Abstract Strength and deformability properties of sedimentary rocks are difficult to characterize as these geomaterials show anisotropic mechanical behavior, which cannot be adequately evaluated by an isotropic constitutive model. This essay proposes a cross-anisotropic elastoplastic model to evaluate stress–strain relationships of sedimentary rocks. The approach couples the twelve-parameter Lade–Kim isotropic model with a non-uniform scaling of the stress tensor and includes two scaling parameters that link the orientation of the bedding planes with the loading direction. The anisotropic model parameters can be conveniently determined using Bayesian analysis. We illustrate our method using triaxial tests on a variety of confining stresses and bedding plane orientations for a travertine and a Tournemire shale. Our results demonstrate that the predicted maximum deviatoric stresses and the simulated stress–strain curves are shown to be in good agreement with the measured data.

中文翻译：

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应用于沉积岩的交叉各向异性弹塑性模型

摘要 沉积岩的强度和变形特性难以表征，因为这些岩土材料表现出各向异性的力学行为，不能通过各向同性本构模型进行充分评估。本文提出了一个交叉各向异性弹塑性模型来评估沉积岩的应力-应变关系。该方法将十二参数 Lade-Kim 各向同性模型与应力张量的非均匀缩放相结合，并包括两个缩放参数，将层理平面的方向与加载方向联系起来。使用贝叶斯分析可以方便地确定各向异性模型参数。我们对石灰华和 Tournemire 页岩的各种围压和层理平面方向使用三轴测试来说明我们的方法。