坏都从拉伸破坏转变为剪切破坏。在三轴试验中，两层岩石样件的强度随着界面角度的增大先增大后减小。相比之下，三层类岩石试件的强度呈现下降趋势，从剪切膨胀或拉伸破坏过渡到剪切破坏。利用损伤本构模型计算复合材料试件的抗压强度，结果与实验值的偏差不超过2.5%，曲线整体形状吻合较好。因此，可以肯定的是，本研究开发的损伤本构模型可以准确捕获软硬夹层岩石样件中应力应变关系的峰值前阶段，从而提供其力学行为的有效表示。