Abstract A micro-mechanical model to study the microscopic and macroscopic behavior of unsaturated soils under different suctions is proposed in this study. In the model, a novel pore-scale numerical method for simulating the liquid–solid interfaces is proposed first. A discretization of the particle surface using Fibonacci-Lattice is then introduced to calculate the capillary forces from the complex liquid–solid interfaces. The joint influence of capillary forces and the interparticle contact forces on the motion of the particles are handled by the discrete element method (DEM). The effective stress parameter estimated by the model is compared with the experimental results for unsaturated soils, which confirms the validity of the proposed micro-mechanical model. The microscopic responses (liquid–solid interfaces, capillary forces, contact forces and coordination numbers) and macroscopic responses (strength, stress–strain relationship and volume change) of unsaturated soils in desaturation tests and triaxial tests are studied by the proposed model.

中文翻译：

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基于DEM的非饱和土微观力学模型

摘要 本研究提出了一种研究非饱和土在不同吸力下微观和宏观行为的微观力学模型。在该模型中，首先提出了一种用于模拟液固界面的新型孔隙尺度数值方法。然后引入使用 Fibonacci-Lattice 的粒子表面离散化，以计算复杂的液固界面的毛细管力。毛细管力和颗粒间接触力对颗粒运动的联合影响由离散元法 (DEM) 处理。将模型估计的有效应力参数与非饱和土的实验结果进行比较，证实了所提出的微力学模型的有效性。微观响应（液固界面、毛细管力、