A bounding surface model is formulated to simulate the behavior of clays that are subject to an anisotropic consolidation stress history. Conventional rotational hardening is revisited from the perspective of thermodynamics. As the free energy cannot be accumulated infinitely upon critical state failure, the deviatoric back stress must vanish. This requires the rotated yield surface to be turned back to eventually align on the hydrostatic axis in the stress plane. Noting that most of the previous propositions violate this restriction, an innovative rotational hardening rule is formulated that is thermodynamically admissible. The bounding surface framework that employs the modified yield surface is applied to simulate elastoplastic deformations for overconsolidated clays, with which the overprediction of strength on the “dry” side can be greatly improved with reasonable results. Other important features, including contractive or dilative response and hardening or softening behavior, can also be well‐captured. It has been shown that the model can simulate three types of reconstituted clays that are sheared with initial conditions over a wide range of anisotropic consolidation stress ratios and overconsolidation ratios under both triaxial undrained and drained conditions. Limitations and potential improvement of the model regarding the fabric anisotropy at critical state have been discussed.

中文翻译：

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各向异性超固结土的边界面模型，结合热力学允许的旋转硬化规律

制定边界表面模型以模拟受各向异性固结应力历史影响的粘土的行为。从热力学的角度重新审视了常规的旋转硬化。由于在临界状态失效时不能无限积累自由能，所以偏向背应力必须消失。这要求将旋转的屈服面折回以最终在应力平面中的静液压轴上对齐。注意到大多数先前的主张都违反了这一限制，因此制定了一种创新的旋转硬化规则，该规则在热力学上是允许的。应用采用修正屈服面的边界面框架来模拟超固结黏土的弹塑性变形，这样可以大大改善对“干”侧强度的过度预测，并获得合理的结果。还可以很好地捕获其他重要特征，包括收缩或扩张反应以及硬化或软化行为。结果表明，该模型可以模拟三种类型的再生粘土，这些粘土在三轴不排水和排水条件下，在大范围的各向异性固结应力比和超固结比的初始条件下被剪切。已经讨论了关于临界状态下织物各向异性的模型的局限性和潜在的改进。结果表明，该模型可以模拟三种类型的再生粘土，这些粘土在三轴不排水和排水条件下，在大范围的各向异性固结应力比和超固结比的初始条件下被剪切。已经讨论了关于临界状态下织物各向异性的模型的局限性和潜在的改进。结果表明，该模型可以模拟三种类型的再生粘土，这些粘土在三轴不排水和排水条件下，在大范围的各向异性固结应力比和超固结比的初始条件下被剪切。已经讨论了关于临界状态下织物各向异性的模型的局限性和潜在的改进。