The dilatancy behavior of overconsolidated (OC) clays is a key factor in determining their strength and deformation characteristics. Recognizing the limitations of previous dilatancy relations for OC clays, a novel dilatancy relation is proposed that can effectively capture the changes in dilatancy point, volume dilatancy and contraction with the overconsolidation ratio (OCR). As OC clays revert to the normally consolidated (NC) state, the proposed dilatancy relation smoothly transitions to that of the modified Cam‐clay (MCC) model, ensuring a unified description of the dilatancy relation between OC and NC clays. The dilatancy relation can be easily incorporated into the constitutive model of different theoretical frameworks. Subsequently, this advanced dilatancy relation is integrated into a new elastoplastic constitutive model for OC clays within the framework of bounding surface and generalized plasticity theory. The validity of the proposed model is confirmed through drained triaxial compression and extension, undrained triaxial compression and extension, as well as complex stress path tests for clays with various OCRs, and the simulation results of the proposed model are compared with those of the SANICLAY model. The comparative analysis demonstrate that the model performs well in simulating the behavior of OC clays.

中文翻译：

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具有高级剪胀关系的超固结粘土弹塑性本构模型


超固结（OC）粘土的剪胀行为是决定其强度和变形特性的关键因素。认识到先前OC粘土剪胀关系的局限性，提出了一种新的剪胀关系，可以有效捕获剪胀点、体积剪胀和收缩随超固结比（OCR）的变化。当OC粘土恢复到正常固结（NC）状态时，所提出的剪胀关系平滑过渡到修正的Cam-clay（MCC）模型，确保了OC和NC粘土之间剪胀关系的统一描述。剪胀关系可以很容易地纳入不同理论框架的本构模型中。随后，这种先进的剪胀关系被集成到边界表面和广义塑性理论框架内的 OC 粘土的新弹塑性本构模型中。通过排水三轴压缩和拉伸、不排水三轴压缩和拉伸以及不同OCR粘土的复杂应力路径试验验证了模型的有效性，并将模型的模拟结果与SANICLAY模型的模拟结果进行了比较。对比分析表明该模型在模拟 OC 粘土的行为方面表现良好。