A three‐dimensional (3D) soil–structure interface model is proposed within the two‐mechanism constitutive theory and bounding surface theory originally established for soils. The proposed model has two main characteristics: first, the model is formulated based on two different and superposed deformation mechanisms. The first mechanism is due to the stress ratio increment, and the second is due to the normal stress increment. Each mechanism induces a shear strain component and a normal strain component. The proposed model can be reduced to the conventional single‐mechanism interface model. Second, the plastic modulus and stress dilatancy are defined using the bounding surface theory. The plastic flow rule under cyclic loading is modified and assumed to be dependent on both the stress state of the mapping point and the stress reversal loading direction. The proposed model was validated against the available 3D interface tests and was found to satisfactorily reflect the salient features of the interfaces under monotonic and cyclic loading paths with different normal boundaries. The problem in which the elastic normal stiffness in conventional single‐mechanism interface models is often underestimated to enhance the simulation performance under varying normal stress conditions is solved by incorporating the second mechanism. And the effect of the second mechanism on the modeling behavior is discussed. The modified plastic flow direction accurately simulates the 3D cyclic shear response, and the difference between the model simulation and test result increases with the number of cycles by use of the plastic flow direction defined in conventional bounding surface theory.

中文翻译：

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二维循环荷载的双力学土-结构界面模型

在最初为土壤建立的两力学本构理论和边界表面理论中，提出了三维（3D）土壤-结构界面模型。所提出的模型具有两个主要特征：首先，该模型是基于两种不同且重叠的变形机制制定的。第一种机制是由于应力比增加，第二种机制是由于法向应力增加。每种机制都产生剪切应变分量和法向应变分量。所提出的模型可以简化为传统的单机制接口模型。其次，使用边界面理论定义塑性模量和应力膨胀率。修改了周期性载荷下的塑性流动规律，并假定其既取决于映射点的应力状态，又取决于应力反向载荷方向。所提出的模型已针对可用的3D接口测试进行了验证，并被发现可以令人满意地反映具有不同法线边界的单调和循环加载路径下的界面的显着特征。通过结合第二种机制，可以解决传统单机构界面模型中弹性法向刚度经常被低估以增强在变化的法向应力条件下的仿真性能的问题。并讨论了第二种机制对建模行为的影响。修改后的塑料流动方向可准确模拟3D循环剪切响应，