Abstract Very limited attention was paid on the micro–response of sand as it interacts with geomembrane and the effect of surface hardness on the interaction at the microscopic level. In this study, a coupled finite difference–discrete model was adopted with which to analyze the shear behavior of sand–smooth geomembrane interface. The model was validated using published experimental data. The numerical results show that the effects of normal stress and surface hardness on the interface strength depend on the shear mechanism (sliding or plowing) at the interface. There exists a critical normal stress at which the mechanism transforms from predominant sliding to predominant plowing. There is a high level of coupling effect between normal stress and surface hardness on the interface strength. Micro–topographical analysis of geomembrane provides clear insights into the shear mechanism at the interface, supporting the results obtained from interface shear tests. No shear band is formed during shearing for a sand–smooth geomembrane interface. The shear resistance of sand–smooth geomembrane interface relies on interface indentations and characteristics rather than on the formation of shear band.

中文翻译：

---

使用 FDM-DEM 耦合模拟对光滑土工膜-砂界面进行微观分析

摘要 砂与土工膜相互作用时的微观响应以及表面硬度对微观层面相互作用的影响很少受到关注。在这项研究中，采用耦合的有限差分离散模型来分析砂光土工膜界面的剪切行为。该模型使用已发表的实验数据进行了验证。数值结果表明，法向应力和表面硬度对界面强度的影响取决于界面处的剪切机制（滑动或犁切）。存在一个临界法向应力，在该应力下，机制从主导滑动转变为主导犁耕。法向应力和表面硬度之间对界面强度有高度的耦合作用。土工膜的微观形貌分析提供了对界面剪切机制的清晰洞察，支持从界面剪切测试中获得的结果。对于砂光土工膜界面，在剪切过程中没有形成剪切带。砂光土工膜界面的剪切阻力取决于界面的压痕和特性，而不是剪切带的形成。