Abstract Slope failure is one of the failure modes of natural dams. Turbid seepage flow is often observed on the downstream slope of a natural dam in the field and indicates the migration of fine particles in the dam. However, the coupling of internal erosion and seepage in natural dams during the impounding process is still unclear. This paper studies fine particles migration in a dam and the slope failure mode in the laboratory. Then, a coupling model was proposed with the fines migration equation, unsaturated seepage flow equation, and local stability analysis equation. In addition to the variation in the permeability coefficient due to fine particles migration, the strength parameters and density of the soil are also changed, which is considered in the model. Based on the conditions of the laboratory tests, simulations were conducted with the coupling model, and some parameters, such as pore pressure, porosity, principle stress, and factor of safety, were analyzed. Meanwhile, the influence of internal erosion and seepage on the stability of dams under different conditions is studied. Furthermore, the influence of some model parameters on the internal structure of the dam and its stability are discussed.

中文翻译：

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渗流引发的边坡破坏模式下的天然坝体破坏

摘要 边坡破坏是天然大坝的破坏模式之一。在野外自然坝的下游斜坡上经常观察到浑浊的渗流，这表明大坝中细颗粒的迁移。然而，蓄水过程中天然大坝内部侵蚀与渗流的耦合作用尚不清楚。本文在实验室中研究了大坝中细颗粒的迁移和边坡破坏模式。然后，提出了与细粒迁移方程、非饱和渗流方程和局部稳定性分析方程的耦合模型。除了由于细颗粒迁移导致渗透系数的变化外，土壤的强度参数和密度也发生了变化，这在模型中被考虑在内。根据实验室测试条件，利用耦合模型进行模拟，分析了孔隙压力、孔隙度、主应力、安全系数等参数。同时，研究了不同条件下内部侵蚀和渗流对大坝稳定性的影响。此外，还讨论了一些模型参数对大坝内部结构及其稳定性的影响。