Currently, numerical studies at the real scale of an entire engineering structure considering internal erosion are still rare. This paper presents a three‐dimensional (3D) numerical simulation of the effects of internal erosion within a linear dike located on a foundation. A two‐dimensional (2D) finite element code has been extended to 3D in order to analyze the impact of internal erosion under more realistic hydromechanical conditions. The saturated soil has been considered as a mixture of four interacting constituents: soil skeleton, erodible fines, fluidized fine particles, and fluid. The detachment and transport of the fine particles have been modeled with a mass exchange model between the solid and the fluid phases. An elastoplastic constitutive model for sand‐silt mixtures has been developed to monitor the effect of the evolution of both the porosity and the fines content induced by internal erosion upon the behavior of the soil skeleton. An unsaturated flow condition has been implemented into this coupled hydromechanical model to describe more accurately the seepage within the dike and the foundation. A stabilized finite element method was used to eliminate spurious numerical oscillations in solving the convection‐dominated transport of fluidized particles. This numerical tool was then applied to a specific dike‐on‐foundation case subjected to internal erosion induced by a leakage located at the bottom of the foundation. Different failure modes were observed and analyzed for different boundary conditions, including the significant influence of the leakage cavity size and the elevation of the water level at the upstream and downstream sides of the dike.

中文翻译：

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堤基内部侵蚀的三维水力力学建模

当前，考虑到内部腐蚀的整个工程结构实际规模的数值研究仍然很少。本文介绍了位于基础上的线性堤坝内内部侵蚀影响的三维（3D）数值模拟。二维（2D）有限元代码已扩展到3D，以便分析更实际的水力条件下内部侵蚀的影响。饱和土壤被认为是四种相互作用成分的混合物：土壤骨架，易蚀细粉，流化细粒和流体。细颗粒的分离和传输已通过固相和液相之间的质量交换模型进行了建模。已经开发出了一种粉砂-混合料的弹塑性本构模型，以监测孔隙度和内部侵蚀引起的细粉含量的演变对土壤骨架行为的影响。非饱和流动条件已被应用到该耦合流体力学模型中，以更准确地描述堤坝和地基内的渗流。在解决以对流为主的流化颗粒传输过程中，采用了稳定的有限元方法来消除虚假的数值振荡。然后，将这种数值工具应用于一个特定的地基堤坝案例，该案例由于地基底部的渗漏而引起内部侵蚀。对于不同的边界条件，观察并分析了不同的失效模式，